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1. The frequency f which is generated is given by f 1 44 Ri 2R2 C OBSERVATIONS amp CALCULATIONS C Ri R2 Calculated Frequency Observed Frequency 1 2 3 RESULT Time period of 555 timer can be changed by varying values of resistors and capacitor There is a minor change in the calculated and observed frequency for a given resistor and capacitor 31 Engineering Worksho Lab Session 04 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 04 a OBJECT Studying basics behind the construction of a power supply THEORY Current A flow of electric charge or the charge flowing per second is called Current I It is measured in Amperes A Electric current is carried either by the flow of negatively charged electrons or of positively charged ions or in semiconductors by positive holes where electrons are missing from a crystal structure Types of Current There are two types of current 1 Direct Current called DC 2 Alternating Current called AC Direct Current A direct current DC is a steady electric current stream of electrons flowing in one direction as opposed to an alternating current which reverses direction periodically Direct current is produced by simple batteries in cassette players flashlights and toys The main applications of direct current are in the fields of electronics traction battery powere
2. oe eS 36 Engineering Worksho Lab Session 04 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Circuit Diagram Figure 4 a 5 Circuit Diagram for Power RESULT 37 Engineering Worksho Lab Session 04 b NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 04 b OBJECT Constructing a full wave rectifier COMPONENTS REQUIRED Multimeter diodes capacitor transformer bread board THEORY PN Junction Diode If donor impurities are introduced into one side and acceptor impurities into the other side of a single crystal of semiconductor as shown in figure 4 b 1 a PN junction is formed It is also called a diode Donor Atom Acceptor Atom Free Electrone Free hole N Type T P Type P N Junction Figure 4 b 1 PN junction in a diode Capacitance A capacitor stores electric charge It consists of a pair of plates set very close to each other but separated by an insulator layer When voltage is applied across a capacitor it stores charge If batteries are now removed the charge remains trapped in the capacitor This trapped charge is called capacitance Capacitance is measured in Farad F capacitors are used in different values like pico farad pF Nano farad nF micro farad uF etc Micro farad uF 10 F Nano farad nF 10 F Pico farad
3. places with the male to ship orders in the office while he cooks exotic food and attends to the offspring Once each week local residents have the rare opportunity to spot the elusive Olivers as they gather food in their aging Toyota Each winter the male of the spemes disappears mto his octagonal office Fa and comes out only for sicting sliding and mips to the mailbox The female and young dwell in the main house fight though she occasionally switches tsa Document Done Figure 28 1 The first lt img gt tag in the above code occurs between a lt div align center gt tag and the closing lt div gt tag It can be seen in the figure that this causes the image as well as the text above it to be centered on the page The user can also make text wrap around images as it does around the two cartoon images at the bottom of Figure 1 This can be done by including an ALIGN attribute within the lt IMG gt tag itself as shown in the second and third lt IMG gt tags in Figure 1 lt IMG ALIGN left gt aligns the image to the left and causes text to wrap around the right side of it And lt img align right gt aligns the image to the right and causes text to wrap around the left side of it lt img align center gt cannot be used because text won t wrap around a centered image The user must use lt div align center gt if he wants an image to be centered on the page Vertical Image Alignment The user c
4. Formi Use Anows To View Data Figure 12 1 4 Save and run the project Use the arrows on the data control to scroll through the data 5 On any record change the data in the author name or year born field Move ahead then move back to the record you changed Note that your changes remain in effect The data control automatically updates a record when you move off of the record Note This exercise demonstrated that you can create a simple but functional application that allows the user to browse through the rows of a database table or result set and to update rows in that table without writing any code EXERCISES To be assigned by Lab teacher 80 Engineering Workshop Lab Session 13 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 13 OBJECT Designing a Simple Stop Watch using VB Timer Control THEORY The Timer control allows you to perform a task at a specified interval or to wait for a specified length of time STEPS To create a simple Stopwatch you will create a new project as previously explained Once the project is created and you have selected a form for the form design you will want to create three labels which will all have default names Labell Label2 and Label3 You will also need to drag the btnStart and the btnExit to the form For each of the Labels change the text to the number 0 for the btnStart you will want to
5. Department of Computer amp Information Systems Engineering 1ey this is the peak 0 10 20 30 40 50 t Figure 24 4 Further functions related to PLOT will be discussed in proceeding lab sessions b Stem Plot discrete sequence data A two dimensional stem plot displays data as lines extending from a baseline along the x axis A circle the default or other marker whose y position represents the data value terminates each stem stem Y plots the data sequence Y as stems that extend from equally spaced and automatically generated values along the x axis When Y is a matrix stem plots all elements in a row against the same x value stem X Y plots X versus the columns of Y X and Y must be vectors or matrices of the same size Additionally X can be a row or a column vector and Y a matrix with length X rows figure t linspace 2 pi 2 pi 10 h stem t cos t fi11 set get h BaseLine LineStyle set h MarkerFaceColor red 112 Engineering Workshop Lab Session 19 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 0 8 p 8 4 0 6 4 l l 0 4 F 4 0 2 i l 2 r l 4 ty Tj oboch EEEE AE OE AELE E EE A J i L J 0 2 i 0 4 4 h o 0 6 4 0 8 F 4 1 m iaaa al i 1 al 8 6 4 2 0 2 4 6 8 Figure 24 5 EXERCISES 1 Wr
6. In the following sections you will examine several controls used for making choices The controls used are as follows Check Box Switches one or more options on or off Option Button Selects a single choice from a group List Box Displays a list of user defined items Combo Box Like a list box but also displays selected item Check Boxes The CheckBox control is similar to the option button except that a list of choices can be made using check boxes where you cannot choose more than one selection using an OptionButton By ticking the CheckBox the value is set to True This control can also be grayed when the state of the CheckBox is unavailable but you must manage that state through code The following code demonstrates changing the text of a CheckBox control when a user checks or unchecks the control Private Sub Check Click If Check1l Value 1 Then Check1 Caption Checked Else Check1 Caption Unchecked End If End Sub Note If you set the check box s Style property to 1 Graphical pictures are used to indicate checked and unchecked Option Buttons Option buttons also called radio buttons exist in a group and only one of them can be selected at a time They are used to present a fixed list of mutually exclusive choices You can use option buttons in two basic ways in code 67 Engineering Workshop Lab Session 09 NED University of Engineering amp Technology Department of Computer amp Inf
7. Square Wave Emi Wi fl al Center Clockwise Triangle Wave Figure 2 c 2 7 DC OFFSET Control The DC offset control can provide up to 10V open circuit or 5V into 50 23 Engineering Worksho Lab Session 02 c NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 10 11 12 13 Clockwise rotation admixes positive voltage and counter clockwise rotation admixes negative voltage Q Fig 4 3 shows the various operating conditions encountered when using DC offset A Zero DC offset with Maximum signal 5V y JASS B Offset limits without clipping AVY aren KA 5V gt m eee am a mal a oe Positive DC offset Negative DC offset jat i a a A C Excessive offset ov ATAM BrT 5V lt oe me eee eas Ae Positive DC offset Negative DC offset All examples Output terminated in 500 Figure 2 c 3 DC Offset control AMPLITUDE PUEL 20dB Control Amplitude of output signal can be controlled by this knob Maximum attenuation is more than 20dB when the knob is rotated fully counter clockwise Pulling this knob make attenuation of 20dB so the output signal can be attenuated by 40dB when this is pulled and rotated fully counter clockwise FREQUENCY RANGE Selector Select one of the following seven ranges of oscillation frequency as desired FUNCTION Selector Push one of the three knobs to get a de
8. 1 8014 5 4043 9 0072 3 6029 2 7022 4 5036 1 8014 EXERCISES 1 Write matlab instruction to create two matrices A and B with both of 3x3 dimension Engineering Workshop Lab Session 18 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 2 Apply element by element matrix multiplication on the matrices A and B created in above exercise 3 What would happen if we multiply A of dimension 3x3 with a matrix C of dimension 2x2 Try it yourself and write down your observation 107 Engineering Workshop Lab Session 18 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 19 OBJECT Graphical Representation of Mathematical Equations THEORY The MATLAB environment offers a variety of data plotting functions plus a set of GUI tools to create and modify graphic displays The GUI tools afford most of the control over graphic properties and options that typed commands such as annotate get and set provide A figure is a MATLAB window that contains graphic displays usually data plots and UI components You create figures explicitly with the figure function and implicitly whenever you plot graphics and no figure is active By default figure windows are resizable and include pull down menus and toolbars A plot is any graphic display you can create within a figure window Plots can display tabular data geom
9. 2 Multiplier Tolerance Total Resistance Observed Resistance RESULT Values of Resistors were checked using colour code and Multimeter and they were found approximately same Volage across circuit is checked by shifting the knob of multimeter to voltage mesuring dial and found the circuit is properly connected Current drop in the circuit circuit is found and verfied that the circuit is properly connected with the help of DMM 14 Engineering Worksho Lab Session 02 b NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 02 b OBJECT Familiarization and working with Oscilloscope COMPONENTS REQUIRED Oscilloscope Function generator power supplies THEORY With its many switches and knobs a modern oscilloscope can easily intimidate the faint of heart yet the scope is an essential tool for electronics troubleshooting and you must become familiar with it Accordingly the rest of this laboratory session will be devoted to becoming acquainted with such an instrument and seeing some of the things it can do The oscilloscope we use is the Tektronix TDS210 illustrated in Fig 2 b 1 If you don t have a TDS210 any dual trace oscilloscope analog or digital can be used for these labs as long as the bandwidth is high enough ideally 30 MHz or higher While the description below may not correspond exactly to your scope with
10. AC in an electric circuit to direct current DC Alternating current which is the type used around the home travels in one direction first and then in the opposite direction Direct current flows in one direction only and can be made by batteries Diodes work by restricting the flow of electrons to one direction only gt C Figure 1 2 Circuit Symbol Figure 1 3 Physical View How to test a diode To test a silicon diode such as a 1N914 or a 1N4001 all you need is an ohm meter If you are using an analog VOM type meter set the meter to one of the lower ohms scale say 0 2K and measure the resistance of the diode both ways If you get zero both ways the diode is faulty If 4 Engineering Workshop Lab Session 01 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering you et INFINITY both ways the diode is faulty again If you get INFINITY one way and some reading the other way the value is not important then the diode is good If you use a digital multi meter DMM then there should be a special setting on the Ohms range for testing diodes Often the setting is marked with a diode symbol as figure 1 2 Measure the diode resistance both ways One way the meter should indicate an open circuit the other way you should get a reading That indicates the diode is good If you measure an open circuit both ways the diode is open If you measure low resistance both ways the diod
11. Forml Height Left Caption Forml Left 1lTop Caption Forml Top TOO 8 This code causes the current values of the form s width Height Left and Top properties to be displayed in the appropriate Label controls Because this code is in the form s Resize event procedure the labels will be updated whenever the size of the form changes whether programmatically or by user action 10 Save the form and project if you want however you probably don t need to bother because this is just a simple demonstration Measurements in Visual Basic By default all distances are measured in twips A twip is device independent unit of measure equivalent to 1 20 of a printer s point which means that there are 1440 twips per inch The actual physical size of a twip varies depending on screen resolution You can specify another unit of measure for positioning and sizing objects within a container using the container s ScaleMode property However the screen s scale mode cannot be changed so a form s Left Top Height and Width properties are always measured in twips Testing the Form Resize program After completing the project run it Change the form s width and height by dragging its edges notice how the form s labels report the modified Width and Height properties This action illustrates how an object s properties can be changed at runtime by user action Next click the Widen Form command button to cause
12. When preparing homework solutions it is often necessary to save the sequence of commands and output results in a file to be turned in with the homework The diary command allows this diary file name causes a copy of all subsequent terminal input and most of the resulting output to be written on the file named file namewdiary off suspends it diary on turns it back on diary by itself toggles the diary state Diary files may be edited later with a text editor to add comments or remove mistaken entries Often the consultants wish to see a diary file of your session to assist them in troubleshooting your MATLAB problems Suppressing Output If you simply type a statement and press Return or Enter MATLAB automatically displays the results on screen However if you end the line with a semicolon MATLAB performs the computation but does not display any output This is particularly useful when you generate large matrices For example A ones 100 Entering Long Statements If a statement does not fit on one line use an ellipsis three periods followed by Return or Enter to indicate that the statement continues on the next line For example 92 Engineering Workshop Lab Session 15 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Stee NaS E ARS epee a NO ait Lork od 1 8 1 9 1 10 1 11 1 12 Blank spaces around the and signs a
13. amp Information Systems Engineering Some Common ActiveX controls Text Box control is used to enter numeric and textual information needed from the user and to display certain information back to the user Label control is used to display captions and other information to the user Labels are similar to Text Boxes except that the user can t edit the information presented in them Command Button control is used to initiate program actions by clicking on it Common Properties All objects in Visual Basic do not have the same set of properties However several properties are common to many objects Important common properties include the following Name Index Left Top Height Width Enabled Visible Creating the Form Resize Program by Changing Properties at Runtime Now we develop a VB project that illustrates how the objects properties can be changed at runtime This sample project presents the users with a standard form They can modify the form s size or position simply by using the mouse to drag the form or one of its edges Perform the following steps to create your own version of this project 1 Create a new standard EXE project 2 Add four label controls to the form aligned ina column at the left side of the form These labels will be used as captions for other information you generally don t need to modify the name properties for labels used in this manner as they won t be referred to in c
14. amp Information Systems Engineering which styles of various aspects of the web page Table 7 1 shows some of the attributes that can be used to control the style sheet Style Purpose Background Can set the background for the entire page or for a heading table cell or paragraph Color Allows the user to set the color of the text either in hexadecimal format or by color name font family Determines what style of font will be used font size Sets the size of the text in points pt pixels px inches in or centimeters cm font style Sets the type as normal or italic font weight Sets the thickness of the type where 100 is the least heavy and 900 is boldest letter spacing Indicates the space between each character on the line in points pixels inches centimeters and percentages line height Controls the space between lines of type text align Aligns the text left centered right or justified text decoration Sets how the text will be displayed including underlined struck out or blinking Table 28 1 Attributes for style sheets To use these attributes place them after the tag for which the style is to be set and without brackets A semicolon separates each attribute Curly braces are used For example consider the following code lt html gt lt head gt lt tiltle gt MSIB Style Sheet lt title gt lt style gt body color FFFFFF font size l2pt color white t
15. bx c 0 New Equation Draw Graph Figure 14 1 83 Engineering Workshop Lab Session 14 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering EXERCISES Design Quadratic Function Graph Plotter and then write down appropriate code for it 84 Section Three Mathematical Modeling using MATLAB Engineering Workshop Lab Session 15 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 15 OBJECT Starting out with MATLAB THEORY MATLAB is an interactive program for numerical computation and data visualization It was originally developed in FORTRAN as a MATrix LABoratory for solving numerical linear algebra problems The original application may seem boring except to linear algebra enthusiasts but MATLAB has advanced to solve nonlinear problems and provide detailed graphics It is easy to use yet very powerful A few short commands can accomplish the same results that required a major programming effort only a few years ago MATLAB features a family of add on_application specific solutions called toolboxes These toolboxes allow you to learn and apply specialized technology Toolboxes are comprehensive collections of MATLAB functions M files that extend the MATLAB environment to solve particular classes of problems Areas in which toolboxes are available include communications signal p
16. end of row when used in matrices element by element multiplication v element by element division denotes a column in a matrix or creates a vector The MATLAB Workspace We can view the variables currently in the workspace by typing who Your variables are ans x y Z leaving 621420 bytes of memory free More detail about the size of the matrices can be obtained by typing whos Name Size Total Complex ans 1 by J 1 No X 1 by 6 6 No y 6 by 1 6 No Z 1 by 6 6 No Grand total is 19 8 152 bytes leaving 622256 bytes of memory free We can also find the size of a matrix or vector by typing m n size x 90 Engineering Workshop Lab Session 15 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 1 6 m n where m represents the number of rows and n represents the number of columns If we do not put place arguments for the rows and columns we find size x ans 1 6 Since x is a vector we can also use the length command length x ans 6 It should be noted that MATLAB is case sensitive with respect to variable names An X matrix can coexist with an x matrix MATLAB is not case sensitive with respect to built in MATLAB functions For example the length command can be upper or lower case LENGTH x ans 6 Notice that we have not named an upper case X varia
17. lt pre gt Special Characters 128 Engineering Workshop Lab Session 21 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Most fonts now include special characters for European languages such as the accented e in Caf There are also a few mathematical symbols and special punctuation marks such as the circular bullet To insert such special characters at any point in an HTML document by inserting the appropriate code for that character For example the word Caf would look like Caf amp 233 in the text Each symbol also has a mnemonic name that might be easier to remember than the number Another way to write Caf for instance is Caf amp eacute Character Numeric Code Code Name Description 7 amp H 34 amp quot Quotation mark amp amp H 38 amp amp Ampersand lt amp O60 amp lt Less than gt amp H 62 amp gt Greater than Cents amp 162 amp cent Cent sign sterling amp 163 amp pound Pound sterling amp 166 amp brvbar or brkbar Broken vertical bar SS amp 167 amp sect Section sign amp 169 amp copy Copyright amp 174 amp reg Registered trademark deg amp 176 amp deg Degree sign amp 177 amp plusmn Plus or minus amp 178 amp sup2 Superscript two amp 179 amp sup3 Superscript three amp 183 amp middot M
18. makes the array visible only to the form or module in which it s declared Using Dim within a module automatically makes the array available anywhere in the program as if the Public keyword were used e ArrayName is the name of the array e SubscriptOfCols is the number of the highest column in the array e SubscriptOfRows is the number of the highest row in the array e Asis the Visual Basic keyword that denotes type declaration e DataType is any valid Visual Basic data type Sample declarations for multi dimensional arrays are Dim asngSales l To 4 1 To 5 As declares a 2 dimensional array Single four rows tndexed 1 to 4 by five columns indexed 1 to 5 Dim asngResults 3 To 12 2 To declares a 3 dimensional array 6 As Single the first dimension has four elements indexed 0 to 3 within that the second dimension has 12 elements indexed 1 to 12 and within that the third dimension has five elements indexed 2 to 6 Printing Items of an Array v To refer to an individual element of an array in a procedural statement place the desired index in parentheses next to the array name For example the following statement will display the 5th element of aintCount on the form assuming the first or second declaration above Print intCount 4 v To refer to an individual element of a multi dimensional array in a procedural statement place the desired indices in parentheses next to the array name you
19. 8 track space figure This means that tracks can be no less than 10 thou wide and the spacing between tracks or pads or any part of the copper can be no less than 8 though The figures are almost always quoted in thou s with track width first and then spacing Real world typical figures are 10 10 and 8 8 for basic boards The IPC standard recommends 4 thou as being a lower limit Once you get to 6thou tracks and below though you are getting into the serious end of the business and you should be consulting your board manufacturer first The lower the track space figure the greater care the manufacturer has to take when aligning and etching the board They will pass this cost onto you so make sure that you don t go any lower than you need to As a guide with home made PCB manufacturing processes like laser printed transparencies and pre coated photo resist boards it is possible to easily get 10 10 and even 8 8 spacing Changing your track from large to small and then back to large again is known as necking or necking down This is often required when you have to go between IC or component pads This allows you to have nice big low impedance tracks but still have the flexibility to route between tight spots 44 Engineering Workshop Lab Session 05 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Figure 5 1 Tracks and pads The thickness of the copper
20. IC The 555 timer IC was first introduced around 1971 by the Signetic Corporation as the SE555 NE555 and was called the IC time machine This timer uses a maze of transistors diodes and the resistors The 555 comes in two packages either the round metal can called the T Packager or the more familiar 8 pin Div V package Inside the IC are the resistors and 3 diodes depending on the manufacturer The equivalent circuit providing the functions of control triggering level sensing or comparison discharge and power output Some features of 555 IC are Supply voltage between 4 5 and 18 volts supply 3 to 6 mA and rise and fall time of 100 msec 28 Engineering Workshop Lab Session 03 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Functions of Different Pins Pin I Ground The ground or common pin is the most ve supply potential of the device which is normally connected to circuit common when operated from the supply voltage Pin 2 Trigger It is the input to the lower comparator and is used to set the latch which in turn causes the output to go high This is the beginning of the timing sequence in monostable operation Triggering is accomplished by taking the pin from above to below a volt level of 3 Volts The action of the trigger input level sensitive allowing slow rate of change wave forms as well as pulse to be used as trigger sources The minimu
21. If 1 volt is connected across the If 10 volts are connected across the input of this step up transformer input of this step down transformer there will be 10 volts at the output there will be 1 volt at the output Figure 4 a 3 Transformer The coils or windings are not connected electrically but they are linked magnetically The two windings have at least some magnetic flux magnetic field lines common to both If one winding 34 Engineering Worksho Lab Session 04 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering the primary is connected to an AC supply the current produces an alternating magnetic flux in the core which induces an electromotive force emf in the other winding the secondary Regulating ICs Regulating ICs consist of Zener Diodes which have fixed output voltage even though the current through it changes The Zener Diode is got to be reverse biased for normal operation st t t ji gt 5 gt O om amp g 3 Nd Uj_ ipy nd ng Figure 4 a 4 Regulating IC Working The circuit functions in the following steps 1 Stepping Down of A C Signal 2 Rectification 3 Filtration 4 Regulation 1 Stepping Down of A C Signal The power supply is connected with an A C source of 220 V The current is allowed to flow to the step down transformer via the on off switch and a2 A fuse The transformer changes the 220 V signal at input into
22. Value Band 1 Band 2 Multiplier Tolerance Total Resistance Observed Resistance Resistor 2 Band 1 Band 2 Multiplier Tolerance Total Resistance Observed Resistance Resistor 3 Band 1 Band 2 Multiplier Tolerance Total Resistance Observed Resistance Resistor 4 Band 1 Band 2 Multiplier Tolerance Total Resistance Observed Resistance Engineering Workshop Lab Session 01 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Diode Diode Good Bad Diode 1 Diode 2 Capacitor Printed Value Capacitor 1 Capacitor 2 Capacitor 3 Transistor Transistor Type NPN PNP Transistor 1 Transistor 1 RESULT Diodes were checked and found good bad Values of capacitors were verified using Multimeter Transistors were checked for NPN PNP Engineering Worksho Lab Session 02 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 02 a OBJECT Familiarization and working with Multimeters COMPONENTS REQUIRED Variety of Resistors Variable Carbon Wire wound Fuse able Film resistance etc Digital multimeter DMM or Digital Voltmeter DVM THEORY Cur
23. a waiting period IRC Internet Relay Chat or IRC is a multiuser version of a program called talk Talk allowed only one to one conversations so it was pretty limited Using IRC large groups of people can simultaneously participate in discussion groups called channels Internet Protocols Several standards in place on the Web allow information to be transferred the way it is many of them relate to specifications for protocols that predate the Web such as FTP and Gopher Connectionless versus Connection Oriented Protocols Connectionless protocols differ from connection oriented protocols in the way requests and responses to requests are handled With a connectionless protocol clients connect to the server make a request get a response and then disconnect With a connection oriented protocol clients connect to the server make a request get a response and then maintain the connection to handle future requests In connection oriented protocols when the user connects to an FTP server the connection remains open after he downloads a file The maintenance of this connection requires system resources A server with too many open connections quickly gets bogged down Additionally processes that aren t disconnected cleanly can cause problems on the server The worst of these processes runs out of control uses system resources and eventually crashes the server The best of these processes simply eats up system resources In contras
24. are poly and roots Both these commands produce inverse result of each other Poly command is used to generate polynomial coefficient vector from the given roots where as roots command is used to generate roots of the given polynomial equation Example MATLAB displays polynomials as row vectors containing the coefficients ordered by descending powers The characteristic equation of the matrix A 1 2 3 4 5 6 7 8 0 is returned in a row vector by poly p poly A p 1 6 72 27 99 Engineering Workshop Lab Session 17 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering The roots of this polynomial eigenvalues of matrix A are returned in a column vector by roots r roots p r 12 1229 5 7345 0 3884 EXERCISES 1 For given equations Divide f1 x by f2 x and write the values of their quotient and remainder f1 x 3x 15x 10x 3x 15x 40 f2 x 3x 2x 6 100 Engineering Workshop Lab Session 17 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 18 OBJECT Matrix Operations THEORY Entering Matrices The best way for you to get started with MATLAB is to learn how to handle matrices Start MATLAB and follow along with each example You can enter matrices into MATLAB by entering an explicit list of elements or generating matrices using built in functions Y
25. box Then the text box is cleared and the focus is got to the text box The number of entered values will is increased according to the number of items added to the listbox Remove button removes the selected item from the list as soon as you pressed the Remove button The number of items is decreased in the listbox and the value is displayed in the label The code for the clear button clears the listbox when Enter a Name Amount Entered you press it And the number of items shown in the label becomes 0 71 Engineering Workshop Lab Session 10 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 10 OBJECT Understanding Arrays in Visual Basic THEORY An array is a collection of similar variables in which each has the same name and all are of the same type Remember that a variable can be thought of as a cup that holds an unknown value or an always changing value Arrays can be of different sizes One array might have three elements another might have 30 elements and it s even possible for an array to have no elements at all only the possibility of having elements that are created at a later time DECLARING ARRAYS You can declare or dimension an array in two ways By using a single variable and by using the To keyword Declaring an array like declaring a single variable To declare an array as you would a single variable you use the follo
26. careful study of its manual you should be able to figure out how to use your scope to carry out these exercises The TDS210 is not entirely as it appears In the past you may have used an oscilloscope that displayed voltage as a function of time on a cathode ray tube CRT While the TDS210 can perform a similar function it does not contain a CRT part of the reason it is so light and compact HORIZONTAL AUTOSET Seconds per MEASURE CONTROLS TRIGGER LEVEL TRIGGER MENU Volts per Division Horizontal and Vertical Info Trigger Level CALIBRATION on oom SEC DIV CONTACT POINT OPTION TE N BUTTONS CONTROLS Figure 2 b 1 Osilloscope Controls 15 Engineering Worksho Lab Session 02 b NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Until the 1990s most oscilloscopes were purely analog devices an input voltage passed through an amplifier and was applied to the deflection plates of a CRT to control the position of the electron beam The position of the beam was thus a direct analog of the input voltage In the past few years analog scopes have been largely superseded by digital devices such as the TDS210 although low end analog scopes are still in common use for TV repair etc A digital scope operates on the same principle as a digital music recorder In a digital scope the input signal is sampled digitized and stored in memory The digitized signal can the
27. defined automatically Deleting Rows and Columns You can delete rows and columns from a matrix using just a pair of square brackets Start with A I Fr NO e NOW 102 Engineering Workshop Lab Session 18 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering If you delete a single element from a matrix the result is not a matrix anymore So expressions like X 1 2 will result in an error However using a single subscript deletes a single element or sequence of elements and reshapes the remaining elements into a row vector So X 2 2 10 results in X 16 9 2 7 13 12 1 Scalar Expansion Matrices and scalars can be combined in several different ways For example a scalar is subtracted from a matrix by subtracting it from each element The average value of the elements in matrix A is 8 5 so B A 8 5 forms a matrix whose column sums are zero B 7 5 Oto Ola 4 5 3 55 ha 2 5 0 5 0 5 eS J s5 35 4 5 65 8 5 a sum B ans 0 0 0 0 With scalar expansion MATLAB assigns a specified scalar to all indices in a range For example B 1 2 2 3 0 zeroes out a portion of B B ican 0 0 4 5 aie ae 0 0 SOSS 0S S255 E 3 5 4 5 6 5 5 5 a eer 103 Engineering Workshop Lab Session 18 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Basic Matrix Operations Mat
28. histog Sl 4 23 11 1 54 PM lt Figure 20 2 SUMMARY OF DESKTOP TOOLS Array Editor View array contents in a table format and edit the values Command Window Run MATLAB functions The main window in which commands are keyed in after the command prompt gt gt Results of most printing commands are displayed in this window e Command History View a log of the functions you entered in the Command Window copy them execute them and more This window records all of the executed commands as well as the date and time when these commands were executed This feature comes very handy when recalling previously executed commands Previously entered commands can also be re invoked using up arrow key e Current Directory Browser View files perform file operations such as open find files and file content and manage and tune your files e Help Browser View and search the documentation for all your Math Works products 87 Engineering Workshop Lab Session 15 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering e Start Button Run tools and access documentation for all of your Math Works products and create and use MATLAB shortcuts e Workspace Browser This window is used to organize the loaded variables and displays the information such as size and class of these variables View and make changes to the contents of the workspace Quitting MATLAB To end your MATLAB ses
29. in the other If changing voltage is fed across the input coil the primary then a similar changing voltage will appear across the output coil the secondary There is no physical connection between input coil primary coil and output coil secondary coil but these coil are connected through magnetic field If the primary and secondary winding have the same number of turns then the output voltage must be similar to the input It means output voltage depends on the ratio of input and output coils If input coil has 100 number of turns and output coil has 10 number of turns the ratio is 100 10 then output voltage must be ten time less than the input voltage 40 Engineering Worksho Lab Session 04 b NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering The transformer which is shown in figure 6 6 is single output transformer For multiple outputs we use centre tape transformer as show in figure 6 7 AS Primary Winding Secondary Winding a Figure 4 b 6 Transformer Single output ao Primary Winding Center tape Transformer a Secondary Winding Figure 4 b 7 Center tapped transformer RESULT 1 Draw a full wave output diagram 41 Engineering Workshop Lab Session 05 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 05 OBJECT Designing Printed Circuit Boards THEORY You ve d
30. is evident that the polynomial equation is represented in terms of its Coefficient vector Note in the above example that the missing values of polynomial are replaced by zeros in the coefficient vector Operations on Polynomial Following are the operations we will discuss in this section in detail a Addition amp Subtraction Operation b Multiplication amp Division Operation c Polyval Function d Operation on roots 97 Engineering Workshop Lab Session 17 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering a Addition amp Subtraction Operation Addition and subtraction operation of two polynomials is quite simple using matlab It s just about adding or subtracting the Coefficient vector of two polynomials as illustrated in the following example Example f1 x 3x6 15x5 10x3 3x2 15x 40 f2 x 3x3 2x 6 pl 3 15 0 10 3 15 40 p2 00 0 3 0 2 6 p pltp2 p 3 15 0 7 3 13 46 sf x 3x6 15x5 7x3 3x2 13x 46 Similarly for subtraction operation just change the fifth instruction from p p1 p2 to p p1 p2 b Multiplication amp Division Operation For polynomial Multiplication we can use matlab s built in function that is conv which stands for convolution operation Syntax conv u v conv ssy Shape W Ww w cony u v convolves vectors u and v Algebraically convolution is the same operation as multiplying t
31. knob Time Division 250us Turn SECONDS DIV knob Trigger Source Channel 1 Push TRIGGER MENU select Channel 1 from the Source menu c Turn on the function generator Attach another BNC to alligator cable to the output connector be careful not to attach it to the Sync TTL output Attach the red alligator clips from both cables together Repeat with the black clips d You will now configure the function generator to output a 10Vpp peak to peak 1 KHz sinusoidal wave Use the output arrows to select the sinusoidal wave pattern Highlight the Frequency option FREQ under Display Modify and use the MODIFIER and RANGE controls to set an output frequency of 1 KHz Highlight the Amplitude option AMPL and adjust Vp peak voltage for 5 volts e You should now see a sinusoidal wave on the oscilloscope If not then ask a lab assistant for help The problem may be with some oscilloscope settings some buried function generator settings or the physical connection f Now make sure the sinusoidal wave is vertically centred on your scope Press the Ch 7 menu button Select the Ground option under the Coupling submenu The Channel 1 vertical position should be set to 0 00 divs 0 00V If it is not adjust using the Vertical Position knob g Since the cosine wave is the standard for sinusoidal wave patterns adjust the horizontal position of the wave so that the positive peak amplitude intercepts the vertic
32. mail message lt a gt Link Colors There are three separate attributes for link colors that cab be included in the body tag e link value color colors links that haven t been visited recently e vlink value color colors recently visited links e alink value color makes links briefly blink in the specified color when someone clicks on them For example lt body bgcolor red text yellow link white vlink gray alink green gt Cascading Style Sheets For a User keeping all his pages consistent is difficult It becomes very tedious to remember backgrounds style font color hyperlink colors heading sizes and so much more and then to code them one at a time into every page By using cascading style sheets however the user can set the style of his page once and be done with it A cascading style sheet is a separate non HTML document with file extension css cascading style sheet in which the user can specify all the stylistic aspects of his web page Once a style sheet has been created all web pages cab be linked to it giving the web site an easy to achieve uniformity The language for cascading style sheets is not straight HTML but it s just as easy Just like an HTML document it contains the lt html gt and lt head gt tags along with a new tag lt style gt within 135 Engineering Workshop Lab Session 23 NED University of Engineering amp Technology Department of Computer
33. major rule of PCB design and the one most often missed by beginners is to lay out your board on a fixed grid This is called a snap grid as your cursor components and tracks will snap into fixed grid positions Not just any size grid mind you but a fairly coarse one 100 thou is a standard placement grid for very basic through hole work with 50 thou being a standard for general tracking work like running tracks between through hole pads For even finer work you may use a 25 thou snap grid or even lower Many designers will argue over the merits of a 20 thou grid v s a 25 thou grid for instance In practice 25 thou is often more useful as it allows you to go exactly half way between 50 thou spaced pads Why is a coarse snap grid so important It s important because it will keep your components neat and symmetrical aesthetically pleasing if you may It s not just for aesthetics though it makes future editing dragging movement and alignment of your tracks components and blocks of components easier as your layout grows in size and complexity A bad and amateurish PCB design is instantly recognizable as many of the tracks will not line up exactly in the center of pads Little bits of tracks will be tacked on to fill in gaps etc This is the result of not using a snap grid effectively 43 Engineering Workshop Lab Session 05 NED University of Engineering amp Technology Department of Computer amp Information Sys
34. per period 5 What is the range of trigger level that gives stable triggering on the calibrator signal How does it compare with the amplitude of the calibrator waveform Does this make sense Explain Engineering Worksho Lab Session 02 b NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 6 Look at each of the waveforms available from the function generator square sine and triangle Try out the frequency and voltage controls and explain how they work Adjust the function generator s frequency to about 1 kHz 8 What do you see if neither channel causes triggering for example if the trigger threshold is set too high or too low 20 Engineering Worksho Lab Session 02 c NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 02 c OBJECT Familiarization and working with Function Generator COMPONENTS REQUIRED Oscilloscope Function Generator FG 8002 Variable power supplies connecting wires THEORY Function generators are among the most important and versatile piece of equipment In electronics design and troubleshooting the circuit under scrutiny often requires a controllable signal to simulate its normal operation The testing of physical system and transducers often needs stable and reliable signals The signal levels needed range from micro volts to tens of volts or more Modern DDS Direct D
35. the AddItem RemoveItem and Clear methods to modify the contents of the list Both can present a sorted or an unsorted list Both support the ItemData array and NewIndex property However one box can do some things that the other cannot The combo box mainly lacks support for multiple selections The key advantage of the combo box though is that it allows the users to enter choices that are not on the list This feature is not available in List box EXERCISES 1 Open a new Project and save the Form as CheckBox frm and save the Project as CheckBox vbp Design the Form as shown Object ject Property Setting F Caption CheckBox QET Name frmCheckBox sheni Caption Bold CheckBox Name chkBold Caption Italic Baid CheckBox Name chkItalic Caption Underline Bo CheckBox k chkUnderline Undelline Caption Red OptionButton E WE Caption Blue OptionButton k ee 69 Engineering Worksho Lab Session 09 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering i Caption Green OptionButton EE Name txtDisplay Caption Exit CommandButton E ee Complete the following code and run your project e Following code is typed in the Click events of the CheckBoxes Private Sub chkBold_Click If chkBold Value 1 Then txtDisplay FontBold True Else txtDisplay FontBold False End If End Sub Private Sub chkItalic_ClickQ Complete code End Su
36. the applied voltages and pushed towards the depletion region This results in a decrease in the width of the depletion region and consequently the energy needed to cross that barrier This makes is easier for current to flow and if the applied voltages are large enough typically 0 6 V for silicon the pn device will start to conduct freely Reverse Biasing In order to increase the size of the depletion region and thereby make it tougher for current to flow one should reverse bias the device To do this electric voltages are applied such that a positive voltage is in contact with the n type end of the device and a negative voltage is placed in contact with the p type semi conductor When this electric field is set up the positive voltage will attract the negative electrons from the n type semiconductor drawing them away from the depletion region Conversely the negative voltage will attract the positive holes away from the depletion region These new forces of attraction result in an enlargement of the depletion region and consequently the energy gap between regions Unfortunately there is a limit to the sensitivity and the amount of external voltage that can be applied This voltage is determined by the resistance of the particular semi conductors At some maximum applied voltage the semi conductor device will breakdown and will start to conduct freely Diodes A diode is an electronic component that converts alternating current
37. Practical Workbook Engineering Workshop Roll No Group No Department Dept of Computer amp Information Systems Engineering NED University of Engineering amp Technology Karachi 75270 Pakistan INTRODUCTION Engineering Workshop covers those practical oriented topics whose knowledge is considered essential for the engineering students but they cannot be included in any other course Primarily these topics help the students understand other courses in a better way and allow them to use the basic computer engineering laboratory equipment Through this workshop course the objective of producing engineers having sound practical as well as theoretical knowledge is accomplished This workbook comprises four sections First section begins with the introduction and testing of various electronic components Also students are made to implement certain circuits and observe functions of some related ICs Second section covers Visual Basic programming It gives introduction to forms and ActiveX controls Here students learn to write programs using multiple forms and develop applications such as simple and scientific calculator text editor etc with graphical interfaces It also shows how to use database connectivity with visual basic The third section of the workbook explores the environment and some of the most commonly used features of MATLAB MATLAB is a powerful tool for performing various mathematical g
38. S210 need to be told by the user what attenuation setting is in use As mentioned above your scope should also have a built in calibrator circuit that puts out a standard square wave you can use to test the probe see Fig 2 b 1 The probe s coaxial connector slips over the CH 1 or CH 2 input jack and turns clockwise to lock into place The probe tip has a springloaded sheath that slides back allowing you to grab the calibrator signal contact with a metal hook or grabber An attenuating scope probe can distort a signal The manufacturer therefore provides a compensation adjustment screw which needs to be tuned for minimum distortion The screw is usually located on the assembly that connects the probe to the scope or occasionally on the tip assembly Display the calibrator square wave signal on the scope If the signal looks distorted i e not square carefully adjust the probe compensation using a small screwdriver If you have trouble achieving a stable display try autoset Check your other probe Make sure that both probes work are properly compensated and have equal calibrations Sketch the observed waveform Consult your oscilloscope user manual for more information about carrying out a probe test 16 Engineering Worksho Lab Session 02 b NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Note that each probe also has a
39. The pulsating D C is filtered by using a 2200 uF 35V capacitor to make it more manageable for the regulator and thus we get a pure D C During the first quarter cycle the rising voltage charges the capacitor and when the voltage starts to reduce the capacitor starts to discharge and thus a stabilized D C voltage is obtained Although the D C obtained is almost a pure one but it may contain some ripples Thus one more capacitor of 0 1 uF is used This capacitor further filters the D C voltage and thus a pure D C is obtained This pure D C is then fed to the regulating ICs of Model 7812 and 7805 4 Regulation The regulators have fixed outputs i e output of Regulator 7812 is 12 V whereas that of Regulator 7805 is 5 V The output obtained from these regulating ICs may contain some ripples therefore these outputs are further filtered by using capacitors of 100 uF 25 V and 100 uF 16 V respectively EXERCISES Construct a power supply with two D C outputs i e 12 Volts and 5 Volts Components Required Component Quantity Transformer Input 220 V Output 14 V 2A Diode Model IN4001 Capacitor 2200 uF 35V Capacitor 0 1 uF 104 pF Capacitor 100 uF 25 V Capacitor 100 uF 16 V Regulator 7812 for 12 V output Regulator 7815 for 5 V output Bread Board 1 Banana Jacks 2 Sets 2 Black amp 2 Red Fuse Holder 1 Fuse 220 V 2A 1 On Off Switch with Indicator 1 Plug Cord amp Casing 1
40. Web page e Anchor A link that takes the user to a different part of the same Web page e FAQ Stands for Frequently Asked Questions Many times newcomers to a newsgroup will ask questions that the old timers have heard over and over again FAQs are written and posted periodically to reduce the number of redundant questions e Hits When conducting an Internet search on the Web each result of a particular search is called a hit Finding Information on the Internet The Internet isn t called the Information Superhighway for nothing The Internet is information Sometimes unfiltered many times even useless more information is available on the Internet 118 Engineering Workshop Lab Session 20 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering than any one person could ever deal with There are Search Engines which can help the user find just about anything he wants A search engine is a computer program that indexes a database and then enables users to search it for relevant information Using the WWW for Communication The most popular use of the Internet is the World Wide Web In the following sections are a few ways people are using the Internet to communicate with one another Personal Communication Email E mail makes up a majority of Internet traffic today They provide a cheap fast and convenient way of communicating with each other Some of the terms which users c
41. a 14 V signal at output The transformer works on the principal of mutual inductance According to which if two coils are wound close together so that they are magnetically coupled then any changing currents in one coil will induce changing currents in the other If changing voltage is fed across the input coil the primary then a similar changing voltage will appear across the output coil the secondary There is no physical connection between input coil primary coil and output coil secondary coil but these coils are connected with magnetic field The coil with the most turns corresponds to the higher voltage in the transformer To step down from a high voltage to a lower one the primary coil must have more windings than the secondary 2 Rectification The current is then allowed to pass through the bridge rectifier made by using four 1N4001 diodes The diode bridge rectifies the A C signal into a pulsating D C form During the positive half cycle diodes D and D3 conducts the current in the positive direction while during the negative half cycle the gets reverse biased and hence stops the flow of current On the other hand diodes Dz and D conducts during the negative half cycle This pulsating D C is then allowed to pass through the capacitor for filtration 35 Engineering Worksho Lab Session 04 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 3 Filtration
42. ads may lead to hairline shorts and other etching problems during the manufacturing process These can be very hard to fault find once your board is assembled Once again don t push the limits of your manufacturer unless you have to stay above their recommended minimum spacing if at all possible At least 15 thou is a good clearance limit for basic through hole designs with 10 thou or 8 thou being used for more dense surface mount layouts If you go below this it s a good idea to consult with your PCB manufacturer first For 240V mains on PCB s there are various legal requirements and you ll need to consult the relevant standards if you are doing this sort of work As a rule of thumb an absolute minimum of 8mm 315 thou spacing should be allowed between 240V tracks and isolated signal tracks Good design practice would dictate that you would have much larger clearances than this anyway For non mains voltages the IPC standard has a set of tables that define the clearance required for various voltages A simplified table is shown here The clearance will vary depending on whether the tracks are on an internal layers or the external surface They also vary with the operational height of the board above sea level due to the thinning of the atmosphere at high altitudes Conformal coating also improves these figures for a given clearance and this is often used on military spec PCBs 47 E ngineering Worksho Lab Sessio
43. al axis This can be adjusted using the Horizontal Position 25 Engineering Worksho Lab Session 02 c NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering You should now have a stable cosine wave with an amplitude of 5 volts a phase shift of 0 degrees and a frequency of 1 KHz see equation 1 display on the oscilloscope h Using the cursors The oscilloscopes are equipped with a set of horizontal and vertical cursors to aid in obtaining measurements You can use these to measure various parameters like peak voltage period and frequency Measure the Peak to Peak amplitude of the waveform using the horizontal cursors To do this press Cursor and then select Voltage under the Type submenu Use the Vertical Position knobs to place the cursors at Vp and Vp Under the delta submenu the peak to peak voltage will be recorded Repeat this process to measure the Peak Voltage Measure both the Period and Frequency of the waveform using the vertical cursors To do this press Cursor and then select Time under the Type submenu Use the Vertical Position knobs to again place the cursors The delta submenu displays both the period and frequency measurements EXERCISES 1 Perform the same operation as demonstrated in the above exercise using a square wave and write down you observations along with the waveform you observe on the system 2 Measure the parameters for the following sin
44. an t edit the information presented in them e CommanaButton controls which the user can click to initiate program actions 56 Engineering Workshop Lab Session 07 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering e All these controls are part of the basic set of controls found in Visual Basic s Toolbox Adding a Control to a Form In order for a Visual Basic program to use a control that control must be placed on a form For your loan calculator program you begin by placing a TextBox control on the main form i Click the tool for the TextBox control in the Toolbox ii Move the mouse pointer to the form ili Move the pointer to one corner of the area where you want to draw the control iv Click and hold the left mouse button v Drag the mouse to where you want the diagonally opposite corner of the control release the mouse button The control will be drawn on the form vi The procedures used to draw the TextBox control are the same as those for drawing most controls on a form Setting a Control s Properties After you have added a control to a form you will usually want to set one or more of the control s properties Properties are settings that control the appearance and behavior of an object For the text box you just added you want to set the Name and Text properties Every control must have a unique name which is represented by the value of its Name property Vi
45. an choose between these and several other options to align images vertically 138 Engineering Workshop Lab Session 23 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering e To line up the top of an image with the top of the tallest image or letter on the same line use lt img align top gt e To line up the bottom of an image with the bottom of the text use lt img align bottom gt e To line up the bottom of an image with the bottom of the lowest image or letter on the same line use lt img align absbottom gt If there are some larger images on the same line aLign absbottom might place an image lower than align bottom e To line up the middle of an image with the middle of the text use lt img align middle gt e To line up the middle of an image with the overall vertical center of everything on the line use lt img align absmiddle gt This might be higher or lower than align middle depending on the size and alignment of other images on the same line If no align attributes are included in an lt img gt tag the image will line up with the bottom of any text next to it Images That Are Links With the same lt a href gt tag used to make text links the user can make any image into a clickable link to another page Normally Web browsers draw a colored rectangle around the edge of each image link Like text links the rectangle will usually appear blue to p
46. annel see Fig 2 b 1 These adjust the sensitivity volts per vertical division on the screen and offset the vertical position on the screen that corresponds to zero volts The CH 1 and CH 2 menu buttons can be used to turn the display of each channel on or off they also select which control settings are programmed by the push buttons just to the right of the screen Horizontal sweep To the right of the vertical controls are the horizontal controls see Fig 2 b 1 Normally the scope displays voltage on the vertical axis and time on the horizontal axis The sec div knob sets the sensitivity of the horizontal axis i e the interval of time per horizontal division on the screen The position knob moves the image horizontally on the screen Triggering Triggering is probably the most complicated function performed by the scope To create a stable image of a repetitive waveform the scope must trigger its display at a particular voltage known as the trigger threshold The display is synchronized whenever the input signal crosses that voltage so that many images of the signal occurring one after another can be superimposed in the same place on the screen The level knob sets the threshold voltage for triggering You can select whether triggering occurs when the threshold voltage is crossed from below rising edge 17 Engineering Worksho Lab Session 02 b NED University of Engineering amp Technology Depar
47. ates increasing the electric field between them until it discharges all its energy in a rapid burst Polar Capacitors amp Non Polar Capacitors Ht 4H Figure 1 1 Capacitor Engineering Workshop Lab Session 01 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Value Type Code Value Type Code 1 5pF Ceramic 1 000pF 0 001luF Ceramic Mylar 102 3 3pF Ceramic 1 500pF 0 0015uF Ceramic Mylar 152 10pF Ceramic 2 000pF 0 002uF Ceramic Mylar 202 15pF Ceramic 2 200pF 0 0022uF Ceramic Mylar 222 20pF Ceramic 4 700pF 0 0047uF Ceramic Mylar 472 30pF Ceramic 5 000pF 0 005uF Ceramic Mylar 502 33pF Ceramic 5 600pF 0 0056uF Ceramic Mylar 562 47pF Ceramic 6 800pF 0 0068uF Ceramic Mylar 682 56pF Ceramic 0 01uF Ceramic Mylar 102 68pF Ceramic 0 015uF Mylar 7T5pF Ceramic 0 02uF Mylar 203 82pF Ceramic 0 022uF Mylar 223 91pF Ceramic 0 033uF Mylar 333 100pF Ceramic 101 0 047uF Mylar 473 120pF Ceramic 121 0 05uF Mylar 503 130pF Ceramic 131 0 056uF Mylar 563 150pF Ceramic 151 0 068uF Mylar 683 180pF Ceramic 181 0 1uF Mylar 104 220pF Ceramic 221 0 2uF Mylar 204 330pF Ceramic 331 0 22uF Mylar 224 470pF Ceramic 471 0 33uF Mylar 334 560pF Ceramic 561 0 47uF Mylar 474 680pF Ceramic 681 0 56uF Mylar 564 750pF Ceramic 751 luF Mylar 105 820pF Ceramic 821 2uF Mylar 205 Table 1 1 Capacitor code guide chart Semiconductors Some nonmetals such as silicon conduct electricity under certain conditi
48. b Private Sub chkUnderline_ClickQ Complete code End Sub e Following code is typed in the Click events of the OptionButtons Private Sub optBlue_ClickQ txtDisplay ForeColor vbBlue End Sub Private Sub optRed_ClickQ Complete code End Sub Private Sub optGreen_Click Complete code End Sub Private Sub cmdExit_Click End End Sub e To terminate the program following code is typed in the ClickQ event of the Exit button 2 Open a new Standard EXE project is opened an named the Form as Listbox frm and save the project as Listbox vbp This project Add Remove Clear the list of items and finally close the application Design the application as shown below and write appropriate programe to run the project 70 Engineering Workshop Lab Session 09 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Object Property Settings Caption ListBox Form Name frmListBox Text empty TextBox Name txtName Caption Enter a name Label Name lblName ListBox Name IstName Caption Amount Entered Label Name Ibl1Amount Caption empty Label Name Ib Display Border Style 1 Fixed Single Caption Add CommandButton Name cmdAdd Caption Remove CommandButton Name cmdRemove Caption Clear CommandButton Name cmdClear Caption Exit CommandButton Name cmdExit The click event of the Add button adds the text to the List Box list box that was typed in the Text
49. ble See what happens when we try to find the length of X LENGTH X 2 Undefined function or variable Symbol in question gt X Sometimes it is desirable to clear all of the variables in a workspace This is done by simply typing clear more frequently you may wish to clear a particular variable such as x clear x You may wish to quit MATLAB but save your variables so you don t have to retype or recalculate them during your next MATLAB session To save all of your variables use save file nam Saving your variables does not remove them from your workspace only clear can do that You can also save just a few of your variables 91 Engineering Workshop Lab Session 15 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Save File name xX y z To load a set of previously saved variables load file name m files You can create your own matrices using M files which are text files containing MATLAB code Use the MATLAB Editor or another text editor to create a file containing the same statements you would type at the MATLAB command line Save the file under a name that ends in m For example create a file containing these five lines A 16 3 2 13 5 10 11 8 9 6 7 12 4 15 14 1 Store the file under the name first m Then the statement first reads the file and creates a variable A containing our example matrix Diary
50. can change the appearance of these graphic components or add annotations to the graph to present your data in a particular way One of the figure MATLAB Dock figure in toolbars figure window MATLAB desktop Edt View Insert Tools Desktop Window Help gUll ALVDAL a o0 amp amo 0 8 06 04 Axes in which Line plots MATLAB plots data representing data Figure 24 1 Plotting For a standard solid line plot simply type plot x z 109 Engineering Workshop Lab Session 19 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering X Figure 24 2 Axis labels are added by using the following commands xlabel x ylabel z For more plotting options type help plot Two Dimensional Plotting Functions There are a number of two dimensional plotting function some of them are mentioned here as under e Plot e Stem e Ezplot e Bar Pie We will discuss only two of the above a Plot Plot vectors or matrices PLOT X Y plots vector X versus vector Y If X or Y is a matrix then the vector is plotted versus the rows or columns of the matrix whichever lines up PLOT X1 Y1 X2 Y2 is another way of producing multiple lines on the plot PLOT X1 Y1 X2 Y2 uses a dotted line for the first curve and the point symbol for the second curve Other line and point types are solid plus reds dashed star gree
51. can unload itself as in Unload Me Note When all forms of a VB project are unloaded the application ends The End statement automatically unloads all forms in a project but will not trigger the Unload event so any code you have in the Unload event will not execute therefore ending an application with End does not give the user a second chance to keep working with the program The End statement ends the program abruptly Using Controls Visual Basic controls let you perform a wide variety of tasks including editing text displaying pictures and interfacing with a database In Visual Basic controls are objects designed to perform specific tasks Like form objects controls have associated properties events and methods Because of Visual Basic s design you are not limited to using only the controls provided by Microsoft The design allows easy integration of third party controls which has led to a thriving market for these custom controls With this amount of third party involvement chances are that you can find a control to perform almost any task you want from data acquisition to custom reporting to specialized graphics processing to game play and everything in between Visual Basic allows you to create your own ActiveX controls for use in your programs and in any other program that adheres to ActiveX standards 63 Engineering Workshop Lab Session 08 NED University of Engineering amp Technology Department of Computer
52. ch a p type material is sandwiched between two n type materials is called an npn transistor Engineering Worksho Lab Session 01 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering x Figure 1 4 NPN Transistor Figure 1 5 PNP Transistor PNP Transistor The transistor in which an n type material is sandwiched between two p type materials is called a pnp transistor How to test a Transistor for NPN or PNP If you have a transistor and you do not know if it is PNP or NPN then you can find it out using your Ohm meter if you know which lead of your meter is internally connected to the positive terminal of the battery inside the meter Assuming you know where C B and E are on the transistor do the following Connect the positive lead of your Ohm meter to the base Touch the other lead of your meter to the collector If you get a reading the transistor is NPN To verify move the lead from the collector to the emitter and you should still get a reading If your meter reads open circuit then connect the negative lead t the base and touch the positive lead to the collector If you get a reading then the transistor is PNP Verify by measuring from base to emitter Field Effect Transistor FET One type of field effect transistor consists of a narrow channel of n type material within some p type material through which current can flow The channel has an input connection known a
53. changes the text to Start Stop and for the btnExit change the text to Exit Lastly you will create a timer which will be called tmrTime in the toolbox In order for this timer to count at the correct intervals you muct change the timer interval to 1000 which signifies 1 second After you have finished with the design of the application you will need to put some code in to make it function CODE Following code will be written in the click event of btnStart Private Sub btnStart_Click If tmrTime Enabled False Then tmrTime Enabled True Else tmrTime Enabled False End If End Sub The next step is to code the timer itself which will allow the timer to continue counting upward until the Start Stop button is pushed To do this you will click on tmrTime and enter into the code editor Private Sub tmrTime_timer Label3 Caption Val Label3 Caption Val 1 If Label3 Caption 6 Then Label2 Caption Val Label2 Caption Val 1 81 Engineering Workshop Lab Session 13 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Label3 Caption ElseIf Label2 Caption 6 Then Label1 Caption Val Label1 Caption Val 1 Label2 Caption End If End Sub The next code will make it so that when the form is loaded the timer won t start until the Start Stop button is clicked The following code must be typed into the Code Editor to make this happen Private Sub F
54. d After a listserver administrator sets up a listserver he or she usually leaves it alone and lets it take care of itself Two exceptions to this rule are the private and moderated Listserver A private listserver is simply one which requires an administrator s approval to join the list With a moderated listserver a human being usually approves subscription additions and removals also but in addition approves message submissions before they are finalized Usually list servers that deal with highly volatile issues are moderated Sending Messages to a List The list servers provides an address of the list to its subscribers A subscriber can send message to this address which is received by all other subscribers The sender may receive a copy of his message shortly after sending it As with sending messages responding to listserver messages means replying to all subscribers of the list Most list servers are set up this way However some list servers are also set up to route replies automatically to the original sender To find out which way the listserver is set up simply compose a reply to a listserver message If the To field contains the listserver address the listserver is set up in the standard way If the reply goes to the individual the second type of listserver setup is used Usenet and Newsgroups A Usenet has a machine that is dedicated solely to storing and serving news the user can read from and post to the news server using a
55. d property help you to manage this process The Visible property determines whether an object can be seen on the screen The Enabled property determines whether the user can interact with an object You can set both properties to either True or False If the Visible property is set to False the object is not shown and the users will not know that the object is even there If the Enabled property is set to False the object is Visible provided that the Visible property is True but the users cannot use it Typically if an object is disabled it is shown on the screen in a grayed out or dimmed mode This mode provides a visual indication that the object is unavailable EXERCISES 1 What are controls Explain with examples of some ActiveX controls 2 What do you understand by the term property of an object Describe the different properties to control an object s size and position 1 What is twip What is its advantage How other units can be used in Visual Basic 66 Engineering Workshop Lab Session 09 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 9 OBJECT Understanding Controls for Making Choices in Programming THEORY The input data for some variables may be limited to only two or at most a few fixed choices If you set up a program to handle only the words yes and no your program will have a problem if users type Maybe or if they mistype a word
56. d several related pages The user might think of a Web site as an interactive electronic book e Web Browser A software program that lets the user finds see and hear material on the World Wide Web including text graphics sound and video Popular browsers are Internet Explorer Netscape and AltaVista Most online services have their own browsers e Uniform Resource Locator URL The World Wide Web address of a site on the Internet e Webmaster The individual responsible for maintaining and updating the content of a World Wide Web document Webmasters are the creative force behind the World Wide Web e Home page Frequently the cover of a particular Web site The home page is the main or first page displayed for an organization s or person s World Wide Web site e Hypertext Transfer Protocol HTTP A standard used by World Wide Web servers to provide rules for moving text images sound video and other multimedia files across the Internet e Bookmark A saved link to a Web site that has been added to a list of saved links so that the user can simply click on it rather than having to retype the address when visiting the site again e Link Short for hypertext link A link provides a path that connects the user from one part of a World Wide Web document to another part of the same document a different document or another resource A link usually appears as a uniquely colored word that the user can click to be transported to another
57. d vehicles and some electric trains and electrochemical processing Alternating current in the form of mains electricity is often converted into direct current inside electrical appliances particularly if they contain electronic components Alternating Current An alternating current AC regularly reverses its direction the electrons that make up the current constantly change their direction of movement Alternating current is used almost universally in mains electricity supplies in which it reverses direction with a set frequency for example mains electricity in Europe and Asia including Pakistan has a frequency of 50 Hz while in Canada and the United States it has a frequency of 60 Hz Its advantage over direct current is that the voltage may be easily increased stepped up or decreased stepped down using a transformer according to need High voltages are used to generate and transmit electricity to our homes because this helps to reduce the energy lost in the process PN junction When one n type semiconductor and one p type semiconductor are placed together the resulting device has some very special properties The region that is formed by adjoining a p type semiconductor and an n type semiconductor is called a pn junction 32 Engineering Worksho Lab Session 04 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Rectifiers There are three types
58. dd an image in the background use background URL of image in the body tag This will add a background image to the whole document It will actually tile the image across the page Providing a Preview Image The user can speed things up by providing a small image file to be displayed while someone is waiting for a full sized image file to download Put the name of the smaller file after the word lowsrc in the same image tag as the full sized SRC image lt img src bigfile gif lowsrc tinyfile jpg gt What happens here is that the Web browser makes its first pass through the document and when it sees the lowsrc tag it loads that presumably smaller image first Then it makes a second pass through the document and loads the main image Though this attribute was originally designed with the intention that the LOWSRC image would be a low resolution or highly compressed version of the SRC image the user can also use two entirely different images to get atwo frame animation effect Image Maps An image map is an image on a Web page that leads to two or more different links depending on which part of the image someone clicks Mapping Regions Within an Image To make any type of image map the user needs to figure out the numerical pixel coordinates of each region within the image that is to be a clickable link An easy way to find coordinates of a region is to open it in any image editor like Paint Shop Pro and watch the coordina
59. e another down to as many levels as required EXERCISES 1 Write HTML code for producing the following effect in a web page 10 Chair 20 Table 30 Box 30 Board 2 How would you display a list of the following form Y Karachi Z Islamabad AA Peshawar AB Lahore Engineering Workshop Lab Session 22 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 3 Use multi level list tags to form a web page having the text of the following form a West German Languages i English 1 British i BBC li Cockney iii Dubliner b American i Newscaster ii Drawl iii Jive ii Dutch 1 Hollander 2 Flemish 3 Afrikaans b East German Languages i Gothic ii German iii Yiddish Lab Session 23 OBJECT Applying links and inserting images in web pages with HTML THEORY 133 Engineering Workshop Lab Session 23 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Linking to Other Web Pages Absolute Addresses The tag to create a link is called lt A gt which stands for anchor The address of the page to link to is put between these tags in quotes after href like lt a href http netletter com dicko welcome htm gt Click here lt a gt The link above would display the words Click here in blue with an underline When someone clicks on it they would see the Web page named welco
60. e is shorted Transistors A transistor is an electronic semiconductor device in which one electric current controls another current It can be used either as an amplifier or a switch They are made by sandwiching one type of doped semiconductor between two layers of another type The three parts that make up a transistor are the base the emitter and the collector Computers contain millions of transistors that respond in a few nanoseconds to changes in current This enables computers to operate extremely quickly Types of Transistors The most common type of transistor the junction or bipolar transistor has three electrodes called the emitter base and collector The input signal voltage is most frequently applied between the base and the emitter and the output is taken between the collector and the emitter since the emitter is common to both input and output circuits this is called the common emitter configuration The basic types of transistors are the junction or bipolar type and the field effect transistor FET Both types can be incorporated into integrated circuits Junction Transistor A junction transistor consists of regions of n type negative type or p type positive type material made by adding an appropriate impurity in a process known as doping The base must be of the opposite type of material from that of the other two electrodes and so both npn and pnp transistors exist NPN Transistor The transistor in whi
61. e reading Figure 2 a 3 Every voltmeter has impedance which is the meters internal resistance The impedance of a conventional analog voltmeter is expressed in ohms per volt Impedance is the biggest difference between analog and digital voltmeters Since most digital voltmeters have 50 times more impedance than analog voltmeters digital meters are more accurate when measuring voltage in high resistance circuits Ammeter Figure 2 a 4 11 Engineering Worksho Lab Session 02 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Ammeters measures amperage or current flow in a circuit and provide information on current draw as well as current continuity High current flow indicates a short circuit unintentional ground or a defective component Some type of defect has lowered the circuit resistance Low current flow may indicate high resistance or a poor connection in the circuit or a discharged battery No current indicates an open circuit or loss of power Figure 2 a 5 Ammeters must always be connected in series with the circuit never in parallel That is all the circuit current must flow through the meter It is connected by attaching the positive lead to the positive side of the battery circuit and the negative lead to negative or ground side of the circuit Note These meters have extremely low internal resistance If connected in parallel the current ru
62. e waves can pass through vacuum Matter Waves These waves are associated with the moving particles when a very light particle move with a very high velocity approaching the speed of light Travelling Waves The waves advancing in a medium with a definite velocity are called travelling waves Transverse Waves The waves in which particles of the medium vibrate perpendicularly to the direction of propagation of waves are called transverse waves Compressional Waves The waves in which the particles of the medium vibrate along the direction of the propagation of waves are called compressional or longitudinal waves Sinusoidal Waves The waves whose displacement varies with the sine of phase angle it is maximum at 90 in one direction and at 180 in other direction and zero at 0 and 360 are called sinusoidal waves Coherent Waves Two waves having same wavelength A same frequency v same amplitude y same time period T and same phase producing the crests and troughs at the same time are called coherent waves 30 Engineering Workshop Lab Session 03 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Standing Waves When two waves having same frequency and amplitude propagate with the same speed in a medium in opposite direction due to the superposition they vibrate in loops producing standing waves Relation of 555 Timer IC
63. echnology Department of Computer amp Information Systems Engineering you want the first element of your array to be element number 1 The Option Base statement can only have the number 0 or 1 after it and 0 is the default so you never need to code Option Base 0 Example This example shows to declare an array of integers having five elements in it Dim iMyArray 4 As Integer Assigning value to each element of array iMyArray as iMyArray 0 9 iMyArray 1 342 iMyArray 2 2746 iMyArray 3 0 iMyArray 4 8901 Changing the value of fourth elemnt to 35 as iMyArray 3 35 Declaring an array with the To keyword You can also declare an array by using the To keyword within the subscript syntax For example if you want to create an array of five Integer variables in which the first element is number 1 and the last element is number 5 you use Dim iMyArray 1 To 5 as Integer This method provides an easy way to start your element numbering at a value other than 0 zero Some examples for the declaration of one dimensional arrays are im aint As Integer oe a 10 element array indexed 0 to same as above with explicit lower bound ement array indexed 1 To array indexed 3 To array indexed 4 13 Engineering Workshop Lab Session 10 NED University of Engineering amp Technology Department of C
64. ectifier is similar to a full wave rectifier because it produces a full wave output voltage Diodes D and D3 conduct on the positive half cycle and D3 and D4 conduct on negative half cycle As a result the rectifed load current flows during both half cycles During both half cycles the load voltage has the same polarity and the load current is in the same direction The circuit has changed the A C input voltgae to the plulsating D C output voltage 39 Engineering Worksho Lab Session 04 b NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering The advantage of using Bridge Recitifer over Full Wave Rectifieir is that the entire secondary voltage can be used 220 n Vin n Vout Figure 4 b 4 Bridge rectifier Inductance When current flow through a wire it creates a magnetic field This field grows outward from the center of the conductor as increases or collapse back into the center of the conductor When current starts flowing a magnetic field is created which grows outwards from the center of the conductor When current decreases then the surrounding magnetic field starts to collapse back into the conductor NO ZIN 7V 7 Flow of Currant ATA e Magnetic field Figure 4 b 5 Principle of induction Transformers If two coils are wound close together so that they are magnetically coupled then any changing currents in one coil will induce changing currents
65. ectory lists these types of lists are rarely used and most browsers treat them identically to unordered lists Directory lists use lt dir gt and lt dir gt tags and menu lists use lt menu gt and lt menu gt tags For example lt ol type i start 4 gt lt li gt Milk lt li gt Bread lt li gt Egg lt li value 14 gt Dark Chocolate lt li gt Avocados lt ol gt Following is the output in the body portion of the browser iv Milk v Bread vi Egg xiv Dark Chocolate XV Avocados Lists Within Lists 131 Engineering Workshop Lab Session 22 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Although definition lists are officially supposed to be used for defining terms many Web page authors use them anywhere they d like to see some indentation In practice the user can indent any text simply by putting lt DL gt lt DD gt at the beginning of it and lt DL gt at the end The user can indent items further by nesting one list inside another like this lt DL gt lt DD gt This item will be indented lt DL gt lt DD gt This will be indented further lt DL gt lt DL gt lt DD gt And this will be indented very far indeed lt DL gt lt DL gt lt DL gt lt DL gt Just make sure to always have the same number of closing lt DL gt tags as opening lt DL gt tags Ordered and unordered lists can also be nested inside on
66. ed twice once to name a portion and then to jump to that portion through a link To give a name to the specific point on the page lt a name top gt lt a gt Now to jump to the above named tag lt a href top gt Return to top of document lt a gt The symbol means that the word top refers to a named anchor point within the current document rather than a separate page So when a reader clicks on Return to top of document the Web browser will display the part of the page starting with the lt A NAME top gt tag 134 Engineering Workshop Lab Session 23 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Linking to a Specific Part of Another Page The user can even link to a named anchor on another page by including the address or name of that page followed by and the anchor name for example lt a href mailto articles htm two gt II The President lt a gt Clicking on II The President will bring up the page named articles htm and go directly to the point where lt a name two gt occurs on that page Linking E mail Addresses to a Web Page The lt A gt tag also allows a user to link to his e mail address This can be made almost completely effortless for the senders of mails to send a message at a specified email address by providing a clickable link to that e mail address instead For example lt a href mailto abc hotmail com gt Send me an e
67. edure for the control named cmdExit Visual Basic will execute any code located within this sub procedure whenever the click event occurs to this command button To cause the program to end when the user clicks the Exit button you simply need to add one line of code Visual Basic s End statement to the cmdExit_Click procedure Private Sub cmdExit Click End End Sub Specifying Event Procedures Look at the two drop down list boxes near the top of the Code window The Object box the one on the left lists all the objects that have been placed on the current form as well as the form itself The Procedure box on the right lists all the events that apply to whichever object is currently selected in the Object box Using these two drop down list boxes enables you to navigate to any portion of the Code window When you double click a control at design time the code window automatically opens to the default event for the control you clicked unless some event other than the default already has code in its event procedure Event Procedure For The cmdCalculate Command Button Private Sub emdCalculat e Click Dim Payment As Single Payment Pmt txtIntRate Text 0 01 12 txtTerm Text txtPrincipal Text 0 chkPay Value MsgBox Format Payment 00 End Sub Single variable data type representing floating point numbers Pmt library function for calculating monthly loan payments Formats libra
68. eis any valid Visual Basic data type such as Integer or Double When redimensioning an array the DataType is optional and can t be changed with the Redim keyword unless the array is of type Variant Example Using ReDim re dimension the array iMyArray as ReDim Preserve iMyArray 9 Multidimensional Arrays So far the arrays in this lab session have been one dimensional arrays that is they are a one row collection of variables In Visual Basic however you can create arrays that have up to 60 dimensions Think of a two dimensional array as a tic tac toe board a set of columns and rows that intersect to form a grid Each grid cell has a location defined as ColumnNumber RowNumber Notice that each element is defined by the coordinates of the column position and the row position For example the array element iVar O 0 is 5 and the element 1Var 2 2 is 49 To create a two dimensional array use the following syntax Dim Public Private ArrayName SubscriptOfCols _SubscriptOfRows As DataType 74 Engineering Workshop Lab Session 10 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering In this syntax e Dim Public and Private are Visual Basic keywords that declare the array and its scope If you use Dim the array is private to the procedure in which it s declared Public makes the array visible from anywhere in the program and Private within a form or module s General section
69. entire documents to e mail messages e Date This header is not visible to the senders many e mail servers require it to process e mail This header is filled by the current Time and Date control panels of the user s PC Mailing Lists List servers After the advent of e mail users soon realized that being able to send e mail to groups of people for collaboration and discussion would be very helpful This e mail list server managed a large 119 Engineering Workshop Lab Session 20 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering number of mailing lists each one addressing a specific area of interest for network users and each having an independent set of list members This service made the exchange of ideas and information among the members very convenient How List servers Work A mailing list program runs on a computer and defines a unique e mail address to distribute all e mail sent to it This listserver software automates the process of enabling people to add and remove their names called subscribing and unsubscribing from these lists as well as a host of other functions After this listserver is set up anyone who subscribes to the listserver can send e mail to it that e mail is in most cases automatically distributed to everyone on the mailing list Who Maintains the List servers A person usually doesn t maintain the list server List servers are automate
70. eople who haven t visited the link recently and purple to people who have visited it All the same rules and possibilities discussed in Intra Page and E mail Links apply to image links exactly as they do for text links Scaling Images Adding borders amp White Spaces Backgroung Images Two attributes used with the lt img gt tag to specify an image s width and height are width value and height value These attributes indicate the exact size of the image in pixels For example lt img src myimage jpg width 109 height 175 alt This is my picture gt The user can specify an image to have a particular height and or width even if the original dimensions of the image don t match Navigator and IE will then scale the image stretching it accordingly The user can control the amount of horizontal space both left and right with the hspace value in pixels and the amount of vertical space both top and bottom with the vspace value in pixels attributes in the lt img gt tag To specify a border around an image use the attribute border value I being the thinnest in the lt img gt tag The color of the border will be same as that of text An image s border width does not count toward determining an image s height or width 139 Engineering Workshop Lab Session 23 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering To a
71. es The TDS210 has many more features than the ones we ve described so far Particularly useful are the digital measurement features Push the measure button to program these You can use them to measure the amplitude period and frequency of a signal The scope does not measure amplitude directly How then can you derive the amplitude from something the scope does measure EXERCISE 1 Explain briefly the various pieces of information displayed around the edges of the screen Engineering Worksho Lab Session 02 b NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering The following exercises will give you practice in understanding the various settings For each you should study the description in your oscilloscope user s manual The description belowis specific to the TDS210 if you have a different model your manual will explain the corresponding settings for your scope 2 Display a waveform from the calibrator on channel 1 What happens when you adjust the position knob The volts div knob 3 How many periods of the square wave are you displaying on the screen How many divisions are there per period What time interval corresponds to a horizontal division Explain how these observations are consistent with the known period of the calibrator signal 4 Adjust the sec div knob to display a larger number of periods Now what is the time per division How many divisions are there
72. es that control the default colors and background properties for the page Creating a Simple Web Page Remember to save the file with a HTML or HTM file extension the standard extension for all HTML formatted documents Then view it in the browser The following code will create a simple Start page in order to illustrate the fundamentals of HTML mentioned above Type it in HTML editor lt html gt lt head gt lt title gt My First HTML Page lt title gt lt head gt lt body gt My Start Page lt body gt Other Important tags Paragraph Tags When a Web browser displays HTML pages it pays no attention to line endings or the number of spaces between words To set apart a block of text as a paragraph it should be placed in between a pair of paragraph tags lt p gt and lt p gt Any text places between these two tags will be set apart as a paragraph with a blank line above it and a blank line below it To set alignment of the paragraph use the attribute align Values that can be used with this attribute are center left and right For example lt p align center gt The text here becomes a paragraph lt p gt This will centrally align the given text leaving lines above and below it Break Sometimes the user wants to force a line break in text without beginning a new paragraph For this break tag lt br gt is used The text which immediately follows will jump to the next line This tag does not
73. esigned your circuit perhaps even bread boarded a working prototype and now it s time to turn it into a nice Printed Circuit Board PCB design For some designers the PCB design will be a natural and easy extension of the design process But for many others the process of designing and laying out a PCB can be a very daunting task There are even very experienced circuit designers who know very little about PCB design and as such leave it up to the expert specialist PCB designers Many companies even have their own dedicated PCB design departments This is not surprising considering that it often takes a great deal of knowledge and talent to position hundreds of components and thousands of tracks into an intricate some say artistic design that meets a whole host of physical and electrical requirements Proper PCB design is very often an integral part of a design In many designs high speed digital low level analog and RF to name a few the PCB layout may make or break the operation and electrical performance of the design It must be remembered that PCB traces have resistance inductance and capacitance just like your circuit does Back in the pre computer CAD days PCBs were designed and laid out by hand using adhesive tapes and pads on clear drafting film Many hours were spent slouched over a fluorescent light box cutting placing ripping up and routing tracks by hand Bishop Graphics Letraset and even Dalo pens will be names that evoke
74. etchant which is corrosive and toxic due to its metal content The etchant removes copper on all surfaces exposed by the resist Undercut occurs when etchant attacks the thin edge of copper under the resist this can reduce conductor widths and cause open circuits Careful control of etch time is required to prevent undercut Where metallic plating is used as a resist it can overhang which can cause short circuits between adjacent traces when closely spaced Overhang can be removed by wire brushing the board after etching Lamination Some PCBs have trace layers inside the PCB and are called multi layer PCBs These are formed by bonding together separately etched thin boards 51 Engineering Workshop Lab Session 06 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Drilling Holes through a PCB are typically drilled with small diameter drill bits made of solid coated tungsten carbide Coated tungsten carbide is recommended since many board materials are very abrasive and drilling must be high RPM and high feed to be cost effective Drill bits must also remain sharp to not mar or tear the traces Drilling with high speed steel is simply not feasible since the drill bits will dull quickly and thus tear the copper and ruin the boards The drilling is performed by automated drilling machines with placement controlled by a drill tape or drill file These computer generated files are al
75. etric objects surface and image objects and annotations such as titles legends and color bars Figures can contain any number of plots Each plot is created within a 2 D or a 3 D data space called axes You can explicitly create axes with the axes or subplot functions A graphis a plot of data within a 2 D or 3 D axes Most plots made with MATLAB functions and GUIs are therefore graphs When you graph a one dimensional variable e g rand 100 1 the indices of the data vector in this case1 100 become assigned as x values and plots the data vector as y values Some types of graphs can display more than one variable at a time others cannot MATLAB plotting functions and tools direct their output to a figure window Each figure is a separate window that you can dock in the desktop and collect together with other plots in a Figure Group To illustrate the basic components of a graph execute the following code to create a plot of a family of sine curves 108 Engineering Workshop Lab Session 19 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering x 0 2 20 y sin x sqrt x 1 y 2 sin x 2 sqrt x 1 y 3 sin x 3 sqrt x 1 plot x y The resulting figure contains a 2 D set of axes This graphic identifies the components and tools of a figure window The plot function uses a default line style and color to distinguish the data sets plotted in the graph You
76. ext align center hl font weight 800 font stze 24pt color white text align center a link font size 14pt font weight 500 color FFFF80 lt style gt lt head gt lt htm1 gt To link this file saved with css extension an additional HTML tag is added on each page In the lt head gt section insert a lt link gt tag as shown below lt link rel stylesheet href msie css type text css gt The attribute href is used to specify the names of the page containing the style sheet file The attribute rel specifies the relationship between the linked file and the HTML document The attribute type defines the type of page the user is linking to Putting Images on a Web Page 136 Engineering Workshop Lab Session 23 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering To put an image jpg gif etc on a Web page first move the image file into the same directory folder as the HTML text file Then insert the following HTML tag at the point in the text where the image is to be appeared using the name of the image file instead of myimage gif lt img src myimage gif gt Here img stands for image and src stands for source which is a reference to the location of the image file Just as with the lt A HREF gt tag the user can specify any complete Internet address as the lt img src gt Or he can specify just the filename if an image will be l
77. fond or not so fond memories Those days are well and truly gone with computer based PCB design having replaced this method completely in both hobbyist and professional electronics Computer based CAD programs allow the utmost in flexibility in board design and editing over the traditional techniques What used to take hours can now be done in seconds The steps involved in PCB design can be listed here as under The Schematic Before begin to lay out your PCB you MUST have a complete and accurate schematic diagram A PCB design is a manufactured version of your schematic so it is natural for the PCB design to be influenced by the original schematic If your schematic is neat logical and clearly laid out then it really does make your PCB design job a lot easier Good practice will have signals flowing from inputs at the left to outputs on the right With electrically important sections drawn correctly the way the designer would like them to be laid out on the PCB Like putting bypass capacitors next to the component they are meant for Little notes on the schematic that aid in the layout are very useful For instance this pin requires a guard track to signal ground makes it clear to the person laying out the board what precautions must be taken Even if it is you who 42 Engineering Workshop Lab Session 05 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering designed the circui
78. g out with MATLAB Solving Linear Algebra Problems Part I Solving Linear Algebra Problems Part II Matrix Operations Graphical Representation of Mathematical Functions Section Four Working with HTML Introduction to Internet Basics Applying HTML Basic tags Applying Lists tags in HTML Applying Links and Inserting Images in Webpages with HTML 86 94 97 101 108 115 124 130 133 Section One Working with Basic Electronic Components Engineering Workshop Lab Session 01 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 01 OBJECT Exploring the electronic components COMPONENTS REQUIRED Capacitors Transistors different Diodes and inductor THEORY Conductors A conductor is any substance that allows an electrical charge to flow easily through it Metals such as copper are good conductors because their atoms have many electrons negatively charged particles that can readily flow Insulators An insulator is any substance that cannot easily allow a flow of charge Plastics and ceramics are good insulators Electrons in the molecules of these materials are restricted They cannot readily form an electric current Capacitor Capacitor is an electrical component used for storing charge composed of pairs of conducting plates separated by an insulating material called a dielectric A potential difference builds up as charge is stored on the pl
79. have an ending tag Font Color 126 Engineering Workshop Lab Session 21 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering The use of font color tag is similar to the font size tag except that the attribute used here is color For example lt font color red gt Text to b ffected here lt font gt Color name can also be replaced by six digit hexadecimal color code which are used to express amount of red blue and green in any given color Codes for some of the common colors are 000000 black FFFFFF white FF0000 red 00FF00 green 0000FF blue A020F0 purple A52A2A brown The hash mark in front of the codes is entirely optional More Text Styling amp Formatting Tags The following tags can be used to add various styles to text e lt font size value gt Defines the size of the font from 1 to 7 with 1 being the smallest e lt font face value gt Will display the text in the font face like Times New Roman etc specified as value if that font 1s on the computer of the person looking at the page e lt I gt lt Lor lt em gt lt em gt Emphasis the text usually puts it in italics e lt b gt lt b gt or Stronger emphasis usually puts it in bold lt strong gt lt strong gt e lt blink gt lt blink gt Causes text to blink irritatingly e lt small gt Small text e lt big gt Big text e
80. he polynomials whose coefficients are the elements of u and v Similarly deconv operation is used for division of two polynomials operations Syntax q r deconv v u q r deconv v u deconvolves vector u out of vector v using long division The quotient is returned in vector q and the remainder in vector r such that v conv u q r If u and v are vectors of polynomial coefficients convolving them is equivalent to multiplying the two polynomials and deconvolution is polynomial division The result of dividing v by u is quotient q and remainder r Example If u 1 2 3 4 v 10 20 30 the convolution is c conv u v c 98 Engineering Workshop Lab Session 17 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 10 40 100 160 170 120 Use deconvolution to recover u q r deconv c u q 10 20 30 r 0 0 0 0 0 0 This gives a quotient equal to v and a zero remainder c Polyval Function y polyval p x returns the value of a polynomial of degree n evaluated at x The input argument p is a vector of length n 1 whose elements are the coefficients in descending powers of the polynomial to be evaluated y px pox PX Pail Example p x 8x 2x 1 is evaluated at x 5 7 and 9 with p 3 2 1 polyval p 5 7 9 which results in ans 86 162 262 d Operation on Roots Matlab introduces two commands interchangeably that
81. iature end mill to route away the undesired copper leaving only the traces o By using a liquid proof marker that draws tracks on the copper sheet leaving only the region required for conducting purpose and afterwords performing chemical etching to convert remaining portion as insulator The method we are going to use in this lab session Chemical etching Chemical etching is done with ferric chloride ammonium persulfate or sometimes hydrochloric acid For PTH plated through holes additional steps of electroless deposition are done after the holes are drilled then copper is electroplated to build up the thickness the boards are screened and plated with tin lead The tin lead becomes the resist leaving the bare copper to be etched away The simplest method used for small scale production and often by hobbyists is immersion etching in which the board is submerged in etching solution such as ferric chloride Compared with methods used for mass production the etching time is long Heat and agitation can be applied to the bath to speed the etching rate As more copper is consumed from the boards the etchant becomes saturated and less effective different etchants have different capacities for copper with some as high as 150 grams of copper per litre of solution In commercial use etchants can be regenrated to restore their activity and the dissolved copper recovered and sold Small scale etching requires attention to disposal of used
82. iddle dot i amp 185 amp supl Superscript one dieresis amp 188 amp frac14 Fraction one fourth i amp H 189 amp frac12 Fraction one half P amp 190 amp frac34 Fraction three fourths amp 198 amp AElig Capital AE ligature amp 230 amp aelig Small ae ligature E amp 201 amp Eacute Accented capital E E amp 233 amp eacute Accented small e X amp 215 Multiply sign S amp H 247 Division sign Table 26 1 Special Characters EXERCISES 1 Write a complete HTML Web page with the title Foo Bar Home Page and a heading at the top which reads Happy Hour at the Foo Bar followed by the words Come on down in regular type Engineering Workshop Lab Session 21 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 2 Write the HTML to produce the following Come for eheap free H2O on May 7 at 9 00PM 3 What s the difference between the following two lines of HTML Deep lt TT gt S p aac e lt TT gt Quest Deep lt PRE gt S p aac e lt PRE gt Quest 4 How would you say We re having our annual Nixon Impeachment Day SALE today in normal sized blue text but with the word SALE at the largest possible size in bright red Lab Session 22 OBJECT Applying list tags in HTML THEORY 130 Engineering Workshop Lab Session 22 NED University of Engineering amp Technology Department of Computer amp Information System
83. iece of code lt html gt lt head gt lt title gt The Olivers and Their House lt head gt lt title gt lt body gt lt div align center gt Deep in the wilds of Elmore Vermont lies the lair of the rare and secretive lt i gt Familla Oliveria lt t gt lt p gt lt img src house jpg alt Our Humble Abode gt lt div gt 137 Engineering Workshop Lab Session 23 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering lt img src dicko gif align left alt Dick gt Each winter the male of the species disappears into his octagonal office lt i gt left and comes out only for skiing sliding and trips to the mailbox lt img src jan gif align right alt Jan gt The female and young dwell in the main house lt i gt right lt i gt Though she occasionally switches places with the male to Ship orders in the office while he cooks exotic food and Attends to the offspring Once each week local residents Have the rare opportunity to spot the illusive Olivers as They gather food in their aging Toyota lt body gt lt html gt Say the above code generates the following on a web page bis Netscape The Olivers and Their House Bile Edit sw Go Bookmarks Options Directory Window Help Deep in the wilds of Elmore Vermont lies the lair of the rare and secretive Fami ia Oliveria
84. igital Synthesis function generator are able to prove a wide variety of signals Today s basic units are capable of sine square and triangle outputs from less than 1 Hz to at least 1 MHz with variable amplitude and adjustable DC offset Many generators include extra features such as higher frequency capability variable symmetry frequency sweep AM FM operation and gated burst mode More advance model offer a variety of additional waveforms and arbitrary waveforms generator can supply user can define periodic waveforms Function generators are used where stable and repeatable stimulus signals are needed Here are some common use and users Research and development Educational institutions Electronics and electrical equipment repair businesses Stimulus response testing frequency response characterization and in circuit signal injection Electronic hobbyists To use a function generator to its best advantage the user should have a basic understanding of the instrument s controls features and operating modes This lab session provides useful information to those with little knowledge of function generator as well as the experienced technician or engineer who wishes to refresh his her memory or explore new uses for function generators and more sophisticated arbitrary waveform generators First we will explain the controls of a typical function generator Next we will look at the theory of how a DDS function generator work
85. imit of total resistance allowable from pin 6 to Ve Pin 7 Discharge This pin is the open collected of npn transistor the emitter of which goes to ground The conduction state of this transistor is identical in tuning to that of the output stage It is on when the output is low and off when the output is high Maximum collector current is internally designed these by removing restriction on capacitor site due to peak pulse current discharge In certain applications this open collector output can be used as an auxiliary output terminal with current sinking capability similar to the output Pin 8 Vt or Vcc The V pin also referred to as Vec is the positive supply voltage terminal of 555 timer IC Supply voltage operating range for the 555 is 4 5 Volts min to 16 Volts max and it is specified for operation between 5 Volts and 15 Volts The device will operate essentially the same over this range of voltages without change in time period Actually the most significant operation capability which increases for both current and voltage range as the supply voltage is increased the supply voltage is increased sensitivity of time interval to supply voltage change is low typically 0 1 per Volt Types of Waves Mechanical Waves The waves which require medium for propagation are called mechanical waves Electromagnetic Waves The waves that do not require medium for propagation are called electromagnetic waves Thes
86. ineering layers This ratio gets more important the smaller the pad and hole become and is particularly relevant to vias There are some common practices used when it comes to generic component pads Pads for leaded components like resistors capacitors and diodes should be round with around 70 thou diameter being common Dual In Line DIL components like IC s are better suited with oval shaped pads 60 thou high by 90 100 thou wide is common Pin 1 of the chip should always be a different pad shape usually rectangular and with the same dimensions as the other pins Most surface mount components use rectangular pads although surface mount SO package ICs should use oval pads Again with pin being rectangular Other components that rely on pin numbering like connectors and SIP resistor packs should also follow the rectangular pin 1 rule Octagonal pads are seldom used and should generally be avoided As a general rule use circular or oval pads unless you need to use rectangular Vias Vias connect the tracks from one side of your board to another by way of a hole in your board On all but cheap home made and low end commercial prototypes vias are made with electrically plated holes called Plated Through Holes PTH Plated through holes allow electrical connection between different layers on your board What is the difference between a via and a pad Practically speaking there is no real difference they are both just elec
87. inner experienc of the world Click on one of the elements to the right to read more about it lt body gt lt html gt Say the following figure shows how the image map in the above code appears to a reader about to click on the AIR link 141 Engineering Worksho Lab Session 23 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering bix Netscape The Medieval Elements Eile Edit View Go Bookmarks Options Directory Window Help The Medieval Elements Scientific knowledge has progressed far beyond the four elements of carth water air and fire as an explanation of objectwe physical phenomena However many people still view these four qualities as essential elements of ow subjectwe mner expenence of the world Click on one of the elements to the nght to read more about it al file CiintmifCh 11 fein him Figure 28 2 EXERCISES 1 Your home page will be at http www mysite com home htm when you put it on the Internet Write the HTML code to go on that page so that when someone clicks on the words All about me they see the page located at http www mysite com mylife htm 2 Write code to have a link from guide maine katahdin htm to the guide arizona superstitions htm page 4 Write the HTML to make a tiny image of a mouse named mouse jpg appear between the words Wee sleekit c
88. inputs It may thus be used to terminates an output pulse prematurely to gate oscillations from on and off etc Pin 5 Control Voltage This pin allows accessible to the 7 3 V voltage divider pint the reference level for the upper comparator It allows indirect access to the lower comparator from the point to the lower comparator input Use of this terminal is the option of the flexibility by permitting modification of the tuning period When the 555 timer is used in a voltage controlled mode it voltage controlled operation ranges from about 1 Volt less than V down to within 2 Volts of ground voltages can be safely applied outside these limits but they should be confined within the limits of V and ground for reliability Pin 6 Threshold Pin 6 is one of the input to the upper comparator and is used to reset the latch which causes the output to go low Resetting via the terminal is accomplished by taking the terminal from below to above a voltage level of 3 V The action of the threshold pin is level sensitive allowing slow rate of change of wave forms The voltage range that can be safely applied to the threshold termed the threshold 29 Engineering Workshop Lab Session 03 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering current must also flow into this terminal from the external circuit This current is typically 100 nA and will define the upper l
89. ite down a major difference between plot and stem command 2 Write down matlab instructions to plot the cosine wave between a time interval of 2 to 2 with a step size of 0 002 seconds 3 For the mathematical expression x e write down matlab instruction to draw plot a curve for x ranges from 1 to 50 with a step size of one 113 Engineering Workshop Lab Session 19 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 114 Section Four Working with HTML Lab Session 20 OBJECT Introduction to Internet basics THEORY Internet Engineering Workshop Lab Session 20 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Internet is a worldwide collection of computer networks that allows people to find and use information and communicate with others How Internet Started The Internet called ARPAnet began as a project in 1973 by the U S Defense Advanced Research Projects Agency DARPA ARPAnet developed a set of protocols known as Transmission Control Protocol Internet Protocol or TCP IP that would allow networked computers to talk freely across different platforms and networks The Internet continued to support a few hundred government scientists for over a decade until in 1986 the U S National Science Foundation NSF initiated the development of the NSFnet for government and educational institutions The bigge
90. its as voltage volts Engineering Worksho Lab Session 02 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Definition of the Volt A volt is the practical and SI unit of potential difference voltage and electromotive force e m f It is named for Alessandro Volta In the 18th century he carried out important experiments on current and how it flows The potential difference across a conductor is defined to be 1 volt when 1 joule of work is done to give it a charge of 1 coulomb Alternative units of voltage would therefore be joules per coulomb where 1 J C 1 V Resistance It is the hindrance or opposition to flow of electrons through a circuit Electrical resistance is measured in ohms symbol Q Resistors Resistors are components that are used deliberately to add resistance to a circuit helping to control current and protect other components They are made with a resistive metal carbon or metal that is very thin Colour Band 1 Band 2 Band 3 Multiplier Tolerance Black 0 0 0 1 Brown 1 1 1 10 1 Red 2 2 2 100 2 Orange 3 3 3 1000 Yellow 4 4 4 10000 Green 5 3 5 100000 Blue 6 6 6 1000000 Violet 7 7 7 10000000 Grey 8 8 8 100000000 White 9 9 9 Silver 5 Gold 10 Table 2 a 1 Resistor color band chart Ohm s Law Ohm s law states that for a given electrical c
91. lly include one or more types of interface Connection that allow computer control FUNCTION GENERATOR FG 8002 i ss i ere o4 X 1e O 000 ooooo000 D id jE sg 2 f Piy FRONT PANEL REAR PANEL Figure 2 c 1 22 Engineering Worksho Lab Session 02 c NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering FRONT PANEL 1 POWER Switch Pressing this push switch turns on power Ze POWER Lamp LED lights up when power is on 3 Frequency Dial This Variable potentiometer varies output frequency within the selected range with the frequency range selector 4 SWEEP WIDTH PULL ON Control Pulling the knob selects internal sweep and rotating it controls sweep width Rotate it counter clockwise to get a minimum sweep width 1 1 and rotate it clockwise to get a maximum sweep width 100 1 To get a maximum sweep width set the frequency dial to minimum scale below 0 2 scales Pushing the knob selects external sweep which is implemented when external sweep voltage is applied to the VCF input connector 5 SWEEP RATE Control This controls weep rate sweep frequency of internal sweep oscillator 6 SYMMERTRY Control This controls symmetry duty cycle of output signal waveform within range of 10 1 to 1 10 Fig 4 2 Shows waveforms varied by symmetry control PULL Counter clockwise Knob position PUSH Waveform
92. lt super gt Superscript e lt sub gt Subscript e lt strike gt Strikethrough draws a line through text e lt u gt Underline Background Color Text Color amp Base Font This command bgcolor is used to change the background color and is added as RGB code to the existing body tag By default background color of all WebPages is white To change the color of whole text in the body text command is used as attribute in the body tag For example lt body bgcolor blue text white gt This will write white text on a blue background Similarly to set a single font for all the text in the body use lt basefont SIZE 5 gt just after the lt BODY gt tag lt basefont gt is just a time saving tag for setting the overall size of all text in a document The size of all headings will also be relative to the lt BASEFONT SIZE gt This tag can t take any attributes other than SIZE and doesn t require a closing lt BASEFONT gt tag 127 Engineering Workshop Lab Session 21 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering The lt hr gt tag The lt hr gt tag causes a horizontal rule line Inserting a horizontal rule with the lt hr gt tag also causes a line break even if a lt br gt tag in not included along with it For a little extra blank space above or below a horizontal rule a lt p gt tag before or after the lt HR gt tag can be used No ending tag is required Va
93. m allowable pulse width for triggering is some what dependent upon pulse level but in general if it is greater than 1 usec triggering will be reliable Pin 3 Output The output of the 555 timer comes from a high current to totem pole Stage made up of transistors The state of the output pin will always reflect the inverse of the logic state of the latch and this may be seen Since the latch itself is not directly accessible this relationship may be explained in terms of latch input trigger conditions To trigger the output to a hi9gh condition the trigger input is taken from a higher to a lower level This causes the latch to be set and the output to go high Activation of the lower comparator is the only manner in which the output can be placed in the high place state This output can be returned to a low state by causing the threshold to go from a lower to a higher level which rests the latch The output can also be made to go low by taking the reset to a low state near ground Pin 4 Reset It is also used to reset the latch and return the output to a low state The reset voltage threshold level is 0 7 volts amp a sink current of 0 1 mA from this pin is required to reset the device These levels are relatively independent of operation V level thus the reset input is TTL compatible for any supply voltage The reset input is an overriding function that is it will force the output to low state regardless of the state of either of the other
94. m keep no information about completed transactions and processes When a client breaks a connection with a server running a stateless protocol no data has to be cleaned up or logged By not tracking state information there s less overhead on the server so it can generally handle transactions swiftly Understanding Telnet Telnet is a method of establishing a direct terminal connection to an Internet host computer Telnet provides commands that can establish connection of a Local machine to a Remote machine thus creating a transparent bi directional link such that all characters entered by the user on one machine can be sent to a process on another machine and all the output from that process can be sent back to the user A local machine is the user s computer and a remote machine is simply a server to which he connects via means of a modem or network connection The process on the remote machine asks the user for a login name and a password Once the correct information has been received the process_acts as a proxy for the user who can compute on a remote machine just as any local user can Understanding FTP FTP is quite similar to telnet with the exception that telnet executes any command for the user where as FTP responds to a predefined set of file related commands only FTP provides a fast reliable and efficient way to access files on remote systems With FTP the user can log onto an FTP server search for a file within a directory
95. mand button or simply a button to cause something to happen You can add a command button to a form just like you add other controls by using the mouse to draw it Add and set their Name and Caption properties according to Table 7 2 Table 7 2 Name and Caption Properties for the Loan Calculator Program s CommandButton Controls Name Property Caption Property cmdCalculate Calculate Payment cmdExit Exit Changing a Form s Properties The default name for a project s first form is Forml subsequently added forms are named Form2 Form3 and so on Click an empty area of the form to deselect any control s that may be selected Use the properties window to change the Name property of the Loan Calculator project s one and only form to frmMain Finally your project should appear like Figure 7 3 58 Engineering Worksho Lab Session 07 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering a Figure 7 3 Now that you ve completed designing the Loan Calculator s interface this would be an excellent time to save your work so far If you have added new components forms modules and so on since the last save you will be prompted fora filename and location for each of the newly added components Coding Your Program s Actions The user interface of the Loan Calculator program is now complete However it doesn t actually do anything at thi
96. me htm which is located in the dicko folder on the Web server computer whose address is netletter com href stands for Hypertext Reference and is called an attribute of the lt a gt tag Linking Between User s Own Pages When the user creates a link from one page to another page on the same computer it isn t necessary to specify a complete Internet address If the two pages are in the same directory folder the user can simply use the name of the HTME file like this lt a href pagetwo htm gt Click here to go to page 2 lt a gt Relative Addresses If the user has many pages he ll want to put them in more than one directory folder In that case he still shouldn t use the full Internet address to link between them He can use relative addresses which include only enough information to find one page from another A relative address describes the path from one Web page to another instead of an absolute Internet address For instance suppose the user is creating a page named zoo htm in a directory folder named web pages on the hard drive He wants to include a link to_a page named african htm which is in a sub folder named elephants within web pages The link would look like this lt a href elephants african htm gt Learn about African elephants lt a gt Intra Page and E mail Links Using Named Anchors The lt a gt tag can also be used to create link to a portion on the same web page To make such links the lt a gt tag is us
97. must have one index per dimension separated by commas Examples Print strSales 2 3 Print strResults 0 11 5 75 Engineering Workshop Lab Session 10 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering EXERCISES 1 What is an array Describe the declaration of arrays 76 Engineering Workshop Lab Session 11 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 11 OBJECT Performing Mathematical functions in Visual Basic THEORY The mathematical functions are very useful and important in programming because very often we need to deal with mathematical concepts in programming such as chance and probability variables mathematical logics calculations coordinates time intervals and etc The common mathematical functions in Visual Basic are Rnd Sqr Int Abs Exp Log Sin Cos Tan Fix and Round Using Rnd Function Rnd is very useful when we deal with the concept of chance and probability The Rnd function returns a random value between 0 and 1 In Example below when you run the program you will get an output of 10 random numbers between 0 and 1 Randomize Timer is a vital statement here as it will randomize the process Example Private Sub Form Activate Randomize Timer For x 1 to 10 Print Rnd Next x End Sub Note Always execute the Randomize statement at least once in
98. n but can also be used in the real world A Loan Calculator program will be demonstrated that calculates the periodic payment needed to repay loan based on various factors such as the loan term and interest rate The users will be able to input and modify values for these and other variable factors perform the calculation and view the results Creating Your Program s User Interface A program s user interface refers to the part of the program that the user sees and interacts with As you develop this application s interface you ll see how to use some of the many tools provided in Visual Basic s Integrated Development Environment IDE Getting Started C RABAS 7 4 E New Existing Recent oe a Sl Let s begin by creating a new project A project is simply a set of files that store information about the components that make up an application program To create a Visual Basic Xx Bw BS B program you customize your project s various components Le ea rn is es me SEMEL Activex EXE Activex DLL ActiveX VB Application Control Wizard To get started with the Loan Calculator program start Visual ae Basic you will see the New Project dialog box shown in Figure 7 1 If Visual Basic is already running or if you don t see the New Project dialog choose File New Project T Don t show this dialog in the future Figure 7 1 The New Project dialog box enables you to specify the type of project you want
99. n 05 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 51 160 0 6mm 101 150V 0 6mm 151 170V 1 25mm 171 250V 125mm 251 300V 1 25mm 301 500V 2 5mm EXERCISES 1 How you can differ PCB designing from other assembling projects Clearances for Electrical Conductors Voltage DC or Peak AC Internal External lt 3050m 0 15 DIr 16 30V 0 4mm 31 50V 0 6mm What sort of unit system is preffered in PCB designing Imperial or Metric What do you understand by the term thou Discuss briefly the concept of necking 48 Engineering Workshop Lab Session 05 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 5 What are Vias How they help connecting two different layers Is there any difference between vias and pads 49 Engineering Workshop Lab Session 06 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 06 OBJECT Demonstrating Printed Circuit Boards THEORY In this lab we are going to implement a circuit on PCB Printed Circuit Board We are going to use the concepts built in the previous lab session regarding different aspects of PCB design You have already implemented the circuit mentioned below in Fig 6 1 using breadboard veroboard in previous lab session We are going to implement the very same circuit wi
100. n alligator clip sometimes referred to as the reference lead or ground clip This connects to the shield of the coaxial cable It is useful for reducing noise when looking at high frequency time intervals of order nanoseconds or low voltage signals Since it is connected directly to the scope s case which is grounded via the third prong of the AC power plug it must never be allowed to touch a point in a circuit other than ground Otherwise you will create a short circuit by connecting multiple points to ground which could damage circuit components This is no trouble if you are measuring a voltage with respect to ground But if you want to measure a voltage drop between two points in a circuit neither of which is at ground first observe one point with the probe and then the other The difference between the two measurements is the voltage across the element During this process the reference lead should remain firmly attached to ground and should not be moved Alternatively you can use two probes and configure the scope to subtract one input from the other Warning A short circuit will occur if the probe s reference lead is connected anywhere other than ground Display Your oscilloscope user s manual will explain the information displayed on the scope s screen Record the various settings timebase calibration vertical scale factors etc Vertical controls There is a set of vertical controls for each ch
101. n be displayed on a computer screen One of your first objectives will be to set up the scope to do some of the things for which you may already have used simpler scopes After that you can learn about multiple traces and triggering In order to have something to look at on the scope you can use your breadboard s built in function generator a device capable of producing square waves sinusoidal waves and triangular waves of adjustable amplitude and frequency But start by using the built in calibrator signal provided by the scope on a metal contact labeled probe comp or something similar often located near the lower right hand corner of the display screen Note that a leg folds down from the bottom of the scope near the front face This adjusts the viewing angle for greater comfort when you are seated at a workbench so we recommend that you use it Probes and probe test Oscilloscopes come with probes cables that have a coaxial connector similar to that used for cable TV on one end for connecting to the scope and a special tip on the other for connecting to any desired point in the circuit to be tested To increase the scope s input impedance and affect the circuit under test as little as possible we generally use a 10 X attenuating probe which has circuitry inside that divides the signal voltage by ten Some scopes sense the nature of the probe and automatically correct for this factor of ten others such as the TD
102. n g dotted circle o blue b dashdot x mark x white w point etc invisible i 110 Engineering Workshop Lab Session 19 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering PLOT Y plots the columns of Y versus their index PLOT Y is equivalent to PLOT real Y imag Y if Y is complex In all other uses of PLOT the imaginary part is ignored See SEMI LOGLOG POLAR GRID SHG CLC CLG TITLE XLABEL YLABEL AXIS HOLD MESH CONTOUR SUBPLOT Text can be added directly to a figure using the gtext command gtext string displays the graph window puts up a cross hair and waits for a mouse button or keyboard key to be pressed The cross hair can be positioned with the mouse Pressing a mouse button or any key writes the text string onto the graph at the selected location Example Consider now the following equation yO 54e We can solve this for a vector of t values by two simple commands t 0 1 50 y 4 exp 0 1 t and we can obtain a plot by typing plot t y Notice that we could shorten the sequence of commands by typing plot t 4 exp 0 1 t t Figure 24 3 Example We can plot the function y t t e t by using y t exp 0 1 t plot t y gtext hey this is the peak xlabel t ylabel y 111 Engineering Worksho Lab Session 19 NED University of Engineering amp Technology
103. nd j represent the imaginary number V 1 by default i ans 0 1 0000i j ans 0 1 0000i sqrt 3 ans 0 1 73211 Note that these variables i and j can be redefined as the index in a for loop for example not included in your course Matrices can be created where some of the elements are complex and the others are real a sgrt 4 l ssgqrt 4 5 95 Engineering Workshop Lab Session 16 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering a 2 0000 1 0000 O 2 0000i 5 0000 Recall that the semicolon designates the end of a row EXERCISES 1 Write matlab commands to solve for the equation assigned by the lab teacher 96 Engineering Workshop Lab Session 16 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 17 OBJECT Solving Linear Algebra Problems polynomial equations THEORY e Scalar Operations e Solving Complex Variable e Solving Polynomial Equations Solving Polynomial Equation Representing Polynomial Equation For representing polynomial equation in MATLAB we can define a polynomial equation as follow MATLAB Representation Coefficient Actual Polynomial Equation vector 12345 y x 2x 3x 4x 5 10305 y x 4 3x745 1 2 i 3 4 3 5i y x 24i x 3x 4 3i x 5i Thus from the above example it
104. news client The user then can read what he wants when he wants instead of having tons of list server mail jamming up his mailbox These news servers organize distribute and keep track of thousands of messages Newsgroups cover topics regarding recreation society culture business and computers of course Usenet can be thought of as a structure or umbrella that encompasses the thousands of newsgroups that make up Usenet Usenet and News groups sound pretty similar to the list servers but the way each works is different The first difference between a list server and a newsgroup is in the way messages are received With list servers messages are sent directly to the user s mailbox where he has to sort 120 Engineering Workshop Lab Session 20 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering them out and decide what to read Newsgroup messages on the other hand are posted to something like a public electronic bulletin board where the user has to go to read the messages Another difference is one of access Anybody with an e mail address can subscribe to a list server To read newsgroups however the Internet service provider must provide the access Communicate in Real Time In the last few years the Internet has been hit by a wave of real time communication The processes of getting information talking to others and collaborating with colleagues no longer require
105. nning through the parallel branch created by the meter may be high enough to damage the meter along with the circuit the meter is connected to The current should not exceed the maximum rating of the meter Ohmmeters An ohmmeter is powered by an internal battery that applies a small voltage to a circuit or component and measures how much current flow through the circuit or component It then displays the result as resistance Ohmmeters are used for checking continuity and measuring the resistance of components Zero resistance indicate a short while infinite resistance indicates an open in a circuit or device A reading higher than the specification indicates a faulty component or a high resistance problem such as burnt contacts corroded terminals or loose connection 12 Engineering Worksho Lab Session 02 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Multimeter You are probably already familiar with multimeters They allow measurement of voltage current and resistance Just as with wristwatches and clocks in recent years digital meters commonly abbreviated to DMM for digital multimeter or DVM for digital voltmeter have superseded the analog meters that were used for the first century and a half or so of electrical work The multimeters we use have various input jacks that accept banana plugs and you can connect the meter to the circuit under test using tw
106. not know the exact command for the function that you are after another useful command is Lookfor This command works somewhat like an index If you did not know the command for the exponential function was exp you could type lookfor exponential EXP Exponential EXPM Matrix exponential EXPM1 Matrix exponential via Pade approximation EXPM2 Matrix exponential via Taylor series approximation EXPM3 Matrix exponential via eigenvalues and eigenvectors EXPME Used by LINSIM to calculate matrix exponentials Summary of Commonly Used Commands clear removes all variables from workspace cle clears command window diary save the text of a MATLAB session exp exponential function 89 Engineering Workshop Lab Session 15 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering format output display format function user generated function gtext place text on a plot help To access help documentation hold holds current plot and allows new plot to be placed on current plot length length of a vector ookfor keyword search on help variables plot plots vectors size size of the array subplot multiple plots in a figure window who view variables in workspace whos view variables in workspace with more detail size etc i matrix multiplication i Transpose suppress printing also
107. ntation MATLAB provides extensive documentation in both printed and online format to help you learn about and use all of its features If you are a new user start with Getting Started book It covers all the primary MATLAB features at a high level including many examples The MATLAB online help provides task oriented and reference information about MATLAB features MATLAB documentation is also available in printed form and in PDF format 88 Engineering Workshop Lab Session 15 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering GETTING STARTED This session provides a brief overview of essential MATLAB commands You will learn this material more quickly if you use MATLAB interactively as you are reviewing this manual The MATLAB commands will be shown in the following font style Monaco font the prompt for a user input is shown by the double arrow gt gt MATLAB has an extensive on line help facility For example type help pi at the prompt help pi PI PI 4 atan 1 3 1415926535897 so we see that MATLAB has the number z built in As another example help exp EXP EXP X is the exponential of the elements of X e to the X Sometimes you do not know the exact command to perform a particular operation In this case one can simply type help and MATLAB will provide a list of commands and m files to be discussed later that are available If you do
108. o banana plug leads The input jacks are described in Table given below Depending on how you configure the meter and its leads it displays the voltage difference between the two leads the current flowing through the meter from one lead to the other or the resistance connected between the leads Multimeters usually have a selector knob that allows you to select what is to be measured and to set the full scale range of the display to handle inputs of various size Note to obtain the highest measurement precision set the knob to the lowest setting for which the input does not cause overflow Input jack Purpose Limits COM reference point used for all measurements VQ input for voltage or resistance measurements 1000 V DC 750 V AC mA input for current measurements low scale 200 mA 10A input for current measurements high scale 10A OBSERVATIONS Resistors 1 Color Value Band 1 Band 2 Multiplier Tolerance Total Resistance Observed Resistance Resistor 2 Band 1 Band 2 Multiplier Tolerance Total Resistance 13 Engineering Worksho Lab Session 02 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Resistor 3 Observed Resistance Band 1 Band 2 Multiplier Tolerance Total Resistance Observed Resistance Resistor 4 Band 1 Band
109. oad it before showing it The Show method is typically used to transfer control from one form to another The syntax is formname Show For example if you are in Form1 and you want to display Form2 the syntax would be Form2 Show The Hide method of a form removes the form from the screen makes it invisible but the form still remains in memory The syntax is formname Hide To refer to the form in which code is currently running i e the current form or the active form you can of course refer to the form by its name as in the example above Forml Hide 62 Engineering Workshop Lab Session 08 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering As an alternative you can use the keyword Me The keyword Me refers to the form in which code is currently running Me Hide Finally any time you want to execute a method of the form on itself you can simply code the method name omitting the formname or the Me as in Hide The Load and Unload Statements The Load statement loads a form into memory but does not display it When you code the Load statement for a form the Form_Load event of that form will be triggered The syntax is Load formname The Unload statement removes a form from memory and from the screen When you code the Unload statement for a form the Form_Unload event of that form will be triggered The syntax iS Unload formname A form
110. ocated in the same directory folder as the HTML file Relative addresses can also be used Labeling an Image Consider the following piece of code lt img src myimage gif alt My Picture gt The lt img gt tag above includes a short text message alt My Picture The ALT stands for alternate text because this message will appear in place of the image in older Web browsers that don t display graphics and also by browsers where loading images feature is turned off Loading images feature is turned off so that the users can see the text on Web pages without wasting time downloading images they don t care about When automatic image loading is off the alt message appears instead of an image Clicking on that message causes the image to be downloaded and displayed If the image file is large or there are a lot of images on the same page the alt message may be on the screen quite a while before it is replaced by the image Both Netscape Communicator and Microsoft Internet Explorer support this graphics turning off feature In IE graphics can be turned off by deselecting View Options General Show Pictures Internet Explorer also displays the ALT message whenever someone holds the mouse over a graphic image without clicking Horizontal Image Alignment lt div align value gt can be used to align part of page to the center right margin or left margin Both text and images are affected by these tags For example consider the following p
111. ode Change the four label controls caption properties to Height Width Left and Top Working from top to bottom 3 Add another column of four Label controls just to the right of first set Change their Name properties to lblHeight IblWidth IblLeft and lbITop Change their Caption properties to nothing clear out the default captions 4 Add a CommandButton control near the bottom of the form Change its Name property to cmdWiden and change its Caption property to Widen Form 5 Select the form and change its Width property to 4000 twips 6 Double click the command button to bring up the code window You should see an empty cmdWiden_Click subprocedure 7 Press the Tab button and then type the code Form1 Width Form1 Width 100 This line of code causes the value of Form1 s Width property to increase by 100 twips each time the command button is clicked 64 Engineering Workshop Lab Session 08 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 8 Drop down the Code window s Object box and select Form Drop down the code window s Event box and select Resize You are presented with the shell of the Form_Resize event procedure The Resize event occurs whenever the width and or height of the form is changed either through user actions or program code 9 Add the following lines of code to the Form_Resize event procedure lWidth Caption Forml Width lHeight Caption
112. of all the Different Computers on the Internet Every computer on the Internet also has a unique number and it s called the ZP address An IP address is used by Internet Protocol IP to identify each computer on the Internet An IP address consists of four numbers between 0 and 255 each separated by a period A typical IP address might be 35 8 7 92 The Internet uses Domain Names to hide the hard to remember IP addresses The domain name is an English version of an IP address After all it is easier to remember www companyx com than 192 63 7 45 Some computers called Domain Name Servers even translate domain names into IP addresses for fast access on the Internet 117 Engineering Workshop Lab Session 20 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Understanding World Wide Web The World Wide Web a hypertext based system is the fastest growing part of the Internet as well as the most exciting In time most daily activities may very well take place through the World Wide Web It is practically entertaining as well as provides practical education and business Web Site Terminology The most important parts of the World Wide Web are the elements such as servers pages hot links and more all of which comprise the bulk of the World Wide Web The following are some related terms e Web site A collection of World Wide Web documents usually consisting of a home page an
113. of rectifiers namely half wave rectifier full wave rectifier and bridge rectifier The rectifier user for this power supply is bridge rectifier Bridge Rectifier Figure 4 a 1 Bridge rectifier The bridge rectifier is similar to a full wave rectifier because it produces a full wave output voltage Diodes D and D3 conduct on the positive half cycle and D3 and D4 conduct on negative half cycle As a result the rectifed load current flows during both half cycles During both half cycles the load voltage has the same polarity and the load current is in the same direction The circuit has changed the A C input voltgae to the plulsating D C output voltage The advantage of using Bridge Recitifer over Full Wave Rectifieir is that the entire secondary voltage can be used Capacitor Input Filter The capacitor input filter produces a D C output voltage equal to the peak value of the rectified voltage This type of filter is the most widely used in power supplies Other type of filter is choke input filter which is not used due to its high cost and weight Initially the capacitor is uncharged During the first quarter cycle the diode is forward biased Since it ideally acts like a closed switch the capacitor charges and its voltage equals the source voltage at each instant of the first quarter cycle The charging continues until the input reaches its maximum value At this point the capacitor voltage equals the peak value of the rectified vol
114. of v we could use v 1 ans rPwWoNnN OW re If we wished to look at the second column of v we could use v 2 ans 5 10 TS 20 25 30 And we can construct the same plot as before by using gives a dotted line If you have been putting in variables through this and the tutorial on vectors then you probably have a lot of variables defined If you lose track of what variables you have defined the whos command will let you know all of the variables you have in your work space gt gt whos Name Size Bytes Class A 3x3 72 double array B 3x3 72 double array v 1x5 40 double array Grand total is 23 elements using 184 bytes 105 Engineering Workshop Lab Session 18 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Applying Built In Matrix functions Once you are able to create and manipulate a matrix you can perform many standard operations on it For example you can find the inverse of a matrix You must be careful however since the operations are numerical manipulations done on digital computers In the example the matrix A is not a full matrix but matlab s inverse routine will still return a matrix gt gt A 1 2 2 3 ans 2 3 4 5 gt gt A 1 2 2 3 ans 2 4 3 5 gt gt inv A Warning Matrix is close to singular or badly scaled Results may be inaccurate RCOND 4 565062e 18 ans 1 0e 15 2 7022 4 5036
115. ome across while using email are as follows e POP This term stands for Post Office Protocol which is the technical name for the way some e mail clients receive their mail e SMTP This term stands for Simple Mail Transport Protocol which is another technical name for the way e mail messages are sent on the Internet by the clients Incoming message store Mail Client Outgoing message Figure 25 3 Sending and receiving emails e Spam Any mass mailed material meant for self promotion advertisement or pure silliness Spam or electronic junk mail is probably one of the most offensive aspects of the Internet Every e mail message contains two basic parts the header and the body The body is simply the text that the user wants the person on the other end to see on receiving the message The following are the different headers the user needs to be concerned about when sending e mail e To The To field contains the e mail address of the person to whom the e mail is being sent e From This field includes sender s e mail address e Subject It contains a very short 20 30 characters description of what the message is about e CC It stands for Carbon Copy and contains the e mail addresses of additional recipients e BCC It stands for Blind Carbon Copy gives the sender a way of copying an e mail message to another person without the first person he sends the message knowing about it e Attachments It enables the user to attach
116. omputer amp Information Systems Engineering Dim aintCount As Integer declares a variable length array whose bounds will be determined at run time Note from the above declarations that the lower bound is not restricted to 0 or 1 and it can even be negative Changing the number of elements in an array Although you usually set the number of elements in an array when you declare it it s possible to alter the size of the array When you change the number of elements in an existing array you redimension it To do so use the ReDim keyword in the following syntax ReDim Preserve ArrayName Subscript As DataType In this syntax e ReDim is the Visual Basic keyword denoting that the array is being redimensioned e Preserve is an optional Visual Basic keyword that forces all pre existing elements in the array to hold their values If you don t use the Preserve keyword when you redimension the array the value of all elements will be changed to zero for numeric data types and a zero length string for variable length strings Fixed length strings will be filled with zeros and variants will be initialized to EMPTY which could be either zero or a zero length string depending on the expression e ArrayName is the name of the array e Subscript is the subscript for the highest element in the array e As is the Visual Basic keyword that signifies a type declaration When redimensioning an array the As keyword is optional e DataTyp
117. on the PCB is nominally specified in ounces per square foot with loz copper being the most common You can order other thicknesses like 0 50z 20z and 4oz The thicker copper layers are useful for high current high reliability designs Track Width Reference Table for 10deg C temp rise Track Width is in Thous mils Pad sizes shapes and dimensions will depend not only upon the component you are using but also the manufacturing process used to assemble the board among other things There are a whole slew of standards and theories behind pad sizes and layouts and this will be explained later Suffice it to say at this stage that your PCB package should come with a set of basic component libraries that will get you started For all but the simplest boards though you ll have to modify these basic components to suit your purpose Over time you will build up your own library of components suitable for various requirements There is an important parameter known as the pad hole ratio This is the ratio of the pad size to the hole size Each manufacturer will have his own minimum specification for this As a simple rule of thumb the pad should be at least 1 8 times the diameter of the hole or at least 0 5mm larger This is to allow for alignment tolerances on the drill and the artwork on top and bottom 45 Engineering Workshop Lab Session 05 NED University of Engineering amp Technology Department of Computer amp Information Systems Eng
118. onductor the voltage across the ends is directly proportional to the current flowing the conductor when temperature and other physical conditions are kept constant Ohm s law is written as Val gt V IxR where V is the voltage is the current and R is the resistance The units of voltage current and resistance are the volt V ampere A and ohm Q respectively 10 Engineering Worksho Lab Session 02 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Instruments to measure basic quantities Voltage and Current Voltmeter Figure 2 a 1 Voltmeters measures voltage or voltage drop in a circuit Voltage drop can be used to locate excessive resistance in the circuit which could cause poor performance Lack of voltage at a given point may indicate an open circuit or ground On the other hand low voltage or high voltage drop may indicate a high resistance problem like a poor connection 2 3 shui inf mil E Q KT yp Ss A yO DA V Figure 2 a 2 Voltmeters must be connected in parallel with the device or circuit so that the meter can tap off a small amount of current That is the positive or read lead is connected to the circuit closest to the positive side of the battery The negative or black lead is connected to ground or negative side of the battery If a voltmeter is connected in Series its high resistance would reduce circuit current and cause a fals
119. ons but are not good conductors Because of this they are classified as semiconductors In a pure state they conduct electricity very poorly and so they are doped with impurities to make them better conductors Semiconductors are used to make many electronic components Doping The process of modifying the structure of a semi conducting material such as silicon to enhance its conducting properties Doping can involve the addition of atoms with extra electrons to carry negative charge or the insertion of electron deficient atoms creating holes that act as positive charge carriers pn junction When one n type semi conductor and one p type semi conductor are placed together the resulting device has some very special properties The region that is formed by adjoining a p type semiconductor and an n type semiconductor is called a pn junction 3 Engineering Workshop Lab Session 01 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Forward Biasing In order to forward bias the device and decrease the size of the depletion region one should set up an electric field such that a positive voltage is in contact with the p type end of the device and a negative voltage is in contact with the n type semi conductor The result of this applied voltage is that the holes in the p type side of the device and the electrons in the n type side of the device are both repelled from
120. orm _Load tmrTime Enabled False End Sub Next to exit the application when you are finished using it write the following code Private Sub btnExit_Click Unload Me End Sub EXERCISES To be assigned by Lab teacher 82 Engineering Workshop Lab Session 14 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 14 OBJECT Designing Quadratic Function Graph Plotter in VB THEORY The general format of a quadratic equation is f x ax bx c where a b and c are constant This is a program that can plot graphs for quadratic functions STEPS This program employs a picture box as the plot area and three text boxes to obtain the values of the coefficients a b c of the quadratic equation from the users We also need to modify the scale factor in the properties windows of the picture box We are using a scale of 0 5 cm to represent 1 unit Besides we need to make some transformation as the coordinates in VB start from top left but we want it to start from the middle We can use the Pset method to draw the graph using a very small increment Pset is a method that draws a dot on the screen the syntax is Pset x y color Where x y is the coordinates of the dot and color is the color of the dot The default color is black Using the For Next loop together with Pset we can draw a line on the screen P i I Quadratic Function Graph Plotter Sr e ax
121. ormation Systems Engineering Q Use the click event if you want to take an action when users select an option This method is useful when you are using option buttons that are in a control array as in the following example Private Sub optWash Click Index as Integer Select Case Index Case 0 MsgBox You selected Normal Case 1 MsgBox You selected Heavy Duty Case 2 MsgBox You selected Pots and Pans End Select End Sub a Do not write any code in the option button events Instead use an if statement to check their state as shown here Private Sub cmdStartWash Click If optHeavy True Then DoHeavyWash Else DoNormalWash Endif End Sub This second method is useful if you do not want something to happen immediately when users select options It is possible to have multiple option buttons on a form selected at the same time For this you have to separate the option buttons into groups by using container controls Using a container such as the Frame allows you to group option buttons The List Box The List Box control is used to present a list of choices The key parts of the list box are the following Item List This is the list of items from which the users can select These items are added to the list in the design environment or by your program as it is running Selected Item This item is chosen by the users Depending on the style of list you choose a selected item i
122. ou only have to follow a few basic conventions Separate the elements of a row with blanks or commas Use a semicolon to indicate the end of each row Surround the entire list of elements with square brackets Consider the following vector x recall that a vector is simply a matrix with only one row or column M x 1 3 5 7 9 11 135 7 9 11 x Notice that a row vector is the default We could have used spaces as the delimiter between Columns x 1 3 5 7 9 11 1 3 5 7 9 11 x There is a faster way to enter matrices or vectors that have a linear pattern For example the following command creates the previous vector 1 2 11 here what does 2 indicate Will be discussed in proceeding lab sessions x 1 35 7 9 11 101 Engineering Workshop Lab Session 18 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Transposing a row vector yields a column vector is the transpose command in MATLAB x KY IK rPwWoN OWE Say that we want to create a vector z which has elements from 5 to 30 by 5 s z 5 5 30 z 5 1015 20 25 30 If we wish to suppress printing we can add a semicolon after any MATLAB command z 5 5 30 The z vector is generated but not printed in the command window We can find the value of the third element in the z vector z 3 by typing z 3 ans 15 Notice that a new variable ans was
123. ow rin and the words tim rous beastie 5 How would you give a Web page a black background and make all text including links bright green 142 Engineering Workshop Lab Session 23 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 6 You have a 200x200 pixel image named quarters gif for your Web page When someone clicks in the top left quarter of the image you want them to get a page named toplft htm When they click on the top right quarter they should get toprgt htm Clicking on the bottom left should bring up btmlft htm and the bottom right should lead to btmrgt htm Write the HTML to implement this as a client side image map 143
124. pF 10 F Rectifiers Half Wave Rectifier The AC source produces a sinusoidal voltage Assuming an ideal diode the positive half cycle of source voltage will forward bias the diode Since the switch is closed the positive half cycle of source voltage will appear across the load resistor On the negative half cycle the diode is 38 Engineering Worksho Lab Session 04 b NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering reverse biased In this case the ideal diode will appear as an open switch and no voltage appears across the load resistor Thus a unidirectional load current is produced i e it flows in only one direction Figure 4 b 2 Half wave rectifier Full Wave Rectifier The full wave rectifier is equivalent to two half wave rectifiers Because of the centre tap in transformer each of these rectifiers hasan input voltage equal to half the secondary voltage Diode D conducts on the positive half cycle and diode D2 conducts on the negative half cycle The full wave rectifier acts the same as two back to back half wave rectifiers During both half cycles the load voltage has the same polarity and the load current is in the same direction The circuit is called a full wave rectifier because it has changed the A C input voltage to the pulsating D C output voltage RS D1 APR fS re e Figure 4 b 3 Full wave rectifier Bridge Rectifier The bridge r
125. port you to a site or anywhere else in the world The new document is located by its URL and can be another HTML document pictures sound files etc HTML is designed to be platform independent not bound to a particular hardware or software environment HTML Editors HTML programs are written as plain ASCII text files Any text editor can work as HTML editor Notepad is one of most widely used HTML editors around However working with Notepad one needs to be very well versed with HTML tags For a little more power and flexibility commercial HTML editors like Adobe Pagemill and Microsoft FrontPage are also available which provide a What You See Is What You Get authoring environment Internet Browser A browser essentially an HTML viewer which interprets the embedded formatting codes in the HTML document and displays it accordingly The two most popular ones are Microsoft s IE Internet Explorer and Netscape Communicator Essentials for every HTML Page Tags An HTML tag is a coded command used to indicate how part of a Web page should be displayed In every HTML page the words starting with lt and ending with gt are actually called HTML tags because they tag pieces of text and tell the Web browser what kind of text it is This allows the Web browser to display the text appropriately Most HTML tags have two parts an opening tag to indicate where a piece of text begins and a closing tag to show where the piece of tex
126. raphical engineering and different kinds of operations It covers matrix operations waveform graphs etc The last section covers a bit basic of Internet and all the basic use of HTML which will be helpful in understanding the concepts of web pages and their designing CONTENTS Lab Session No Object Page No Section One Working with Basic Electronic Components 1 Exploring the electronic components 2 2a Familiarization and working with Multimeters 9 2b Familiarization and working with Oscilloscope 15 2c Familiarization and working with Function Generator 21 3 Constructing a frequency generator by the use of 555 timer IC 28 4a Studying basics behind the construction of a power supply 32 4b Constructing a full wave rectifier 38 5 Designing Printed Circuit Boards 42 6 Demonstrating Printed Circuit Boards 50 Section Two Visual Basic Programming 07 Creating first program in Visual Basic 55 08 Learning the Visual Basic building blocks and develop programs using 62 them 09 Understanding Controls for Making Choices in Programming 67 10 Understanding Arrays in Visual Basic 12 11 Performing Mathematical functions in Visual Basic 11 12 Connecting to an Access database using the VB Data Control 79 13 Designing a Simple Stop Watch using VB Timer Control 81 14 Designing Quadratic Function Graph Plotter in VB 83 15 16 17 18 19 20 21 22 23 Section Three Mathematical Modeling Using MATLAB Startin
127. re optional but they improve readability EXERCISES 1 Describe in your own words how you think MATLAB is helpful in solving mathematical problems 3 Does MATLAB provides any mechanism to execute pre stored commands Can you create a code file in MATLAB Also give proper explanation Engineering Workshop Lab Session 15 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 16 OBJECT Solving Linear Algebra Problems THEORY Scalar Operations Solving Complex Variable Solving Polynomial Equations 1 Scalar Operations Scalar assignment statements A scalar variable is created and assigned a value in MATLAB with a simple statement of the form a 2 35 b 2 a pi a 2 The first statement creates a variable called a and assigns it the real number value 2 35 A real number is represented in MATLAB in double precision floating point format The second statement creates a variable b and assigns it the value computed using the formula on the right hand side of the statement Only variables that have already been created can appear on the RHS of assignment statements The variable pi is a predefined constant with value z MATLAB variable names must begin with a letter This can be followed by any combination of letters digits and underscores MATLAB distinguishes between uppercase and lowercase characters A and a are different variables The ending semicolon If yo
128. rent A flow of electric charge or the charge flowing per second is called Current I It is measured in Amperes A Electric current is carried either by the flow of negatively charged electrons or of positively charged ions or in semiconductors by positive holes where electrons are missing from a crystal structure Voltage People often very loosely speak of the voltage flowing through a circuit but this is both misleading and incorrect It is current that flows through a circuit Voltage is the difference in potential between two points in a circuit and as such it is correct to speak of the voltage across some component of the circuit or the potential difference between two points It is the difference in potential that causes a current to flow Potential Difference The potential difference between points A and B is the work done in bringing a unit charge from A to B The work is measured in joules and the unit of potential difference is the volt From this definition if a charge of Q coulombs is moved through a potential difference of V volts the work done W in joules is given by W QV Electromotive Force E M F If a potential difference can be used to drive a current through a circuit it is known as an electromotive force e m f It is the same as the voltage measured across a source of current when no current is actually being supplied E m f is not really a force at all it is measured in the same un
129. rent types of transmission lines c The phone system requires that each participant in the in the system have a unique ID i e phone number 123 Engineering Workshop Lab Session 20 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 2 Which one is correct a the more RAM you have the faster you can go on the internet b the more megahertz on your PC the faster you can go on the internet c the higher your modem speed the faster you can go on the internet 3 Of the two computers listed below which one would likely enable you to navigate the Internet more effectively a A386SX 66MHz PC with 4MB of RAM and a 14 4Kbps modem b A Pentium 100MHz PC with 16MB of RAM and a 28 8Kbps modem 7 One of the advantages of list servers is that they all work the same True or false 8 Which is the fastest connection a 14 4 modem b 28 8 modem c 33 6 modem d ISDN line Lab Session 21 OBJECT Applying HTML basic tags THEORY HTML Hypertext Markup Language 124 Engineering Workshop Lab Session 21 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Hypertext is the text stored in electronic form with cross reference links between pages Hypertext documents are written in languages called Markup Languages HTML Hypertext markup language is one of such languages It features hypertext links which can trans
130. rious attributes like width size align color etc can be used with to customize the line For example lt hr width 50 align left size 10 nonshade color green gt Headings For creating headings on WebPages a separate command heading lt h gt is used Headings can also be made by using font command and its size attributes but heading command can do it in a simpler way For example consider the following text without using heading tag lt p align center gt lt b gt lt font size 6 gt welcome lt font gt lt b gt lt p gt With heading command it will reduce to the following piece of code lt hl align center gt welcome lt h1 gt The heading tags come in six unique sizes ranging from lt h1l gt to lt h6 gt with 6 being the smallest Beside align attribute other attributes like color etc can also be used with the heading tag Predefined amp Type Writer Text By using type writer command lt tt gt and lt tt gt all the text appears on the Webpage as type writer mono spaced text Since HTML shows the text continuous lots of time and instructions are required to put text containing spaces and tabs But anything written in between the predefining tags lt pre gt and lt pre gt makes the browser process the spaces as well as tabs and enter keys This command shows the text in only type writer format For example lt pre gt To The Chairman CISE NEDUET Karachi SUBJECT Application for job
131. rix multiplication is straight forward I 2 34 3 6 b 2 3 5 6 O A He Il using the a matrix that was generated above c a b c 6 0000 9 0000 12 0000 20 0000 2 00001 25 0000 4 0000i 30 0000 6 0000i Notice again that MATLAB automatically deals with complex numbers Sometimes it is desirable to perform an element by element multiplication For example d i j b G j c i j is performed by using the command d c b a 1 0e 02 0 0600 0 1800 0 3600 0 8000 0 0800i 1 2500 0 2000i 1 8000 0 3600i Similarly element by element division b j c j can be performed using Other matrix operations include i taking matrix to a power and ii the matrix exponential These are operations on a square matrix a 2 f 4 0000 2 00001 3 0000 O 6 0000i 25 0000 2 00001 g expm a g 7 2232 1 80191 1 0380 0 21511 0 4302 2 07601 0 0429 0 29621 A matrix can be constructed from 2 or more vectors If we wish to create a matrix v which consists of 2 columns the first column containing the vector x in column form and the second column containing the vector z in column form we can use the following v x z 104 Engineering Workshop Lab Session 18 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering y ie 28 3 10 I LS 7 20 Qo 25 Li 30 If we wished to look at the first column
132. rocessing control systems neural networks fuzzy logic simulation and many others Starting MATLAB On Windows platforms start MATLAB by double clicking the MATLAB shortcut icon on your Windows desktop MATLAB 7 0 Figure 20 1 Or you can also access MATLAB through start menu by following the below mentioned path Start gt Programs gt MATLAB 7 0 In case you are using 7 Edition gt MATLAB 7 0 Getting Familiar with MATLAB Environment The MATLAB environment consists of five main parts 1 Development Environment 86 Engineering Workshop Lab Session 15 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering On Starting MATLAB you will encounter the basic GUI of MATLAB as shown in the Figure below This is the set of tools and facilities that help you use MATLAB functions and files Many of these tools are graphical user interfaces It includes the MATLAB desktop and Command Window a command history an editor and debugger and browsers for viewing help the workspace files and the search path File Edit Debug Desktop Window Help Daw d Ba o a q ry Current Directory C MATLABT work Shortcuts Z How to Add Z What s New a x Bat peas E Value To get started select MATLAB Help or Demos from the Help menu gt gt countS count5 1 else if 11 i 3 gt 200 1 count 6 count6 1 else count 7 count7 1 end 4 23 11 ae
133. ry function to round off numbers Msgbox display function to show output chkPay name property of a checkbox that is added to the form 60 Engineering Workshop Lab Session 07 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering EXERCISES 1 Design a simple age calculator 61 Engineering Workshop Lab Session 08 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 8 OBJECT Learning the Visual Basic building blocks and develop programs using them THEORY The objects like forms and controls are known as a program s visual component Compare this to a program s code component which refers to the program code that the program has created In this lesson we will examine some of the fundamentals necessary to build a program s visual component We will discuss the properties and methods of forms in detail here We will see how we can define the appearance and behavior of a control by working with its properties methods and events Forms A form is a container that holds all the other controls such as labels text boxes and pictures that make up part of a program s user interface Most of our programs will use a number of forms Showing and Hiding Forms The Show method of a form displays that form on the screen If the form to be shown is not already loaded into memory the Show method will l
134. s The next section is on controls applications and contains the majority of the material in this lab session 21 Engineering Worksho Lab Session 02 c NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering There are a variety of function generators on the markets spanning the cost range from a few tens of dollars to tens of thousands of dollars Some are dedicated instrument the ones we will look at in more detail some are black boxes with USB interfaces and an Output terminal some are plugged into computer or instrumentation buses and some are software programs that run on a PC to generate waveforms on the parallel port or via a sound card There are also inexpensive Kits for hobbyists The software only function generator tends to be the least expensive and can be attractive for students and hobbyists on a budget They are also the most limited in frequency capabilities often just spanning the audio range The black boxes are next in cost and have the advantage of portability and low power They are often intended to operate with laptop computers Generators that plug into different buses e g PC VXI are appropriate where space is at a premium and a custom measurement system needs to be put together for e g a dedicated purpose Dedicated bench top generators are self Contained with needed control and display The more expensive dedicated instruments add features and usua
135. s Engineering Arranging Text in Lists There are three basic types of HTML lists e Ordered lists they are indented lists that have numbers or letters in front of each item It begins with the lt OL gt tag and ends with a closing lt OL gt tag Numbers and line breaks appear automatically at each lt LI gt tag and the entire list is indented In lt OL gt tag attribute type value can be used to specify the number formats The value indicates 1 Arabic numbers a lowercase alphanumeric A uppercase alphanumeric I lowercase roman numbers I uppercase roman numbers Another attribute that can be used is start value where value indicates the beginning of the list s number sequence In addition lt LI gt tag can use an attribute value value to force to make a particular list item to have a certain number e Unordered lists they are indented lists with a special bullet symbol in front of each item It opens with the lt UL gt tag and closes with lt UL gt It looks just like an ordered list except that bullets appear at each lt LI gt tag instead of numbers e Definition lists they are indented lists without any number or symbol in front of each item It starts with the lt DL gt tag and ends with lt DL gt The lt DT gt tag goes in front of each term to be defined with a lt DD gt tag in front of each definition Line breaks and indentation appear automatically e Menu and dir
136. s indicated by a highlight bar or by a check in the box next to the item Scrollbar This part indicates that more items are available on the list than will fit in the box and provides the users with an easy way to view the additional items With the list box the choices are set up by you the programmer the users can select only from the items you decide 68 Engineering Workshop Lab Session 09 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering The Combo Box Another control that enables us to present lists to the users is the ComboBox control Combo boxes are so named because they combine the features found in both text boxes and list boxes The combo box can be used in three different forms The drop down combo box Presents the users with a text box combined with a drop down list The users can either select item from the list portion or type an item in the text box portion The simple combo box portion Displays a text box and a list that doesn t drop down As with the drop down combo box the users can either select an item from the list portion or type an item in the text box portion The drop down list Displays a drop down list box from which the users can make a choice The users cannot enter items that are not in the list At design time you set the style of the combo box with its Style property The combo box has much in common with the list box Both use
137. s point In order for your program to become functional you need to write some code The term code refers to one or more lines of programming commands written in a particular programming language Visual Basic in your case Responding to Events Visual Basic is an object oriented event driven language This means that a program s interface is comprised of objects controls forms and so forth the program is taught what actions to perform when events happen to those objects An event is usually initiated by the user By anticipating the possible events that can and should occur to the various objects in your program you can write code to respond to those events appropriately 59 Engineering Workshop Lab Session 07 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Double click the Exit button that you placed on the sample application s form You will see a new window called a Code Window The Code window contains a template or shell of a sub procedure beginning with the words Private Sub and ending with the words End Sub A sub procedure also known simply as a procedure is a discrete sequence of code statements that has a name and is executed as a unit Private Sub cmdExit Click End Sub The part after the words Private Sub denotes the sub procedure s name This particular sub procedure is named cmdExit_Click a predefined name that denotes the Click event proc
138. s the source and an output connection known as the drain The size of current that can flow through the channel is influenced by the voltage on a third connection known as the gate that is made to the p type material The gate is so called because changing the voltage applied to it makes the size of the channel narrower closing the gate and reducing the current that can flow between the source and the drain The source corresponds to the emitter of a junction transistor the drain to the collector and the gate to the base One of the main advantages of FETs is that they can be made much smaller than junction transistors so they are widely used in computer chips Transformers A transformer is two coils of wire called the primary coil and the secondary coil wrapped around a piece of iron It makes AC voltages larger or smaller depending on how the coils are arranged A transformer with more windings in the secondary coil than in the primary increases voltage and is called a step up transformer The reverse arrangement a step down transformer decreases voltage Engineering Worksho Lab Session 01 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Mathematically Vs Vp Ns Np Voltage in secondary coil voltage in primary coil number of coils in secondary coil number of coils in primary coil 3 Figure 1 6 Transformer OBSERVATIONS Resistors 1 Color
139. sion select File gt Exit MATLAB in the desktop or type quit or exit in the Command Window 2 The MATLAB Mathematical Function Library This is a vast collection of computational algorithms ranging from elementary functions like sum sine cosine and complex arithmetic to more sophisticated functions like matrix inverse matrix Eigen values Bessel functions and fast Fourier transforms 3 The MATLAB Language This is a high level matrix array language with control flow statements functions data structures input output and object oriented programming features It allows both rapid creations of small programs as well as large and complex application programs 4 Graphics MATLAB has extensive facilities for displaying vectors and matrices as graphs as well as annotating and printing these graphs It includes high level functions for two dimensional and three dimensional data visualization image processing animation and presentation graphics It also includes low level functions that allow you to fully customize the appearance of graphics as well as to build complete graphical user interfaces on your MATLAB applications 5 The MATLAB Application Program Interface API This is a library that allows you to write C and FORTRAN programs that interact with MATLAB It includes facilities for calling routines from MATLAB dynamic linking calling MATLAB as a computational engine and for reading and writing MAT files MATLAB Docume
140. sired waveform out of sine wave triangle wave and square wave VCF IN Connector Frequency of output signal can be varied by applying voltage to this connector Application of voltage from 0 to 10V provides frequency variation up to 100 1 To maximum variation set the frequency dial to minimum scale below 0 2 scale TTL OUTPUT Connector TTL level square waves output from here OUTPUT Connector This is the main output connector for sine wave triangle wave and square wave selected with the FUNCTION Selector 24 Engineering Worksho Lab Session 02 c NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering 14 Voltage Selector Select rated voltage 110V or 220V according to the power line voltage to be applied to the instrument 15 Power Cord Connect to a power connector for supplying AC power 16 FUSE Holder Fuse holder for AC power supply Use a specified fuse for safety of the instrument Working with Function Generator The purpose of this lab is familiarizing you with the basic functions of an oscilloscope and function generators 1 Setting Up The Oscilloscope and Function Generator a Turn on the oscilloscope with the button on the top Attach a BNC to alligator cable to the Channel 1 BNC input connector b On the oscilloscope set the following controls Channel 1 Volts Division 2 The CH J menu button enables disables the channel turn VOLTS DIV
141. so called numerically controlled drill NCD files or Excellon files The drill file describes the location and size of each drilled hole These holes are often filled with annular rings hollow rivets to create vias Exposed conductor plating and coating PCBs are plated with solder tin or gold over nickel as a resist for etching away the unneeded underlying copper After PCBs are etched and then rinsed with water the soldermask is applied and then any exposed copper is coated with solder nickel gold or some other anti corrosion coating Solder resist Areas that should not be soldered may be covered with a polymer solder resist solder mask coating The solder resist prevents solder from bridging between conductors and creating short circuits Solder resist also provides some protection from the environment Solder resist is typically 20 30 micrometres thick Test Unpopulated boards may be subjected to a bare board test where each circuit connection as defined in a netlist is verified as correct on the finished board For high volume production a Bed of nails tester a fixture or a Rigid needle adapter is used to make contact with copper lands or holes on one or both sides of the board to facilitate testing A computer will instruct the electrical test unit to apply a small voltage to each contact point on the bed of nails as required and verify that such voltage appears at other appropriate contact points A short on a board wo
142. st turning point came in 1991 when NSF dropped its funding of the Internet and lifted the ban on commercial traffic on its cables After 1991 new commercial systems sprang up almost overnight With them of course came the marketing and popularization of the Internet Soon after that many Internet service providers emerged and the companies began to see the enormous potential for business on the Internet In addition users also began to see some of the incredible applications for which they could use the Internet At first the World Wide Web contained only a few Server and Client machines Server and client are computers that forms the basis for the entire Internet In a general sense a server is any computer that serves or delivers information and data A client is any computer that requests or receives the information and data Within a period of a couple years however the computing population caught onto the benefits and excitement of this new development and the World Wide Web population growth exploded Internet Terminology The most important parts of the World Wide Web are the elements such as servers pages hot links and more all of which comprise the bulk of the World Wide Web The following are some related terms e Address The unique location of an information site on the Internet or a specific file for example a Web page e Internet Protocol A set of rules On the Internet this translates into the set of rules computers
143. structure and download the file The user also can upload files to the FTP server Searching the file structures on FTP servers is a time consuming process especially if he doesn t know the directory of the file he is looking for The basic functions of FTP have been extended in different ways The most popular extension is Archie which lets the user search file archives easily by using keywords FTP File Transfer Protocol is nothing more than a set of rules for transferring files FTP is a fast efficient and reliable way to transfer information This service is designed to enable the user to connect his local machine to a remote computer on the Internet browse through the files and programs that are available on the computer and then retrieve those files to his computer Any type of file whether compressed or uncompressed can be downloaded using FTP however files with no compression are always fastest FTP is a connection oriented protocol 122 Engineering Workshop Lab Session 20 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Understanding HTTP The major shortcoming of early Internet protocols was the inability to access information through a common interface Generally files available through one interface weren t available through another It was time consuming and frustrating it was to track down information This give way for the use of URLs uniform Resource Locator
144. sual Basic assigns a default name to every control placed on a form To change the name of the first text box you placed on the form for the Loan Calculator project you must first make sure the control is selected The selected control is the one for which properties will be changed in the Properties window Now that the control is selected look at the Properties window The left column of the Properties window is alist of properties that apply to the selected object at design time Each property s current value is denoted in the right side of the Properties window A TextBox control s Text property represents the text that s entered in the box that is what is displayed inside the box on the screen As the user types in a text box Visual Basic constantly modifies the text box s Text property to reflect the current contents of the box Adding the Remaining Text Boxes and a Check Box Now that you have added one TextBox control to the form it should be a simple matter to add the other text boxes that you need for your Loan Calculator program Add two more text boxes to the form name them txtIntRate and txtTerm Clear their Text properties as well You need to add a check box with the name of chkPay to the form Labeling Your Program s Controls The label will then act as a caption for the text box containing a brief description of what data is to be entered there The key difference between a Label control and a TextBox control is
145. t for connectionless protocol because the connection isn t maintained no system resources are used after the transaction is finished Consequently HTTP servers are limited only by active connections and can generally handle thousands of transactions with low system overhead The drawback to connectionless protocols is that when the same client requests more data the connection must be reestablished To Web users this means a delay whenever they request more information Stateless versus Stateful Protocols 121 Engineering Workshop Lab Session 20 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Stateless protocols differ from stateful protocols in the way information about requests is maintained With a stateless protocol no information about a transaction is maintained after a transaction has been processed With a stateful protocol state information is kept even after a transaction has been processed Servers using stateful protocols maintain information about transactions and processes such as the status of the connection the processes running the status of the processes running and so on Generally this state information resides in memory and uses up system resources When a client breaks a connection with a server running a stateful protocol the state information has to be cleaned up and is often logged as well Stateless protocols are light because servers using the
146. t and drew the schematic notes not only remind yourself when it comes to laying out the board but they are useful for people reviewing the design Your schematic really should be drawn with the PCB design in mind The schematics for PCB Design can be drawn with the help of available design aid software The softwares that are mainly used for this purpose are orcad and workbench You also learn in preceding lab session how to design circuits with the help of these softwares Imperial and Metric As any long time PCB designer will tell you you should always use imperial units i e inches when designing PCBs This isn t just for the sake of nostalgia although that is a major reason The majority of electronic components were and still are manufactured with imperial pin spacing So this is no time to get stubborn and refuse to use anything but metric units metric will make laying out of your board a lot harder and_ a lot messier Some PCB designers will tell you not to use metric millimeters for ANYTHING to do with a PCB design In the practical world though you ll have to use both imperial inches thous and the metric millimeter mm So which units do you use for what As a general rule use thous for tracks pads spacings and grids which are most of your basic design and layout requirements Only use mm for mechanical and manufacturing type requirements like hole sizes and board dimensions Working to Grids The second
147. t ends Closing tags start with a forward slash just after the lt symbol Many tags also include attributes in the form attribute name attribute value which add options to that particular tag Tags may be in either upper case or lower case Every Web page created must include the following tags e lt html gt tag Putting lt html gt at the very beginning of a document simply indicates that this is a Web page The lt htm1 gt at the end indicates that the Web page is over e lt head gt tag Encloses the header of the document Information that goes includes title together with other information to make the page more search engine friendly lt head gt is the ending tag e lt title gt tag The header must include the this title tag which contains the page title This title appears in the title bar of the browser and is used when saving bookmarks Only one title can appear in a document and the title cannot contain links or highlighting lt title gt is the ending tag 125 Engineering Workshop Lab Session 21 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering e lt body gt tag The lt body gt tag tells the Web browser where the actual body text of the page begins and lt body gt indicates where it ends It contains all the text images hyperlinks and other material to be displayed in the main display area of the Web browser window It has numerous attribut
148. tage After the input voltage reaches the peak it starts to decrease As soon as the input voltage is less then the peak value the diode turns off In this case it acts like the open switch During the remaining cycle the capacitor stays fully charged and the diode remains open This is why output voltage is constant and equal to the peak value 33 Engineering Worksho Lab Session 04 a NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering gt f Figure 4 a 2 Capacitor input filter Transformers A transformer is two coils of wire called the primary coil and the secondary coil wrapped around a piece of iron It makes AC voltages larger or smaller depending on how the coils are arranged Step Up and Step Down Transformers A transformer with more windings in the secondary coil than in the primary increases voltage and is called a step up transformer The reverse arrangement a step down transformer decreases voltage Mathematically V V gt Ns Np Voltage in secondary coil voltage in primary coil number of coils in secondary coil number of coils in primary coil A transformer works because the alternating voltage carried in one coil induces an alternating voltage in the other coil This is called mutual inductance 100 V at output 1 000 V across input 100 V across input 1 000 V at output Step up transformer Step down transformer
149. tems Engineering Good PCB layout practice would involve you starting out with a coarse grid like 50 thou and using a progressively finer snap grid if your design becomes tight on space Drop to 25 thou and 10 thou for finer routing and placement when needed This will do 99 of boards Make sure the finer grid you choose is a nice even division of your standard 100 thou PCB design is always done looking from the top of your board looking through the various layers as if they were transparent This is how all the PCB packages work The only time you will look at your board from the bottom is for manufacturing or checking purposes Tracks There is no recommended standard for track sizes What size track you use will depend upon in order of importance the electrical requirements of the design the routing space and clearance you have available and your own personal preference Every design will have a different set of electrical requirements which can vary between tracks on the board All but basic non critical designs will require a mixture of track sizes As a general rule though the bigger the track width the better Bigger tracks have lower DC resistance lower inductance can be easier and cheaper for the manufacturer to etch and are easier to inspect and rework The lower limit of your track width will depend upon the track space resolution that your PCB manufacturer is capable of For example a manufacturer may quote a 10
150. tes at the bottom of the screen as the rectangle selection tool is used to select a rectangular region of the image Image editing and animating software can be used to create new interlaced progressive transparent and even animated images Creating Image Maps Once the coordinates have been written down an HTML image map can be created Just after the lt body gt tag in the Web page put a map tag with attribute name specifying the reference name to mark that area For example lt map name heads gt Now the user needs to type an lt area gt tag for each region of the image This tag can have attributes like e Shape rect indicates that the region is rectangular See next section for other shapes e coords x1 y1 x2 y2 gives the top left x y and bottom right x2 y2 corner coordinates for the rectangular region 140 Engineering Workshop Lab Session 23 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering e href URL of the page specifies the page that clicking on the region will link to Any address or filename that can be used in an ordinary lt a href gt link tag can be placed here After the lt AREA gt tags insert a closing lt MAP gt tag To place the actual image map on the page use an ordinary lt img gt tag and add a usemap attribute Use the name put in the lt map gt tag preceded by a symbol For example lt img src r
151. th PCB in this lab session VCC SV To 15V Figure 6 1 Patterning etching The vast majority of printed circuit boards are made by bonding a layer of copper over the entire substrate sometimes on both sides creating a blank PCB then removing unwanted copper after applying a temporary mask e g by etching leaving only the desired copper traces A few PCBs are made by adding traces to the bare substrate or a substrate with a very thin layer of copper usually by a complex process of multiple electroplating steps The PCB manufacturing method primarily depends on whether it is for production volume or sample prototype quantities Circuit Schematics Imprint The print of the circuit depends on the requirement which can be categorize as follow e Commercial o silk screen printing the main commercial method 50 Engineering Workshop Lab Session 06 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering o Photographic methods used when fine linewidths are required e Non Commercial o Laser printed resist Laser print onto paper o Print onto transparent film and use as photomask along with photo sensitized boards o Laser resist ablation Spray black paint onto copper clad laminate place into CNC laser plotter The laser raster scans the PCB and ablates vaporizes the paint where no resist is wanted o Use a CNC mill with a spade shaped i e 45 degree cutter or min
152. that a 57 Engineering Workshop Lab Session 07 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Label control contains text that the user cannot change The text contained in a Label control is stored in its Caption property as opposed to a Text Box control s Text property To add a Label control to a form follow these steps i Select the Label control s tool in the Toolbox ii Draw a Label control to the left of the first TextBox control ili In the properties window Change the Label control s name property to lblPrincipal iv Change the Label control s Caption property to Principal v Change the Label control s Alignment property to 1 Right Justify using the drop down arrow next to the property setting This makes the label align its caption along the right side next to its corresponding text box as is common with caption labels Create three more label controls one for each of the remaining text boxes and the last for the check box Use the recommended values for the Name and Caption properties outlined in Table i Table 7 1 Name and Caption Properties for the Loan Calculator Program s Label Controls Name Property Caption Property Lb1Principal Principal LblIntRate Annual Interest Rate LblTerm Term Years LblPay Pay early Adding a Command Button A user can click a CommandButton control also commonly known as a com
153. the form s width to increase The Width label is updated with the new property value This example illustrates a programmatic modification of a property even though a user initiated the action that led to the width change the actual property change was performed by a code statement Finally try moving the form by dragging the form s title bar By doing so you the user in this case are modifying the form s Top and Left properties One problem with this example is that the revised Top and Left properties aren t automatically displayed in the Label controls This result is due to the fact that the code to update the labels is contained in the form s Resize event procedure and the form wasn t resized when you moved it Unfortunately no event is similar to a Resize event that occurs when a form is repositioned Using properties to control user interaction Even if your application includes many forms and controls you probably don t want the users to have access to all of them at the same time For example suppose you are writing a program that allows users to enter expense reports You might have a command to allow the users to print the 65 Engineering Workshop Lab Session 08 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering expense reports but you would not want the command to be available unless the reports balance Two properties the Visible property and the Enable
154. the program prior to using Rnd function otherwise the same set of random numbers will be generated on every execution of the program The Numeric and Trigonometric Functions The numeric functions are Int Sqr Abs Exp Fix Round and Log a Int is the function that converts a number into an integer by truncating its decimal part and the resulting integer is the largest integer that is smaller than the number For example Int 2 4 2 Int 4 8 4 Int 4 6 5 Int 0 032 0 and so on b Sqr is the function that computes the square root of a number For example Sqr 4 2 Sqr 9 2 and etc c Abs is the function that returns the absolute value of a number So Abs 8 8 and Abs 8 8 11 Engineering Workshop Lab Session 11 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering d Exp of a number x is the value of e For example Exp 1 e 2 7182818284590 e Fix and Int are the same if the number is a positive number as both truncate the decimal part of the number and return an integer However when the number is negative it will return the smallest integer that is larger than the number For example Fix 6 34 6 while Int 6 34 7 f Round is the function that rounds up a number to a certain number of decimal places The Format is Round n m which means to round a number n to m decimal places For example Round 7 2567 2 7 26 g Log is the function that ret
155. tment of Computer amp Information Systems Engineering triggering or from above falling edge triggering using the trigger menu or for some scope models using trigger control knobs and switches You can also select the signal source for the triggering circuitry to be channel 1 channel 2 an external trigger signal or the 120 V AC power line and control various other triggering features as well Since setting up the trigger can be tricky the TDS210 provides an automatic setup feature via the autoset button which can lock in on almost any repetitive signal presented at the input and adjust the voltage sensitivity and offset the time sensitivity and the triggering to produce a stable display After getting a stable display of the calibrator signal adjust the level knob in each direction until the scope just barely stops triggering Next connect the scope probe to the breadboard s function generator you can do this by inserting a wire into the appropriate breadboard socket and grabbing the other end of the wire with the scope probe s grabber The function generator s amplitude and frequency are adjusted by means of sliders and slide switches Display both scope channels with one channel looking at the output of the function generator and the other looking at the scope s calibrator signal Make sure the vertical sensitivity and offset are adjusted for each channel so that the signal trace is visible Additional featur
156. to create For the Loan Calculator project select the Standard EXE option and click OK You will then be placed in Visual Basic s design environment as illustrated in Figure 7 2 In this figure the word design appears in the title bar This means that you are in design mode A new standard EXE project consists of one form or window which will usually be your program s main user interface Visual Basic applications are comprised of one or more components such as forms code modules and classes along with controls and other components 55 Engineering Worksho Lab Session 07 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering i Project Microsoft Visual Basic design File Edit View Project Format Debug Run Query Diagram Tools Add Ins Window Help B 4 Ble els BBM oo x me Fe te General w Projecti Formi Form Project1 Project1 E3 Forms S Gone eran Formi Formi Dee e Te E ICRI E E E E EASE gla Form1 Form parce eae line saan eo bier aa a een Oy RRR Aen Alphabetic Categorized xj T O E A S E T atte OA EN E A E O A meh at al Formi R Mee Sie TEE a O E A I S leh E ey eens Ai S A e a 1 3D Oo ee E ek Ped ne emi ae ice eat False Eades eae Rena ite eemehice Ai he ear ReMi Nee a vey E mee cd C amp Hs000000F amp E E ley oe E N ae ae 2 Sizable 6 N EEE E E A E A N E Form True ral fe
157. trically plated holes But there are differences when it comes to PCB design packages Pads and Vias are and should be treated differently You can globally edit them separately and do some more advanced things to be discussed later So don t use a pad in place of a via and vice versa Holes in vias are usually a fair bit smaller than component pads with 0 5 0 7mm being typical Using a via to connect two layers is commonly called stitching as you are effectively electrically stitching both layers together like threading a needle back and forth through material Polygons Polygons are available on many PCB packages A polygon automatically fills in or floods a desired area with copper which flows around other pads and tracks They are very useful for laying down ground planes Make sure you place polygons after you have placed all of your tacks and pads Polygon can either be solid fills of copper or hatched copper tracks in a crisscross fashion Solid fills are preferred hatched fills are basically a thing of the past 46 Engineering Workshop Lab Session 05 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering An example of a Solid Polygon Fill Left and a Hatched Polygon Fill Right Figure 5 2 Clearances Electrical clearances are an important requirement for all boards Too tight a clearance between tracks and p
158. u omit the semi colon at the end of a MATLAB assignment command you get an echo response gt gt x 1 5 x 1 5000 This echo is useful for checking the value of a scalar variable or small matrix just type in the variable name without a semicolon but is undesirable most of the time 94 Engineering Workshop Lab Session 16 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Short long bank format Notice that the value of x was only printed to five significant digits This is called short output format If you issue the command format long and then repeat the above you get the output x 1 50000000000000 The command format bank will result in variable values being printed with only two decimal places and format without any argument will revert to the default format Values are represented internally in double precision floating point format and the format command controls how they are displayed Scalar mathematical operations If a and b are scalar variables then the standard mathematical operations are denoted as follows addition a b subtraction a b multiplication a b division a b exponentiation a b As usual exponentiation takes precedence over multiplication and division which take precedence over addition and subtraction In complex formulas it s a good idea to use parentheses for clarity a 2 b 2 1 2 b 3 2 Solving Complex variables Both i a
159. uld be a connection where there should not be one an open is between two points that should be connected but are not Printed circuit assembly After the printed circuit board PCB is completed electronic components must be attached to form a functional printed circuit assembly or PCA sometimes called a printed circuit board assembly PCBA In through hole construction component leads are inserted in holes In surface mount construction the components are placed on pads or lands on the outer surfaces of the PCB In both kinds of construction component leads are electrically and mechanically fixed to the board with a molten metal solder 52 Engineering Workshop Lab Session 06 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering EXERCISES In this exercise you have to mention each and every step taken by you to fabricate the PCB for the timer circuit given in Fig 9 1 Did you follow all the necessary steps mentioned in this lab session for the fabrication If not then mention why 53 Section Two Visual Basic Programming Engineering Workshop Lab Session 07 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 7 OBJECT Creating First Program in Visual Basic THEORY In this lesson we are creating a sample program that not only demonstrates the fundamentals of creating a Visual Basic applicatio
160. urce DatabaseName biblio mdb DefaultT ype seJet default IRecordSource Authors choose from list Note When you use the Data Control in a project the properties that must be set are DatabaseName and RecordSource in that order DatabaseName is the name of the database you want to use and the RecordSource is the name of the table in that database that you want to use 3 On your form create a text box for each field in the Authors table with labels If you were to open the database in Access you would see that the three fields of the Authors table are Au_ID Author and Year Born Set the properties of the three textboxes as follows Name DataSource DataField txtAuthID txtAuthor datAuthors txt YearBorn datAuthors In addition set the Enabled property of txtAuthID to False 79 Engineering Workshop Lab Session 12 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering When you want a control such as a text box to display data from a database the properties that must be set are DataSource and Datafield The DataSource is the name of the data control on the form it should already be configured and the DataField is the name of the particular field in the database that should be displayed in the control this field will be in the table that was chosen for the RecordSource of the data control At this point your form should resemble the screen shot below
161. urns the natural Logarithm of a number For example Log 10 2 302585 h Cos is the function that returns trigonometric cosine of a number in radians i Sin is the function that returns trigonometric sine of a number in radians j Tan is the function that returns trigonometric tangent of a number in radians EXERCISES 1 Take a number input from user and calculate the following for it 1 Square root 1i Log i1i Sin iv Cos For the trigonometric functions convert degrees into radians and display the converted values also 3 Create an advance scientific calculator that performs all operations that are explored in this lab session and attach code 78 Engineering Workshop Lab Session 12 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 12 OBJECT Connecting to an Access database using the VB Data Control THEORY Ms Access is a database management tool that enables one to have good command of data collected The program enables one to retrieve sort summarize and report results speedily and effectively In this lab session we are going to learn the steps for connecting access database using the Visual Basic data control STEPS 1 Open anew Visual Basic project 2 Puta data control an intrinsic control located in the VB toolbox on the form and set the properties as follows Property Wate TS i DatabaseName DefaultType RecordSo
162. use to communicate across networks e TCP IP An abbreviation for Transmission Control Protocol Internet Protocol Set of rules used to connect computers on the internet e Megahertz MHz One hertz represents a single cycle of current per second in a circuit A cycle is merely the time it takes an electron to make a trip between two points in a circuit A megahertz represents 1 00 00 000 cycles per second PC speed is usually gauged in megahertz so a 66MHz processor can complete 6 60 00 000 cycles in one second e Download To copy a file from one computer system to another From the Internet user s point of view to download a file is to request it from another computer or from a Web page on another computer and to receive it e Upload Transferring a file to a host computer from the user s computer usually using FTP e Internet Service Provider ISP An organization or company that provides users access to the Internet 116 Engineering Worksho Lab Session 20 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering amp ye N d A Figure 25 1 Figure 25 2 How Data is Transmitted Consider figure 25 1 Each of the points in the figure 25 2 called Routing Station performs a number of functions Generally the computer or computers at each routing station on the Internet are referred to as Nodes Tasks such as deciding what type of data is being transmitted
163. ushmore gif usemap heads gt Image Maps with Non rectangular Regions Some images don t lend themselves to being broken up into neat rectangular regions Fortunately HTML image maps let the user create other shapes as well To make polygonal regions use shape poly in the lt area gt tag and put each of the corner points in the coords attribute For circular regions use shape circle and put the center point and radius in pixels in the coords attribute Consider the following code lt html gt lt head gt lt title gt The Medieval Elements lt title gt lt head gt lt body background gradient jpg gt lt map name elements gt lt area shape poly coords 217 215 185 84 109 159 href earth htm gt lt area shape poly coords 5 218 139 185 64 108 href water htm gt lt area shape poly coords 5 7 33 141 112 61 href air htm gt lt area shape poly coords 216 5 86 39 161 109 href fire htm gt lt area shape circle coords 111 111 30 href ether htm gt lt map gt lt img src ewaf gif width 220 height 220 border 0 align right usemap elements gt lt h2 gt The Midieval Elements lt h2 gt Scientific knowledge has progressed far beyond the four elements of earth water air and fire as an explanation of objective physical phenomena lt p gt However many people still view these four qualities as essential elements of our subjective
164. usoidal wave v t 5 cos 62832t 0 volts a What is the frequency of the waveform in hertz What is the period What is Vp b Adjust the function generator to output the waveform in equation 2 Start bringing up the frequency from 1 KHz to the value you calculated in part a and notice what happens to the waveform displayed on the oscilloscope Readjust the sec div knob on the scope until one or two periods take up most of the screen What happens to the signal displayed on the scope as the frequency from the function generator gets higher 26 Engineering Worksho Lab Session 02 c NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering c With the cursors measure Vp peak and Vpp peak to peak and record these values in your lab book d With the cursors measure the frequency of the waveform and record this value in your lab book e Sketch the waveform as best as you can in your lab book Be sure to fully label your plot with axes units and divisions 27 Engineering Workshop Lab Session 03 NED University of Engineering amp Technology Department of Computer amp Information Systems Engineering Lab Session 03 OBJECT Constructing a frequency generator by the use of 555 timer IC COMPONENTS REQUIRED 555 IC Oscilloscope Bread board CIRCUIT DIAGRAM VCC SV To 15V Figure 3 1 Circuit diagram of frequency generator using 555 timer IC THEORY 555 Timer
165. where is it going which node will the data go to next 1s all the data here are performed at each station These questions are some of the many that an Internet node asks and answers with every transmission What is Digital Transmission A typical computer transmission is carried out as digital data in short bursts Digital data transmission can be thought of as a series of bullets being fired from a gun All digital data is made up of a series of Os and 1s that are grouped in unique sequences Each sequence of Os and Is can mean an infinite number of things to the computers translating them into what the user see on the screen A single sequence of digital data is called a Packet As each packet of data is sent through the various networks it has a distinct digital marker that tells the routing computer which packet it belongs to as can be seen in Figure 12 2 Sending data in packets offers enormous advantages during transfer If an interruption occurs in transmission for example a computer can simply hold all the packets with identical markers until all the packets have arrived and then put them back together again as illustrated in Figure 12 2 Sending data this way also means that multiple computers can send packets through the same wire at the same time because they can be reconstructed at the other end according to their markers Both of these factors contribute to faster and more reliable data transmission How the Internet Keeps Track
166. which supplied common easy to use interface to access and retrieve files and also made sure that the information available through previous protocols is accessible on the Web as well With URLs using other protocols in the Web documents is easy as the user simply specifies the protocol in a reference to a URL Although the specification for URLs is an important specification for finding files on the Web many other specifications play a major role in defining the Web Specifications for HTTP define how hypertext documents are transferred HTTP is the primary protocol used to distribute information on the Web It s a powerful fast and versatile protocol that allows for easy exchange of files and is evolving along with other Web technologies To achieve this speed versatility and robustness HTTP is defined as a connectionless and stateless protocol which means that generally the client and server don t maintain a connection or state information about the connection Types of Connections Different kind of connections are available Some of which are e Modems e ISDN e Cable Modems e TI Line e T3 Line EXERCISES 1 Internet system is somewhat analogous to the phone system Whether the following statements are true for an internet system Give reasons a A typical phone call can actually stop at dozens of relay stations before reaching its destination b The phone system transmits data such as voice video text and sound via diffe
167. wing syntax Dim Public Private ArrayName Subscript As DataType In this syntax e Dim Public and Private are Visual Basic keywords that declare the array and its scope If you use Dim the array is private to the procedure in which it is declared Public makes the array visible from anywhere in the program and Private within the General section of a form or module makes the array visible only to the form or module in which it s declared If you use Dim within a module s procedure the array will be available to only that procedure but if you use Dim in the module s Declarations section the array will be available to all procedures within the module e ArrayName is the name of the array e Subscript is the number of the highest element in the array Remember that the first element in an array is usually zero so if you declare an array in which Subscript is 6 you ll have seven element positions and therefore seven elements e Asis the Visual Basic keyword that signifies a type declaration e DataType is any valid Visual Basic data type such as Integer or Double Option base When you declare an array the first element of the array is usually O zero It s possible however to force the first element of an array to be 1 To do this insert the statement Option Base 1 in the General section of a module within your project You have to do this only when 72 Engineering Workshop Lab Session 10 NED University of Engineering amp T
168. y ContralRay Trie Figure 7 2 Saving Your Work Now let s save the sample Loan Calculator project Choose File Save Project or click the Save Project button on the toolbar You will first be prompted to save your application s one form Form1 This displays the Save File As dialog box so you can specify the name and location of your application s files Change the filename to the more descriptive LoanCalcMain After you have saved the form you will be presented with the Save Project dialog box where you can specify the name and location of the project file The default location will now be the same location where you saved the form file Change the suggested filename Projectl vbp to Loan Calculator the extension VBP for Visual Basic Project will be added for you Click Save to finish Getting Information from the User Controls in Visual Basic are tools that can be placed in the form to perform various tasks We can use them to create all levels of Windows applications The user interface for the loan calculator program will be responsible for accepting input displaying output and initiating the loan calculations You use three of Visual Basic s most commonly used controls e TextBox controls to accept textual information needed from the user and to display certain information back to the user e Label controls to act as captions displaying information to the user Labels are similar to text boxes except that the user c

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