SC200C Scope Clock Board Kit Assembly and User Manual
Contents
1. SN74HC125N Date Filename Number Wed 19 2008 SC200C5 sch Drawn Drawn by Forbes Sheet 1 of 4 D Forbes 6 C 5 3 m 18 8k 20 0K R32 cuan VANN dy 0 1uF 5 U1 B 10KT R5 1000pF 9 5 R16 P ub 20 0 2200HM LM6132 1 6132 tf E LM6132 one Circle Generator Height 5 RIS X ANN ELE _ 19 ax 10 0K 29 2 8 POSSA ANN YSUM W 20 0K U2 A 0 Size YCEN NER R22 20 0 1 6132 16 05 8 R28 10 0K NEG5 e NNW 40 2K LM6132 mE l R25 R24 R20 gt gt POS5A DACLD 55 DACDATA DACCLK 2006 DACCS R8 R7 _ 7 LM6132 Shape _ 4 LM6132 mE Ly ac 1000pF 10 d d DACs L NEGS Scope Clock Number Rev CSEL1 SC200 CD4052P Circle Selector Date Filename Wed Mar 19 2008 SC200C5 sch Drawn by D Forbes Sheet 2 of Deflection Amplifiers2. RIS Astig 1 iM m 2 3 4 5 POS250 5 R41 R42 E 2 R43 R44 5 249 249 249 249 Q1 Q2 Q3 Q4 e Mpswa2 d MPSw42 d D6 05 401 02 07 D8 010 4003 X 011 012 1414 5 RAS Rae E A Maras V A 5 BR RAP E AC M qat NA148UF1004 S page Z UF1004 INA148 NA148UF1004 S page Z UF1004 INA148 5 Q6 Q7 8 MPSW42 MPsw42 MPSW42 D13 014 015 016 14148 144148 A 144148 1 4148 A POS5A e e e 9 9 e e e 9 019 025 012 K 5 6 5 J TENE MPSAQ6 6 21 11 R51 R56 2 2K 26 2 2K R49 R50 R53 R52 R54 R55 R58 R57 B uF 220K 10 0K 10 0K 330K 220K 10 0K 10 0K 330K NEG5 e e e e e e e XOUT YOUT Scope Clock Rev SC200 Date Wed Mar 19 2008 Drawn by D Forbes Filename SC200C5 sch Sheet 3 of 4 Number BLNK R36 P5 PWRGOOD 1 20 0 R63 R62 POS NAVV POS250 NEG 185A 1 121 121 DCN TS1T1A Deflection Supply A 78105 1147 10 25 P6KE18A 3 4 E E m POSSGPS 56 D41 4 uF300V 29 5 po 5 D42 53
3. GND CLK CTI RES 0 0 a gt Dy eeemc je 9 9290709 00900008 00000000 os ed HHETESTTI c NSZIOHVZNS gt COLES COX 2 00000000 Alaa las 59 612 HC9 8GP32 DIP ve 9609 5 EZO 8 e 2 2 57100000 T e ln 00006000018 266899 010 28005 66668 NNSA 52 L 153 OFF ON ev amp e Q N Thu Apr 10 2008 11 23 02 50 Ln ee TOP SILK SCREEN TOP MASK Cathode Corner 2602 E Helen Tucson AZ 520 795 7228 SC200C Scope Clock PCB Clock Generator 74HC4060 550 POS5D R35 R37 R38 RESET ns 10 0K lt gt 10 0K 2 10 0K Processor 50 M 3 1 HC908GP32 DIP Meet l PWRGOOD GND CLK ul 1000pF PWRGOC 1 0M bie 16 possp EN 5 1 gar 7 2 8 POSAR 74 151 __ pACCLK l 1 U11 A pi tis 24 DACDATA 5 CLK40D 12 gt 3 Rau PiE pau PSON 6 R40 SN74HC125N NY 11 SN74HC74N 0 50 12 11 o 550 R26 2 PROG RUN el 10 0 U11 B 4 1 BLNK 4 26 e 5 l an 10 0177 232 8 9 8
4. UF1004 4 poa teurasv L2 5 10uF25V 4 10 YY Y 55 PSON 5 1 C31 28 R64 RS JU Bog cao L1 c30 27 1 21K non LM2586T HS 1 uH 16uF25V 1 uF25V NEGS nium s R72 3 3K High Voltage Supply Focus w Sook Brighit ANN ANN AAA _ 657 2 371 0 C36 0M C351 0M C34 C331 0M M Lu md MM T T i T T 026 J 025 024 023 4 022 J 021 4 020 019 018 iL UF1004 ie UF1004 iL UF1004 iL UF1004 iL UF1004D17 01 500 Q1uF5 0V Q1uF5 0V 01 500 01 500 T rs pau C53 D38 Blanking 550 JE Di 0 47uF50V m 55 5 R68 47 5 1N4148 R70 lt gt 10 0K 4 7K T R71 Q13 C52 D36 MPSA 6 Jk 100F25V ZX p35 2 4 1 0K 1N4148 10 25 D33 1F2 5V T 1N52248 JE D34 1N5224B Filename Wed Mar 19 2008 SC200C5 sch Scope Clock Size Number pr scam Date Drawn Drawn by Forbes D Forbes Sheet 4 of 4
5. then a circle will be produced The DACs are four digital to analog converters whose job is to scale the circle size and position the center of the circle on the screen These are special DACs called multiplying DACs A multiplying DAC will multiply in the analog domain the voltage applied to its reference input by a scale factor equal to the number loaded into the DAC divided by its input number range For example if a 1 volt peak to peak sine wave is fed into the DAC and its register is loaded with 64 which is 1 4 of its range of 256 then the output will be a 1 4 volt peak to peak sine wave Two of the DACs are used to scale the sine waves for the X and Y axes The other two have 5 volts as their input and simply produce X and Y offset voltages to move the circle on the screen There are two summers one each for the X and Y axes A summer adds the offset voltage and the sine wave and another offset voltage from the centering knob to produce a signal that is amplified and sent to the oscilloscope tube deflection plates The arc blanker switches the electron beam on and off as the sine waves sweep out the circle on the screen It is made from an 8 way multiplexer that selects one bit of the arc code byte at a time as the circle is swept The selection is done by using three higher frequency bits from the frequency divider that produces the 38 4 KHz square wave The selected control bit is passed to the blanking circuit which shifts it in v
6. IRQ input Since the interrupt 18 edge triggered pulse width is not critical The software detects an interrupt on this pin to enter the 1PPS timekeeping mode Until and unless such an interrupt occurs the clock will use the crystal oscillator divided by the CPU s timer as the time source When the IRQ interrupt happens the software changes to a mode in which it advances the seconds counter on each receipt of an interrupt The clock will not keep time if the 1 PPS signal is connected then removed This could be changed in the software Feel free to Optional GPS input on Com port The clock may listen to the NMEA 0183 text strings sent from a GPS receiver connected to the serial port The clock was designed to connect directly to the Garmin GPS 18 LVC receiver but will work with any GPS receiver that puts out an RS 232 or TTL level active low serial data stream The default baud rate is 4800 8 N 1 The string that is monitored is the GPRMC sentence which contains the time date position and course information Course is not too interesting unless the clock is mounted in a moving vehicle SC200C Clock User Manual 4 10 08 30 e 9 H 2 2424 OZY 09606 9 60 en 00909 8 ze ve e2 e Ze je ge 0 91812 amp 000000000 e 5 200225 0 0000000000000000000 ev
7. Japanese manufacturers mark the negative lead of the electrolytic capacitors with a big white stripe but the PC board marks the positive hole with a sign The positive leads of the capacitors are longer So put the long leads into the plus holes Bend the legs 30 degrees to hold them in place Double check that the signs on the PC board are away from the white stripes on all the capacitors Solder the square pad of each capacitor then turn the board over and straighten all the capacitors Solder the remaining leg Cut off all excess wire Step Qty Description Marking RefDes 52 12 Cap Elect 10uF 25V 100 C27 32 C39 40 C47 48 C52 C54 53 3 Cap Elect 0 47uF 50V 0 47uF C53 C55 C57 54 2 Cap Elect luF 450V C38 C46 55 2 Cap Gel 1F 2 5V 1 49 50 Install and solder the large white Molex headers Pull out the pin with the missing hole on P2 This may be done with cutters used as a lever Make sure they are oriented as shown on the PC board legend Solder one pin on each header then check for flatness and reheat and reposition if needed Again don t hold your thumb on the pins while heating Use the bench as the thumb and move the board slightly while heating the pin to get them to sit flat Check that the parts are all seated flat then solder the remaining pins Step Qty Description Marking RefDes 56 1 Header 2Pin 156 P5 57 1 Header 5Pin 156 P1 58 1 Header 6Pin 156 P2 Install the fuse next Spread the legs 30 degrees to
8. X or Y signal presented to one transistor is developed across the emitter coupling resistor to generate a current difference which causes a varying voltage to be generated across the high voltage pullup resistor The gain is controlled by the emitter coupling resistor s value The output stage has a pair of high voltage amplifiers which serve to speed up the operation by actively pulling the output high or low as needed The two diodes on the emitter of the upper transistor direct current into the base of one transistor or the other depending on whether the output needs to be driven higher or lower This allows the output voltage to be driven high faster than the RC time constant of the CRT capacitance and the load resistor The result is a slew rate of about 150 volts per microsecond Character display The characters are formed from circles lines and arcs The basic method of drawing a circle on a CRT is called a Lissajous pattern This is something that every student of electronics learns about early in school then promptly forgets The only other known use of this numeric display technique is in the HP 1600 logic analyzer A Lissajous pattern is displayed by applying sine waves of different phases to the X and Y deflection plates of a CRT A sine wave on the Y plates and a cosine wave on the X plates give a circle If the phase difference is zero then the circle collapses to a slanted line If Y 0 the line is horizontal etc Each character i
9. do this You can press a row of pins against the tabltop and press down on the chip to make them go together or you nay be able to use a smooth jawed vice to compress the part slightly After squeezing the legs together install the chips listed below Sometimes a row of pins doesn t want to go into the row of holes in that case use the wide side of a knife to push the pins into position Be sure to align the notched end of the chip with the notch mark on the PC board Bend over two corner pins on each chip to keep the part in the board while installing the other chips Double check that each chip s notch is at the same end of the chip as the board legend s notch After all the chips are installed solder two corner pins on each chip to finalize their position Check that all chips are fully inserted If a chip is not fully seated on the board adjust if necessary by heating the pin and pressing the corner down with a thumb Then solder the rest of the pins on all the chips Step Qty Description Marking RefDes 24 1 IC optocoupler 6N137 017 28 1 IC buffer 74HC125 011 29 1 IC multiplexer 7 151 04 30 1 IC counter 14bit 74HC4060 U6 31 1 IC flipflop D 7AHC74A U5 32 IC multiplexer CD4052 U7 33 4 IC opamp dual LM6132B U1 3 U9 34 1 IC interface RS 232 232 U12 The next part is the crystal Bend its legs to the rear so that it will lie flat on the PC board Then place its legs through the holes hold it in place and bend the
10. is what is printed on the part or its color if unmarked Resistor color codes are abbreviated RefDes is the reference designator the code printed on the board silkscreen that identifies which part goes where A photograph of the top side of the assembled board is shown on the next page Refer to this photo to see how the parts fit SC200C Clock User Manual 4 10 08 Step by step guide The PC board has already had some parts soldered to it these are the parts that are only available in surface mount form the parts you need to install are old fashioned through hole parts The first parts to install are the small glass diodes To install a diode first pull it loose from the tape strip then bend the legs at right angles to the body using your thumb and finger The leg will want to bend about 1 16 from the end of the body resulting in the proper 0 30 leg spacing to fit on the board The diodes have a stripe on one end which is shown on the PC board legend When installing a diode be sure to orient it so that the diode s stripe is at the same end as the board s stripe Insert the diode into the board all the way so that the body is touching the board at both ends Then hold the diode in place with a finger while bending the legs apart from each other about 30 degrees This will hold the diode in place until it s soldered down It is reasonable to install a row of diodes at a time before soldering them This saves a lot of asse
11. provided It must be mounted on spacers to keep the bottom of the PC board at least 1 4 inch away from the baseplate or chassis Connecting Screen Controls If the scope clock PC board is installed in an old oscilloscope cabinet it may be desired to connect up some of the front panel controls to control the scope clock board The obvious candidates are Inten Focus Astig H Cent V Cent Height and Width This is a reasonable thing to do with one caveat there is HIGH VOLTAGE on the Bright Focus and Astig controls The Bright control has about 1300V on it the Focus has about 900V and Astig has 300V Consequently special high voltage controls must be used Clarostat 392JB available at Digikey and Newark is a good choice The controls in the oscilloscope may be up to the task if they are not too old but it is best to get new controls of the proper resistance values Astig and Focus values are not critical but should be at least 500K ohms Be sure to fully insulate the Focus and Bright controls from the user AND from the chassis since they have over 1000V DC on them The Height and Width control wires may require shielding since they are connected to the X Y signals that move the beam It may be best to leave these as internal adjustments The centering controls should not cause a problem being remotely mounted but it is a good idea to connect a 0 1uF capacitor from the center terminal to one end terminal of each control to reduce i
12. the screen edge marks Repeat the above adjustments as needed to get the best balance between circle size shape and arc end positions Perfection is neither necessary nor obtainable Regulating the time You may skip the following procedure if you are using a GPS and or 1PPS source to run the clock In that case the oscillator is not used for timekeeping so its frequency is not critical Unlike most wall clocks the scope clock gets its operating frequency from a crystal oscillator This is because a switching power supply does not provide an isolated low voltage source of AC line frequency which is how most other electric clocks obtain their timing Set the oscillator frequency by adjusting the trimmer capacitor C13 with a small slot screwdriver or tuning wand The slot has an arrow in it when it points to the flat side of the capacitor the oscillator is running fast and pointing the other way is slow In between positions to either clockwise or counter clockwise rotation have the same effect since the capacitor is made of two half circles of metal on rotating and stationary ceramic discs The capacitor is shipped with the arrow pointing to the round end which is the slow setting Rotate the capacitor clockwise to set the clock faster so it will be easy to remember that clockwise is faster and counterclockwise is slower A frequency counter may be used to measure the frequency which will speed up the regulating procedure substa
13. 1 1 4W Red Red Brn Blk Brn R16 SC200C Clock User Manual 4 10 08 9 13 8 Res 249K 2 196 1 4AW Red Yel Wht Org Brn R41 48 Install the resistors shown below After they are all placed in the board solder all their legs and remove the excess leg lengths with cutters Step Qty Description Marking RefDes 14 1 Res 3 32KQ 1 1 4W Org Org Red Brn Brn R72 15 2 Res 332KQ 1 1 4W Org Org Red Org Brn R52 R57 16 1 Res 332Q 1 1 4W Org Org Red Blk Brn R71 17 1 Res 4 75K 2 190 1 4W Yel Vio Grn Brn Brn R70 18 3 Res 40 2K 2 190 1 4W Yel Blk Red Red Brn R28 29 R67 19 1 Res 80 6KQ2 1 1 4W Gry Blk Blu Red Brn R15 Note If you are building the board to run a low voltage CRT such as a DG7 32 you need to install some jumpers on the board Use resistor leads for these jumpers Jumpers go in the following places 1 Instead of R59 R60 bend the resistor lead into a U shape first 2 Across C41 C43 C44 hold a resistor lead across the top of the capacitor with pliers and solder both ends then trim to length The next parts to install are the small ceramic capacitors supplied on tape They need to be cut off the tape before installing These have both legs coming out one end so no bending is required to get them in the board Step Qty Description Marking RefDes 20 2 Cap Cer 100pF 50V 101 C3 4 21 5 1000 50 102 5 7 23 22 2 Cap Cer 22pF 50V 22J C10 C12 23 1 Cap Cer 27pF 50V 27 11 The next parts to instal
14. 9 10 48 1 Pot 500K 375 RA 504 R11 Install the grey ribbon cable header next Align the notch in the housing with the mark on the PC board Hold the board flat against the bench to keep the part flat while soldering one pin then check it for flatness Solder the remaining pins Step Qty Description Marking RefDes 49 1 Header 2x5pin grey P4 Install the tall TO 92 transistors next These need to be cut from the tape before installing The transistor legs are formed to fit into the PC board with no extra bending Note that one side of the transistor is flat Match that with the flat side on the legend Again after each transistor is installed spread the two outer legs about 30 degrees to hold it in place Solder the center leg of each transistor then turn the board over and straighten all the transistors so they stand perfectly straight up important if you will be displaying the PC board Turn the board over and solder the two outer legs of each transistor Cut off all excess wire Step Qty Description Marking RefDes 50 8 Transistor NPN 300V MPSW42 1 8 SC200C Clock User Manual 4 10 08 13 Install the 8 pin header next Align the plastic tab with the mark on the PC board Hold the board flat against the bench to keep the part flat while soldering one pin then check it for flatness Solder the remaining pins Step Qty Description Marking RefDes 51 1 Header 8Pin 100 white Install the electrolytic capacitors next Note that the
15. C Clock User Manual 4 10 08 19 Shell 6 pin 6 pin 6 pin 6 pin 6 pin 6 pin 5 pin 5 pin 5 pin 5 pin 5 pin Pin UA Color Brown Red Orange Yellow none Green Blue Violet Grey White Black SC200C Clock User Manual 4 10 08 20 Initial Checkout Before applying power to the clock for the first time switch S1 to the Run position and switch S2 to the On position These switches are only used to reprogram the processor and will never be changed in normal operation The potentiometer adjustments should be at or near the center of their travel as shipped from the manufacturer The component values have been selected to produce a usable image with the controls centered although the Bright control should be turned clockwise about 60 degrees to ensure a visible display especially with an old CRT DO NOT TOUCH ANY METAL PARTS ON THE POWER SUPPLY HALF OF THE BOARD WHILE POWER IS APPLIED There are hazardous voltages present in the area marked with white stripes and the lightning bolt symbol Wait a second after unplugging power for the big capacitor to discharge before touching parts on the power supply board Plug the CRT socket onto the CRT gently but firmly Rotate the socket first to line up with the key on the CRT center post The pins may be stiff It is sometimes necessary to place the CRT face down on a table using a folded towel as a cushion then press the socket down over the C
16. CATHODE CORNER SC200C Scope Clock Board Kit Assembly and User Manual Copyright C 2008 Cathode Corner rights reserved Table of Contents P E 3 T 4 CRT Selection oo dc et E esent a dd aiu aa dtu Ee 5 PC Board ASS TI DIV s oon e ne IRA REA d o AME I d E Ud 7 Wirin Harness Assembly scr eo ne ee I e qa 16 HCC uu als Liu c Mofc etc ecu 2l Installing m Your Own Cabinet eee e te PRETEREA 24 the 166E 25 Proeramimine the 80 biete NU bash 26 Theory 27 e E 31 SC200C Clock User Manual 4 10 08 2 Foreword The Manual This user manual is divided into sections The sections are arranged in the order that you will build the clock and make it work The Theory of Operation section at the end is provided for the curious and may be skipped as it is not necessary to know exactly how the clock works in order to make it work The text refers to the photo page on occasion A page of color photographs is included in the Appendix to show clearly those things that are hard to explain in words Contacting Cathode Corner If you are having trouble assembling your clock gett
17. RT pins Plug the 6 pin CRT plug into P2 Plug the 5 pin CRT plug onto P1 Plug the encoder cable onto P3 Plug the power cable onto P5 Connect the AC adapter to the power cable Plug the AC adapter into a live outlet Wait 10 seconds for an faint orange glow from inside the base end of the CRT indicating that the heater is working If this glow doesn t appear skip ahead to the Troubleshooting section below After another 10 seconds the CRT should display the splash screen shown on the CRT photo page Don t worry if the display is too tall or off center you will fix that in the following steps If the screen image doesn t appear skip ahead to the Troubleshooting section below Push the encoder button by pressing the encoder shaft in The splash screen should be replaced by a menu Display Adjustment There is a menu selection called Align CRT which contains several alignment aids Select it by turning the encoder until the Align CRT selection is bright then pushing the button You should see a circle or ellipse several short lines around the screen and a row of letters in the middle with the word Done below them The purpose of each of these items is described below Adjust Bright so that the display is bright enough to see but not overly bright Adjust Focus to make the lines as sharp as possible in the center of the screen A flat face CRT may be out of focus near the edges of the display Adjust Astig to make the lines sh
18. arp in both directions as follows Turn Focus counterclockwise a bit to make the lines blurry Turn Astig until the defocus is the same in both horizontal and vertical directions 1 the line width is the same in all directions Now readjust Focus till the lines are sharp Adjust X Cent and Y Cent so that the display is reasonably centered Adjust Width so that the marks at left and right sides are about 1 4 in from the edge of the screen Readjust X Cent as needed to center the screen hortizontally SC200C Clock User Manual 4 10 08 21 Adjust Height so that the marks at top and bottom are about 1 4 in from the edge of the screen Adjust Y Cent as needed to center the screen vertically Adjust O Size so that the big circle crosses the horizontal alignment marks to the left and right of the center letters not the screen edge marks Adjust O Height so that the circle is as tall as it is wide The vertical alignment marks help you judge this You can redo this later so don t put too much effort into it now Adjst O Shape so that the circle crosses the 45 degree angle marks evenly It may not land on them but split the difference The circle should appear symmetrical instead of slanted to one side or the other Adjust O Rot so that the 2 and the S have the same size of gaps between their curved sections This will change the circle size Adjust O Size again so that the circle crosses the center of the left and right alignment marks not
19. attaching the wires to the terminals The wires pass through the same numbered holes in the insulating ring The insulating ring is then slid down the wires and reinstalled on the socket after all the wires have been soldered There is no need to use heat shrink tubing with this type of socket Other sockets have removable pins and a fiberglass cover plate held on with screws These do not need heat shrink tubing either Strip 1 4 of insulation off the unterminated end of each wire Solder the wires to the CRT pins per the table above Bend each wire s bare end into a J shape and hook it through the socket terminal first to ensure a tight mechanical connection If your socket requires heat shrink tubing cut ten 1 2 long pieces of 3 16 diameter heat shrink tubing Slide one piece of tubing over each wire on the CRT socket Shrink the tubing over the CRT socket terminals using a match or lighter for heat or a heat gun if you have one It is best to hold the socket assembly by the wires when doing this so that you don t burn your fingers Twist together the violet and grey wires to form a pair Twist together the white and black wires to form a pair Twist together the red and orange wires to form a pair Plug the Molex pins into the white 5 pin and 6 pin connector shells per the table below Pin 1 is closest to the corner of the PC board when plugged in See the photo on the photo page to be sure you have the correct pin arrangement SC200
20. ceiver It is a flat cable with crimp style connectors at each end No special tools are required to crimp this sort of connector just a vise or clamp in which the connector parts can be squeezed together However the process itself involves many small steps so pay attention and do them in the proper sequence to ensure good results It is difficult to reuse the connectors once they have been crimped Qty Description 1 16 Cable flat 1Ocond 1 Conn DE9 IDC w separate strain relief 1 Conn 2x5 IDC w separate strain relief The ribbon cable needs some preparation before assembly Trim both ends square with a pair of scissors don t worry the copper wire is softer than the steel blades Notice the red stripe along one edge This is pin 1 Since the DE9 connector has only nine pins it is designed for 9 conductor cable However the 2x5 connector uses 10 conductor cable To solve this problem peel away about one inch of the conductor farthest away from the red stripe on one end of the cable and cut off the loose end This is the SC200C Clock User Manual 4 10 08 17 end that accepts the DE9 connector The other end accepts the 2x5 pin connector The photo page shows the cable after shortening the tenth wire Now examine the 2x5 connector which is black Separate the three pieces the body the cover and the strain relief The cover is a U shaped piece with nine ridges on the inside to guide the ribbon cable conductors into place The strain rel
21. e small metal tab back up with a knife blade then insert it into the correct spot The encoder has a 6mm diameter shaft and comes with a mounting nut and washer It mounts in a 7mm 280 hole in a panel up to 3mm 1 8 thick Power wiring The scope clock uses 12VDC and is typically provided with a plug in AC adapter with a coaxial DC power plug at the end of a long cable The wiring kit contains a matching panel mount coaxial DC power jack You may use the supplied AC adapter or you may use your own source of 12VDC power If you choose to use the supplied AC adapter the coaxial DC power jack must be wired to the 2 pin Molex plug using the supplied red and black 24 gauge wires with large pins on one end Qty Description 1 DC jack w nut washer Black 2 12 Wires thin Large Molex pin 1 Shell Molex 156 2 Pin Strip 1 4 of insulation from the other end of each wire Cut two 1 2 long pieces of small heat shrink tubing Slide one piece over each wire Solder the two wires to the DC power jack as shown on the photo page Twist the two wires together Plug the two pins into the 2 pin Molex shell as shown on the photo page If you will provide your own source of 12VDC connect the red wire to the positive connection of your 12VDC source and the black wire to the negative connection Plug the two pins into the 2 pin Molex shell as shown on the photo page Serial wiring The serial cable connects the scope clock board to a PC or a GPS re
22. ering the third anode with high voltage makes a much brighter display on these tubes If you need pinout information feel free to request it from Cathode Corner We have many data sheets and other info available for free Tube Pinout OK Base Comments 1 1 8 LV Loctal Low quality display 1DP1 9 LV 9 pin low voltage needs power supply mods 1EP1 11V Yes unidekar 2API 11 LV magnal low voltage needs power supply mods 2BPI 12 duodecal 3BPI 14A Yes diheptal 1 magnal 3FP7 14B Yes diheptal needs HV multiplier for A3 3GP1 magnal 3JPx 14J Yes diheptal needs HV multiplier for A3 3KPI 11M odd Yes magnal Sell it to a Pilot TV owner for big 3LOli 12 LV Russian low voltage needs power supply mods 3MP1 12 odd Yes duodecal Non standard duodecal pinout 3RPI 12 duodecal 3SPI 12 duodecal 3WPI 12 duodecal Left amp Right swapped 11 147 Yes diheptal needs HV multiplier for A3 3ASPI 8 Yes small octal plus button for A2 3E50 8 Yes small octal plus button for A2 14 Yes diheptal needs HV multiplier for A3 SC200C Clock User Manual 4 10 08 5 5 1 5 1 5 1 5 S5LP1 6LOli 7JP1 DG7 32 SC200C Clock User Manual 11 14 12 11 11 12 14 14 12 LV magnal diheptal duodecal magnal magnal Russian diheptal diheptal duodecal needs HV multiplie
23. hold it in place while soldering Cut off the excess wire after soldering Step Qty Description Marking RefDes 59 Polyfuse 1 85A R185 Install the power transformer T1 Hold the board flat as you solder two corner pins to make it sit flat on the PC board Check that it s fully seated and adjust if necessary It may not lie perfectly flat since the winding wires are wrapped on the pins sometimes interfering with full seating Solder the remaining pins Cut off the excess pin length when done soldering SC200C Clock User Manual 4 10 08 14 Step Qty Description Marking RefDes 60 Transformer power T 1596 01 Install and solder the large capacitor next Again the sign is the long leg Cut off the excess length when done soldering Step Qty Description Marking RefDes 61 1 Cap Elect 1000uF 25V 1000uF C58 Install the switching controller IC last Hold the beige thermal pad onto the heatsink with its hole matching the top hole the notch is at the bottom Mount the IC on the heat sink with the 4 40 x 5 16 screw lockwasher and nut in the top hole Put the screw through the back of the heatsink put the lockwasher and nut on the screw end which will be on the front of the IC and tighten the screw snug but not tight Make sure that the IC is straight on the heatsink Mount the heat sink IC assembly to the board using the two 4 1 4 self tapping machine screws Solder the pins then clip the excess lead length Tighten
24. ief is smooth on the inside The connector body has a triangle an outward bump and a groove all on one side The triangle is the pin 1 indicator The bump is a polarizing feature that mates with a corresponding notch in the PC board receptacle Ignore the groove The body also has two rows of teeth that press into the ribbon cable to cut its insulation and connect to the copper wires inside Fit the connector cover to the body by inserting the cover tabs into the slots in the body so that the cover goes near the teeth but don t press it in It will slide in halfway easily then meet some resistance Slide one end of the ribbon cable into the gap making sure that the red stripe is close to the triangle Gently squeeze the cover down over the cable with your thumb Check that the cable end is flush with the edge of the body and that the cable is at right angles to the body Clamp the connector in a vise or C clamp check again for cable alignment with the body and turn the crank to compress the connector fully You may hear one or two clicks as the cover latches snap shut Congratulations you have crimped one end Fold the cable over the cover then press the strain relief into the connector and squeeze it into place by hand The blue DE9 connector works in the same way The cover doesn t fall off so just leave it in place Pin 1 is indicated by a tiny 1 printed on the mating face of the connector Repeat the crimping procedure described in de
25. illoscope to the low voltage power supply winding at the cathode striped end of D29 to observe the behavior of the switching controller use the large mounting hole near P5 for a ground connection It should be oscillating at 100 KHz with a squarish wave that has three parts high low and medium voltage The square part should be about 8 volts Measure the voltage across U1 pin 4 to pin 8 This should be 10 0V SC200C Clock User Manual 4 10 08 23 Installing in Your Own Cabinet Selecting a Cabinet The scope clock in its bare board form is neither cat nor child friendly It requires a cabinet that will support the CRT safely protect the user from coming in contact with the high voltages present on the PC board and allow for adjustment of the controls The controls R7 R11 on the edge of the board require adjustment after the clock is set into operating position so they should be made accessible either with holes in the cabinet or by having the cover removable A third option is to wire up these controls to front panel potentiometers Be aware that the Bright Astig and Focus controls have HIGH VOLTAGE on them and must be well insulated from both a metal cabinet and from the user One popular type of cabinet to use is an old oscilloscope The oscilloscope cabinet will already have suitable controls on the front panel and it provides a secure mounting for the CRT Mounting the PC Board The PC board is mounted with the six mounting holes
26. ing it to work or you just want to talk with us about clocks you may contact Cathode Corner in any of the following ways Visit Cathode Corner on the Web at www cathodecorner com Phone 520 795 7228 Email david cathodecorner com Mailing address Cathode Corner 2602 E Helen Tucson AZ 85716 USA SC200C Clock User Manual 4 10 08 3 Introduction The Clock The SC200 scope clock is an electronic clock that displays the time on a small oscilloscope tube using artfully drawn numbers While most digital clocks use a seven segment display optimized for low cost and ease of manufacture the SC200 display is optimized for aesthetic appeal Features Clean display the text looks like a schoolteacher wrote it Works with most electrostatic CRTs from 1 2 to 7 diameter 12 or 24 hour display modes selectable DST etc Pleasant menu based user interface uses rotary encoder with push switch Serial port allows connection to PC or GPS receiver Garmin GPS 18 LVC recommended Packaging The clock PC board and CRT should be installed in a suitable cabinet of the user s choosing Wiring harnesses are provided to simplify this task A plastic cabinet will be available from Cathode Corner in the near future Source Code The source code of the software that runs the SC200 is available at www cathodecorner com and is licensed under the GPL Feel free to add features to your clock but please consider sharing your work with others in the spi
27. ive and negative DC outputs These 8 volt outputs are further filtered and regulated to produce clean 5 volts for the analog circuitry 5 volts for the digital circuitry and an extra 5 volt supply for a GPS receiver The high voltage supply uses a doubler to make 280V for the deflection plates This supply makes lots of current to run the four high speed deflection amplifiers A lower current multiplier chain produces the cathode voltage of 1200V using a total of 10 diodes and 10 capacitors This circuit uses very small capacitors to produce less than one milliampere of current so it s not nearly as dangerous as a big old fashioned power transformer The high voltage power supply may be built differently to generate a lower voltage for such tubes as the 1CP1 and DG7 32 that only need 600 800V to operate In this case three of the multiplier stages are bypassed The filament supply is straight AC since AC heats up a wire as well as DC does A separate winding on the secondary feeds a voltage doubler which powers the digital optoisolator used for the modulation signal This optoisolator is a special photodiode unit with sub microsecond switching time Its 5 volt operating voltage is too low to switch the CRT grid on and off so yet another winding powers the 50 volt grid modulation supply SC200C Clock User Manual 4 10 08 27 CRT Beam circuits The CRT requires the correct DC voltages at all of its electrodes in order to form a bright ye
28. l are the loose small ceramic capacitors An extra capacitor is supplied in case you lose one After installing each capacitor spread the legs apart about 30 degrees to keep it in place until soldering Solder all the capacitors when finished with the installation Step Qty Description Marking RefDes 24 17 Cap Cer 0 1uF 50V 104K C2 C8 9 C14 22 C24 26 C51 C56 The large plastic diodes are next These parts have a stripe on one end which is shown on the PC board legend When installing a diode be sure to orient it so that the diode s stripe is at the same end as the board s stripe These diodes lead spacing is 0 40 like the resistors The diode body is shorter than the resistor body but the legs are stiffer so they bend with a larger radius Install the diodes shown below After they are all placed in the board solder all their legs and remove the excess leg lengths with cutters Note If you are building the board to run a low voltage CRT such as DG7 32 do not install diodes D18 19 or D21 D24 Step Qty Description Marking RefDes SC200C Clock User Manual 4 10 08 10 25 18 Diode fast 400V UF1004 D1 4 D17 28 D40 D42 26 1 Diode TVS 18V P6KEI8A D41 Next are the small integrated circuits or chips The chips are supplied with their two rows of pins angled outward to facilitate automatic insertion Since you are not automatic this is just a hindrance You need to squeeze the two rows of pins together but there is no easy way to
29. l the small black two pin header next This part can be tricky to install since the metal pins will burn your fingers after poking holes in them Check that your health insurance is paid up SC200C Clock User Manual 4 10 08 12 The best method is to press the board against the bench while soldering one pin to get it in place then reheat that pin while wiggling the board to get it to sit straight if needed Then solder the other pin Step Qty Description Marking RefDes 43 1 Header 2pin black Install the two inductors next Spread the legs 30 degrees to hold them in place while soldering Cut off the excess wire after soldering Step Qty Description Marking RefDes 44 2 Ind 10uH Radial 103 L1 2 Install the square trim pots next There are four different 3 digit values so be sure to get the right part in the right place The kit may contain an extra trim pot marked 203 It is not used Spread the legs on each of these pots after installing Solder the center pin of each pot then reheat the pin while pressing on the pot with your thumb to make sure it s fully seated Turn the board over and square up each pot double checking that they are flat against the PC board Straighten them with respect to the board edge for a neat appearance Solder the outer two legs of each pot then cut off the excess wire lengths Step Qty Description Marking RefDes 45 7 10 375 103 R2 8 46 1 Pot 50K 375 RA 503 RI 47 2 Pot 1M 375 RA 105 R
30. legs apart 30 degrees to hold it in place Turn the board over and solder the legs Cut off the excess leg length Step Qty Description Marking RefDes 35 Xtal 19 6608MHz 19 66 YI Install the variable capacitor next Align the flat end of the capacitor with the flat end on the silkscreen Its legs are kinked to hold it in place while soldering Solder it Step Qty Description Marking RefDes 36 1 Cap Var 3 10pF blue C13 SC200C Clock User Manual 4 10 08 11 Install the microprocessor next Press together the two rows of legs as described previously Be sure to align the notched end of the part with the notch mark on the PC board Solder two corner pins check that it is fully inserted adjust if necessary by heating the pins Then solder the rest of the pins Step Qty Description Marking RefDes 37 1 1 MC908GP32 U8 Install the short TO 92 parts next These need to be cut from the tape before installing The legs are formed to fit into the PC board with no extra bending Note that one side of the package is flat Match that with the flat side on the legend Again after each part is installed spread the two outer legs about 30 degrees to hold it in place Turn the board over and solder the center leg of each part then turn the board over and straighten all the parts so they stand perfectly straight up important if you will be displaying the PC board Turn the board over and solder the two outer legs of each pa
31. mbly time Just be sure to solder all of the legs Then trim the excess wire from the solder joints Install the diodes shown below After they are all placed in the board solder all their legs and remove the excess leg lengths with cutters Step Qty Description Marking RefDes la 8 Diode switching 1N4148 D5 12 Install the diodes shown below After they are all placed in the board solder all their legs and remove the excess leg lengths with cutters Step Qty Description Marking RefDes 1b 10 Diode switching 1N4148 D13 16 D35 39 D43 SC200C Clock User Manual 4 10 08 8 Install the diodes shown below After they are all placed in the board solder all their legs and remove the excess leg lengths with cutters Step Qty Description Marking RefDes 2 4 Diode Schottky BAT48 blue D29 32 3 2 Diode Zener 3 0V 1N5224B D33 34 The resistors are the blue cylinders with colored bands supplied on two strips of tape The color code is shown with each resistor step so you can just find the strip of resistors with that color code and install them You may be familiar with resistors with ony four bands These resistors have five bands they are 1 tolerance precision resistors with three dignificant figures of resistance value There is a wider gap between the fourth and fifth bands to help you hold the resistor the right way You may want to use an ohmmeter to verify the resistor values since the brown orange and red stripes can be confusingly si
32. milar Install the resistors shown below After they are all placed in the board solder all their legs and remove the excess leg lengths with cutters Note If you are building the board to run a low voltage CRT such as a DG7 32 do not install resistors R59 60 Step Qty Description Marking RefDes 4 2 Res 1 00K 2 190 1 4W Brn Blk Blk Brn Brn R40 R69 5 5 Res 1 00MQ 1 1 4W Brn Blk Blk Yel Brn R18 R59 61 R66 6 1 Res 1 21KQ 1 1 4W Brn Red Brn Brn Brn R64 Install the resistors shown below The kit comes with an extra 10 0KQ resistor After they are all placed in the board solder all their legs and remove the excess leg lengths with cutters Step Qty Description Marking RefDes 7 15 Res 10 0K9 1 1 4W Brn Blk Blk Red Brn R19 22 R25 26 R35 R37 39 R50 R53 R55 R58 R68 Install the resistors shown below One of the 20 0K resistors is not on the tape with the others After they are all placed in the board solder all their legs and remove the excess leg lengths with cutters Step Qty Description Marking RefDes 8 2 Res 121KQ 1 1 4W Brn Red Brn Org Brn R62 63 9 2 Res 2 21KQ 1 1 4W Red Red Brn Brn Brn R51 R56 10 13 Res 20 0K 2 190 1 4W Red Blk Blk Red Brn R12 14 R17 R23 24 R27 R30 34 R36 Install the resistors shown below After they are all placed in the board solder all their legs and remove the excess leg lengths with cutters Step Qty Description Marking RefDes 11 2 Res 221KQ 1 1 4W Red Red Brn Org Brn R49 R54 12 1 Res 22102
33. nduced noise SC200C Clock User Manual 4 10 08 24 Using the Clock Introduction The scope clock is a versatile clock and can do things that no ordinary clock can do The operating modes and controls are described below Navigating the menus The main operating mode of the clock is as a clock Turning the knob when in clock mode will select different display formats Choose one that you like and leave it there Or change it now and then variety is nice Pressing the encoder button enters the main menu menu has one bright item called the selection The selection may be changed by turning the knob The selection may be acted upon by pressing the button The setting menus have items that can not only be selected but their values can be changed These are called fields Examples are the hour minute day DST on off mode etc To enter setting mode press the button when a field is selected The field will blink to indicate that it is in setting mode Now the control functions are different Turning the knob changes the value of the field and pressing the button makes the next field blink After the button is pressed on the last field on a screen the blinking mode is exited This takes some getting used to but is a fairly efficient way to control the clock with one knob The word Done at the bottom of each menu provides a way to return to the previous menu In the case of the main menu selecting Done returns to clock mode Set
34. ntially This assumes that you have access to a calibrated frequency counter Connect the probe to the H1 pin labeled CLK connect the ground lead to H1 pin GND and adjust for 19 6608 MHz The use of a metallic adjusting tool may throw off the frequency a small amount due to its capacitance so be sure to remove the tool when checking the frequency Since crystal oscillators drift with age the clock regulation may need to be reset periodically Adjust the trimmer capacitor C13 as needed annually if possible SC200C Clock User Manual 4 10 08 22 Final Adjustments The Scope Clock is sensitive to the placement direction since the CRT beam is deflected to some extent by the Earth s magnetic field Consequently the X Cent and Y Cent controls will need to be adjusted whenever the clock is reoriented or moved The Bright control also may need adjustment to match the ambient lighting Troubleshooting If the power supply makes a buzzing noise for more than a few seconds or there is no orange glow or no image display then there is likely a problem in the circuitry It is reasonable to suspect a solder bridge or mis installed part Unplug the AC adapter then unplug all connectors from the board Inspect the board carefully for components installed backwards in the power supply areas especially diodes If this does not reveal the problem look for solder bridges or component leads that are touching where they should not be You may connect an osc
35. oltage and applies it to the grid of the CRT If you look closely exactly when the hour changes you will see the entire display move slightly This is the screensaver feature by moving the display hourly it will take much longer for a particular spot on the CRT s phosphor to be burned in The screensaver is implemented in software by adding a small X Y displacement to the entire image The path taken by the screen image is a zig zag This displacement is changed slightly once an hour and goes through a prime number of steps 31 before retracing its path in the other direction so as to cycle through the hours in an evenly distributed sequence so that no hour digit is favored in any position on the screen Computer program The software running on the computer is a complex real time embedded control program It has to keep track of the time send new display segments to the display circuits on a regular basis keep track of the rotary encoder movement and keep in sync with the power line frequency for a stable display SC200C Clock User Manual 4 10 08 29 1PPS input An optional one pulse per second 1PPS input allows the clock to take its timekeeping reference from an external atomic clock GPS receiver or other accurate reference source The required input signal is TTL or RS 232 level The clock advances the time on the rising edge of the pulse The signal is inverted by the 232 line receiver and fed to the CPU s interrupt request
36. r for A3 needs HV multiplier for A3 needs HV multiplier for A3 low voltage needs power supply mods 4 10 08 PC Board Assembly The SC200 scope clock is not difficult to assemble but it is recommended that the builder have some experience soldering circuit boards together before beginning this project This instruction manual has not been created with the man years of effort that Heathkit put into theirs That said the circuit board is carefully laid out to allow the parts to be installed easily and the assembly order was arranged to have the lowest profile parts installed first so that placing the board upside down will hold the parts in place in most cases Tools needed Soldering Iron 1 16 wide tip 650 700 degrees F adjustable temperature preferred Solder 63 37 60 40 is OK 031 diameter or smaller rosin or no clean flux Small diagonal cutters Small long nose pliers 1 Phillips screwdriver Getting Started Dump the parts from the bag into a large tray to make them easy to sort Then sort out the parts by type for easy identification as they are needed If any parts are missing contact Cathode Corner see page 3 for assistance The steps below each have a header Step Qty Description Marking RefDes Step is in numerical order Qty is how many parts of this exact type to install Description tells what the part is and its value or part number Res is resistor Cap is capacitor Ind is inductor etc Marking
37. rit of free software Thank you SC200C Clock User Manual 4 10 08 CRT Selection The scope clock needs an electrostatic deflection CRT to operate Magnetic deflection tubes simply won t work The other big requirement is that the filament use 6 3V at 0 6 amps or less The clock works best with a tube made for 1500 to 2000V second anode voltage such as the 3RP1 By modifying the power supply it is possible to make the board put out less voltage so that it will work with a 600 to 1000V tube such as the DG7 32 The clock has been run with tubes as small as the 7 8 1DP1 and as large as the 7 7VP31 Small diameter tubes can be hard to read at a distance and large tubes tend to be long and therefore difficult to package The ideal display for general use is a 3 diameter tube Cathode Corner maintains a stock of and 3RP1 A tubes for sale Below is a list of CRTs that will work with the scope clock The OK column says whether each tube will work with the scope clock LV means that the low voltage modification must be made when building the PC board The details of this modification are in the assembly instructions The Base column has the name of the socket that the tube uses The names are weird but they are meaningful to a CRT dealer Cathode Corner maintains a supply of newish and used CRT sockets for sale if you need one The HV multiplier is a small PC board that generates 1500V for the third anode of tubes that provide it Pow
38. rt Cut off all excess wire Step Qty Description Marking RefDes 38 5 Transistor NPN 80V 5 06 Q9 13 39 3 IC regulator 5V KY5050 U14 16 Install the straight leg TO 92 regulator next Bend the two outer legs to resemble the parts you just installed Note that one side of the regulator is flat Match that with the flat side on the legend Again after the regulator is installed spread the two outer legs about 30 degrees to hold it in place Solder the center leg of the regulator then turn the board over and straighten it to stand perfectly straight up important if you will be displaying the PC board Turn the board over and solder the two outer legs Cut off all excess wire Step Qty Description Marking RefDes 40 1 IC regulator 5V 791 05 013 Install the two slide switches next These parts will fall out so install one at a time Put a switch in the board solder one pin then reheat that pin while pressing on the switch with your thumb to make sure it s fully seated Check that it is fully seated and even then solder the other pins Repeat for the other switch Step Qty Description Marking RefDes 41 2 Switch slide DPDT S2 3 Install the pushbutton switch next This part has formed legs to hold it in place while soldering However the formed legs make it a bit hard to install Press down on the switch body with two thumbnails to get it in the holes Solder it Step Qty Description Marking RefDes 42 1 Switch tactile SI Instal
39. s energy in the transformer while the switch is on then transfers that energy to the secondaries when the switch turns off Its voltage ratio is controlled by the duty cycle of the switch relative to the load current This supply is both of these types in one its outputs are all fed through voltage doublers so that both halves of the cycle are used This is done to allow the voltage multiplier for the high voltage negative supply to be regulated as well as the lower voltage supplies The reason is that a forward converter develops a secondary voltage proportional to the turns ratio whereas a flyback converter develops a secondary voltage proportional to the duty cycle These two functions are different with regard to line voltage so a regulator designed for one will work poorly when used the other way The switching IC is a Simple Switcher made by National It interrupts the current flowing through the primary winding of T1 at a rate of 100 Kilohertz and controls the duty cycle of this interruption to provide regulated voltage outputs Moving on to the regulator the deflection voltage is the one actually regulated The other voltages follow this voltage in proportion to their turns ratios The regulator samples the deflection voltage through a resistive divider and compares it to an internal 1 2V reference The low voltage supply is pretty straightforward Since both phases of the switching cycle are used one winding can generate both posit
40. s made up of one to five segments Each segment has a center position X and Y size a shape code and an arc byte The center position places the segment within the character s cell space The size values set the X and Y radii of the circle ellipse The shape code tells whether will be a positive slope line x cos y cos a negative slope line x cos y cos or a circle x cos y sin The 8 bit arc code tells the circuitry which octants of the circle to blank out to make an arc such as in the letter S SC200C Clock User Manual 4 10 08 28 The scope clock has special circuitry called a circle generator This consists of five parts The wave shaper the shape selector the DACs the X Y summer and the arc blanker The wave shaper starts with a 38 4 KHz square wave that is produced by dividing the 19 6608 MHz processor clock by 512 This square wave is sent through a series of low pass and band pass filters to turn it into a 38 4 KHz sine wave then through more filters to shift its phase by 90 degrees The sine wave is also inverted to produce a negative wave needed to make a backslash The wave selector determines which version of the wave is sent to the Y axis The X axis always receives the original sine wave If that wave is sent to the Y axis also then a forward slash a line with positive slope will be produced If the inverted wave is sent to the Y axis then a backslash will be produced If a 90 degree quadrature wave is sent to the Y axis
41. t small spot on the screen The cathode may be considered as the starting point of this system The grid requires a negative voltage relative to the cathode This voltage is adjusted by the Intensity control and for night dimming purposes may be controlled by an optional CdS photocell Blanking is active for that part of the circle that is to be blanked when drawing an arc and whenever the beam is being moved from one location to another Blanking is accomplished by switching the grid to a much more negative voltage by the Z modulation circuit to cut off the beam The focus anode requires about 500 volts with respect to the cathode This voltage is adjustable over a wide range to accommodate different CRTs with different focus voltage requirements The second anode requires about 1500V with respect to the cathode for most 2 to 5 CRTs This voltage is adjusted by the Astigmatism control This control changes the second anode voltage with respect to the voltage on the deflection plates since the deflection plates have the secondary effect of acting as focusing lenses first in one axis then the other axis The magnitude of this effect depends on the voltage on the second anode relative to the average DC voltage on the deflection plates Deflection Amplifiers The deflection amplifiers are differential input and output totem pole amplifiers The input stage is a differential amplifier circuit referred to as a long tail pair The voltage from the
42. tail above Fold over the cable and install the strain relief CRT wiring The kit is supplied with 10 different colored pieces of thick high voltage wire each with a large Molex pin crimped to one end These wires will be cut to length then the free end of each wire will be soldered to a CRT socket pin and insulated with heat shrink tubing Finally the Molex pins will be inserted into their shells Qty Description 10 12 Wires heavy Large Molex pin 8 3 16 Heat shrink tubing Black large 1 Shell Molex 156 5 Pin 1 Shell Molex 156 6 Pin CRT pinouts vary but the ones listed in the CRT Selection section as magnal large 11 pin with octal size key duodecal large 12 pin with large key and diheptal really large 14 pin are almost all the same These pinouts are listed below Note that the magnal base sometimes has the cathode on the heater pin 11 Since pin 2 is no connect on these tubes and the orange and yellow wores are connectged together on the PC board this works SC200C Clock User Manual 4 10 08 18 Signal Wire Magnal Duodecal Diheptal Name Color Pin Pin Pin Grid Brown 10 2 3 Heater Red 1 12 14 Heater Orange 11 1 1 Cathode Yellow 2 3 2 Anodel Green 4 4 5 Anode2 Blue 7 8 9 Down Violet 9 7 7 Up Grey 6 6 8 Left White 8 10 10 Right Black 3 9 11 The big Cinch 14 pin diheptal sockets are made of two parts On these sockets there is an insulating ring that fits over the solder terminals that must be removed before
43. the screw that holds the IC to the heatsink Step Qty Description Marking RefDes 62 1 Heatsink TO220 62 1 IC switcher LM2586 018 62 1 Thermal pad TO220 62 1 Nut hex 4 40 62 1 lockwasher Z4 62 1 Screw 4 40x5 16 62 2 Screw 4x1 4 PC board assembly is complete You may choose to remove the solder flux from the PC board with commercially available flux remover or you may leave it intact Rosin core flux will not hurt the board if left in place Inspect your work Using a magnifying glass look at every solder joint to make sure it is soldered well Look at all polarized components to be sure that the stripe or notch or flat side on the part agrees with that on the silkscreen SC200C Clock User Manual 4 10 08 15 Wiring Harness Assembly The wiring kit The scope clock wiring kit comes with every wire and connector you will need to make the clock operational except the CRT socket unless ordered separately See the CRT Selection section to determine which type of CRT socket you will be using Getting Started Dump the parts from the bag into a large tray to make them easy to sort Then sort out the parts by type for easy identification as they are needed If any parts are missing contact Cathode Corner see page 3 for assistance Encoder wiring The kit is supplied with a low cost rotary encoder with internal pushbutton to use in testing the clock This encoder may be replaced by a larger higher quality unit if desired The s
44. ting the time Pressing the button cycles the time setting feature through the fields of the time and date causing one field at a time to blink Turning the knob changes the number from 00 59 or whatever is appropriate for that field The months cycle through from Jan to Dec and back to Jan When you are done setting the date another press of the button will light up the Done field Pressing the button to select this will exit the time setting menu and return to the main menu SC200C Clock User Manual 4 10 08 25 Programming the Processor The processor is pre programmed with the most up to date control software version available at time of shipment However since the source code is published you may wish to reprogram the clock If you know HC908 assembly language you may be comfortable writing code yourself If not other customers may provide enhancements that you may wish to add to your clock In either case the code has to be put ointo the processor chip to be used The SC200 clock board has the ability to be reprogrammed over the COM port using a free as in beer application called ICSO8 You may download this from the vendor at www pemicro com or you may find a copy on the MegaSquirt support page at http www bgsoflex com ics08asm zip You will also need A PC running Windows with a COM serial port A DE9 M F cable to connect to the clock board In the course of researching the above I discovered that the MegaSquirt fuel injec
45. tion controller uses the GP32 processor and has a wonderful serial bootloader program built in that makes programming much easier I plan to incorporate this bootloader idea into the next version of the scope clock perhaps you could help if you are familiar with it The source code files contain descriptions of what they do Take some time to read these files and you will get a better understanding of how the clock code is structured and how it all works If you have any specific questions feel free to send an email to Cathode Corner The SC200C has a set of switches used to program the processor These re normally set to Run and On They are flipped during the programming process The On Off switch is used when the programming software requests a power cycle The Prog Run switch is flipped to Prog just before selecting the algorithm The algorithm to use is gp32 highspeed 08p To get the processor out of programming mode to execute the code switch to Off the Run then On SC200C Clock User Manual 4 10 08 26 Theory of Operation Power Supply The power supply is of the switching type The 12 volt DC input power is switched through a high frequency transformer to produce the necessary operating voltages The most common types of switching power supplies are flyback and forward converters A forward converter uses the power driven when the primary switch is conducting and multiplies that voltage by the turns ratio A flyback converter store
46. upplied encoder generates 12 quadrature pulses per revolution with 24 detents The ratio of pulses to detents may be changed in software if you choose to use a different encoder Qty Description 1 Encoder w nut washer Green 3 12 Wires thin Small Molex pin 3 5 3 32 Heat shrink tubing Black small 1 Shell Molex 100 8 Pin Strip 1 4 of insulation off the end of each wire Cut five 3 8 long pieces of small heat shrink tubing Slide one tubing piece over each wire The encoder has three pins on one side and two pins on the other side Tin each pin by applying some solder to it Also tin the five stripped wire ends This will make soldering the wires easier Solder the wires on the encoder pins according to the table below The left right pin assignment is based on the shaft pointing up The photo page shows the connections on each side of the encoder Since the wires and terminals are tinned you can solder them together by holding the wire on top of the pin and heating both with the iron No extra solder is needed Encoder Wire Molex Side Pin Color Pin 3pin Left Red 2 3pin Middle Brown 1 3pin Right Orange 3 2pin Left Violet 7 2pin Right Grey 8 SC200C Clock User Manual 4 10 08 16 Twist the five wires loosely together Plug the Molex pins into the 8 pin housing The pin arrangement is shown on the photo page If you make a mistake press down on the metal tab of the pin through the slot in the housing and pull out the pin Pry th
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