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User Manual - WS Ataras Engineering, Inc.

1. 12345678 9101112131415161718 3 1 AMA P gt 2 T Es BO B1 B2 B3 B4 B5 B6 B7 LC 5 Figure 8 4 BD8 and Panel Layout Ready To protect the contacts on the card edge connector you should use a strain relief of some kind For the larger gauge wires to your tracks and layout common we suggest you use a Cinch Barrier Block part number 9 140 The current Digikey catalog 1 800 344 4539 lists this with their part number CBB109 ND For the smaller gauge wires to your signals a simple cable clamp will do A nylon cable clamp from the Richco line also available from Digikey will do They come in several diameters so pick the right size for the wire bundle going to the signals You want the clamp to hold the wires securely and keep them from putting strain on the connector pins Incidentally the screw barrier strip is a good idea for troubleshooting It makes is easy for you to disconnect blocks or to swap BD8 detectors to aid in fa
2. Ve E 5 1234567891011 1213 14 15 16 17 18 a 6 Figure 8 3 BD8 Board Assembly Diagram The items shown are 1 2 3 4 BD8 Printed Circuit board with the top view shown Mode plug with positions for four mode jumpers none shown Card edge connector Your BD8 plugs into this connector Contact 1 of the 36 contact fingers on the card edge connector Contact 1 is labeled on the connector itself and corresponds to the top left contact on the PC board Contact A is immediately below contact 1 The top row of contacts are numbered from 1 to 18 the bottom row is lettered Letters G I and are not used Pan head 24 40 stainless steel machine screw 2 places used to fasten the card edge connector to the right angle mounting brackets Flat 4 stainless steel washer 4 places used to protect surfaces from the screws and lock washers 31 7 Internal tooth 4 lock washer 2 places used to secure the mounting screws and brackets 8 Stainless steel 4 40 hex nut 2 places 9 Round head 4 wood screw 2 places used to attach mounting brackets to th
3. tasse seta 44 87 TESTING YOUR BD8 DETECTOR INSTALLATION eere ene sna tn 46 8 7 1 TROUBLE SHOOTING SUGGESTIONS sees 46 9 CUSTOMER SUPPOR Tac azienda nnt d a Ede E Dk a ea Ced 49 91 TECHNICAL ASSISTANCE reser rnei totas sata sine SNE SE 49 9 2 LIMITED nL 50 LIST OF FIGURES FIGURE 4 1 TWO RAIL SWITCHED CAB 8 17 FIGURE 4 2 COMMON RAIL LAYOUT WIRING seen eene 18 FIGURE 4 3 COMMAND CONTROL LAYOUT 19 FIGURE 5 1 TYPICAL ABS APB BLOCK 5 5 nennen nennen 21 EFIGURE 5 2 TYPICAT CTC SIGNALS redeo eie pe b ee te aio 21 FIGURE 5 3 HIDDEN JUNCTION DETECTION esee nennen 22 FIGURE 5 4 HIDDEN HOLDING OR STAGING 23 FIGURE 6 1 TAP WIRE CONNECTED TO LAYOUT COMMON 25 FIGURE 7 1 POWER ROUTING SWITCH SET FOR MAIN LINE eene nennen 27 FIGURE 7 2 POWER ROUTING SWITCH SET FOR 2 2 2 4 eene eee 27 FIGURE 7 3 POWER ROUTING AND SEPARATE SIDING 28 FIGURE 7 4 POWER RAIL ROUTING TO MAIN 28 FIGURE 7 5 POWER RAIL ROUTINE TO
4. 4404404200000 0 neen tren nest ES 28 FIGURE 7 6 POWER ROUTING WITH STRAIGHT STOCK RAIL 29 FIGURE 8 1 DC CONTROL WITH BD8 DETECTOR 30 FIGURE 8 2 COMMAND CONTROL WITH BD8 DETECTOR 30 FIGURE 8 3 BD8 BOARD ASSEMBLY DIAGRAM nennen nennen 31 FIGURE 8 4 BD8 33 FIGURE 8 5 COMMAND CONTROL JUMPER 8 eene tnnt 34 FIGURE 8 6 DC CONTROL OCCUPIED V ACANT OUTPUT 1 ceste netten trennen nenne 35 FIGURE 8 7 EAST WEST REPORTING SOUTH RAIL 35 FIGURE 8 8 EAST WEST REPORTING NORTH RAIL COMMON serene nennen 36 FIGURE 8 9 READING THE SOFTWARE VERSION 36 FIGURE 8 10 RAPID OUTPUT 5 net entren teen teen nenne nnne ener enn eene nenne tnn 37 FIGURE 8 11 SLOW SPEED OCCUPIED V ACANT 38 FIGURE 8 12 SLOW SPEED EAST WEST 5 38 FIGURE 8 13 DRIVING MULTIPLE LED S FROM A SINGLE OUTPUT eerte 42 FIGURE 8 14 LED RESISTOR INSTALLATION 43 FIGURE 8 15 CONNECTING INDUCTIVE 5 44 FIGURE 8 16 DC CONTROL WITH STANDING TRAIN 45 FIGURE 8
5. Figure 8 14 LED Resistor Installation Method Let s work out a simple example to see how to calculate the current limiting resistors Suppose your diode has a forward voltage drop of 1 7 volts and gives the desired brightness with a current of 20 milliamps R 5 17 0 02 165 Ohms In this case pick a standard value of 160 ohms for each of the resistors Then calculate the power dissipation of the resistor P RxI 2160x002 20 064 watts In this case a 160 ohm 1 4 watt 5 tolerance resistor costing only pennies would be just fine Simply substitute the forward voltage and current for the LED s you use into these equations to select the proper resistors As long as the resistor power rating is higher than the power you calculated you will be OK You can use the BD8 outputs to operate low voltage typically 1 5 volts incandescent bulbs in much the same way as LED s The connections are all the same However you must use an external power supply with incandescent bulbs Such bulbs draw a very high surge current when they are first turned on This surge current can be enough to overload the BD8 power supply The power supply won t be damaged but when the supply drops too low the processor chip resets and restarts This will cause the BD8 to operate incorrectly or not at all 43 The second difference is that your dropping resistors will almost certainly be different values because bulbs normally draw a much higher current
6. CMD CONTROL 8 NORTH RAIL gt 5 EAST WEST Figure 8 9 Reading the Software Version Number 36 Check each output from your BD8 and mark down for each block that outputs are on Note that it is possible for both outputs to be on depending on the specific version number being reported Table 8 1 Record of Software Version Number BLOCK OCCUPIED VACANT OUTPUT OUTPUT 8 2 3 1 Rapid Sequencing of Outputs In this mode your BD8 very rapidly turns on and off each of the outputs This gives you a quick check to see that all outputs are functioning and that the wiring between the outputs and your LED s bulbs or relays are functioning The sequencing is probably too fast for your relays to operate And your incandescent bulbs may not blink at full brightness but your LED s should light fully although briefly seLF TEST B CMD CONTROL 5 EAST WEST 7 NORTHRAIL Figure 8 10 Rapid Output Sequencing In this mode your BD8 is not detecting trains it is automatically activating its outputs in a high speed sequence This is the same sequence as the slow East West sequence but the entire scan completes 3 times per second rather than once in 64 seconds 8 2 3 2 Occupied Vacant Sequencing of Outputs In this mode your BD8 turns on and off each of the outputs one at a time Each output is on for two seconds This is enough time for bulbs and even relays to respond You can activate this mode by pl
7. not including the surge current If you are using low voltage incandescent bulbs check their spec sheet to see what their voltage and current requirements happen to be Once again recall that with DCC there can be no connections between the outputs of separate boosters This includes any connections between pins on BD8 boards connected to separate boosters as well If in doubt please contact either the manufacturer of your DCC system or us for technical assistance When using the BD8 to operate inductive loads such as motors or relays be sure to use a protection diode as shown in Figure 8 15 with each such load The protection diode is shown with dashed lines and shaded because the BD8 includes diodes wired internally as shown To use them simply connect pin to the positive output terminal of your relay supply This of course means that all of these inductive loads relays and motors connected to any particular BD8 have to operate off the same DC power supply They serve to protect the BD8 output chips from excessive voltages generated when these loads are switched off Without them you will almost certainly blow out some integrated circuits Relay i em SPDT Voltage for To BD8 Output To BD8 Surge Diodes Pin Voltage To BD8 Common _ for Figure 8 15 Connecting Inductive Loads 8 6 STANDING TRAIN DETECTION For the BD8 to detect a train there must be some small current flow If you are
8. signals 3 OCCUPANCY DETECTION AND REPORTING You may have many reasons for installing a system which reports the presence or absence of trains in various sections of track displaying train locations to operators progressive cab control trackside signals grade crossing gates sound effects etc There are several different techniques available for doing this If we overlook any particular technique it is not to give offense The next few sections discuss some of the options available for detecting trains along with their strengths and weaknesses As you will see the BD8 successfully overcomes every limitation normally present in occupancy detector systems 3 1 OPTICALLY BASED SYSTEMS An optically based detector uses a light source and light detector arranged so that the train physically prevents the light from reaching the detector when it is present These systems have the benefit of being totally isolated from train running power They can therefore be used on any layout no matter how it is wired But they also are limited in that the light source and detector have to be positioned so that the train blocks the light This means that they only detect at a single point To detect trains throughout a block many detectors with overlapping fields of view would be required Also depending on the specific design the visual systems can be sensitive to ambient light or the stability of the voltage powering the system And empty log cars can
9. the condition of a detection block which has no train present within it WEST BOUND the condition of a detection block which has a train present and moving west 15 4 2 DC CONTROL SYSTEMS With DC control the layout is divided into many electrically separate blocks so that the speed and direction of trains in different blocks can be controlled independently However all trains within a given block receive the same voltage and polarity and will therefore move in the same direction and as determined by the specific motor and gearbox at more or less the same speed People use countless ways for generating this voltage batteries variable transformers DC supplies with rheostats DC supplies with various forms of transistorized or integrated circuit voltage control circuits SCR controls and even motor generator sets Such layouts have at least two cabs and some method for the connecting cabs one at a time to each block Many different systems have been developed over the years and you will hear names such as cab control tower cab control route cab control progressive cab control and more All of these systems were developed to allow multi train operation on a layout The whole purpose is to allow different engineers to operate their trains over the layout with as little interaction and confusion as possible Regardless of the details involved in generating the voltage and current used to run each train the power routing system ta
10. For electrical purposes rails need to have names If your railroad runs east west you have a NORTH RAIL and a SOUTH RAIL If your railroad runs north south you have an EAST RAIL and a WEST RAIL While a particular rail is normally always NORTH or SOUTH note that in certain special situations such as frogs turntables or reversing sections a particular rail may change depending on the route a train will take through the frog or the assignment of NORTH or SOUTH to the adjoining rail in an adjacent section of track SIGNALING the presentation of train presence or movement information to the engineers dispatcher and other people involved in operating the railroad For model railroads this can be done to achieve scenic effects with trackside signals or grade crossing gates or flashers or to display train position on control panels to show train position in areas of limited visibility to the operators such as hidden staging yards SOUTH BOUND the condition of a detection block which has a train present and moving south TRAIN DIRECTION the direction the train is moving For prototype railroads direction is determined by timetable direction On east west railroads a train is moving either east or west On north south railroads trains are moving either north or south Sometimes the difference determined geographically other times the choice is arbitrary For your railroad you decide whether your trains move east west or north south VACANT
11. activate LED s on control or CTC panels to show train positions This would be especially helpful where hidden track is involved Note that no jumpers are used for this mode JP1 SELFTEST 00 CMD CONTROL 8 NORTHRAIL 5 EAST WEST o o Figure 8 6 DC Contro Occupied Vacant Output 8 2 1 3 DC Control East West Output South Rail Common The EAST WEST outputs are used with DC controlled layouts to primarily to indicate the direction a train is moving You may have need of this to help operate hidden track With two adjacent LED s on a panel both will be on if a train is present and standing However as soon as you connect a cab or open its throttle a bit one light will go out The remaining lit LED will show which way the train will move This is a real help particularly with new or inexperienced operators when they are told to bring a train out of a hidden staging yard If in addition to the EAST WEST output you would like to have a separate OCCUPIED output or both OCCUPIED and VACANT outputs you will need to provide some additional circuitry With EAST WEST Detection your BD8 needs to know which of your rails is the common rail In this mode the SOUTH rail is your common rail 1 SELF TEST 9 CMD CONTROL 8 NORTHRAIL o 5 EAST WEST Figure 8 7 East West Reporting South Rail Common 35 8 2 1 4 DC Control East West Output North Rail Common This mode is used to obtain EAST WEST output o
12. activates the reed switch Its contacts can be wired to logic or latching relays to show that a train has passed But this is just another version of a gate detection system of the comments about optically based detection apply to magnetic detection Except that optical detection seems to be better at detecting exact position than magnetic detection And magnetic detection is not at all suited for detection over a field of view of any meaningful size 3 3 SWITCHED ELECTRICAL CONTACTS Several different techniques have been used over the years to detect trains using switched contacts of one kind or another Sometimes they are activated by the weight of the train passing over the electrical switch and sometimes by the wheels physically contacting a wire mounted next to the rails Most of these systems are simple and cost effective The weight operated switches seem to present a significant installation challenge Getting them set up to operate with a relatively heavy engine O scale is fairly simple getting them adjusted to operate with a relatively light car HO or N scale is great way to induce a headache But all of these techniques operate in a gate mode just like the optical or magnetic detectors only detecting trains at a point This really isn t occupancy detection but such switching techniques can serve some useful purposes And 10 like all electrical contacts switch operation can be impaired by dirt and oxidation
13. ago that you envision a north pole in the center of the oval The rail closest to the center would then be the north rail If he had lived in the southern hemisphere his suggestion may have been different but it doesn t matter First without common rail wiring your layout wiring diagram probably look something like Figure 4 1 Two Rail Switched Cab Circuits As you can see each of the two cab outputs is routed through a cab select switch to the two rails of each block There is no single wire shared by all of the cabs each is totally independent Not shown are wires or switch points used for routing power Perhaps you have some additional toggle switches used to connect reverse loops or crossings There are several steps to go through in making the conversion We recommend that you make the conversion in simple easy to correct steps Doing all of the rewiring and then testing to see if it all works is very macho but not very bright Based on our experience with the conversion process we are going to recommend a step by step approach which will minimize your aspirin consumption 23 6 1 ELECTRICALLY INDEPENDENT CABS Cab independence of course is essential to common rail This lets us connect any one output terminal of each together without causing any problems The most obvious indication that the cabs are electrically independent is simple to see Any two cabs that have separate power cords are electrically independent If you have
14. and allows current to reach the BD8 even with the throttle off This is shown in Figure 8 17 Zero Output Throttle Modification below Use a full wave bridge rectifier with a current rating at least equal to the maximum output current of your throttle The voltage rating of the rectifier is not critical Use the lowest available voltage unit you can find 50 volts PIV is a typical rating for lowest cost FULL WAVE OUTPUT TO 0 VOLTS OUTPUT BRIDGE CAB SELECT WHEN STOPPED RECTIFIER SWITCHES CAB COMMON OUTPUT TO LAYOUT COMMON Figure 8 17 Zero Output Throttle Modification 8 7 1 7 STRANGE OPERATION OF VACANT BLOCKS If the signals in one block change when the train is nowhere near the block you may have too small a layout common wire Double check your estimate for the current in the layout common and the wire gauge you picked There could be a problem with this If this doesn t fix it contact us by phone fax or letter and let us know exactly what kind of strange operation you have We ll probably have some questions easy ones to help us understand your layout and installation and then make some suggestions about other things to check Another possible cause for this problem has to do with command control If the wiring to a block has a very large capacitance any block detector may show a vacant block to be occupied The BD8 has included special processing to minimize this effect If however you have used twisted pair wires to
15. any of the dual throttle cabs on the market you will have to do some experimentation to see if they are electrically independent First with the unit unplugged from the wall and the throttle outputs disconnected from the layout use an ohmmeter to check for continuity between the two throttles Measure from each output of one throttle to each output of the other and reverse to ohmmeter leads as well to make sure that there are no internal diodes connected In all of these resistance checks look for infinite resistance or an open circuit indication Any low resistance under 10 K ohms is a pretty good indication that the throttles are not independent Then plug the power supply into the wall outlet leaving it disconnected from the layout and set the output voltage of each throttle to 3 volts With your voltmeter on the 10 volt DC or higher scale measure the voltage between each output of one throttle and each output of the other This will give a total of four voltage readings In each case you will read 0 volts if the throttles are independent if they are not you will measure 6 volts for one measurement and 6 for another If the two throttles in a dual power pack are not internally isolated you can use only one of them in your new wiring Sorry about that Then reconnect only one of the throttles if they are not independent or both if they are independent 6 2 FINDING THE CAB COMMON OUTPUTS Once you have selected the common rail id
16. as a train enters the switch itself all three of the signals will automatically return to STOP This automatically protects the rear of the train Also no matter what the type of signaling the industrial tracks along the way are interlocked into the signal system If the switch to a spur or the derail on the spur itself and not in their safe positions the signals protecting the entrances to the block will display STOP Normally this will be a permissive stop allowing the crew to stop and then proceed at restricted speed watching for a train or obstruction 5 2 SPECIAL MODEL RAILROAD APPLICATIONS As modelers we can include all of the signaling the prototype uses especially along our visible track But much of our track is hidden It really doesn t make sense to install trackside signals in places where neither the operators nor spectators can see them But it does make sense to provide train detection and display block occupancy to help us operate trains in our hidden track There are two typical situations that we have on our layouts that would benefit from occupancy display When installed as shown in the next several figures train detection will allow you and your operators to function as smoothly over hidden track as you do with the visible track N3 P3 Figure 5 3 Hidden Junction Detection In this figure the three blocks labeled N1 N2 and N3 are normal length blocks probably about a trains length The blo
17. be very difficult to detect in any case since they have little cross sectional area available to block the light beam Sometimes people attempt to provide detection for long or serpentine blocks by using detectors at the beginning and end of a block a technique called gate detection This can work well if trains always move through the block But what if a train enters and then backs out Or stops completely say between operating sessions Or what if the train separates Or can leave through or enter through multiple paths These are all factors that tend to limit the use optical detectors for signaling detection purposes But this doesn t mean that optical detectors have no place in train detection Use them to take advantage of their real feature the detection of a train at a single point Use them to help to spot cars at difficult to see locations to position hopper cars exactly right for the rotary car dumper to work perfectly etc 3 2 MAGNETICALLY BASED SYSTEMS Magnetically operated detectors typically use a reed switch along with a permanent magnet to perform detection The reed switch is activated by the presence of a magnetic field Increase the magnetic field by bringing a magnet close and the contacts switch remove the magnet and the contacts open Normally the reed switch will be buried in the ballast between two ties and magnets will be attached to the bottoms of engines and perhaps cars As the train passes the magnet briefly
18. common is connected to your common rail circuit Make sure that your other logic shares this connection Finally just connect the desired BD8 output on the card edge connector to the logic circuit you have BD8 5 Volts Pin 16 Parallel LED s only 2 shown To additional LED s or bulbs if any Resistor values are based on LED forward voltage and current and the brightness you want To BD8 output Figure 8 13 Driving Multiple LED s From a Single Output Figure 8 13 Driving Multiple LED s From a Single Output shows how to drive two LED s from a single BD8 output You must calculate the proper resistor values based on the LED s you use Typically an LED has a forward voltage drop of approximately 1 7 volts To calculate the proper resistance value subtract the forward voltage drop of your diodes from 5 volts the BD8 power supply output voltage and divide the difference by the diode forward current Color light signals use a single individual color LED to display each aspect Normally these will be GREEN and RED LED s to represent the PROCEED and STOP aspects Figure 8 14 LED Resistor Installation Method below shows how to connect the two LED s of a signal if you only need to display the aspect at a single location trackside or on a panel Since only one LED is ever on at one time you only need one resistor to limit the current However since red LED s are normally much brighter than either green or yellow LED s man
19. connect to your blocks very long runs of such wire could exhibit enough capacitance to cause the problem To confirm that this is the problem temporarily disconnect both wires of the twisted pair at both ends and run two separate feed wires that are not paired If the problem goes away then capacitance is your problem Route the two new wires in a neat fashion and uses them permanently 48 8 7 1 8 WHEN ALL ELSE FAILS When you have done everything you know how to do and have followed the installation and test suggestions in this manual and still things aren t working please contact us We will do all we can to help solve the problem While our BD8 board may not be working correctly this has not yet been the case But we have always been able to help our customers get everything working properly We ll help you too 9 CUSTOMER SUPPORT We understand that many model railroaders have limited experience or training in electronics and may be somewhat apprehensive about installing train detection and signaling systems Our goal is to make our expertise available to those in the hobby who could benefit We are doing this by developing products and associated manuals which take care of as many of the details as possible and explain clearly how you can finish your installation and enjoy the additional operational features that are now possible If you have questions or recommendations please write We will do our best to help you get the
20. do not function as you expect double check your wiring With these self test modes the BD8 isn t doing train detection it is simply operating the outputs So any problem will be somewhere in your output wiring or the power supplies you are using for the output devices Finally when you see that the outputs operate properly then set the BD8 to the operational mode you will be using and again run a train everywhere in the block and through all connecting routes Watch your output devices signals bulbs panel LED s or relays or whatever you have and see that they activate properly as your train enters or leaves the block When your first block is working pat yourself on the back take a break and then repeat the process for the remaining blocks 41 8 5 CONNECTING THE OUTPUTS The BD8 outputs are limited to 150 milliamps each Naturally you can use much smaller wire for these circuits especially if you are only operating LED s or logic signals For these latter cases the current per output will be less than 20 milliamps You could probably use flat ribbon cable if appropriate for your situation Even though it is normally about 28 gauge wire for such low currents it won t matter unless your layout is as big as Yankee Stadium If you are using the BD8 to generate logic signals take care to provide a good ground path between the BD8 common pins and the ground connection for your other logic Also remember that the BD8
21. from 0 to 7 If your layout needs more than one assign a letter to each BD8 BD8 A for the first BD8 B for the second and so on and label the blocks with the BD8 letter and block number For example if you have two BD8s the first will have blocks labeled AO through A7 and the second will have blocks labeled BO through B7 Assign the labels any way you want The purpose is simply to know how and where to connect the wires This drawing will be the master signaling system drawing for your layout Before continuing here if your layout is not already wired for common rail power distribution follow the instructions in Section 6 CONVERTING TO COMMON RAIL WIRING If you follow the instructions doing everything one step at a time you won t have any big problems Suggestions are included with each step to help you get everything right And the steps have been planned out so that you can continue to operate your layout even if the conversion takes weeks or even months There is no need to shut down your layout completely while installing signaling The next step is to connect your BD8 boards to your layout There are two types of connections to make The first group of connections will merge the BD8 into your common rail circuit so that the BD8 can detect your trains When you have finished connecting your BD8 into the common rail feeds to your detected blocks your wiring will look something like if you are using DC control It will look like i
22. have only one purpose for their signal system to help trains stop safely before reaching another train and obstruction or other unsafe situation Naturally we may want to include signaling to add realism to our layout But there are aspects about model railroads that have no prototypical equivalent For example how often does a prototypical train pull into a hidden staging yard or under a hydrocal mountain We will also give some suggestions about using train detection to help you operate your layout especially those portions which are hidden from view 5 1 PROTOTYPICAL SIGNALING SYSTEMS In the space we have available here we cannot include complete coverage of this topic But we will provide enough information to help you get started There are a number of books and magazine articles available that will help you expand your knowledge of the subject And if you are attempting to model a specific prototype in a specific era the final guide will be the railroad s Employee Time Table and Rule Book While the figures and signal arrangements may be considered typical or AAR standard each individual railroad is free to add to or even modify the AAR standards as it sees fit The main focus of a prototype signaling system is to help the engineer stop his train safely But they also want trains to be able to move as quickly as possible when they are not stopping The key issue is stopping distance There are three primary factors that d
23. indicate a routine on the siding and STOP to indicate STOP Some railroads will have a two head signal with the upper head signaling use of the main and the lower head signaling use of the siding Thus GREEN or RED routes a train onto the main RED over GREEN or RED over YELLOW will route the train onto the siding The yellow aspect indicates using approach speed into the siding On the frog side there will be one signal for both tracks These are both absolute signals and the dispatcher will set one of these signals to display either CLEAR or APPROACH to allow a train to depart Figure 5 2 Typical CTC Signals It should be noted that except at passing tracks and junctions where the dispatcher issues orders by signal indication the remaining signals are normal ABS APB signals And even the dispatcher controlled signals will have their aspects overridden by the ABS APB detection circuits if trains are in the blocks ahead of the signals With CTC the track circuits that detect the trains will control the aspect display at trackside but they will also indicate occupied blocks on the dispatcher s panel so he can see where trains are And a special track circuit detects 21 trains which on dispatcher controlled switches and prevents him from throwing a switch beneath a train This is indicated by the short detection blocks containing the switches in Figure 5 2 Usually as soon
24. most satisfaction available from your investment in our BD8 9 1 TECHNICAL ASSISTANCE We are available to provide reasonable assistance to help you get the greatest possible benefit from the BD8 Block Occupancy Detector Feel free to write to us with any questions or comments you may have Please enclose a large SASE if you are expecting a reply We will do our best to clear up any issues you may raise about the use of the BD8 We welcome any suggestions you may have for improvements to the BD8 or for any related products you would like to see available All such recommendations will be considered as we plan our future product offerings You can write to us at The Signaling Solution Inc PO Box 37 Shelburn IN 47885 VOICE 812 533 1345 9 4 cst FAX 708 570 6140 Or visit our website and send an email message 49 9 2 LIMITED WARRANTY Your satisfaction with the BD8 is our primary concern The BD8 Block Occupancy Detector is warranted to be free of defects in materials and workmanship for a period of 90 days from date of purchase This does not cover damage due to misuse use improper installation or connection to excessive voltages or currents We will at our option repair or replace any defective unit The BD8 Block Occupancy Detector is further warranted for 30 days to perform in a satisfactory manner when connected as described in this manual Should you feel that your BD8 is not performing as you would expect simply write t
25. operate your LED s For typical LED s with a current of about 15 milliamps this works out to be at least three LED s per block that can be on at the same time The outputs when active will switch to ground sinking current from a positive supply If configured for LED or logic output no additional power supply is needed unless the total load current required for the LED s exceeds the limit of the BD8 power supply If configured to activate relays incandescent bulbs or some other type of device you must provide the compatible supply Any such supply must have a maximum voltage of 16 volts DC above ground to avoid damaging the BD8 output integrated circuits When ordering signals with LED s included be sure the diodes are wired with their anodes in common TOMAR signals also available from us are fine quality signals wired in this manner Other brands are also compatible if the diodes have individually wired cathodes The anodes can be wired separately or in common Since each of the 16 outputs can handle 150 milliamps at the same time you can use the BD8 even if your needs exceed the current capacity of the internal supply Simply provide an external power supply of the necessary voltage not to exceed 16 volts DC and having sufficient current capacity Use the external power supply to power your devices use the internal power supply to power the BD8 2 2 2 OCCUPIED VACANT DETECTION When used with a command control system or in
26. rails to match the polarity of these rails as a train enters and exits the reversing section Some additional modifications may be necessary if you are routing power through track switches More on that in Section 7 POWER ROUTING THROUGH SWITCHES 18 4 3 COMMAND CONTROL SYSTEMS Command Control systems and there are several good ones available are gaining a share of the market They offer the greatest flexibility currently available for operating multiple trains on a layout As the NMRA DCC standard gains wider acceptance we can all expect to see this form of control used more and more Figure 4 3 below shows the typical wiring for a layout using command control While the different systems use their own methods for implementing the control and power stations the layouts all seem to be wired as shown TO OTHER BOOSTERS OR POWER STATIONS BOOTE TRACK POWER FEED C N POINTS N Exi sp ie c ciicilci fe R o NORTH RAIL 0 L 5 T SOUTH RAIL IS COMMON RAIL 1112113 1415 5 R A N s TRACK POWER LAYOUT COMMON CONNECTION FEED POINTS NOTE Gaps are only used to isolate frogs or to separate power stations Think of the entire layout as one single block Cab connections to control station depend on the specific command control system used Figure 4 3 Command Con
27. three or four normal block occupancy detector boards Because of a high level of electronic integration the BD8 is offered complete with built in test functions power supply and PC board edge connector The BD8 has several operating modes available We explain what these modes are and how you can configure your unit properly in this manual If you need special assistance please write call or fax in your questions We will do what we can to help you get the most from your investment If you have any suggestions or recommendations please share them with us We are happy to hear from you and are committed to being THE SUPPLIER of the finest most cost effective model railroad control devices available to the railroad hobbyist FOR A FAST START This manual is divided into a number of logical sections each intended to answer specific questions or to provide help of a specific type So to help you to find the information you need here are some suggestions a see description of the features and functions of your BD8 Block Occupancy Detector Board read Section 2 BD8 OPERATIONAL FEATURES b Tolearn more about general train detection methods and ways to use the output of your train detection board read Section 3 OCCUPANCY DETECTION AND REPORTING c To learn more about layout control systems and the type of system your BD8 is designed to operate with read Section 4 TRAIN CONTROL SYSTEMS d If you are routing track power thr
28. to count all of the current load from all of the trains that may be running at the same time Also with train detection boards installed the voltage drop should be less than about 0 25 volts This normally means that the layout common wire will be fairly heavy with 8 10 or 12 gauge sizes being used often Let s say that the total length of your layout common wire is 100 feet and that the total current of all your operating engines and cars with lights etc will be a total of 5 amps The total resistance to give a worst case voltage drop of 0 25 volts would have to be 0 05 ohms From the table above 8 gauge wire would be close enough One good source of such heavy wire is the electrical department of a major hardware store You can get 10 gauge stranded wire type THHN for about 10 cents per foot as this is being written Use two 10 gauge wires together to get the equivalent of 7 gauge wire and a slightly lower total resistance Table 8 3 lists all of the block specific connections on the BD8 connector Each of the eight blocks is listed along with the connector pins assigned to its common rail input occupied and vacant outputs 39 Use care in connecting these wires to the PC board connector pins especially for the larger size wires If you haven t had experience soldering connector pins like this ask an experienced friend to help or read about how to do it and practice See NMRA data sheet D1g 10 Soldering Electrical and Electro
29. 17 ZERO OUTPUT THROTTLE MODIFICATION seen 48 LIST OF TABLES TABLE 2 1 OUTPUTS FOR DIRECTIONAL DETECTION nennen nennen 8 TABLE 4 1 DIRECTION AND RAIL USAGE tete peer ede o eee e e ee revente pereo 14 TABLE 8 1 RECORD OF SOFTWARE VERSION 37 TABLE 8 2 RESISTANCE TABLE FOR WIRE E EAE E 39 TABLE 8 3 COMMON RAIL AND OUTPUT 222 40 TABLE 8 4 GENERAL PURPOSE BD8 1 40 1 INTRODUCTION Your BD8 Block Occupancy Detector is the latest in train detection systems It works with layouts using either Command Control or DC Control systems for operating trains In addition for DC Control systems the BD8 can report block status in either OCCUPIED VACANT form or it can report in VACANT STANDING EAST WEST form With the OCCUPIED V ACANT form of output your BD8 is all you need for two color signaling The VACANT STANDING EAST WEST form of output is particularly helpful with hidden track By having two LED s on your control panel both will be on if the block is occupied and no cab is selected when you select a cab only one will turn on to indicate the direction the train will move Best of all because of the advanced techniques used one BD8 board will provide train detection in 8 different blocks And will do this for about the same cost as
30. 2 2 21 2 2 24 6 2 FINDING THE CAB COMMON 8 4 02 24 6 3 INSTALLING THE LAYOUT COMMON 25 6 4 CONNECTING NON DETECTED BLOCKS eessserseseseccceosorsesesecoeroroesesereeoesoroesesecoroesesecocsesoroesesecoeeesoe 26 7 POWER ROUTING THROUGH SWITCHES 27 INSTALLING YOUR 29 81 PHYSICAL INSTALLATION OF THE BD8 BOARD eren eene 32 8 2 CONFIGURING YOUR BD8 DETECTOR 4 4 24 0 110 thats tastes sosta sone ta sens enses suse tatus 34 82 1 NORMAL OPERATIONAL MODES essere 34 8 2 2 SELF TEST MODES aide i nah ante ee eret 36 8 2 3 Software Version Number ou pO eg pl tu ERE 36 83 SELECTING THE WIRE SIZES eee eee eee esent tetas tata sns 39 84 CONNECTING TO THE TRACK 8 4 4 010000 1 0 00 3 506 000 0 000 4000000 040 0404 200 40 0000 4 41 85 CONNECTING THE OUTPUTS eese esee tasa tata sias 42 8 6 STANDING TRAIN DETECTION eerte eene estne
31. BD8 BLOCK OCCUPANCY DETECTOR By The Signaling Solution Inc PO Box 37 Shelburn IN 47879 Rev C 8 21 2009 Copyright 1996 2003 2009 The Signaling Solution Inc All Rights Reserved TABLE OF CONTENTS 1 HINER QO DUCTION 5 2 BD8 OPERATIONAL 8 2 40 0 6 24 CURRENT SENSING ruin 6 23 TYPES OF OUTPUT aao e bs Ec on uitiis 7 221 OUTPUT CAPACITY oe tae dodenus 7 229 tis NM istud uoce 7 223 DETECTION ueque Mc 8 2 224 LED ACTIVATION tul le iode gl 8 2082 IEOGIC SIGNAL ACTIVATION x 6d CD AA d 8 226 RELAY ACTIVATION ee uic actes toe doped 9 229 BUILT IN SELE TEST isisisi in qb nana B Qu T qM A GC DOE 9 244 ASSEMBEED AND TESTED titii cii p tid d mice 9 3 OCCUPANCY DETECTION AND REPORTING ener 9 3 1 OPTICALLY BASED SYSTEMS tasasicncntanyohanashoakhoindahducabinhontenkaiinsae 10 32 MAGNETICALLY BASED SYSTEMS scssiscsssedeseiasssssstsacosssossousansonotcodenapnionsedndssnenpeossnconsecndenssosbinabadens 10 3 3 SWITCHED ELECTRICAL CONTACT
32. BD8 sees current flowing in only one direction it concludes that the train is moving in the corresponding direction BLOCK 1 BLOCK 2 BLOCK 3 CAB SELECTOR CAB SELECTOR CAB SELECTOR 7 t t TO OTHER 1 t 1 1 7 1 SELECTOR SWITCHES ul NI NORTH 4 7 K Ohm K Ohm 4 7 K Ohm m DECKS NORTH RAIL C B B B B CONTROL BLOCK 1 CONTROL BLOCK 2 CONTROL BLOCK 3 L 1 2 3 4 5 T DETECTION BLOCK 0 DETECTION BLOCK 1 S SOUTH RAIL BLOCK 0 BLOCK 1 r BD8 OCCUPANCY OTHER 6 UP TO BLOCK 6 MORE DETECTOR BOARD DETECTORS BLOCKS COMMON 4 PINS LAYOUT COMMON CONNECTION TO OTHER BOARDS NOTE Detection blocks SOUTH rail and control blocks NORTH rail can be different Detection outputs from BD8 are not shown in this figure 12 Volt AC transformer must be isolated from cab circuitry Figure 8 16 DC Control With Standing Train Detection We suggest that you use 4 7 ohm watt axial lead resistors They are readily available at low cost and are easy to install A convenient method would be to install resistors for all of the blocks controlled by a control panel on an insulated mounting board behind the control panel Then simply run a wire from one end of each up to the power rail output pin on each cab select switch Connect the o
33. Even reed relays which not sensitive to dirt should have special metal alloy contacts if they are to function properly in low current logic circuits 3 4 CURRENT DETECTION SYSTEMS Current detection systems operate by detecting the current that passes through a motor or lights when a train is running in a block There are many flavors of such systems and they generally have similar advantages and disadvantages A major benefit of current detection systems is that they can easily detect train current regardless of how long a block may be or how the track is routed And as long as some current is present they will respond properly to trains that stop or enter and back out of a block But they will generally introduce some drop in the voltage that actually reaches the motor How significant this is depends on the specific technique used The next few paragraphs will describe the principle techniques of which we are aware 3 4 1 RELAY CURRENT SENSING Specially designed relays have been used to detect the current flowing in a track circuit In this case the current passes through the relay coil along with the train motor and lights Relays have several benefits First they are difficult to burn out and since the coil is electrically isolated from the switched contacts properly designed relays can be used with any form of DC or even AC train control And contacts can easily be designed to switch many amps and thus control any type of load c
34. S wiisssscsssssussssscscenistncensssshsvcvitaitvesesctausbthebdestnsmrissebatabedshSnastsnes 10 34 8 68 2224 11 34 1 RELAY CURRENT SENSING cicatrice at RR DL 11 3 4 2 JRANSISTOR CURRENT SENSING 11 3 4 3 DIODE CURRENT SENSING 12 3 4 4 ISOLATED CURRENT SENSING 12 4 TRAIN CONTROL SYSTEMS uas aS ann ni nn mda a 13 AL TERMINOLOGY zs uccide a dp REO dca Ste aes utr 13 42 DC CONTROL SYSTEMS pem 16 471 TWO RAIL SWITCHED SYSTEMS suut 16 4227 COMMON RAIL SYSTEMS cirios BER etui bet cett Ra nere 17 43 COMMAND CONTROL SYSTEMS 554 iud tieb ideni Durs qus ite etai p E 19 5 PLANNING YOUR TRAIN DETECTION SYSTEM 02224470 20 51 SIGNALING SYSTEMS sssssssssssssssscosssssssnsssesssnescessuessssncnsssensssescessusssescosssensansscees 20 5 2 SPECIAL MODEL RAILROAD APPLICATIONS ccsssssssscsssessessrsessessrsessessesessessssessessesessessesesees 22 6 CONVERTING TO COMMON RAIL WIRING eene 23 61 ELECTRICALLY INDEPENDENT 8
35. acing the mode jumpers as shown and then watch your signals turn on and off in a known sequence Beginning with the block 0 outputs first the vacant output will turn on After 2 seconds the vacant output will turn off and the occupied output will turn on After two more seconds it will turn off and the block 1 vacant output will turn on This sequence repeats from block 0 to block 7 and then starts over for as long as you leave the BD8 in this mode 37 c 79 sELF TEST CMD CONTROL n NORTH RAIL EAST WEST n Figure 8 11 Slow Speed Occupied Vacant Sequencing When using this mode watch your outputs carefully See that each turns on and off in the proper order If something doesn t operate properly track down the problem beginning at the BD8 output When an output is on you can measure 5 volts DC if you put your voltmeters positive probe on the BD8 5 volt output pin 16 and the negative probe on the output pin you want to check Measured this way an output will show volts when off and 5 volts when on If you are using the BD8 with an external power supply for your output devices such as relays or bulbs you will need to measure in a slightly different way Set your voltmeter for the voltage of the external power supply and put the positive probe on the positive output of the external power supply As before put the negative probe on the BD8 output you want to check You should read 0 volts when the output
36. ail to its power rail Check throughout the block including any switches or crossings The only right answer is 0 volts This shows that the common rail has been isolated If you get a non zero voltage reading it means that there is still an original wire connecting the common rail back through the cab select switches to layout common Or you may not have put in all the gaps needed to isolate the rail It s time to conduct a search and destroy mission to eliminate all of the old connections to the cab select switch or to cut all necessary gaps You may still have some wires attached to the common rail These will be wires that pick up the stock rails electrically and route them to switch machine contacts for powering the frogs Leave these wires in place When the common rail has been isolated from all of the original feed wires connect it to the layout common Attach a tap wire as described in the prior section and connect the other end of the tap wire to the common rail using the ends of the original feed wires you left attached to the common rail If the block is particularly long you may want to use several tap wires from the layout common Note that at this time the cab select switch is only feeding the power rail the common rail is now being fed by the layout common wire Finally finish work on the block by conducting another sanity check Run an engine in around and through the block using each of the cabs checking each of the r
37. as we don t want to detect a train on the siding while the switch is set for the main everything is just fine But if we want to have a separate block on the siding with a separate detector the standard power routing won t work F C Figure 7 2 Power Routing Switch Set For Siding Figure 7 3 shows the same track with separate train detection on the siding using detector C2 while detector C1 is looking at the main line You can see that we need a gap in the siding common rail near the fouling point of the switch to separate the siding s common rail from the main line block Here is where things get interesting The common rail for the siding is always connected to layout common through the C2 block detector and its power rail is simply a continuous stock rail through the switch And even with the switch set for the main a train on the siding will run 27 FROG CONTACT Figure 7 3 Power Routing and Separate Siding Detection To solve this problem we need to have an extra electrical contact that operates along with the switch to route the power rail through the switch This means two single pole double throw SPDT contacts are needed for a power routing switch with separate detection on the frog side One contact routes power to the frog the second routes the power rail from the point side to one of the power rails on the frog side This is shown below in Figure 7 4 Both of these c
38. at one rail is always considered to be at a constant zero voltage To control train direction of movement the other rail would be taken to a positive or negative voltage Table 4 1 below shows how this works when your engines have been wired according to National Model Railroad Association NMRA standards Note that train movement has nothing to do with the direction the engine is facing Table 4 1 Direction And Rail Usage RR COMMON POWER TRAIN DIRECTION RAIL RAIL MOVEMENT NORTH SOUTH amp Positive NORTH SOUTH amp Negative SOUTH NORTH amp Positive If you have some personal dislike for rail wiring at this point simply call the rails and or NORTH and SOUTH trains will physically move the same way no matter what names we pick The only thing that matters to a motor is the voltage and polarity it sees The rail names are chosen to enable us to communicate with each other and identify the specific items we are talking about We choose a system of getting the voltage to a motor based on our operational needs and desires and our available budget CONTROL BLOCK an electrically isolated section of track used for the control of a train separate from all other trains on the layout Control blocks are generally used only with DC control DC CONTROL a train control system in which the layout is divided into many electrically independent control blocks and a means is provided to connect on
39. between the outputs of separate boosters other forms of command control see your system manual for Cab connections to control station depend on the specific command control system Figure 8 2 Command Control with BD8 Detector Board 30 The second group of wires will connect your BD8 to your signals display LED s or any other logic circuitry you may have Since the connections to LED s logic and relays are all slightly different separate paragraphs below will describe the differences These connections are not shown in the two figures above You only need to connect one end of one wire at a time Just repeat that one simple step for each connection to be made and you can t lose But before we start wiring the 8 into the layout let s install your BD8 physically Figure 8 3 BD8 Board Assembly Diagram below shows how your BD8 and related items will look when ready for installation For your reference the major items are identified individually Other than the mode plug and its jumpers item 2 the power supply indicator LED item 12 and the voltages regulator and heat sink item 11 none of the parts are of interest to you c v dx SELF TEST 5 5 4 CMD CONTROL 8 EAST WEST o NORTH RAIL o
40. ce the detection circuits for each block must also be electrically isolated Such detectors exist but are somewhat more expensive than detectors that can share an electrical ground connection 4 2 2 COMMON RAIL SYSTEMS Common rail electrical systems consider one of the two rails always to be at zero volts or ground Train direction is controlled by setting the polarity of the other rail relative to the common rail positive voltage will move the train in one direction negative voltage in the other Either rail may be selected as the common rail the choice is entirely arbitrary But a given layout must have the same rail as common throughout Figure 4 2 below shows a layout wired using the common rail method Why use a common rail wiring system There are two good reasons First since the common rail is always at the same voltage namely 0 volts you don t have to provide any switching for the common rail when connecting cabs to blocks 17 BLOCK 1 BLOCK 2 BLOCK 3 CAB SELECTOR CAB SELECTOR CAB SELECTOR TO OTHER SELECTOR I SWITCHES A ul by NORTH RAIL SELECTOR N N N N N 4 DECKS NORTH RAIL C BLOCK 1 BLOCK 2 BLOCK 3 1 2 3 4 5 SOUTH RAIL IS COMMON RAIL 5 5 S S S LAYOUT COMMON CONNECTION NOTE Only NORTH rail gapped at block boundaries SOUTH rai
41. ches and signal aspects The actual track conditions such as actual switch positions and the presence of trains will over ride the dispatcher if his actions would cause an unsafe routing or signal aspect to be displayed COMMAND CONTROL a train control system in which some full voltage is always applied to the track along with a special electrical control signal that carries speed and direction information to many different trains independently With command control there are some number of separate independent channels of communication between a central control station and receivers located in the engines Each engine receives its own speed and direction information over an assigned channel and then derives the voltage and polarity applied to its motor from the full voltage always present on the track Different types of command control systems implement their communications channels and form of full voltage in different and usually incompatible ways There is now an NMRA Standard and related Recommended Practices for command control approved by the membership We can all now take advantage of the NMRA Standard Digital Command Control DCC technology knowing that our investment in equipment to operate our trains is protected by the existence of multiple manufacturers making compatible equipment This has been the case with the NMRA Standard for DC control for many decades COMMON RAIL a method of wiring a DC control layout so th
42. cks P1 P2 and P3 are positioning blocks Each is about the length of an engine and they are located so that they protect the fouling points of the switch And block S1 is the switch itself from ahead of the points to a little beyond the fouling points on the frog side Each of these blocks has an occupancy detector connected which controls a single occupied LED on a panel which is visible to everyone operating trains in the junction area The display panel would probably depict the track in the area in schematic form In normal operation an engineer might be told to hold at the junction He would move his train toward the junction watching the display panel to see where his train was As soon as the positioning block shows occupied he stops his train If the switch block shows occupied he has run through the positioning block and is fouling the switch He simply backs up until the switch shows vacant and the positioning block still shows occupied The next situation that we modelers have that the prototype doesn t have is a hidden holding yard Its arrangement of detection blocks the display of occupancy on a panel and the method of operation are very similar 22 a ps P6 N3 P3 NS P8 o PI N2 pos Figure 5 4 Hidden Holding or Staging Yard Again the blocks labeled N are normal blocks those labeled P are positioning blocks and the switch blocks are labeled S Also the block arrangement
43. control current flow stops when the cab stops its train or when no cab is selected for a block Thus with DC control some provision must be made to assure that a small current flows even when the cab has stopped the train A simple technique to do this is illustrated in Figure 8 16 This circuit puts a small AC current through an occupied block when the cab is off When the cab starts its train the DC current over rides the milliampere or so of AC current as the train begins to move This AC current results in an interesting feature with the BD8 a stopped train will be reported as going both east and west This is how we report a standing train if directional reporting is selected 47 8 7 1 6 TRAINS NOT DETECTED WHEN THROTTLE AT 0 Be aware that some electronic throttles have a very low output impedance and place what looks like a short circuit across the rails when the output voltage is zero to stop a train This will shunt the current provided by the resistors shown in Figure 8 16 and keep the BD8 from detecting the train But when you put the reversing switch in the center off position this electronic short circuit is removed and the BD8 will report the block as occupied with a standing train There is a solution for throttles that actually bring their output voltage to zero when the train is stopped We suggest that you install a full wave bridge rectifier in series with the throttle output This works just like a constant lighting circuit
44. dify your present system so you can use the BD8 We will also provide some suggestions for using the BD8 to handle certain typical situations that arise on many layouts 4 1 TERMINOLOGY To allow us to discuss train control we must begin by understanding certain basic terms ABS Automatic Block Signaling a system used to signal track for one direction of traffic flow The signals will automatically protect trains from following movements APB Absolute Permissive Block Signaling a system used to signal track for two directions of traffic flow The signals automatically protect trains from both following and opposing movements BLOCK a section of track separated electrically from other sections to allow trains to be controlled or their presence detected independently of all other blocks Blocks on the prototype are used exclusively for detection purposes On model railroads we use the word to describe track sections separated for detection or for control This latter use of the word block comes up in DC cab control layouts CAB a mechanism of some kind responsible for the speed and direction of a single train It accomplishes this by controlling the voltage and polarity applied to the motor s of a train There are various techniques carry out this control 13 Centralized Traffic Control a system of train dispatching which allows a remotely located dispatcher to route trains through the automatic positioning of track swit
45. e mounting panel 10 Right angle mounting bracket 2 places 11 Voltage regulator and heat sink In operation this will get warm and maybe even hot to the touch depending on the load current from the internal power supply The on board circuitry draws very little current itself Most of the current will be drawn by your LED s 12 Power on LED which glows brightly when the on board power supply is functioning properly 8 1 PHYSICAL INSTALLATION OF THE BD8 BOARD Shown in Figure 8 4 BD8 and Panel Layout Ready below the BD8 mounted to a flat wood panel ready for installation on your layout A piece of 1 x 6 six to eight inches long or a similar size piece of plywood is just fine Then you can attach the panel in an easily accessible location on a table leg or from the bottom of an L girder You will find it much easier to prepare the panel as shown at your workbench Doing this under your layout will probably be more difficult Remember that you will be running wires from the board to the blocks and your signals or control panels Plan how the wires will be routed from the board and to the layout Use cable clamps to keep the various cables from placing any strain on the card edge connector pins and out of the way 32 D JP1 EAST WEST NORTH RAIL nu SELFTEST 9 CMD CONTROL 9
46. e white stripe gets connected to pin 18 the positive power input Connect the other wire in the power cord to pin V To see if all is well plug in the wall module The BD8 power on LED labeled D18 on the board should glow brightly If it doesn t there are a couple of possible problems First the socket you plugged into must be on Second the wires to pins 18 and V may be reversed Finally there may be a short circuit on one of your connections to the card edge connector Track down the problem before continuing 40 8 4 CONNECTING TO THE TRACK BLOCKS With the physical installation complete we are going to connect your BD8 to each of the blocks the board is to detect We will do this one block at a time and test as we go to keep from creating any big problems Pick a block to connect to the BD8 For your first block pick one that is easy to get to Let s making the learning process as easy as possible The block will still have your original wires from the cab select switch to the common and power rails running to the block Our first step is to electrically isolate the common rail from the layout Cut the common rail feed wires so that at least a few inches of useable wire remains attached to the rails And then make sure that the common rail is separated by gaps from all adjacent blocks and frogs Then test the block to make sure you have isolated the common rail Do this by trying to run a train in the block and all con
47. ed in parallel with opposite polarity In this way a positive voltage is generated when the train current is flowing in one direction and a negative voltage is generated when the current flows in the opposite direction This usually requires that the detector board have both positive and negative operating voltages applied adding cost in the form of an extra power supply The BD8 Occupancy Detector uses an advanced form of diode detection and a special technique that eliminates the need for dual power supplies to power the board Special circuitry and signal processing techniques are provided which minimize the sensitivity to wheel and rail dirt 3 4 4 ISOLATED CURRENT SENSING 12 There are several forms of isolated current sensing in use An isolated detector operates much like a relay a circuit element is wired in series with the block and an electrically isolated signal is picked off and used to indicate train presence One such technique uses four high current diodes in series with the track circuit and two optical isolators Depending on the direction of current flow one of the two optical isolators activates Since the current sensing diodes are isolated from the rest of the detection circuitry by the optical isolators this form of detector can be used even on layouts that do not use common rail wiring The system is fairly sensitive and appears to have as its primary weakness a series voltage drop of about 2 volts because there are t
48. entify which output of each cab is connected to the common rail through your cab select switches Turn off all of the cabs for this next step Pick any conveniently located block remove any engines and cars from the block and attach one of your ohmmeter leads to its common rail Then one at a time select each cab and with the cab select switch for the block and touch your other ohmmeter lead to the outputs of the cab One of the outputs will show a very low resistance probably less than an ohm The other output will show a much higher resistance Confirm the reading by reversing the ohmmeter leads In each case the cab output currently connected to your common rail through the cab select switches will show a very low resistance Mark the common rail output on each cab Do this for all of your cabs main line yard or other local service cabs When this is done let s do a sanity check Make a quick and dirty temporary connection between all of the cab common rail outputs that you just identified Then operate a train over the layout using each cab and taking each route siding or spur Everything should still work just as it always did If something isn t working that used to work take the time now to identify the problem There re only two things that could be wrong at this point Either cabs that you thought were isolated really aren t or the cab output you identified as being the common rail output was incorrect Before proceeding c
49. ests the harder it will be to locate the problem Another benefit of the do a little and test approach to this is that it helps you to build your confidence as you go Success breeds success and every time you see something that you did work right no matter how simple or seemingly inconsequential you will see that it s really not that difficult after all The next few paragraphs are a few additional suggestions for ways to prevent or at least identify problems 8 7 1 1 WHAT IF NONE OF YOUR SIGNALS WORK Suppose none of your signals work If at least some of them used to work and now they don t the first thing to check is the power The power LED on the BD8 board should be glowing brightly If it isn t on at all see if the power module is plugged into the wall and the wall outlet is on Then check for a short circuit across the BD8 5 volt power supply There is a resetable fuse on the BD8 board that will protect the board electronics But if there is a short you will have to eliminate the short and allow a minute or so for the fuse to cool before the circuit will restart You should unplug the power module while you wait If this is the first time you have tested anything and the power LED is not on check the power as above But also check to see if the power connections to the card edge connector are correct Unplug the BD8 and measure from pin 18 to pin V directly below You should measure 9 to 12 volts DC with pin 18 positive If t
50. etermine stopping distance the weight of the train the speed of the train and the slope of the track Heavier trains take longer distances to stop faster trains take longer to stop and trains going down hill take longer to stop Even if we are modeling a prototype signaling system as modelers our stopping distances are measured in inches no matter what our speed and our available space is minuscule So we resort to selective compression We will normally have our blocks as long as the typical train on our layout Our passing tracks are usually the same length as well Before the advent of Centralized Traffic Control CTC systems railroads used Automatic Block Signaling ABS to signal for one direction of traffic and Absolute Permissive Block Signaling APB to signal for two directions of traffic For both of these systems the Timetable identified where and when meets and passes were to take place and the rules of train superiority by class and direction told which crews to take the siding and which to use the main Any exceptions to the timetable such as temporary routings extra trains movements opposed to the normal traffic flow were handled using written train orders 20 The train crews were responsible for setting the track switches as they came to sidings and for leaving them in the normal position when leaving With CTC installations a remotely located dispatcher controls the switches and signals at passing tracks but us
51. f block status for DC controlled layouts with the NORTH rail as the common rail In all other respects this mode is the same as the mode described in Section 8 2 1 3 c 0 SELF TEST 5 9 CMD CONTROL 5 EAST WEST NORTH RAIL Figure 8 8 East West Reporting North Rail Common 8 2 2 SELF TEST MODES The four self test modes are used to help you with the installation of your BD8 and to assist you in trouble shooting should any problems develop in the future 8 2 3 Software Version Number Your BD8 includes a processor with a program developed by us to perform all of the functions you have seen described in this manual While we have tested the board under a wide variety of conditions we cannot anticipate every possibility of layout control system throttle design or advance in various technologies To help you and us keep track of any changes that have taken place in the software we have included a way for you to read out and record the version of the software programmed into your processor If it should become necessary to help you with some problem you are having we may need to know the specific version of the software your board is using To record this put your BD8 into this mode and record that blocks are occupied and which are vacant Simply write ON or OFF in the two columns of Table 8 1 In this mode the BD8 is not detecting trains it is using the 16 outputs to report its version number JP1 SELF TEST
52. f which we are aware is the fact that these circuits operate very quickly and can respond easily to momentary breaks in current due to dirty rail or wheels This effect can be reduced somewhat by installing a capacitor in the right place This form of detection is still adequate but it is no longer cost effective to use such high current transistors to carry the train running current 3 4 3 DIODE CURRENT SENSING The next form of current detector uses diodes in the common rail path to the block Very low cost diodes capable of handling 3 amps or more continuously while giving a voltage drop of less than 1 volt are readily available This has the same effect as the power transistors used in the Twin T circuit at a much reduced cost Sensitivity can be just as high or even higher The only thing remaining is to sense the voltage drop across the diode using an operational amplifier or comparator of some kind Today such integrated circuits are readily available at low cost Once the voltage has been detected it can be conditioned to drive relays light emitting diodes LED or logic circuits Techniques of this type result in reduced costs when compared to Twin T and similar transistor based circuits They also operate very quickly and will respond to breaks in current flow due to dirty rail or wheels As with Twin T circuits this can be controlled with a capacitor or other filtering in the right place Generally two diodes are used connect
53. f you are using command control The steps in the remainder of this section will help you to complete the installation 29 BLOCK 1 BLOCK 2 BLOCK 3 CAB SELECTOR CAB SELECTOR CAB SELECTOR in I TO OTHER 2 SELECTOR SWITCHES XA ii Iu NORTH RAIL SELECTOR C C C NORTH RAIL DECKS la e B CONTROL BLOCK 1 CONTROL BLOCK 2 CONTROL BLOCK 3 11121 1 4 5 DETECTION BLOCK 0 DETECTION BLOCK 1 SOUTH RAIL BLOCK 0 BLOCK 1 BD8 OCCUPANCY OTHER 6 UP TO DETECTOR BOARD BLOCK 6 MORE DETECTORS BLOCKS COMMON 4 PINS TO OTHER LAYOUT COMMON CONNECTION D NOTE Detection blocks SOUTH rail and control blocks NORTH rail can be different Detection outputs from BD8 are not shown in this figure Figure 8 1 DC Control with BD8 Detector Board TO BOOSTER TO POWE o N FEED PEE ENERO NIE T B C R s B B L i is T S s e T E SOUTH m T BLOCK 0 BLOCK 1 I BD8 UP DETECTOR OTHER 6 MORE N 5 PEE BLOCKS COMMON 4 PINS DETECTOR TO BD8 BOOSTER COMMON ocr POWE STATIO NOTE Gaps only used to isolate frogs or to separate For DCC do not make ANY connections
54. gnificant output capacity operate both trackside signals and control panel indicators with no additional hardware g Power supply included depending on the type and number of your output devices you may not need any additional power supply h Output flexibility you can operate LED s incandescent bulbs or relays for direct control of signals and other special features OR use the BD8 to provide logic signals to other circuitry or a computer interface if you wish i Modularity add as many BD8 boards as you need for your layout Each will handle 8 more blocks j Furnished assembled and tested no need to understand electronics Just use the mounting hardware and card edge connector included with each unit and follow the instructions and you will have a state of the art train detection and signaling system k Cost there is NO other comparable train detection system with as low a cost per block as the BD8 except our BD16 Block Occupancy Detector Board for 16 blocks The next several paragraphs describe many of these features in detail 2 1 CURRENT SENSING The BD8 uses a pair of 3 amp diodes to generate a small voltage whenever current is flowing to something in a block a motor command control receiver light or anything else that draws current The diodes share a common ground return connection Hence a common rail power distribution must be used to power the blocks connected to any given BD8 Figure 4 3 Command Control Layou
55. he polarity is wrong unplug the wall module swap the wires to pins 18 and V and re measure the voltage It should be OK Then turn off the line power plug in the 8 and try again If you don t get any voltage out of the wall module cord be absolutely sure that the 120 VAC power in on at the wall outlet Plug a lamp or other line powered device into the same outlet and see if it works If the wall outlet is working and still you get no output voltage from the power module contact us Also make sure that if you are using LED s that the polarity is correct If the power is on you can manually activate any single LED by connecting the corresponding output pin on the edge connector to layout common with a test lead 46 8 7 1 2 FIRST TEST WIRING TO SIGNALS If your signals don t seem to be working quite right begin by running one of the slow sequence self test modes Watch carefully to see if the signals operate as you expect Remember the BD8 will activate block 0 outputs block 1 outputs etc and then start over If the self test sequence is correct and your problem seems to be that the wrong signals change when the train moves from block to block then there is probably an error in the wires from the block common rails to the BD8 detectors If the self test sequence is not correct then there is probably an error in the output connections from the BD8 to the signals Look for opens shorts or wires connected to the wrong
56. is off and the voltage of the external supply when it is on Of course the first thing you should do is make sure that the BD8 is turned on Check the D18 LED on the PC board and verify that it is at full brightness If you are using an external power supply make sure that it is on If the output is working properly at the BD8 card edge connector but the output device LED bulb or relay is not working repeat the voltage measurement at the output device itself If you don t get the correct voltage readings check the wiring between the BD8 and the device If you do get the correct voltage readings check the device itself 8 2 3 3 East West Sequencing of Outputs This mode is very similar to the Occupied Vacant Sequencing of Outputs described above Other than the positions of the mode jumpers all of the comments above apply except that the output sequencing is different For this mode each step of the sequence again takes 2 seconds and the pattern begins with block 0 and runs through to block 7 The outputs have the pattern OCCUPIED VACANT BOTH NEITHER n JP1 SELF TEST CMD CONTROL NORTH RAIL EAST WEST Figure 8 12 Slow Speed East West Sequencing Again if you see something that isn t working use your voltmeter to make the voltage measurements described in Section 8 2 3 2 38 8 3 SELECTING THE WIRE SIZES The contacts on the edge connector are used to connect the board to your layout Eight wires will go to the c
57. iven booster will share a single common rail within the associated power district Other systems have power stations of some kind which provide the combined power and control signal voltage to large amounts of track Sometimes particularly for large layouts with many trains running you will want to divide the layout into several sections and power each from a separate power unit This will help in finding short circuits 19 since only the shorted section will stop functioning and it also divides the current drawn by the engines among the power units Most of the units have a current limit somewhere in the 4 to 8 ampere range To wire a layout for non DCC command control follow any specific instructions provided with your system As far as we know the BD8 Occupancy Detector Board will work with all command control systems Should you find that it doesn t simply let us know within 30 days and we will provide a full refund upon return of your BD8 boards in working condition Naturally we are interested in getting whatever information we can about your command control system so we can design a detection system that is compatible 5 PLANNING YOUR TRAIN DETECTION SYSTEM Now is the time to plan your train detection system You probably have a general idea of what you would like to accomplish But to help you clarify any issues that may be undefined we would like to present some ideas that may be helpful The prototype railroads
58. kes only two forms two rail switched systems and common rail switched systems 4 2 1 TWO RAIL SWITCHED SYSTEMS Two rail switched systems have circuitry that routes both rails of a block to the assigned cab In this case all cabs are totally independent electrically and all blocks are totally independent While this seems like a simple straight forward system it does require almost twice as much wiring as is needed with common rail systems Every switch must be a two pole switch Figure 4 1 provides an example of a layout wired this way 16 BLOCK 1 BLOCK 2 BLOCK 3 CAB SELECTOR CAB SELECTOR CAB SELECTOR 7 T T TO OTHER i ss CAB SELECTOR SWITCHES VU NORTH RAIL N N N N N 1 SELECTOR NORTH RAIL DECKS ENE A B B B B B BLOCK 1 BLOCK 2 BLOCK 3 1 2 3 4 5 SOUTH RAIL S S S S S 1 T T TO OTHER 1 mm SELECTOR t SWITCHES 52 1147 m T SOUTH RAIL x SELECTOR DECKS NOTE Both rails gapped at block boundaries Figure 4 1 Two Rail Switched Cab Circuits While this system works it does not provide any advantages for operating your trains Because there are twice as many switched electrical contacts between a cab and an engine reliability is lower This method also complicates occupancy detection sin
59. l leads installed to provide low resistance path to cab Cabs are internally isolated from each other electrically Figure 4 2 Common Rail Layout Wiring Second since the common rail is always at the layout common voltage very simple circuits can be used for train detection by connecting the common rail through the detector circuit to layout common Such detectors usually cost less than isolated detectors Sometimes modelers express the feeling that common rail wiring cannot be used for certain railroad track configurations In each case these modelers have tried to select their common rail using a rule such as the right hand running rail is common Please please do not use such rules In a sense they are correct THAT RULE WILL NOT WORK However if you use a rule that says the north rail is common you will have no problems whatsoever Pick the north rail or the south rail if you prefer but use the same rail as the common rail everywhere on your layout If you use DC control the BD8 will only work if you use common rail wiring for your layout Converting a two rail switched layout to common rail is simple if the cabs are electrically isolated Simply pick a rail to be used as the common rail and then tie together all of the cab lines that connect to that rail bypassing whatever cab select switches you may have Only reversing sections need to be handled with both rails isolated This allows you to reverse the connections to these
60. ly one of several cabs to a given control block at a time allowing that cab to control the speed and direction of all trains in the control block DCC or DIGITAL COMMAND CONTROL A form of command control described by the NMRA Standards and Recommended Practices Command control operates by sending speed and direction messages through the track to decoders in each engine Each decoder accepts only messages sent to it specifically and carries out the command The typical commands will provide speed and direction information additional commands can turn lights on or off sound the bell or whistle etc The important thing is that these messages are sent to all trains 14 wherever they on the layout Hence with DCC we can operate our trains exactly like the prototype cornfield meets and all DETECTION BLOCK an electrically isolated section of track used for detection of a train separate from all other detection blocks on a layout There is no need for control blocks and detection blocks to be identical EAST BOUND the condition of a detection block which has a train present and moving east HEADBLOCK SIGNAL a signal that protects the entrance to or exit from passing tracks LED Light Emitting Diode A solid state device that emits light visible or IR when a small DC current flows through it They are very efficient operate with little temperature rise have very long life and are good for use in signals or on control panels
61. necting routes If the train runs anywhere in the block you still have one or more common rail feeds that need to be removed from the block When all common rail has been isolated run a new common rail feed from the assigned detector in the BD8 to each of the now cut common rail feed wires dropping down from the common rail Again when this is done you should be able to run your train anywhere in the block Try it and see If the train doesn t run in some portion of the block you still have a common rail feed wire to connect Keep looking till you find it and connect it to the BD8 Table 8 3 Common Rail and Output Connections lists the connector pins used for each of the eight detectors After you have connected the block common rail to the detector connect the outputs for the same detector See Section 8 5 CONNECTING THE OUTPUTS for specific information on how to connect to the BD8 Choose the paragraph that describes the output device you are using When you have the output connections installed for a block check them by using one of the three self test modes which sequence through the outputs We suggest that you use either slow speed scan for this test Also remember that there are 16 steps in the occupied vacant sequence and each step takes two seconds There are 32 steps in the east west both neither sequence also at two seconds each So it will take a while for the BD8 to cycle through all of the steps If the outputs for the block
62. nic for basic information Table 8 3 Common Rail and Output Connections BLOCK COMMONRAIL OCCUPIED OR VACANT OR PIN EAST PIN WEST PIN Table 8 4 below lists all of the general purpose connection pins on the BD8 card connector Table 8 4 General Purpose BD8 Connections Layout common connections i Protection Diodes for inductive loads Power input Negative Connect your BD8 layout common connections to the layout common wire Simply run a tap wire from at least two of the BD8 common connections to the nearest place on the layout common wire Pins 5 and E are a good choice Make sure that you are careful in attaching wires to the pins on the edge connector Avoid using too much solder too much pressure and too much heat Carefully strip the insulation off each of the wires in the layout common group and solder the tap wire to each of them Since this is a bare connection fasten it to a riser joist or L girder so that it can t move and come into contact with any other wires Then connect the power supply provided with the BD8 to the card edge connector The power supply has a cord with a low voltage DC output As you receive the power supply there is a plug attached to the end of the cable Cut off the plug as close to the end of the cable as you can Split the two wires back from the end for about 1 1 2 inches strip about inch of insulation from each wire and attached them to the card edge connector The wire with th
63. ns that will help you to test and trouble shoot the board itself and your installation Other than our own BD16 Block Occupancy Detector Board we know of no other train detection product that provides you with this feature First the board has a power on LED which glows brightly when the internal power supply is providing full output If this LED is off or dim you know that something is drawing too much current from the power supply or that the power supply is not plugged in Next by using the mode plugs provided with the unit you can have the BD8 sequence each of its outputs on and off in two second steps or very rapidly if all you need is a quick check Everything you need to know to take advantage of the self test functions is provided later in this manual 2 4 ASSEMBLED AND TESTED We realize that most model railroaders have railroading as their hobby not electronics To give you access to the latest electronic technology without getting you into the electronics field your BD8 comes to you completely assembled and tested You don t have to have any knowledge of electronics to use all of the board s features Simply follow the detailed instructions in this manual to connect the board s 8 inputs to your blocks for train detection and the 16 outputs to your signals or other output devices Depending on how your layout is currently wired it may involve no more than taping into 8 block common rail wires and adding 2 wires per block to your
64. o us describing your specific type of installation the type of electrical control system you are using how you have connected the BD8 and details about what you expected of the BD8 and how it appears to fall short If we cannot clear up any problems you have we will refund your full purchase price upon return of your BD8 in good working order Naturally we cannot be responsible for units that have been damaged by misuse use improper installation or connection OTHER SIGNALING AND LAYOUT CONTROL PRODUCTS WE SUPPLY BD16 Block Occupancy Detector for 16 blocks BD8 Block Occupancy Detector for 8 blocks MSC Master Signal Controller GCC Grade Crossing Controller GCX Grade Crossing Expander Detectable Wheel Sets Signal Mounting Adapters TOMAR Signals switch stands crossing gates and flashing cross bucks Sunrise signals for N scale and HO scale Oregon Rail Supply signals and signal kits And our new CLICS System COMPLETE LAYOUT INTEGRATED CONTROL SYSTEM 50
65. of track that are not going to be connected to your BD8 boards This will normally be yard tracks and probably industrial sidings At this time you will connect the common rails of these areas of track to the layout common wire For your non detected blocks we recommend that you make sure that each such block or section of track has gaps in the common rail to separate it from any adjacent detected blocks Connect these sections of track to the layout common one at a time and then test what you did This way you can keep any problems from growing to unmanageable proportions Also by doing a little at a time you can keep your layout operational while you make this conversion Select a non detected block to reconnect After the common rail has been separated by gaps from other blocks disconnect all of your original feed wires from your cab select switches to the common rail We suggest you cut these wires so that at least a few inches remain connected to the rail and accessible If you make a mistake and cut the wrong wire you can splice the ends back together If not you can use the wire still attached to the rail to make the connection to the layout common wire At this point the common rail for the block should be completely isolated electrically Verify this by connecting a cab to the block and all adjacent blocks using the proper cab select switches Set the cab output for a few volts and measure the voltage in the block from its common r
66. ommon rails of the eight blocks 1 will go to the layout common 16 will go to the red and green LED s and 1 will connect the 5 volt supply to the LED anodes We will identify these connections in detail later What is important now is that you plan for the wiring strain relief for the wires to protect the connector and accessibility for maintenance test and trouble shooting Because the current required to operate LED s bulbs or relays is low typically less than 0 1 amps you can use wires for these circuits of 22 to 26 gauge with no problem The wires carrying train current will probably have to be 18 to 22 gauge People sometimes wonder what size wire to use and that s a good question general rule of thumb is to use heavy enough wire that the resistance of the wire causes no more than a 1 volt drop with the highest expected current flowing Today with a typical motor drawing about 3 amps under load a three unit consist will only draw about 1 amp Thus a 1 ohm total resistance would satisfy this guideline A heavier gauge wire will result in less loss Then consider the round trip wire path from the power pack or booster to the most distant block and back Select a wire size from the following table based on the total wire path length Table 8 2 Resistance Table for Wire For the layout common wire to which all of the common rails are connected all of the train running current will pass This means that you need
67. one of two output modes used with DC control the BD8 will report blocks as either OCCUPIED or VACANT For each block there are two outputs one which is active when the block is OCCUPIED and the other when itis VACANT The two outputs are mutually exclusive Because of this you can usually implement basic two color signaling without any additional circuitry For a prototypical professional installation you will want to interlock the signal aspects to the position of switches just as the prototype does We have developed the SSI Switch Signal Interlock Module to help you with this It provides all of the necessary electronic connections to include switch position in your signaling system One connection to the SSI tells the circuitry the position of the switch other connections from the BD8 or BD16 Block Occupancy Detectors indicate block status And outputs from the SSI go to signals on the frog and point sides to cause the proper aspects to appear The SSI also works with our TC4 Three Color Signal Controller to include switch positions in a three aspect signaling system 2 2 3 DIRECTIONAL DETECTION When used with DC control the BD8 can be configured to indicate not just occupied or vacant but which way the train is moving if it is not standing still This is particularly helpful if you are implementing some form of automatic progressive cab control or using the BD8 to show which way trains are moving in hidden track You probabl
68. onnected to Layout Common Solder tap wire to each Tap wire connects to BD8 layout common wire in the layout pins cab common output or non detected common group 4 places block common rails in this example S S w Layout common 5 S shown run with four parallel wires x 5 N S 6 Figure 6 1 Tap Wire Connected to Layout Common You may need a 100 watt or more iron or soldering gun to heat up 10 gauge wire enough to get a good connection It s better to use a higher wattage and complete the connection quickly than to use a low wattage iron and take all day to heat the wires This won t work well and you ll probably have melted insulation all around the connections Be sure that you physically secure the bare wires so they can t move and possibly contact other circuits Wrapping the connections with electrical tape may also be a good idea This will save you trouble in the future Again do a sanity check by running your layout to see that everything still works Atthis point the only problems were probably caused by the physical disturbance that came from running the layout common wires Since you really haven t changed your existing wiring it should be easy to locate and fix the problems Make sure everything is working before you continue 25 6 4 CONNECTING NON DETECTED BLOCKS You will probably have blocks or other sections
69. ontacts move along with the points Everything in the figure is shown with the switch aligned for the main Note that both siding rails are gapped near the switch s fouling point and the main line block s power rail is also gapped at the fouling point With the switch as shown the lower contact is connecting the main block power rail to the frog F The upper contact is connecting the main block power rail to the part of the main block beyond the frog rail PM The power rail on the siding block PS is not connected to anything nc and a train on the siding will be stopped but could still be detectable by C2 if there was a source of current to detect We ll show you how to do that in a just a bit POWER RAIL CONTACT FROG CONTACT Figure 7 4 Power Rail Routing to Main Line In Figure 7 5 the same switch is aligned for the siding Note that the contacts move with the points and the frog F is now connected to the C1 rail The siding power rail PS is connected to the power rail for the main P and the main line power rail PM beyond the switch is not connected nc A train will now run on the siding but remain stopped on the main POWER RAIL CONTACT PM nc FROG CONTACT Figure 7 5 Power Rail Routine to Siding 28 Just for completeness we ll show the same switch wired with the straight stock rail as the power rail and the curved stock rail as the common rail In Figure 7 6 the common rails are connected to
70. ontrol boards or progressive cab control circuitry Since the BD8 provides what are known as open collector outputs you simply connect a BD8 output to the desired TTL or CMOS input The input circuit will need and usually comes equipped with a pull up resistor connecting the input to 5 volts The resistor raises the input to a logic high when the BD8 output is off the BD8 output pulls the input low when it is on Typically these resistors will have values of 1000 ohms or greater Our TC4 uses 10 000 ohm resistors All of the filtering used to minimize the effects of track and wheel dirt is still operational No additional power supplies are needed by the BD8 to function using this output mode 2 2 6 RELAY ACTIVATION The BD8 also has the output current capacity to switch loads of up to 150 milliamperes per output 16 total However the total load current could be far beyond the capacity of the power supply we include To make use of the total output capacity you will have to supply your own power supply Also if you are connecting an inductive load such as a relay or motor coil to the BD8 you must also use diodes that protect the BD8 outputs from the voltage spikes which are generated when current is turned off in an inductive load Such diodes are included on the BD8 circuit board How to use the diodes is illustrated in Figure 8 15 2 3 BUILT IN SELF TEST The BD8 is a truly unique product in that it provides built in test functio
71. orrect the problem 24 6 3 INSTALLING THE LAYOUT COMMON WIRE Next we will install the layout common wire Review Section 8 2 to choose the correct wire size to use If in doubt use the next larger size Use stranded wire as it s much easier to pull around joists risers and L girders And it will probably be easier to install multiple runs of smaller gauge wire than one run of very heavy wire For example use four runs of 10 gauge wire rather than one run of 4 gauge wire Both approaches give the same effective resistance but 10 gauge wire is probably as heavy as you would want to work with Of course use copper wire not aluminum You will have to solder connections to the layout common and copper is much easier to work with Then run the layout common wire around your entire layout bringing it near to all of the cabs and close to all of the locations you have selected for BD8 installations When the layout common is installed make your permanent connections between the cab common outputs and the layout common Wherever you need to connect a tap wire to the layout common wire carefully skin about one inch of the insulation off each of the common wires and strip a couple of inches of insulation off the end of the tap wire Then take the stripped end of the tap wire and wrap a tight turn around each run of the layout common Solder each of these turns to the layout common using rosin core solder This is shown in Figure 6 1 Tap Wire C
72. ough switches you may need to install some minor changes to this wiring Section 7 POWER ROUTING THROUGH SWITCHES will help you to understand where to make these changes and the simplest way to get it done e Section 8 INSTALLING YOUR BD8 shows you exactly how to install your BD8 with the minimum effort and risk Only read this section if you want it to work right the first time you turn it on f Fortestas you go instructions or trouble shooting help at any time read Section 8 7 TESTING YOUR BD8 DETECTOR g Ifall else fails for emergency relief read Section 9 CUSTOMER SUPPORT 2 8 OPERATIONAL FEATURES The BD8 Block Occupancy Detector is the latest state of the art device for sensing the presence of trains in sections of track and providing control signals to activate signals or other devices on your layout a Capacity each BD8 will detect trains and control two color trackside signals for up to 8 separate blocks b Train detection by current sensing your BD8 will see your train no matter how long or short or how twisted your track is in the block c Works with your layout control system use DC Cab control or Digital Command Control your BD8 will work with either d Direct output of both OCCUPIED and VACANT status you can operate two color signals with no additional hardware e BUILT IN SELF TEST your BD8 will help you with the installation and trouble shooting and help you to identify specific problems f Si
73. outes Fix any problems If the engine does not run everywhere in the block this will probably be due to missing a connection between a tap wire and one or more of the common rail wires Or you may have attached a tap wire to a power rail feed This would result in a short circuit in the block and the engine won t run anywhere as long as the cab select switch is set for the block Repeat this process for each non detected block checking as you go While you are doing this you are only taking one block out of service at a time and only long enough complete its conversion You don t have to cancel any of your operating sessions 26 When you have finished all such blocks go on to Section 7 POWER ROUTING THROUGH SWITCHES 7 POWER ROUTING THROUGH SWITCHES Train detection may also have an effect on your power routing through switches Figure 7 1 shows a normal power routing switch aligned for the main line As you can see both siding rails are electrically connected to the power rail and any train on the siding will see no voltage and will therefore be stopped An electrical contact is shown which operates along with the points to route power to the frog FROG CONTACT Figure 7 1 Power Routing Switch Set For Main Line Figure 7 2 shows the same switch aligned for the siding Now a train on the siding sees both power and common rails and can move while a train on the main sees two common rails and cannot move As long
74. pins on the edge connector 8 7 1 3 BLOCK ALWAYS SHOWS VACANT Normally this would mean that the common rail lead from the block is not going to the proper detector input pin 1 4 A D on the edge connector Or it might be that you still have one of your original feed wires connected to the block common rail This will keep the BD8 from detecting the train Go back to Section 5 and go through the step by step conversion procedure described This will help you solve the problem 8 7 1 4 BLOCK ALWAYS SHOWS OCCUPIED If the vacant LED never turns on and the occupied LED is always on then you probably have some source of current into the BD8 common rail connection This would appear to the BD8 that there is something in the block See if the LED s switch when you disconnect the common rail input to the detector If so then look for some unexpected current source into the common rail This could be a missing or closed gap a wheel bridging a gap or even an engine or piece of rolling stock being detected If both LED s are on when the block is vacant and the vacant LED goes out when it is occupied check the wiring to the occupied LED You probably have a short to common somewhere along the wire from the BD8 output to the LED cathode 8 7 1 5 STANDING TRAINS ARE NOT DETECTED For the BD8 to detect a train some current flow must be present if the block is occupied With command control power is always present on the track However with DC
75. pposite end of all of the resistors together and then to the output of the 12 VAC transformer as shown in the figure above One good way to mount these resistors is to use what is called a turret terminal board Keystone Electronics Corp makes several suitable ones Their part number 15032 provides enough terminal pairs to install 25 resistors You can get these along with the resistors from various distributors Allied Electronics 1 800 433 5700 handles the terminal boards Allied Part No 839 2373 You can get the package of 200 resistors from Digikey 1 800 344 4539 using their part number 4 7KQBK ND 45 8 7 TESTING YOUR BD8 DETECTOR INSTALLATION We thoroughly test each BD8 before shipping it to you But the time may come when you want to see for yourself that the board is working properly Also all of our built in test functions operate the output signals in a predictable way Thus you can select one of the BD8 test functions and see if your lights operate as you expect Make sure that you have recorded exactly which outputs go to which loads 8 7 1 TROUBLE SHOOTING SUGGESTIONS The step by step conversion and installation procedures described throughout this manual should help you avoid most problems and quickly identify the rest as you go The important thing is to make just one or two changes and see if everything is still working If not there is some problem with what you did since the last test The more you do between t
76. rd of anyone used relays for train detection and also using modern can motors in the engines 3 4 2 TRANSISTOR CURRENT SENSING 11 The transistor was first applied to train detection to our knowledge by Linn Westcott in the mid 1950 s He designed the Twin T circuit and later the Twin T with booster transistor for train detection His circuits were very effective and in wide use They had the advantage of high sensitivity yet resulted in a low and almost constant voltage drop in the track circuit They could easily detect milliamp sized currents By equipping your wheel sets with a resistor of some relatively large value these circuits could detect a lone car parked in a block just as the prototype does For practical reasons the layout will usually be wired using common rail wiring with the Twin T circuit installed in the path from the common rail to the layout common return You can avoid the need for common rail wiring by providing a separate isolated power supply for each detector This of course adds a lot to the cost The major limitation of the Twin T circuit is the fact that the full train running current passes through what is normally a low current path through a transistor Thus relatively large and expensive power transistors had to be selected so that the base to emitter path could handle at least three to five amps And these transistors had to be mounted on a heat sink of some fair size The only other limitation o
77. s shown in these two figures are detection blocks The power routing blocks if you are using DC control will include the consecutive and blocks 6 CONVERTING TO COMMON RAIL WIRING If your layout is already wired for common rail power distribution your installation will be somewhat easier But even so there may be some minor alterations in wiring primarily involving power routing through switches under some conditions Begin by selecting your common rail If your layout has already been wired using the common rail system this step is done you need to do is remember which rail you picked The common rail can be either the north rail or the south rail it really doesn t matter Incidentally just for clarity this manual is written assuming that your layout is an East West railroad If you think of your railroad as a North South railroad we suggest that you temporarily think of it as East West This will make it easier to read the manual Otherwise this manual would be almost twice as big Every paragraph would have to appear twice once written with East West and once with North South How do you know which is the north or south rail It s very simple really Look at any section of track on your layout where a west bound train moves from right to left The south rail is the rail closest to you the north rail is the other rail If your layout is an oval of some kind Linn Westcott suggested many years
78. t Wiring shows how the is connected in a typical command control system and Figure 4 2 Common Rail Layout Wiring shows the BD8 connected in a common rail DC control system The diodes are connected in series with the track feed to a block and will result in a voltage drop of approximately 0 7 volts current of less than 1 milliamp and up to the current limit of 3 amps can be detected To prevent burning out the diodes your cabs should have some means for limiting their output current to 3 amps or less if a short circuit occurs This only makes sense even without the BD8 since the cab rail wiring and electrical switches should be protected from excessively high currents The detected current is processed to eliminate any detection chatter due to dirty track or wheels Special processing is also required with DCC controlled layouts to compensate for the effects of the high speed switching of the voltage applied to the track by boosters All of this special processing is performed automatically by special circuitry included in the design of BD8 2 2 TYPES OF OUTPUT The BD8 Block Occupancy Detector comes equipped for three different types of outputs and will also report occupancy in two different ways when used with DC control These details are described below 2 2 1 OUTPUT CAPACITY Included with the BD8 is a five volt power supply which will not only power the board itself but will provide up to 400 milliamps of current to
79. to indication switch positions or block occupancy NORTH BOUND the condition of a detection block which has a train present and moving north OCCUPANCY DETECTION a means for detecting the presence of a train in a block Note that the blocks used to divide the layout for train control purposes can be different from the blocks used for detection A normal highway grade crossing provides a good example of the difference For prototypical control of the crossing gates or flashers three separate occupancy detectors should be used But there is no need or desire to provide for the control of separate trains in these three blocks One train control block is sufficient OCCUPIED the condition of a detection block that has a train present within it OS On Sheet or On Switch The On Sheet usage applies to manual signaling and train control systems in which an operator will record the arrival or departure of a train sheet a form used to keep a record of train movements and presence in blocks The Switch usage applies to automatic signaling systems that detect the presence of a train on a switch and prevent throwing the switch POWER RAIL the rail parallel to the common rail Since the common rail is at 0 volts or ground the power rail is taken to positive or negative voltages with respect to the common rail to control the speed and direction of train movement RAILS the parallel structures that the wheels roll on
80. trol Layout Wiring With Command Control full voltage of some form is always applied to all of the track Included in this voltage is some form of electrical signal that is picked up by a receiver within each engine and decoded to apply the desired voltage and polarity to the motor Note that ultimately the motor needs a DC voltage and polarity to rotate and move the train There are various systems for embedding the control signal in the high current and voltage that appears on the track These systems allow each engineer to control his train anywhere on the layout independent of what the other engineers are doing and without routing power to track blocks In this regard these systems are extremely successful Using a command control system lets you have a cornfield meet if you want to or get careless Command control systems may or may not be common rail systems Specifically the NMRA Standard DCC System uses boosters to provide power to the rails for the engines and other command decoders which are attached to the rails For significant technical reasons there can be NO connections between the outputs of different boosters This means that separate BD8s must be connected to each separate DCC booster As far as the output of a single booster is concerned its output is common rail wired but there is a separate common rail for the power district connected to each separate booster All BD8 boards connected to the output of a g
81. two separate detectors C1 and C2 We assume that is being fed by a cab select switch and is routed by the upper contact to the power rail PM in the main line block beyond the switch POWER RAIL CONTACT PS 3 FROG CONTACT Figure 7 6 Power Routing With Straight Stock Rail Common The power routing we have shown above is something that you will have to add to any of your switches that will have separate detection on the frog side with power being routed through the switch One at a time make the modifications to each of your switches that will operate this way Again after each is modified with the extra electrical contact do a sanity check and run a train through all related routes Make sure it runs when it should run and stops when it should stop If something doesn t work right fix it You have probably not wired one of the contacts properly or have not cut the necessary gaps 8 INSTALLING YOUR BD8 You have probably heard the adage Prior Planning Prevents Poor Performance and model railroading is no exception Before doing anything on your layout we recommend you plan your complete signaling installation even if you have only purchased some of the detectors and signals you will eventually need First make a drawing of your layout showing all of the tracks main line sidings spurs hidden visible built or planned but not yet built Then identify each separate detection block and give it a number
82. u can change the mode of the BD8 at any time by simply adding or removing the jumper plugs on JP1 of the BD8 PC board Within two seconds the function will change to the one you have just selected In normal operations you will simply set the mode required by your layout and leave it From then on whenever you turn on your BD8 it will start in your operational mode and give the type of output indications you wish But in addition to that the four self test modes are available to help you with your installation or to help trouble shoot problems if they should arise All of the modes are described in the paragraphs that follow And each includes a figure showing the correct jumpers to install 82 1 NORMAL OPERATIONAL MODES There are a total of four operational modes for your BD8 Unless you change your layout control system at some time you will probably never have to change modes But you always have the choice 8 2 1 1 Command Control Use this mode if you are using any form of command control Your outputs will indicate the OCCUPIED or VACANT status of your blocks c 79 SELFTEST 2 0 NORTH RAIL o EAST WEST o o Figure 8 5 Command Control Jumper Positions 34 8 2 1 2 DC Control Occupied Vacant Output For DC controlled layouts this will be the most likely mode to use The outputs are OCCUPIED and VACANT and will operate two aspect signals at trackside Or you can use the OCCUPIED output to
83. ually not at industrial spurs The timetable is still used to provide the schedule for the trains But meets and passes are controlled directly by the dispatcher the rules of train superiority are suspended One simple way to tell which type of signaling the prototype is using is to look at the signals at the entrance and exit of passing tracks With ABS and APB systems there are two signals one facing each way located near the switch points These are called headblock signals Trains on the frog side of the switch will stop before reaching the fouling point if the signal they see shows STOP The signal they face as they approach from the point side indicates the condition of the main line block The siding is normally not signaled The signal seen when leaving the passing track area is an absolute signal If it displays STOP a train is not allowed to pass You will normally find a telephone located near absolute signals so the crew can phone for instructions if they find an unexpected STOP aspect Figure 5 1 Typical ABS APB Block Signals With CTC installations there are usually three signals protecting the end of a passing track Since the timetable is no longer used to determine train superiority the signals are used by the dispatcher to issue orders to the crews The signal seen when approaching the points will show CLEAR to indicate a train routing on the main will show APPROACH to
84. ult isolation The small cost for such strips is well worth it If the distance from the BD8 and the blocks is particularly short and your engines are equipped with low current can motors you can probably run your common rail feed wires using 22 gauge wire If you use stranded wire and a 33 tight cable clamp to keep the wires from pulling on the connector contacts you could connect directly to the card edge connector See Section 8 2 for more detail on selecting wire sizes Since the wires to your signals will probably be 22 gauge or finer a simple cable clamp will be adequate Stranded wire will be easier to work with You may want to consider using four conductor modular phone cord It s available almost everywhere and at a very low price The four wires in the bundle are color coded and while fairly fine they are easy to work with The major items in Figure 8 4 are as follows Screw barrier strip with 9 positions Common rail wires for blocks 0 3 from contacts 1 4 Common rail wires for blocks 4 7 from contacts A D Layout common Connect to at least 2 of the four contacts 5 6 E or F 16 occupied and vacant wires to signals or control panels Nylon cable clamp sized to clamp wires snugly Two wire power feed from wall mounted power supply provided with your BD8 SOS ee Ra 8 2 CONFIGURING YOUR BD8 DETECTOR Your BD8 has a total of four self test functions and four operational functions We call these the modes Yo
85. urrent The main limitation of this technique is the issue of balancing the sensitivity of the relay with the voltage dropped across the coil As in most areas of engineering there are conflicting factors that must be considered With a relay a magnetic field of a certain strength must be generated to switch the relay To get sensitivity to low currents many turns of wire are required in the relay coil The more turns there are the higher the resistance of the coil and the larger the voltage drop using heavier wire reduces the voltage drop but increases the physical size and cost of the relay In years past when motors routinely drew an amp or more of current a workable balance in the design of the relay could be reached But todays can motors which draw only 20 as much current are much more difficult to detect And when the train stops so does the current What is there to detect Relay contacts present a further limitation They are subject to dirt and oxidation that can prevent the contacts from closing properly Also when used to switch the very low currents that are involved in logic circuits typically a milliamp or less the contacts should be gold plated to resist oxidation Using gold increases the cost significantly not using gold decreases the reliability significantly Another one of those pesky engineering compromise situations Considering today s motor technology relays may not work at all In fact we haven t seen or hea
86. using command control there will always be a voltage applied to the track and the BD8 will always be able to detect the presence of equipment that draws even a small current Most cars however do not draw any current unless modified in some way We stock non magnetic replacement wheel sets for HO and N scale standard gauge equipment These wheel sets are equipped with a resistor that allows a small but detectable current to flow To make your cars detectable simply replace one or two wheel sets per car with ours On special order we could provide wheel sets for other scales and gauges as well Or you can make your own if you wish We use a 5 1 watt resistor bridging the insulation between the axle and the insulated wheel With a DC controlled layout a special arrangement is necessary to make sure that there is always a voltage applied to each block We recommend that you install a 12 VAC transformer as shown in Figure 8 16 and connect this 44 voltage through 4 7 ohm resistor to each power rail in detectable blocks Even when the cab select switches in the OFF position this very low current AC will be present Since this is an AC voltage if there is a standing train present the BD8 will detect a current that flows alternately in both directions The change in current direction takes place 120 times per second and we all know that a train can t really change direction that fast it has to be standing still If the
87. wo series diodes in the track current path Noise filtering circuitry must be provided to minimize the effects of wheel and rail dirt And additional signal conditioning must be provided to allow such a detector to operate LED s relays or bulbs 4 TRAIN CONTROL SYSTEMS Over the years many different systems have been developed for controlling model railroad trains Today there are two primary ways of controlling trains DC control and Command Control Both systems share the same goal allow each engineer to control the speed and direction of his train They differ in the way they achieve this goal and the electrical complexity and operational flexibility provided Incidentally the BD8 does not control trains It simply detects the currents flowing to 8 different sections of track to determine whether or not trains are present in those separate sections and possibly which way they are moving We do have some customers who have used our detector boards to activate relays when a block is occupied and use the relays break the current to the prior block to prevent rear end collisions automatically This is particularly helpful for modular layouts when they are operating for the public It is sometimes difficult for the crew to converse with the spectators and keep the trains under control This lengthy discussion of train control methods and wiring is to help you to connect the BD8 into whatever train control system you now have or to help you mo
88. y people use a higher resistor value for the red LED so that its brightness matches the brightness of the other two colors Perhaps the simplest way to connect the BD8 outputs to signals using LED s or incandescent bulbs is to use four conductor modular phone cord This wire is readily available everywhere try Radio Shack is large enough to carry the required current and is very low in cost We recommend that you use the black wire for the 5 volt connection and the red and green wires for the corresponding LED s Which leads us to the question of how and where to install the current limiting resistors One method that works well costs little and is very reliable is described here A three pin terminal strip is shown but you could use a 6 pin terminal strip if you had two signals close enough that the leads would reach Also if you are planning to install 3 color signals someday consider using a four or eight pin terminal strip now You will need the extra pins later At the time this is being written you can call Mouser Electronics at 1 800 346 6873 and place an order or request a catalog 42 Terminal strip shown is Mouser Electronics Stock No 159 1003 Heat shrinkable tubing to insulate the connections to the resistors Resistors are soldered in place and covered by heat shrink Modular phone cord f to BD8 outputs Wrap cable wire around resistor lead solder and trim to size
89. y won t ever need this feature with command control the throttle itself indicates true direction of travel There are still two output signals for each block In this case one will be active if the train is moving in east bound the second if the train is moving west bound If the train is standing still or moving in both directions both outputs will be active If the block is empty both outputs will be off This is depicted simply in Table 2 1 below Table 2 1 Outputs for Directional Detection Mode BLOCK STATUS EAST OUTPUT WEST OUTPUT train standing off open circuit The BD8 has a mode jumper plug which plays a part in this If your common rail is the south rail install the jumper Figure 8 7 if your common rail is the north rail Figure 8 8 leave the jumper off 2 2 4 LED ACTIVATION For many applications such as two color signaling the BD8 Occupancy Detector needs no additional circuitry It can operate two color LED signal lights directly Sufficient current capacity is available from the power supply provided with the BD8 to operate a total of 40 LED s of 10 milliamperes each with all on at the same time Each LED must have a current limiting resistor connected in series with it This is shown in detail in Figure 8 13 Driving Multiple LED s From a Single Output 2 2 5 LOGIC SIGNAL ACTIVATION The BD8 can be configured to output logic signals which can be used by other circuitry such as three color signal c

User Manual - WS Ataras Engineering, Inc.

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