Matrix Wiring Diagram?

Discussion in 'HO Scale Model Trains' started by vanda32547, Jun 11, 2002.

  1. vanda32547

    vanda32547 Member

    Does anyone have a good wiring diagram for a spur/siding matrix i.e; where you hit one button on the switchboard diagram to change all the switches to a particular spur or siding?

    I under stand there is some sort of curcuit board needed to do this but have no more details. Hopefully, someone out there knows what I'm talking about and has a wiring diagram and the circuit board specifications.

  2. Gary Pfeil

    Gary Pfeil Active Member

    Bob, I'll give this a shot. Knowing how to do something and explaining it are two different things. You are talking diode matrix. Diodes allow current to pass in only one direction. You want to be able to select a route thru multiple turnouts using just one switch (or probe). Draw a schematic of the turnouts (throat) araingement and draw a box on either side of each turnout to represent the coils. Letter them (A,B, etc) On the bottom of the sheet, draw circles and number them (1,2, etc) these represent the switches or contacts. From switch 1, draw wires to each coil required for the desired route. Do the same for each route. All coils which have more than one wire will require a diode on each wire. When you press a switch for a given route, power will flow to those coils required, and will be prevented from flowing to the other coils. The diodes can be placed on perf board or attached to the lead from each coil. Hope I was able to make this understandable.

  3. cidchase

    cidchase Active Member

    Hi Bob
    I'm an expert on this by no means.
    The only thing I would add (it may already be obvious to you)
    is to use DC to control the turnouts.
    Assuming your pushbuttons are wired to the + side of your power supply, then the band painted around the diode goes toward the coil of the switch machine.
    The other side (common) of all coils connects back to the - side of your power supply. Gary, is this all correct??
  4. Gary Pfeil

    Gary Pfeil Active Member

    Cid, Sounds right to me! Leave it to me to leave out the basics! I should also note that this diode matrix works for twin coil type switch machines, not for slow motion stall motor types. I saw an article on routing for these machines but cannot recall how long ago. Pretty sure it was in MR.

  5. 60103

    60103 Pooh Bah

    It's not absolutely necessary to have a circuit board -- it can be wired in between the switch machines.
    Example: you have switch A on your mainline and switch B dividing the siding into two on the curved side of A.
    wire two pushbuttons to switch machine B. run wires from each coil of switch machine B to the curved side of A. put a diode in each wire (not one for both!) between A and B. Wire a push button to the remaining side of A. Pusing wither button of B will also throw A curved.
    Any more complicated layouts are just expansions of this.
    The matrix diagram is handy for figuring out how you need to put in diodes and where you can skip them.
    Make sure the diodes have the capacity for the number of switches you're throwing at once. This is also a spot where you may want to think about the Capacitor discharge unit. With a big capacitor.
  6. vanda32547

    vanda32547 Member

    Thanks for the info guys...

    You all are some smart fellas out there... and I appreciate the opinions of all of you.

    What rated diode should I use and how many switch machines can I put on one circuit? I suppose I can pick these up at a Radio Shack or similar store? Since I am still in the planning stage of my layout expansion I do have some time to decide how I want to do this.

    Thanks again,
  7. Gary Pfeil

    Gary Pfeil Active Member

    I have to leave the questions regarding size of diodes and capacity of power supply to throw x amount of coils to othjers more knowledgeable. The typical resistance in the coils is practically nothing, so a large amount of current flows. I use an 8 amp 16 volt transformer and have no trouble throwing 5 coils at once. I do not use a cap discharge system. For diode size, I use bmf diodes (big mother f---ing diodes) which I can get free here at work. Just joking, they are not physically large, but are probably way overrated for what I am using them for. To correlate David's example to what i previously wrote, turnout A would have coils A & B and turnout B would have coils C & D. If the straight route thru turnout A continues without further turnouts and is consided track 1, then switch 1 would be conected to coil A. Switch two would be for track 2, requiring coil B and coil C. Track 3 would require coil B and coil D. So coil B is the only coil with two leads. Two diodes are required. These diodes can be placed right at the coil.(B) The line between the diodes and the switches on the panel would be tapped and connected to coils on turnout B. The diodes allow power from either switch 2 or 3 to reach coil B, but that power will be blocked from travelling down the other lead. If the diode goes bad and allows current to flow, both coils of turnout B (coils C & D) will get power and the turnout will not throw, although if power is left on it will smoke nicely. <G>

  8. cidchase

    cidchase Active Member

    Hi Bob
    Try 1N4004 diodes. I think they are rated 1 Amp @ 50VDC, probably available pretty cheap at Radio Shack.
    For longevity of the controls, I would suggest using the same diode as a shunt around each coil to suppress the kick when the coil is turned off.
    These hook up with the painted band to the (+) side of the coil, the other end to the (-) side of the coil.

    I never realized the matrix won't work with stall motors, I guess it's because they reverse direction by changing polarity on the motor. It probably could be gotten around somehow but might turn into a real can of worms. Hmmm...we must be masochists...

    from Olive Branch
  9. kettlestack

    kettlestack Member

    Hi Bob,
    I think this diagram answers your question.
    I would strongly encourage you to use a capacitor discharge unit to power your turnouts. Also it is a good idea not to mix turnout motors from various manufacturers as the ones with lowest resistance can "steal" the power and prevent higher resistance motors from throwing.
    The diagram does not show the "-ve" side of the power source as it is wired directly to all motor "common" leads.
    Radio Shack may very well have pre-drilled etched matrix boards.
    I have seen them for sale but can't remember where.. (I'm in UK but have visited several Radio Shack stores in the states).

    Hope this helps you


    Attached Files:

  10. vanda32547

    vanda32547 Member

    Excellent info...thanks

    Thanks again guys,

    A special thanks to Errol for the diagram this will help alot.

    I am trying to figure out a way to show ya'll a picture of my expansion track plan so you have a better idea of what I am trying to do here. The switches I am using are the cheapy atlas type snap switches with under table coils. I have used them on my main layout and they have worked well. (Not to mention they are easily replaced if and when they go bad wihout disturbing the scenery) Soon as I figure out how I will send a diagram.

    Thanks for all suggestions,
  11. Gary Pfeil

    Gary Pfeil Active Member

    Errol, Thanks for posting the diagram, one of these days I ought to learn how to do more than post text replies. Problem is I never want to sit down at the computer and try to learn. Too many other fun things to do. Thanks again.

  12. vanda32547

    vanda32547 Member

    Ok guys let's give this a try...

    I am trying to attach a couple of diagrams for you fellas to look at and give me your input. The first one is the area where I need the matrix. The other is the addition to my existing layout. Take a look and let me know what you think?


    Attached Files:

  13. vanda32547

    vanda32547 Member

    2nd picture

    The proposed addition...

    Attached Files:

  14. Gary Pfeil

    Gary Pfeil Active Member

    Bob, I assume those are double slips at positions 2,3,6 and 7? I hate to volunteer other people, but I will. Errol, are you there? Seriously, I would be glad to draw out matrix for all possible routes but would have to mail it to you. If you are interested, please send me your address to my email and I will mail drawings to you. I see you are in Miami, I was just on vacation last week at Pompano Beach. I had thought before I went to post and see if there were any points of interest I could visit. Oh well, timing is everything! I would have liked to visit. I'll be going back next year (bought a time share there). Errol or someone else may help you shortly, if not email me and I will.

  15. kettlestack

    kettlestack Member

    Gary, You're on in five! :D :D :D

    I'm up to my ears at present with other things.

    One thing I did notice though, is with a layout like that, total routing for any one train is going to be quite some task to plan out a matrix for.

    Another thing is the qty of turnouts to be operated simultaeneously in the ladder will requre a reasonably powerful CDU with at least a 65,000 microfarad capacitor in it as the power reservoir. This will also require a really good quality pushbutton too as the surge current will be of the order of at least 15 amps (although only for about 10 to 20 milliseconds).
    I certainly wouldn't advise a straight rectified transformer output as the power source. (One turnout motor with a stuck pushbutton can consume up to 100 watts, think what wattage that many turnouts would take!)

    Several of the crossovers etc around the layout are best operated by normal wiring (paired turnouts).

    Just my opinion.

  16. Gary Pfeil

    Gary Pfeil Active Member

    Errol (and Bob) I took a look at the required matrix last night and designed one that has 9 routes. I made some assumptions regarding track usage, primarily that the track to the right of the ladder and just below the main would be used as a switch lead. Bob has told me offlist that what appear to be doubleslips are in fact two regular turnouts. I guessed at their arraingement and will mail to Bob today. Based on my assumptions, traveling right to left on the main there will be three options, stay on the main, take thru siding (track 1 on my diagram, Bob) or travel down ladder to what seems to be a reverse loop track. I have not provided for trains off the main to travel down what appear to be stub ended sidings. These are routed from the switch lead instead. The routings I created require 27 diodes. Errol is right about switches welding themselves together when breaking the contact, and there are seven coils to throw for one route, the one Bob was asking for in the first place. I do not use switches, I use stud and probe, as Shamus does. Again, I leave cap discharge to others, they've been used for decades by multitudes so who am I to argue? I get by without one but I have a heavy duty power supply. Pushbutton switches probably wouldn't survive on my railroad. I tried a Rix pushbutton once, it lasted one throw!
    Bob, the drawing I send you shows the diodes coming off the coil contacts. Since there are so many, it may be easier to mount them on perf board and solder leads to them at your workbench rather than soldering them under the layout. As long as the connections remain the same it won't matter which way you go. For instance, coil D on the drawing has 5 diodes, they could be side by side on perf board, tied together on one end and run to the coil, with 5 leads on the other end going to the studs/switches for the appropriate routes.

  17. vanda32547

    vanda32547 Member

    Thanks Gary

    Thanks gary,

    I will await your mail and then re-read your description so I can follow along. You were right on all of your assumptions. Since this is a new addition to my layout, I wanted the option of running 1 train on the addition by itself while the main layout is also active.

    In addition now I will have a place to do some switching and a place to put in some industries. When I have guests over each layout... my main one and the new addition can be operated independantly allowing for more fun and operations.

    After all planning, building, wiring, scenicing and placing buildings is only half the fun... gotta run them bad boys don'tcha :D

    Thanks again everyone and keep those great ideas and first hand knowledge coming.

  18. fritxchrisler

    fritxchrisler New Member

    Matrix system for turnouts

    If you can get your hands on a booklet, Practical Electronic Projects For Model Railroaders from Kalmbach Books, author Peter J. Thorn (#12023) Your will find the complete instructions for setting up a matrix on your layout. Also you will find the wiring diagrams and pictures of the front and back of the completed projects in many cases. There is also a wiring diagram etd. of a high powered capacidence discharge unit that you can build that will operate up to ten switch motors at one time in the matrix.

    There are many other useful projects in the book that are relitively easy to build and inexpensive. Hope you can find one of these useful and informative books.:) :)

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