4 Track - Switch Machine Ladder Matrix

Using DPST Toggle Switches

And Capacitor Discharge Supplies

  This circuit uses DPST push button switches to control a 4 Track yard ladder matrix circuit.

  DPST relays could also be used to control this circuit. This would permit other circuits or less expensive switch types to control the ladder's turnouts.

  A split, capacitor discharge type power supply is used for power and a quasi diode matrix to control power routing.

  Dashed verticle lines are used on the schematics to make following the + and - current paths easier.

  The diodes are used to prevent short circuiting connections along the vertical lines to other motors. Horizontal lines connected to only one vertical line do not need diodes.

  A power supply large enough to to supply current for all of the switch machines connected in parallel whe the top track of the ladder is selected.

  The capacitors draws current only when they are being charged. A 500 milliamp power supply could power several of the single and multiple switch machine control circuits. The 100 ohm resistors should have a power rating of 5 watts. The time of maximum current use is when power is applied to the circuit.


Capacitor Values

  The value of the capacitors in the circuits is only a suggestion, smaller values may work equally well for a particular switch motor. Turnouts for crossovers may need larger capacitors.


Other Ladder Sizes

  The next circuit is for a three track ladder using DPST or DPDT relays instead of DPST push buttons. It might be cheaper to use relays and SPST push buttons in place of DPST push button switches.

  Using relays would allow the circuit to be controlled by buttons that are far from the switch machines or at multiple locations. Electronic control by another system is also possible.


Stall Motor Switch Mahines

  Minus the capacitor discharge supply, this type of circuit would also work with Stall Motor Switch Mahines such as Tortoise's but the push buttons would have to be held closed until the motors had stopped running. When the push buttons are released the motors would not be powered.

  Relays could also be used and they could remain closed as long as only one relay is energised at a time.


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Please Read Before Using These Circuit Ideas

  The explanations for the circuits on these pages cannot hope to cover every situation on every layout. For this reason be prepared to do some experimenting to get the results you want. This is especially true of circuits such as the "Across Track Infrared Detection" circuits and any other circuit that relies on other than direct electronic inputs, such as switches.

  If you use any of these circuit ideas, ask your parts supplier for a copy of the manufacturers data sheets for any components that you have not used before. These sheets contain a wealth of data and circuit design information that no electronic or print article could approach and will save time and perhaps damage to the components themselves. These data sheets can often be found on the web site of the device manufacturers.

  Although the circuits are functional the pages are not meant to be full descriptions of each circuit but rather as guides for adapting them for use by others. If you have any questions or comments please send them to the email address on the Circuit Index page.

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27 February, 2018