Here Is A Better Switch Machine Driver Circuit

Single Coil Switch Machine Driver Circuit

For: Kato & Rapido Railcrew Machines

  The Single Coil Switch Machine Driver Circuit allows a DPDT toggle switch to control a Kato single coil switch machine motor.

  The handle of the toggle switch can be used to indicate the selected route through the turnout.

  The circuit can also control LEDs that indicate the selected route. The LEDs turn off instantly when the toggle switch is thrown.

  Using the parts values shown below, a turnout can be reversed in about 3 seconds or less.

  This circuit board can also be used to drive Twin Coil Switch machines.

Single Coil Driver Circuit Information

  The next diagram show the basic circuit for the Single Coil Switch Machine Driver. Each printed circuit board has 5 switch machine driver circuits on it.

Single Coil Switch Machine Driver Circuit Notes

Wiring The DPDT Toggle Switch

  The toggle switch is similar to a DPDT polarity reversing switch but has one of the cross jumpers omitted and replaced by as second supply point.

Single Coil Switch Machine Circuit Examples

  The next schematic shows the 5 driver circuit board schematic and examples of the switch machine circuit showing both positions of the toggle switch with arrows indicate the direction of current flow in both states.

  Also shown is a connection for crossover turnouts.

Another example circuit Multiple Location Control For Single Coil Switch Machines

Controlling Relays

  The next diagram shows a 12 volt relay connected to the circuit. The relay could be used to control frog or block power if needed.

PCB Parts List

  The following is a suggested parts list for the Single Coil Switch Machine Driver's circuit board. Resistor values can be change so that the circuit uses less current when idle, see information above for details.

Part Qty. Description DigiKey Part #
D1, 2, 3, 4 10 1N4001 Diode 1N4001FSCT-ND
R1, 2 10 2.2K OHM 1/4W Resistor 2.2KQBK-ND
R3, 4 10 1K OHM 1/2W Resistor 1.0KH-ND
C1, 2 10 1,000uF 25V Aluminum Electrolytic P5156-ND

Part Qty. Larger Capacitors If Needed DigiKey Part #
C1, 2 2 Per Driver 2,200uF 25V Aluminum Electrolytic P5157-ND

  Anti-Ringing Diodes are not required for this circuit.

  T42-1 Push-In Terminals Push-In Terminals can be substituted for the terminal blocks or wires can be soldered directly to the circuit board to reduce costs if desired.

  For other information on other Capacitor Discharge type switch machine power supplies see: Basic Capacitor Discharge - switch machine power supplies.

Resistance, Capacitance, Voltage And Charging Time Calculator

User Built - Single Coil Switch Machine Test Circuit Video

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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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20 March, 2018