Here Is A Better Switch Machine Driver Circuit

Twin Coil Switch Machine Driver Circuit

For: Atlas, Pico & Bachmann Switch Machines

  The Twin Coil Switch Machine Driver Circuit allows toggle switches to control Twin Coil switch machine motors that have separate or common connected coils.

  The handle of the toggle switch can 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 5 seconds or less

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

Twin Coil Driver Circuit Information

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

Twin Coil Switch Machine Driver Circuit Notes

Wiring The DPDT Toggle Switch

Twin Coil Switch Machine Circuit Examples

  The next schematic shows the 5 driver circuit board schematic and examples of switch machine circuits.

Another example circuit Multiple Location Control For Twin 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 - 1N4001 Diode 1N4001FSCT-ND
R1, 2 - 2.2K OHM 1/4W Resistor 2.2KQBK-ND
R3, 4 - 1K OHM 1/2W Resistor 1.0KH-ND
C1, 2 - 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

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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