Model Railway Point Control Switch with Indicator and Frog Switching - Code: RK-PSWI

This is a direct control switch (momentary action - centre off) for twin coil point motors such as Peco, Hornby, Seep or similar. In addition to simply switching power to the point motor coils, the unit provides an indication of the last switch operation, and a set of contacts which can be used for frog power switching, Built in diodes absorb switching surges. Two or more units may control one set of points (e.g. for control from different locations) in which case each will indicate the last switching action.

Advantages of this system
  • Full power to coils ensures best reliability of operation.
  • LEDs indicate the last operation of the control switch.
  • Relay contact outputs to switch frog power.
  • Multiple PSWI units in different physical locations, will each indicate the last operation.
  • Built in diodes absorb switch off surges from motor coils.
  • Can be panel mounted to represent the layout schematic, and be made up with different coloured LEDs.
Disadvantages of the system.
  • High operating current for the motor coils needs relatively heavy wires between supply, switch and motor.
  • Needs a heavier power supply (typically 3 amp or better,) or a capacitor discharge supply. (See below.)

Current draw per unit
Indicating mode - 12V input                 Less than 80mA.
During operation - 12V Coil input         Depends on coil resistance

Capacitor Discharge Supply. Code: RK-CDS

Operating twin coil point motors directly requires a power supply of around 3 amps or so (or more if several pointmotors are to be operated at the same time.) A capacitor discharge supply can provide power to operate these point motors when a basic power supply of only an amp or so is available. In addition, a capacitor discharge supply drastically reduces the possibility of burning out point motors by energising coils for too long.

This unit provides plenty of power (from a massive 30000uF capacitor bank) for use with Peco, Hornby, Seep or similar twin coil point motors. LEDs indicators are red for a valid 12 volt DC supply, and green to show when the unit is ready (recharged to approximately 10.5 volts.)

One of these units can supply any number of point motors, provided the unit is allowed to recharge between each operation of a point motor. It makes the ideal companion for multiple PSWI units (see above, and the diagram at right.)

The amount of current drawn by the unit when charging is jumper selectable. Maximum current provides the shortest recharge time, but current should be selected to match what is available from the powr supply. On the 380mA setting, 98% charge is recovered in 3.7 seconds while on the 680mA setting, charge recovery is 2.1 seconds. Once the unit is charged, current draw drops to approximately 30mA.

Kit price for           RK-PSWI: $19-50           RK-CDS: $24-50

Click here to go to Aztronics web site

All kits available from :
Aztronics Pty Ltd       Phone 8212 6212
170 Sturt St,                     Fax 8212 4212
Adelaide, SA, 5000.                                

Information:         David Crosby

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Last updated 3rd February, 2017.
(C) D. Crosby, March, 2011.