Capacitor Discharge Unit
with SPDT Switch

Capacitor Discharge Unit using SPDT switch kit is available from
Talking Electronics for $13.50 plus $6.50 postage. 
Click HERE  to buy kit.



Talking Electronics has produced a Capacitor Discharge Unit controlled by a standard toggle switch.
See the wiring diagram below to connect the switch, point motor and power to the PC board.
This project puts no load on your power supply and prevents the point motor burning out.
The board also has indicator LEDs to show the position of the points.

PCB overlay and trackwork

All the components fit on the PC board and the project comes with 2 x 1,000u electrolytics. If your supply is less than 12v - 15v AC, you will need 2 x 2,200u - if your supply is say 12v to 14v DC.

All the parts fit neatly on the PC board.
The transistors, diodes, electrolytics and LEDs are identified above and the diagrams show how they are fitted to the board.
The screw terminals allow the board to be easily connected to your power supply via leads into the 2-connector block and the point motor as well as the switch, without the need for any additional soldering.
You can use a PECO PL-23 switch, but a toggle switch is MUCH cheaper.


$13.50 plus $6.50 postage. 
 HERE to buy kit

1 - 100R
1 - 330R
3 - 1k
2 - 2k2
2 - 4k7

2 - 10u 25v electrolytics
1 - 100u 25v electrolytic
2 - 1,000u 25v - 35v. (see text for 2,200u)
4 - 1N 4004 diodes
3 - 3mm red LEDs
2 - BD 679 Darlington transistors

1  -  2-Connector terminal strip
2  -  3-Connector terminal strip

1 - Capacitor Discharge Unit (using switch)        PC Board

Extras: You can get 2 x 2,200 electrolytics in place of the 2 x 1,000u for $3.00 extra

Extras - not in kit:
1  -  SPDT toggle switch
1  -  Point Motor