This circuit is a power supply for single and twin coil, solenoid type switch machines. The circuit uses two capacitors that are common to all switch machines and a one capacitor for each switch machine.
The switch machine are controlled by SPDT and DPDT toggle switches. The handle of the switch cam be used to indicate the routing of the turnout and LEDs can also be used as route indicators.
The circuit board can supply up to eight switch machines. Two machines at a crossover could be powered from one circuit.
2,200uF/25V capacitors are adequate for most twin coil machines and the RailCrew single coil machines.
1,000uF/25V capacitors can be used for switch machines made by KATO.
This circuit board requires a separate DC power source to charge the capacitors. The power source should be in the 12 to 18 volt range with an output current rating of at least 1 amp. Using a power source with a voltage rating at the higher end of the range will supply more power to throw the switch machines. Multiple circuit switch machine boards can be supplied from one power source.
The following are a few example circuits for use with the circuit board available on this page.
The circuit board can be used with the circuits on these pages.
|QTY||DESCRIPTION||DigiKey Part #|
|6||2 Position Terminal Block - 3.5mm||ED2635-ND|
|10||2,200uF 25V Miniature Aluminum Electrolytic||P5157-ND|
|10||1,000uF 25V Miniature Aluminum Electrolytic||P5156-ND|
Capacitor values can be mixed if needed.
A printed circuit board and parts ar available for this circuit. There are 8 switch machine drivers on each board.
The following is an image of the circuit board which is 1.9 inches by 3.0 inches and is drilled to fit terminal blocks with a 3.5mm pin spacing.
The board has been commercially made and is tinned. The NORMAL (N) and REVERSE (R) terminals are marked on its copper side.
Switch Machine Power Supply circuit boards only:
11.00 dollars US each for 1 or 2 circuit boards.
10.00 dollars US for each additional circuit board.
Assembled - Switch Machine Power Supply circuit boards with all parts:
22.00 dollars US each for 1,000uF capacitors and circuit board.
25.00 dollars US each for 2,200uF capacitors and circuit board.
Kit - Switch Machine Power Supply circuit boards with all parts except the terminal blocks:
20.00 dollars US each for 1 or 2 circuit boards.
23.00 dollars US for each additional circuit board.
If you are interested in printed circuit boards please send an email to the following address: firstname.lastname@example.org Subject: Common Capacitor Switch Machine Power Supply
Your message will be answered as soon as possible.
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.
10 April, 2019