I've used a circuitron snapper for switch machines for over a year. Recently it failed. I've replaced it and the rreplacement also failed. Why? Bypassing the snapper worked but machines were vulnerable & one under the table did melt.
LION tried snapper. It too failed. Him replaced it not. Him has no more twin coils, him is 100% Turtle switch machines.
ROAR
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First thing I'd check was what's the instructions say about the max number of machines operated? May not be an issue, but worth verifying if you don't recall.
How is the Snapper failing? If it's the caps melting down, these are usually easy to replace. I've never needed a CDU, but that seems like a common failure point with other electronics and it would seem to be a potential issue for a CDU.
Mike Lehman
Urbana, IL
The Electrolytic capacitors in CDUs can dry up and not provide the burst of current needed to throw the solenoids in twin coil switch machines. If the new one you bought was old stock, the Caps may have dried up a bit and a few discharges finished them off. New capacitors from a source that rotates their stock is the best fix I can think of. Try connecting up an automobile tail light instead of a turnout motor and see how bright a flash you get.
Alan Jones in Sunny Queensland (Oz)
What filled on the CDU? The full wave bridge, series resistor or the caps?
I made one for a local club some years ago using those components and has yet to fail.
Troubleshoot the device. Very easy. I seriously doubt the cab would fail.
Edit.
Ok, not so easy. I see Circuitron uses an SCR. I would look at the part number and try to order a more robust version and also contact Circuitron. They are in the USA the last I knew and must be aware of this issue.
You should be able to troubleshoot this device with a multimeter.
I have replaced SCR's in the past in different equipment.
Circuitron link.
http://www.circuitron.com/index.htm
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.