How to Bench Test MTH Proto-Couplers

PS1 couplers are basically identical and interchangeable to Lionel couplers electrically- so they are TRACK VOLTAGE- AKA an 18V pulse. In theory, I would say a 12-18V source is fine for testing momentary operation

PS2 and 3 couplers are much lower voltage and so do not power them with that high of a voltage. A 9V battery is a good bench test. 6-9V at most.

A 9V battery may not be enough to test and fire a PS1 coupler, but should fire a PS2/PS3 coupler.

I just use 18V from my bench transformer to test PS/1 or TMCC/Legacy couplers, that's the voltage they operate at.  They actually won't reliably fire at lower than around 14-15 volts.

For PS/2 and PS/3 couplers (same thing), I use 6VDC from a bench supply.  Note that they take a couple of amps to fire, so it needs to be a reasonable supply.

@Vernon Barry and @gunrunnerjohn Thank you guys! I do have a good DC bench power supply which I can use for the PS-2&3 couplers. I can use an extra 18VAC transformer I have to check the PS-1 proto-couplers.

@LOVETJ posted:

@Vernon Barry and @gunrunnerjohn Thank you guys! I do have a good DC bench power supply which I can use for the PS-2&3 couplers. I can use an extra 18VAC transformer I have to check the PS-1 proto-couplers.

Remember, the couplers are designed to only get a brief shot of power, if they don't open immediately when you touch the power, don't hold it on them, it doesn't take more than a few seconds to start melting stuff.