Wiring for a signal light

Model Railroader Electronics and DCC
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wiring
wiring480×640 114 KB

Picked this up cheap at a swap meet. It has four wires, two reds and two greens. It looks like the diagram is suggesting I join each pair of red and green wires together to create two leads going to the AC source. Can that be right? And if it is, does it matter which pair goes to negative and which set goes to positive?

Thanks for any help.

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That looks like a ‘vintage’ pre-LED signal. probably has a red and green tinted 14V. incandescent grain of wheat bulb in there.
With the wiring shown you will have both bulbs lit continuously. If your source is AC there is no positive or negative.

You could wire a single pole double throw switch on one side of the leads to give you red OR green lamps illuminated.

Good Luck, Ed

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@gmpullman Ed, thanks for that idea. I’ll do that but first I need an answer to my question. Am I to join red-green on each side? I don’t want to blow the bulbs.

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Yes, you would join red/green on one leg and red/green on the other leg. Both lamps in parallel.
Check first with a 1.5 volt battery, if you see a faint glow from the filaments you’re OK, then move up to a 9V battery. They should be fairly bright.

The AC outputs of some ‘toy’ train transformers can be 16 to 18 volts sometimes. You’re probably better off to use a 12 volt regulated wall wart. Running 14 to 16 volt lamps on 12 volts will extend the life of the lamps. Plus signals shouldn’t be too bright anyway.

Regards, Ed

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@gmpullman Thanks Ed. That’s helpful. I have some other non-LED lights on a wall wart and they work great, not too bright. I suppose I could just run some wires to the buss running off that wall wart, and interrupt one side with the STDP.