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Help with Solid State relay and Neon Indicator Answered

I have a problem using a neon light to indicate when an SSR has switched on. When the neon is connected across the SSR output it lights even though the SSR output is off. There is about 100v on the output, enough to light it. Is there any solution to this. Photo attached.


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Jack A Lopez
Jack A Lopez

1 year ago

Usually a neon indicator lamp wants a fairly large ballast resistor in series with it, like in the range from 10K to 33K, for when it is going to be connected to the mains (110 VAC, or 220 VAC). Also the current that flows through the lamp is small, just a few milliamperes (mA) or so.

Does the lamp in your picture have a built-in, ballast resistor? It is hard for me to see what is inside that little green box.

Maybe it does, or else it would have cooked itself, the first time you connected it across the mains?

I am trying to think what else to try.

One thing might be to wire the input pins together. Those are 3 and 4 in your picture. Then you could be really confident the input voltage was zero. Although, I am not sure how much voltage those input terminals could pick up, just from being left open, flapping in the breeze. Probably just a few 10s of millivolts (mV) or so.