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irreligiosity OP t1_ixf8oxo wrote

Reply to comment by ntyperteasy in How can I trigger a string of PWM RGB LEDs using a solid state relay without introducing resistance and significantly dimming the LEDs ? by irreligiosity

FWIW, I also asked in the electrical engineering sub-reddit, but they have less traffic. I figured it is still technically a DIY question as I have no EE experience outside of DIY.

I was under the impression (maybe mistakenly) that I was able to get around the relay voltage drop by using the Mosfet. I had hooked up the gate pin to the output of the relay, the source pin to the PWM source and the drain pin to the LEDs. I guess I thought once the FET was open, the voltage would flow through it as if the relay wasn't even there.

I'm mostly just trying to solve this problem with things I have on hand because I've spent too much this year switching over to addressable pixel LEDs. I know I can technically buy a dmx receiver that outputs PWM for LEDs, but I'd unfortunately need several for different voltage strands.

Thanks for the help though.

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ntyperteasy t1_ixfcnbh wrote

Do you need to switch fast? Why not just a cheap mechanical relay? The voltage drop should be vanishingly small. Should be good for a year or two... And assuming your PWM is around 100 Hz, most AC rated relays should be ok with that. It's not RF....

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irreligiosity OP t1_ixfd9ok wrote

That didn't even occur to me, I have a bunch of SPDT relays. I just went and tested it and it works great. Thanks for the help.

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