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Optotriac resistor selection

Not if the load current is less than the holding current....................

Reply to
Benderthe.evilrobot
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Gotcha. Thanks for the clarification.

Oh, and you're not alone in looking for a way to switch the HV AC for EL stuff: A search on "use arduino to switch electroluminescent wire AC" turned up:

Switching el wire from Arduino

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Optoisolator with EL wire won't turn off, TRIAC works fine. Why?

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Enjoy...

Frank

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  on public affairs.  For the chief of state under modern conditions, 
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  areas of government to allow solid understanding of any of them, and 
  too little time to think between fifteen-minute appointments and 
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  once penetrated by error, duplicates it forever. 
                         -- Barbara Tuchman / The March of Folly
Reply to
Frnak McKenney

It seems the tricky part of using a TRIAC to accomplish dimming is that it presents a capacitive load, so with the I and V out-of-phase the technique of cutting in the AC voltage some of radians after the zero crossing to reduce the effective RMS voltage (as one would in an old-fashioned incandescent lamp dimmer) doesn't work properly.

Looks a lot of folks accomplish dimming then by modulating the inverter input low voltage, which appears to work but seems like an inefficient and clunky solution. And doesn't let you dim strands independently from the same inverter brick.

So rectify to pulsed DC and MOSFET? Or use some circuit to make the wire look resistive? Or use TRIACs with built in zero-crossing detectors and do some kind of "pulse swallowing" modulation?

Reply to
bitrex

FET inside bridge rectifier or back-to-back fets

Reply to
Lasse Langwadt Christensen

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