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One Channel on CTB-16 will not dim to zero/turn off


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This isn't a new controller.  It worked fine  two years ago, the last time it was used.  This year, one channel will not turn off.  UNLESS, I add a phantom load in the form of a 1W 47 ohm resistor in the circuit.  Same light sets work fine on all other circuits on this controller.  Only channel 3 has the problem.  Does that help any of the hardware gurus out there isolate the problem?

Thanks.  I think I can live with the snubber on the line but would like to correct the controller if there is a problem in there.

Thanks.  Merry Christmas.


Edited by halfast
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Since you didn't tell us, I'm assuming an AC controller as opposed to a DC controller.  However that statement may not be right based on your snubber.  A 47 ohm resistor across 120 volts would draw about 2 1/2 amps, and dissipate over 300 watts - or was that not really 47 ohms?

In any case, assuming it's an AC controller, I would think it's most likely a dying triac.  Since the snubber is taking care of it (at least for now), I would leave it until after the season and then fix it.


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K6CCC, Robongar,

Thanks for the response.  I was thinking that the triac might be the culprit.  It IS an AC controller.   AND, there was a typo on the resistor.  It is a 47K ohm resistor...fat fingers.

Thanks, guys.


Merry Christmas.

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