Cutting the diode on my AM466 did the trick of preventing the flickering flourescent. I'm not concerned with local control.
However, I can report that there is no way to avoid a flickering flourescent when using the AM465 (lamp module) due to the bias requirements for proper operation of the triac in the module (unless maybe using a parallel incandescent bulb is enough to bypass the trickle current away from the flourescent). So, cutting the diode in that module only, and completely, disables local control feedback. No mod on a AM465 could possibly prevent a flourescent from flickering, unless you introduce a relay (as with the AM466 and AM468).
In looking at the diagram for the AM486 (
http://www.laureanno.com), it is apparent that there is still some trickle current available even after cutting the diode due to the input circuitry to the sense input of the IC, but this small amount seems to be insufficient to cause a flourescent to flicker (at least not mine). To completely disable local control you would have to cut the 330K ohm resistor (the one identified to be removed for momentary operation).
Interestingly enough, in my application, if the trickle diode (IN4004) isn't cut, when the AM466 is told to turn off the light, the amount of trickle current present is enough to tell the module to turn the lamp back on. How's that for frustrating?
By the way, in the case of flourescent lights, as I understand it, when the diode is intact, flickering after the light is turned off is caused by the gas in the bulb still being warm enough to fire from that little amount of trickle current needed by the sensing circuitry. When the gas fires, this changes the bias in the sensing circuity, but, as in the case of the AM465, not enough to fool the circuitry into thinking the bulb has been turned on locally. The AM468 circuitry is different enough that the trickle current allowed by the CFL (that I am using) actually generates a bias sufficiently large enough to make the sense input think the bulb has been turned on locally and hence the IC reinforces the issue by firing the triac. Back to the AM465. The current through the bulb is not enough to sustain the gas being fired, so it turns off again. Being still warm, the gas fires again. And so on. Hence the flicker. As the builb cools off, presuming the flickering is not intense enough to keep the gas warm, the flickering eventually stops (it may take hours). If there is a heat source anywhere near the bulb, this will add the degree and duration of the flicker. In my case, my 18" CFL's are mounted on top of a TV set (makes for very good background lighting when on).
So if your CFLs do not turn back on by themselves like mine do (with the AM466 or AM468), then you are fortunate. Like I said, cutting the IN4004 did the trick for me.
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Topic: Flickering Fluorescent Light (Read 58004 times)