🚀 go-pugleaf

Since I don't spend most of my life browsing the home electrical sections,
I just noticed that some light dimmers claim to be RFI free. I assume
they are using a zero voltage switch, to suppress transients.
(zero voltage = zero crossing detector, to fire the triac when the line
voltage is off (0 VAC), instead of firing the triac mid cycle (that's why
normal switches arc))

Now, people on the net are going to wonder why I'm obsessed with dimmers!
But a light dimmer I have installed makes the lightbulb RING alot, and
it's very annoying. The ringing gets worse when you dim the light. I'm
wondering if a "RFI free" dimmer will reduce this ringing. Anyone know?
(I took mine apart, and it's just a triac and some passive things, and 
a couple diodes; no hint of anything fancier).

(I tried suppressing the high frequencies with a 20 uF, 440V cap in parallel,
but the triac didn't exactly like firing with a leading pf...sort of dim
with buzzing going all the way back to the breaker. BTW kids, don't try
this at home, unless you have an oil filled Sprague 440V 60Hz capacitor
to play with on the AC line. This reminds me, I've been meaning to
"reduce" my electricty bill ..... :-)



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 John Paul Morrison                     |  
 University of British Columbia, Canada |  
 Electrical Engineering                 |   .sig file without a cause
 jmorriso@ee.ubc.ca              VE7JPM |  
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