🚀 go-pugleaf

In article <1992Dec26.063254.23524@murdoch.acc.Virginia.EDU> alexander@kronos.pharm.Virginia.EDU (Robert Alexander) writes:
>In article <72415@cup.portal.com> dbell@cup.portal.com (David J Bell) writes:
>>
>>>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?
>>
>You might look more in the direction of using a full wave
>rectifier and a filter cap. If you take the AC out of it
>completely...It CAN'T ring.

At 120 V 60 Hz, the bulb doesn't make any noise. But with the dimmer
(triac + stuff), it does ring, and not at 60Hz (which wouldn't be bad)
but it rings around 2-3 kHz, which is ANNOYING (since hearing is very acute
around there).

I tried the rectifier, but it doesnt' work with the dimmer/triac in
place. :-( So if I wan't a variable voltage, efficient, solidstate
light dimmer that doesn't make NOISE, I'll have to scrounge for some
decent circuits that filter the harmonics. I'm not a power type guy,
so this might take some experimenting. yet another quick, simple
engineering fix turns into a deep learning experience!

>
>You'll wind up with about 140 volts DC and that through a
>rheostat should work on a standard light bulb ok. (I think).
>
140 VDC? I got 168 VDC out, which is what I'd expect from 120 VAC RMS,
minus diode drops.

>My $.02
>
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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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