🚀 go-pugleaf

>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))

Yep...

>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'm afraid the half-cycle pulses would still tend to induce the
ringing. I've also noticed this with dimmers, and wish I could 
eliminate it! Consider also the effect of reducing the RMS output
to, say 10%, by limiting the power to full half-cycles. I would
expect a *great* deal of flicker...

Dave
dbell@cup.portal.com