Rectifying Triac Output

[lhenke]

Hi All,

I've been looking for a circuit design that can rectify the output of a typical household dimmer switch into nice clean 12v DC. The reason I'd like to do this is that I have a light fixture with an incandescent bulb that is perfectly happy to dim with the triac, but I want to run some 12v electronics off the same wire. I took a stab at this but it seems pretty hairy, maybe it just shouldn't be done? I imagine that a dimmable LED bulb contains driver circuitry something like this? Any thoughts would be much appreciated.

 

[Skogsgurra]

A wall-wart is better and safer. Remember that a dimmer usually does't isolate from the grid, so you can easily kill yourself or start a fire.

Your assumption that it shouldnt be done is absolutely right.

There are other issues also - like difficulty to smooth that extremely pulsating voltage. And also avoiding overvoltage that will kill your load when there is interference o the line.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[IRstuff]

There's a reason that dimmable LED and CFL lights are expensive. There's a bit of circuitry involved in getting everything to work right; it's definitely not something for a DIY project.

TTFN
faq731-376

 

[VEBill]

Reading between the lines... You probably need to rewire the room so that you can run a normal 12Vdc output power supply from a normal AC outlet with the normal AC waveform.

If you still need a light dimmer, connect it only to the light fixture.

 

[lhenke]

Thanks for the advice everyone, I'll do a bit of a re-think.