DIYbanter - View Single Post - Using varying 5VDC signal to control voltage on 110VAC circuit

(Larry) wrote in message om...

I
would much rather use this varying current to ... dim my 75W, 110VAC
desk lamp [it's a long story]. So I figure there's got to be
something like a dimmer switch that, instead of being controlled by a
knob, is controlled by varying voltage. Can anybody help?

You can use a small 6.0 V (5.0V) lamp and light couple it to a Photo Cell
with heat srink tubeing,tape ect.
Open up a cheep 120.0VAC light dimmer and connect the photo Cell only across
the the 2 used (soldered connections) of the pot.
This way you are isolated from computer to lamp dimmer.

That's a good idea. What should I look for in the photo cell? Should
I try to match its resistance range to that of the pot? And are you
suggesting that I replace the pot with the photo cell, or connect it
in parallel? [Sorry if these are dumb questions; I want to be certain
before I go blowing things up.]

- Dave