On Jan 27, 8:34 am, "Edwin Pawlowski" wrote:
"Bob" wrote in ...

I installed sixteen dimmer switches around the house, for various purposes.
Don't have any problems at all, but am curious.

When a dimmer switch is turned down so the light is not as bright, does
this
save electricity or does the dimmer switch disperse the voltage drop in
heat?

Thanks for the info. BobThey do save, but not directly proportional to the voltage drop. Your bulbs
will last longer also since they are not operating at full temperature.


The type of dimmers under discussion are semiconductor based, using
Triacs. They are not variable resistor based, which would just
dissipate the energy that is not going to the lights, producing no
energy savings. The Triacs work instead by delaying turning on the
output voltage for part of the 60Hz sine wave, essentially chopping
off varying portions of the leading edge. That chopping action,
which turns a nice sine wave into something with a fast rising edge,
is also what produces RF intereference that is common with these.
There is of course some energy lost as heat in the dimmer, so they are
not 100% efficient, as you can tell by touching one. But a light
dimmed with one of these does save a substantial amount of energy.