Well, every dimmer I've seen in the last
25 years is electronic.
Resisntance dimmers are a thing of the
past .... long, long past.
Modern dimmers use a triac to "chop" the
waveform and they do
produce some heat. Also, when a higher
wattage lamp is dimmed,
the color changes and they become somewhat
less efficient. I don't know exact
numbers, but my guess is that it would
probably cost more to run a dimmed 150
watt lamp to give the same light
output of a 75 wat lamp


kevin wrote:
Hi mm, me again...

Most dimmers (esp the reasonably priced ones) just stick a resistance
in the line. So, they get hot (hence need a little ventilation, esp the
high power ones). This consumes a fair bit of electricity. The smaller
bulb w/ no dimmer is definitely more efficient. I think there are fancy
dimmers that are electronic and chop the phases or something, but these
still won't be 100% efficient.