Are "Contractor Bulbs", them really cheap
bulbs, you get with new light fittings,
these days, we have had a real problem
from these over here in NZ, mainly in
cheap imported (China)linear-type tungsten-
halogen outdoor fittings, we nowadays, throw
the lamp out, that comes with these fittings,
because their life is measured in minutes,
not the 1000-2000hours that they are quoted
as lasting.
Just a short note, on the dimmers, however,
the Triac and Diac in a light dimmer,
require pretty much a perfect sine-wave to
operate correctly, if there are any DC or
Harmonic components in the supply, feeding
them, this can upset their output, quite
appreciably.
When light dimmers first came out over here,
they had a whopping great wire-wound rheostat
as a series voltage dropper resistor, and
these used to hum like crazy, especially
when the lamps were dimmed down low.
Thank God they are gone now, they were
terribly in-efficient(with heat loss) and
to a certain extent they were a fire risk
if the lamps were kept dimmed for long
periods.
