On Sat, 6 Apr 1996, terogers wrote:

> DC offset contributes to uneven emission of from the filament and early
> failure. In heaters (this started as a heater controller) there is the
> added detriment of uneven power distribution. (This from our heater
> manufacturer's engineer; we called him to discuss an observed uneven
> temperature distribution).

It will also make the transformers feeding you your power rather unhappy
if, as might easily be the case for high-power loads like heaters or
theatrical lighting, this assymetrical load were a large fraction of the
total branch load.  Imagine a dimly-lit scene with a great many lamps all
pulling a single half-cycle every couple cycles - the same half-cycle if
they're all controlled by a single controller that doesn't take pains
to avoid such synchrony.  I can almost hear the oil in the transformer
bubbling from here...  :-)