Ross Herbert wrote:
On Mon, 30 Aug 2004 19:54:14 -0700, "Tofer"
wrote:

Hiya everyone,

I have an interesting one for all of you. My wife does improv comedy
at a local bar in my area. In one of her conversations with the
owner, she mentioned that I was "into" eletronics. He asked her if
she would have me look at two of his televisions that aren't
working.

Generally I shy away from "favors" such as this. But, when she told
me the story of what happened to the TV's I got curious.

Apparently he plugged in the sets on a wall circuit that is on a
dimmer for the overhead lights. Needless to say, the TV's didn't
like that very much when the lights were dimmed. They both now give
that neat "click click click" when turned on.

Now I do work on electronics, but computer based for the most part.
Monitors are very close to televisions and that clicking usually
means the MOSFET is not firing the flyback. Would this be the same
for these televisions?

When initially switched on the power supply sees a light load
momentarily and some devices such as relays will operate even with the
dimmer supplying a fairly low voltage. Once the circuits start to load
down the PSU it just can't supply the required current to keep
everything running and the DC output voltages sag and let the relays
drop out. It may also be that the PSU goes into current limiting mode
and simply switches off and then back on. This can repeat endlessly.

The sets are both Sharp 25K-M100. Any info (or "witty jibes" at
plugging in two TV's on a dimmer circuit) would be appreciated.


Plugging even one TV into a socket controlled by a dimmer is the
dumbest idea I ever heard. What would be the purpose of doing this,
unless it was accidental as appears to be the case here?

I did sound for my daughter's elementry school benefit. They dragged out
their brand new P.A. mixer/amp, plugged it into one channel of the stage
light dimmers and pronounced everything 'set up.'

I raced home to get an extension cord, and a speaker snake so that I could
move the unit at least a few feet out in front of the speakers. The guy who
had plugged it up seemed offended. They 'always did it that way.' Even
though I had shown him the obvious difference in sound when done 'that way,'
he was barely mollified. 'It works' was all he could say. Maybe he
couldn't tell the difference. I suspect they went right back to doing it
'that way' after the event.

BTW, many comments on the 'excellent' sound after the show from the generous
scattering of professionals in the crowd...this 'is' Nashville, after all.

jak


Why isn't the dimmer controlled outlet a different type of socket to
the general purpose ones? This way the TV can't be plugged into a
normal outlet.