Some of those electronic light switches that are for
incandescent bulbs only use a SCR instead of a triac so the bulb runs
on half-wave pulsating DC.  If they do that in the circuit, there is
the other half-cycle of AC that is un-touched and will be at about the
same voltage no matter if the light is on or off.  The bulb will burn
at a slightly lower brightness because the over all energy level is
.707 times the RMS level, but it will basically work normally.

        You might even see some flicker at 60 or even a little more at
50 HZ.  Hook that up to a fluorescent tube ballast and you may see the
flicker of flames unless the SCR burns out instantly and shorts at
which time your fluorescent lamp will be perpetually on.

        In other words, "no inductive loads" really means just that.

        While this is slightly off of the topic, I remember my days as
an audio visual technician in the eighties in which we had a brand of
overhead projector that, for some strange reason, used a bulb in
series with a diode.  Occasionally, one of these would come in after
the customer would have blown two or three $20 bulbs in quick
succession and caught on to the fact that something else was wrong.
We would check the diode and find it shorted such that the 85-volt
bulb was now getting the full 120 volts full-wave.  I never understood
the engineering logic behind that design rather than just putting a
120-volt bulb in the socket like everybody else did.

        The other half-cycle, BTW, was just wasted except to drive the
cooling fan.  There was no electronics other than that stupid diode.
I bet the bulb manufacturers came up with that design to sell more
bulbs.:-)

Martin McCormick WB5AGZ  Stillwater, OK
OSU Information Technology Division Network Operations Group

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics