On Wed 08 Oct 2008 08:15:36p, TKM told us...


"The Daring Dufas" wrote in message
...
N8N wrote:
On Oct 6, 12:43 am, Jeff Wisnia wrote:
Thomas G. Marshall wrote:
I have a 100W globe style bulb attached to a simple 2-way dimmer.
The thing
(the bulb) buzzes like crazy on anything other than full on and full
off.
You can even see the filament flapping in the inert breeze.
Is there no way to fully remove this buzzing? I know a little about
the
higher speed switching techniques involved, and I also know about
the wave
deforming that some do. But is there not something foolproof?
Seems like
something that should have been solved by now.
Thanks
Maybe a heavy duty bulb, which has additional filament supports in
it, would be quieter?

You could always add a bridge rectifier and filter cap to the
dimmer's output so the bulb runs on DC. G

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.98*10^14 fathoms per fortnight.

ISTR that maybe 30 years ago there were sold these little buttons that
you were supposed to stick on the bottom of your light bulbs to make
them last longer. they also made the bulbs a little dimmer. I don't
know if they just dropped the voltage or also rectified it. I was
just a little kid at the time so my memory is a little furry. I
couldnt find anything on a web search, anyone remember what I am
thinking of? (I don't know that they really did a whole heck of a
lot...)

nate

Back in the 1980 I had a business partner who's
brother in law tried to get us to sell them for
him. It was a disk that dropped into a regular
Edison 120vac lamp socket. It was just a rectifier,
a simple rectifier that supplied pulsed DC to
the bulb. It was called a Power Saver and the bulb
did light up a bit dimmer.

TDD

There were (are?) two types of socket "buttons". One type uses a diode;
the other a thermistor. The diode type cuts the power to the lamp by 1/2
which translates to a light output reduction of 2/3. Lamp life is long
to indefinite. The lamp also flickers more and that bothers some people.

The thermistor button starts the lamp at a low voltage when the switch
is turned on. Then it ramps the voltage up relatively slowly which some
say lengthens lamp life. But there's also a few volts drop across the
button so the lamp doesn't see the full socket voltage and that
lengthens lamp life too. A problem, however, is the thermistor itself.
It's a resistor and so generates heat in the socket. Sockets are
designed for heat from the lamp; but may not be able to handle the extra
heat from the resistor.

TKM

I had some of these years ago, but I don't know which type. The only
problem I had was that by the time the bulb eventually did burn out, the
little button was also no good...would not work with another bulb.

The light was a bit dimmer, but that was one of things I wanted. I never
noticed if the socket was hotter with the button.

--
Wayne Boatwright
(correct the spelling of "geemail" to reply)

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