TKM wrote:
"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'm aware of that. In the TV repair business we used something
called a glowbar or globar, it was used in the picture tube
degaussing circuit often in pairs, one with a PTC the other
NTC. I have hard wired thermistors in series with lamp sockets
in the past and a regular light bulb seemed to last forever.
I really don't like putting things in the socket itself because
of, as you pointed, the heat. You can also buy industrial light
bulbs that are rated for 130 volts. The light output will be a
little lower than a household bulb but the lamps will last much
longer.

TDD