[Amps] General question on filament life: comments

[Gary Schafer]

> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
> Behalf Of Steve Thompson
> Sent: Sunday, February 11, 2007 6:36 PM
> To: amps at contesting.com
> Subject: Re: [Amps] General question on filament life: comments
> 
> 
> 
> TexasRF at aol.com wrote:
> >
> > Wonder if any study has been given to the life of these lamps when the
> turn
> > on current is limited. In other words, would the "about ready to fail"
> time be
> >  increased by providing some turn on current limiting protection? Maybe
> the
> > turn  on cycles wears the lamp out more than the actual on hours?
> I'm sure I recall a piece by Bob Pease of NatSemi in his 'Pease
> Porridge' column in Electronic Design where he talked about adding surge
> limiter thermistors to lighting circuits and extending bulb life
> enormously. I miss that column a lot these days. I can't remember ever
> changing a bulb that's on a dimmer where it's always wound up from zero.
> 
> Steve

I have dimmers on lots of lights in my house and it seems I replace a light
bulb at least once a month on those circuits. They seem to go bad while they
are on. I can hear them making a rather loud hum when they are about to fail
(probably the sound is generated from the chopping of the dimmer). When in
this condition of making noise, if the light is turned off and back on it
immediately fails upon turn on.

73
Gary  K4FMX