Scott M. Thomas wrote:
>
> Sorry if I missed this, but how much will this increase the life of the
> bulb?
>
> -----Original Message-----

> Hi Mike, the idea is to drop 5% of the mains
> voltage across the series resistor and 95%
> across the bulb. 8% is even better.


Hi Scott, I have seen some bulbs do 5+ years.
Again re the previous list discussion, the 120vac
countries get much less bulb failure due to the
4x power cold starting you get with 240vac countries.
I see normal bulbs fail within weeks.

Mine always blow on cold starting, they make a loud
"pink!" sound. We commonly see 250vac on our mains, that
is a worst case cold start of 355v peak on a 60watt
filament (measured at) 60 ohms cold, about 2kW on that
tiny little piece of wire...

There was some interesting views here before about
using an NTC thermistor, and maybe a small resistor,
in series with the bulb. I would like to play around
with this, I have a heap of 3 leg thermistors from TV
sets which have a NTC and PTC thermistor inside, and
rated for 240v at high currents. :o)

I would also like to see the white LED lighting topic
explored further, high initial costs don't bother me
if it gives power savings over 20 years. I'm using
stuff now that I built 20 years ago.
-Roman

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads