To get the same color (temperature) you need the same watts/surface
area.  So at double the voltage you make the wire a little thinner and
longer, therefore more fragile.  The problem is physics, not an evil
conspiracy.

I suppose you could make tubular wire to raise the resistance/surface
area, but that would be tough!

Sherpa Doug

> -----Original Message-----
> From: Olin Lathrop [mailto:olin_piclist@EMBEDINC.COM]
> Sent: Thursday, July 05, 2001 8:58 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: [EE]: Bulb Life, X-10 turn-on would seem to up life
>
>
> > For the same wattage, the current is half, so equal to the
> wire size.
>
> I'm not totally clear what you are trying to say, but it is
> harder to make a
> 240V bulb at the same wattage as a 120V bulb.  The 240V bulb
> must have 4
> times the resistance of the 120V bulb to end up with the same
> wattage.  This
> means the bulb manufacturer has two choices, make the
> filament longer or
> thinner.  Thinner makes the filament more fragile and reduces
> bulb life for
> obvious reasons.  Longer spreads the same power over more
> filament, reducing
> its temperature and therefore efficiency, which can be made up for by
> thinning the filament...
>
>
> ********************************************************************
> Olin Lathrop, embedded systems consultant in Littleton Massachusetts
> (978) 742-9014, olin@embedinc.com, http://www.embedinc.com
>
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