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RE: - Re: OLD Tubes/Coils (fwd)
nudge, nudge, back to the tesla direction....
Chip
---------- Forwarded message ----------
Date: Sun, 02 Mar 1997 19:20:21 GMT
From: Robert Michaels <robert.michaels-at-online.sme-dot-org>
To: tesla-at-pupman-dot-com
Subject: RE: - Re: OLD Tubes/Coils
T>you said:
T> Under-run the filament somewhat
T> (say 10%) - the life will be greatly increased
T> (I believe filament life goes as the inverse of
T> the =fifth power= of the voltage if I remember
T> correctly [maybe only the =fourth= -- it's
T> a big factor] )
T>[Bill] According to the GE light bulb book, it's the 13th power for lamp
T>filaments (life/rated life to rated volts/applied volts), I don't see why
T>tubes should be different. That makes your case even stronger
Yes, thank you! You're right - the principle are identical.
It's the =brightness= which goes as inverse of the fourth
power.
This is the basis for the so-called "long-life" bulbs sold
in the U.S.: Rather than being designed for 120-volts, they
are designed for 135 or 150 volts. The brightness goes down
somewhat (4th power) but the life increases a whole lot
(13th power).
En -lightened- ly yours,
Robert Michaels