Nova 3 front panel

Fred Cisin cisin at
Fri Jul 22 13:27:10 CDT 2016

On Fri, 22 Jul 2016, Vincent Slyngstad wrote:
>> Somewhere, I have Oshino's write-up about bulb rated voltage and bulb 
>> operating voltage, but I do remember the lifespan varies as some power of 
>> the ratio, and it makes a huge difference.  (There are also formulae for 
>> derating brightness, etc.)
> I found it -- the lifespan varies as the 12th power of the ratio.
> The current varies as the 0.55 power, and the brightness as the 3.5th power 
> (of the reciprocal).
> So, a 12V bulb in a 28V circuit can expect 1/26000 the lifetime, and will 
> take about 1.6X the current to burn about 20X brighter than normal.
> A 28V bulb in a 24V circuit would last about 6.3X it's rated lifetime, take 
> 92% of the rated current, and about 58% as bright.

. . . and that presumably clarifies the "Livermore Firehouse Bulb".

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