On 2016-Jul-22, at 11:00 AM, Vincent Slyngstad wrote: > From: Vincent Slyngstad: Friday, July 22, 2016 10:39 AM >> 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.
Nice to see the data & math on that.
