So... I've been replacing fluorescent tubes with LEDs, and I have a relatively simple question that came up as I dissect some of the tubes that have stopped working.
The tubes I have are rated 14W, contain 4 parallel chains of 28 ~3V white LEDs, and have simple electronics - a bridge rectifier, filter, and some current limiting resistors. Presumably the bulk of the current limiting is supposed to happen in the fluorescent ballast that you're supposed to leave in.
So each LED should be running at approx 14/(28*4) = 0.125W, or about 40mA. That seems ... very reasonable; I thought consumer LED lamps regularly overdrive the LEDs? Am I missing something?
(the LEDs are all mounted on a thin, single-sided glass/epoxy PCB, which slides into an aluminum channel. So while it's not very well attached, there is some heat-sinking as well.)
(At least one of the failed lamps seems to have had the failure mode of the current-limiting resistors heating up enough to de-solder themselves (assuming I didn't break them during disassembly.) :-( )