Jim Cathey wrote:
LED's are commonly seriously overdriven in multiplexed display operations. Huge current spikes that would fry them if continuous. But they're intermittent, as are the load-dump spikes in an automotive system.
Thats what I think would happen too. If you're lucky enough to have a datasheet for the LEDs there is a continuous and a peak current rating. :)
Either way, 60V?!? I don't know if I believe that happening on most vehicles (ie, you had something freaky going on we don't normally see). The reason I say that is one of the projects at my work is to make an engine speed controller so that an HMMV can be at a high enough RPM to generate a 400A 28VDC (yep, 28V) load. We could switch that load on/off and we never saw any monster spikes like that. No doubt it wasn't a clean 28V, but it wasn't quite that insane!! Maybe you were talking about a more local voltage spike and not one across the battery? I'm still new in engineering land so I'm used to being wrong.. ;) As an aside... the current probes measured nearly 800A peak for the stall current on the starter!!
John '79 300SD
