>> so you could put 3 in series on ~ 6.5V supply with no
>> current limiting resistor, makes life simpler (no heat)

There was a discussion on this topic a few months back in a NG. The overall
decision was no current limiting resistor that is a bad idea unless you are
current limiting some other way. The voltage will hover around the forward
voltage (if you're lucky). If you get less than the forward voltage, you get
no light emited. If you get more than the forward voltage, the current can
vary greatly, resulting in frazzled LEDs. Like most components nowadays, the
LEDs will tolerate the abuse for a long while- probably just until the units
are hauled into place at the race track- or until you've sold enough units
to be a real pain in the arse to have to mend....

Ben

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