Guys, i'm fairly new to this, but have been lurking for a while :) I have looked all over the place, but don't seem to be able to find a suitable answer!
I have two bags of two-pin 5mm LEDs - no datasheets, no markings. Several are diffused and coloured, so should be easy enough to guess Vf (i.e. Normal Red ~1.8V, Green ~2.2V etc.) But they are mostly clear :?. For the coloured ones, i'll start at the guess voltage, and increment the current with limiting resistor(s) until I get a brightness that i'm happy with (or burn them out!).
Apart from buying a bench supply with precise control over voltage and current, and tweaking the current until I get a sharp difference in brightness, is there a better way to figure out Vf and VMax without testing to destruction?
The only other answer I can think of, is to just chuck them away and buy a load more where I know the properties (and make sure in future I keep them separate and marked).
Any tips or help would be very much appreciated.