i have some normal 1210 size Chinese bog standard white smd Led's, i cant seem to measure the vf on them, i have tried my normal 2 ways 1 using diode thingy on DMM but that just reads OL and lights the led very very dimly, then i tried the setting psu to max I 20mA 5V and then i normaly subtract the voltage reading from 5V to get the vf, but that isnt working!! all the sheets i have seen say they should be about 3V but these must be under 1V ????
any ideas? as i need to run these at around 25mA
any ideas? as i need to run these at around 25mA