I'm trying to feed a voltage to my superbright leds. Im not sure how many voltages they require to work(6v?) I have a 12V dc supply from my computer's power supply unit, which i connect to the potentialmeter(500K, 1M). I then tap the voltage and pass it directly to my LED. However, when I connect my multimeter to the LED to check the voltage, some LEDs do not light up, but when I remove the multimeter, the LED lights up. Other LEDs do not face such problem. What is happening here? How then do i measure the voltage? Also, I realise that the LEDS burn out way before they turn bright. Am i doing something wrong?