LED light panel Dc supply help

Discussion in 'The Projects Forum' started by ericval_78, Feb 20, 2013.

  1. ericval_78

    Thread Starter New Member

    Feb 20, 2013
    I am designing an LED light panel with 80 diodes at 4 v power drop and 20 ma forward current + 180 diodes at 3 v and 20 ma. I am not sure where to go from here to figure out what driver or power converter to use to power up my light panel. Can someone direct me on how I calculate this?
  2. bertus


    Apr 5, 2008

    What will be the voltage of the used power supply?
    You can calculate the needed resistor with the following formula:
    R = (Vsupply - Vled) / Iled
    Vled may be the summation of a couple of leds in series.
    For safety the voltage accross the resistor must be at least 2 Volts, for better regulation.

    Bill_Marsden has written a nice thread for the use of leds:
    .LEDs, 555s, Flashers, and Light Chasers