Member #652817

Member Since: February 21, 2015

Country: United States

  • Oh come on guys, don't you know how to find out the specs of an LED? build an LM 317 variable constant current driver (you need only a small 2K Pot, 47 ohm resistor and a 317).

    put the pot and resistor in series and connect one end of this to the 317's output and the other end to the ADJ pin. connect the LED+ to the ADJ pin through a multimeter set to measure milliamps, connect the LED- to supply-, turn the pot for max resistance,

    power it up with 5V on the 317's input.

    now the led will glow dimly and the meter will read less than a milliamp. slowly turn down the pot while watching the LED which should slowly increase brightness as you're doing this. At one point, the LED's brightness will suddenly drop. stop turning the pot and back up until it's growing at max brightness again. now check the meter; this is the maximum current that LED can take.

    now disconnect the meter and connect the led directly to your CC supply and measure the voltage across it, this is the max voltage the LED can take. good luck :)

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