yaghoubi
Junior Member level 3
hello
there are 6 power LEDs in series and 24vdc power supply.I used the attached circuit but the current is not constant(when the LEDs get warm , the current increases)
[when I increase power supply in 20VDC the circuit sinks 370ma and the LEDs sink 350ma[after one minute the leds sink 380ma.lm317 can not limit the current] .when I increase the power supply to 24VDC the leds sink 800ma (after one minute the leds sink more current.lm317 can not limit the current)].
I read this link but it didn't help me https://www.edaboard.com/threads/201189/
there are 6 power LEDs in series and 24vdc power supply.I used the attached circuit but the current is not constant(when the LEDs get warm , the current increases)
[when I increase power supply in 20VDC the circuit sinks 370ma and the LEDs sink 350ma[after one minute the leds sink 380ma.lm317 can not limit the current] .when I increase the power supply to 24VDC the leds sink 800ma (after one minute the leds sink more current.lm317 can not limit the current)].
I read this link but it didn't help me https://www.edaboard.com/threads/201189/