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A comment on LEDs may cause retinal toxicity at occupational domestic illuminance. Parent comment

Re:LEDs may cause retinal toxicity at occupational domestic ... by gubby on Friday January 06, 2017 @03:28AM (#13334754)
Not sure this makes sense, when you PWM something like an LED, there is no 'leftover DC power'; the energy unused by the LED each cycle is not wasted.
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Re:LEDs may cause retinal toxicity at occupational domestic ... by lightedman on Friday January 06, 2017 @10:50AM (#13337186)
Yes, there is "leftover DC power" as a diode only allows power in one direction and whatever is left after the LED voltage drop is rectified DC. If I put 12V of LED on a 120V leg, I'll have 108VDC rectified left over after the LEDs take their voltage drop. If no other device uses that power, it just gets dumped out to ground, but it's still unused DC power.

That's not PWM in the video. That's raw mains frequency.

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