this post was submitted on 19 Jul 2023
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So LEDs are generally very bright by default, and there's a limit to how much you can really dim that. The solution used is often to flicker the LED at high speed, imperceptible to human eyes, called Pulse Width Modulation (PWM). Basically, by changing the percentage of time the LED is on (the width of the ON pulse) you change the perceived brightness off the light.
Cheap LED designs do this slower, cause the hardware and LEDs are cheaper. It's not really to save energy, but to adjust brightness and manage heat.
Also, probably more importantly, cheap LED bulb designs just don't deal with AC current as well, so you get the 60Hz flicker from the electrical line cause that doesn't get regulated out correctly when converting to DC.