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Do you often hear the ringing of switching power supplies and devices when you are in a quiet space? (self.asklemmy)

submitted 7 months ago* (last edited 7 months ago) by j4k3 to c/[email protected]

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I'm curious, how many people are aware of these sounds. I have designed, etched, and built my own switching power supplies along with winding my own transformers. I am aware of the source of the noise. So, does anyone else hear these high frequency sounds regularly?

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[–] Aceticon 2 points 7 months ago* (last edited 7 months ago)

I don't think there are any half-wave rectifiers used for those things since the 4 diodes needed for a bridge rectifier are cheap and you can even get the whole bridge as just one package.

The difference is mainly on how much that abs(sin()) wave remains untouched or not.

There are really good AC-DC conversion methods that will output a very steady DC voltage with very low voltage ripple, but from what I've seen cheap LED lights just have a bridge rectifier, a big capacitor, enough led filaments/chips in series to have a large combined voltage drop and a resistor to limit the current, so the LEDs still see a ton of voltage oscillation (transformed into a current oscillation by the resistor that's mean the limit the current, which is what affects LED brightness) hence the flickering.