please help explain this power supply

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Thread Starter


Joined Jan 24, 2017
I found this in my led lamp..(Moderator's note: Description of disallowed mains direct to LED / transformerless power supply circuit removed). With this listed components how is it able to achieve an average voltage of around 5v for charging the batteries..#no schematic
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Joined Jan 8, 2017
As you have not traced out the schematic and posted it any answers will only be guessing. My GUESS is that the reactance of the capacitor provides close to a constant current to the bridge rectifier. My GUESS is that the 100 ohm resistor limits the current that would occur if power was applied to the circuit when the input waveform was near it's positive or negative peak. Discussion of this type of power supply is not allowed under the rules of this forum as they are potentially dangerous.



Joined Aug 21, 2008
This thread is doubly disallowed under the User Agreement.

Restricted topics. The following topics are regularly raised however are considered "off-topic" at all times and will result in Your thread being closed without question
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