Capacitive Power Supply 240 Volts A.C to 5.1 Volts D.C.

359

11:55:32

A capacitive power supply (use X2 capacitors) comprises a capacitor, 1.2uF, that with its reactance limits the current flowing through the diode rectifier bridge . To protect against voltage spikes during switching operations, there is a fuse (shown as SPST switch), connected in series with it. An electrolytic capacitor, 470 uF, is used to smooth the DC voltage and the peak current (in the range of amps) in switching operations. The voltage regulator, which is formed by the current limiting resistor, 100 ohms, and the zener shunt regulator, 5.1 Volt.  If the voltage stability is not too important you can use a Zener diode as a regulator, which is a 2 terminal device and would eliminate two resistors for resistive voltage divider (not shown) in the simulation.

published 7 years ago

hurz

7 years ago

470 Ohm is not a Capacitive dropper. I call it resistive dropper

hurz

7 years ago

BTW, this poor resistor has to drop 90Watt

PrathikP

7 years ago

I think you wanted 470k

westelaudio

7 years ago

I think it's supposed to be a 470k as discharge resistor

lmccoig

7 years ago

The schematic was blurred and the 470 k ohm resistor does send more current through the capacitor. Thanks.

hurz

7 years ago

Sure it's 470k Ohm, cuz it's just a bleeding resistor.

smg2006

6 years ago

What if the capacitor fails and shorts?

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