Hello all ,

I am intend to use capacitor to get 5ma 5V DC from AC220V power. I know there are many circuits on webisite can be found, but here the difficulty is, I want to connect the GND of 5V DC to GND of main DC(about 340V) so my mcu can control the other high voltage DC circuits,please check my circuit. the problem is, I test the voltage of CV2 and CV3 are very low,seems not charged. could you please give me some tips to make the circuit working ?


Thanks a lot for your help. waiting.........

Best regards,

 

 

Attempting to rectify and use the line voltage directly is only creating a deadly shock hazard. Without transformer isolation, every part of the circuit must be assumed to carry a lethal voltage. The value of you capacitors will only give a desired output for one small range of load resistance, as well.

Using such a circuit will be very dangerous. Anybody coming in contact with any part of it may receive a lethal shock.

You need to use a step down transformer to produce an AC level that can be rectified and regulated to make the 5 volts DC. It is simply too dangerous to try to use your circuit.

 

dangerous problem can be ignored, this is part of circuit for a high voltage device design. people will never have chance to touch it. just like your 110v or 220v power cable, swith and lamps in your room, although they are dangerous too, but you will not consider to use a transformer to change the voltage below 30v first ,right?

 

Just please help me to get the 5ma 5V DC,thanks.

 

It is not a safe circuit to play with, and so violates some of our rules -


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Always use a transformer to reduce line voltage and provide safe isolation.