Transformerless 220VAC to 12VDC 100mA Power supply

Post date: Jan 10, 2016 2:59:1 PM

Another transformer-less power supply 12VDC. I was not successful on my last attempt of making a Transformerless 220VAC to 12VDC 30mA Power supply i never manage to get 12 VDC but instead i have 82VDC. Probably something wrong in the value of the ceramic capacitor that i got online or the schematic is wrong. anyway digging a bit more on the net o found this one which is rated for 100ma 12VDC with a zener to do a kind of regulation.

Components:

• Capacitor 225K/400V

• Capacitor 470 μF 100V

• Resistor 470KΩ 1W

• Resistor 100Ω 1W

• Resisitor 220 Ω 1W

• diode type 1N4007

• Diode Zener 15V 1W

• Load Optional: 1 led and resistor according to led power

note: the load should not exceed 100ma...

Schematic:

Prototype:

Output:

Conclusion:

As you can see the output is quite dirty but it produce a kind of DC.

For my prototype i can't find any 225K/400V capacitor. I only manage to find 105K/400V so i put 2 in parallel to make a 2 μF instead of 2.2 μF. Same thing for the zener i didn't find any 15V/1W and instead i use a 16V/1W zener diode.

The circuit produce a dirty 16VDC which is enough to drive some LED or for my future project of safety stair case light.

I notice that the resistor R3 220 Ω 1W is over heating quite lot, probably because of the 2μF capacitor instead of the 2.2 μF. I have ordered 2W resistor to be on the safe side and i have finally found online from Central electronic from bandung (West Java) the 225K/400V capacitor.

I'm waiting maybe tomorrow some more components to do a more reliable one.