i am designing a 12vdc,200mA transformerless power supply using in4007(diode) for rectification,a ceramic capacitor 475k and 10R resistor for limitting,a zener diode (in4742A) for a regulated output.after the connections, the 12Vdc was gotten but am not still getting the output current, the transformerless power supply is needed to drive a relay of 12vdc 160mA.below is the circuit diagram.
Why are you using 1M (R2) ?
Using this high value resistor would not allow you to draw any current. As you know I=E/R, I=12/1,000,000, result =? (12µA).
You may get 12 volts reading on the VOM but those are not usable, only measurable. Here is a circuit which can deliver 12 volts and about 100mA. Hopefully it will operate your relay.
BE CAREFUL OF THE LETHAL VOLTAGE
MOV is 250 volts varistor, ZD is 12 volts/1W zener diode and R3 should be 1W.
Hope it helps.
i wana ask why you used 4A Fuse here...... as you said this is only 100mA power supply???? i think a maximum of 1A fuse should be enough. Kindly explain the reason. and how can i make a Transformerless powersupply of 20A and High?