A power supply without transformer can be made using electronic diagram below. This allows to power a device that requires a voltage of 12 volts, without using a transformer . Using this power supply can be powered a consumer requiring a maximum current of 10 mA.
Circuit is powered from the mains voltage 220 volts. Zener diode connected in emitter transistor is 11 volts Bc109. Triac used must withstand 150V/150mA.
A 12 to 220 volts voltage converter electronic project can be designed using electronic diagram below. This voltage converter is realized using CMOS 4047 integrated circuit, that converts a voltage of 12 volts DC into a 220 volt alternative. CMOS circuit 4047 is used as a multivibrator. From the output pins, pins 10 and 11 a symmetrical square wave is amplified by Darlington transistors T1 and T2, which ultimately reach the transformer secondary coil.
With the potentiometer P1 output frequency can be adjusted within certain limits (50-400Hz).