Transformerless power supply electronic project

A transformerless power supply electronic project can be design using electronic diagram below. This transformerless power supply 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.