These are transformerless power supplies that can feed 5V circuits with current consumption ranges from 20-30 mA to 80-100 mA. Check the C or R values and the configurations.
You can simulate to measure supplied voltage and current. The model for Zener diode is on schematics for it.
Change values and get your needed output current.
The bridged capacitive version worked fine for a 50mA circuit...
PWM generator for test 1/4 bridge, half bridge and full bridge power circuits. 1 side PCB was disined for Iron technolodgy.
This circuits was accembled and work fine.
Note: 78L12 must be change on 7812 if use power > 18V