I would like to power my Attiny13a MCU with a transformerless capacitive power supply. The MCU itself needs only a few milli amps and it will drive 2 LEDs at 15mA each through it's digital pins. So I guess total power consumption might be less than 50mA at 5V.
I have come up with this circuit but I have a few concerns.
- Would this circuit work fine with my MCU?
- Sometimes there is a power outage and my home inverter starts supplying square wave ac - will this damage this circuit?
- Should I use a 65V smoothing capacitor instead of the 25V one?
- Would those 1/4w resistors do their job or should I get 1/2w ones?
- Do I really need the resistor before the zener diode? if so is 100R correct?
- I saw another circuit which has an additional resistor. Is that really needed?
As for safety concern the project will be enclosed in a plastic box placed in the ceiling where no one can reach and I will also add a warning label.
Thanks in advance.