I would like to make a transformerless power supply, I found some description on the Internet like this pdf provided by Microchip. My question is it is possible to use only the phase line(without neutral line) to build a transformerless power supply and power up a microcontroller, for example in the wall mounted light switch I have only the phase.
This is what I found on the Internet, there is only two wire.
I just order one of this bulb dimmer, here is a few picture:
And inside the cover:
It seams that there aren't a battery, how is it possible that this circuit is working?