Change Microchip's PICREF-4 design for 220V

If you really have to ask that, I would suggest that you think twice, before starting this project, since there is a real risk that you might kill yourself or even worse, some of your friends.

I would suggest using an isolation transformer (230:230 V) for the tests.

You should be aware about the creepage distances in PCB design.

The voltage ratings for capacitors should be obvious, but the voltage ratings for various high ohmic resistors should be carefully examined. Although a single resistor might handle the required power dissipation, the 1-10 Mohm resistors might need to be implemented with several resistors in series to get the required voltage handling.

Paul

I'd put the varistor after the 47R, so it doesnt have to short out the power station on spikes, same with the 20MegR. I would not use a 20M anyway, but an attenuator, say/guess 220K and 5k to ground (YMMV).

A couple of other replies in SED, as well

martin