In Reply to: ruls for power supply circuits design posted by shlomi on 07/16/03 at 4:31 AM:
There aren't any rules as such, but here are some guide lines I use and they have served me well:
1) Use a ground plane, this improves EMC.
2) Keep ground plane well clear of mains voltages.
3) Minimum distance between tracks/pads with mains voltage should be atleast 4mm from closest point.
4) Filter lines in and out of the board, use ferrite beads, LC filters, or mains filters.
5) Look at adding surge protection; varistors.
6) Copper wire 1mm^2 cross-section by 1m in length has a resistance of 17mOhms. PCB copper thickness is about 50um thick. You can calculate the resistance of your track and (given the current) calculate the power dissipated.
These are all just rules of thumb.
I hope this helps you out.