Well looks like I've hit the jackpot with this forum... found stuff that I wasn't even looking for. ;-)

I guess I should have stipulated that the circuit requires 5v DC, basically 30v AC in - 5v DC out and draws 25mA.

Melanie, I was having a look at your circuit in the Feb 2006 thread, and what baffled me is the parallel configuration of the Capacitor - Resistor and the fact that you have the Zenar Diode before D2 - D3.

Basiclly it's exactly what I am after, however can you please explain the workings of the circuit and the formulas to work out the capacitor / Resistor values for 30v.

Many thanks,

Volkov