[sdiy] +/- 15v from a wall wart...

[Justin Owen]

-----Original Message-----
From: Paul Perry [pfperry at melbpc.org.au]

>You gain a bit, because the peak voltage of the AC cycle is about 1.4 times the RMS AC voltage.
>So, from a 15V AC source, you would get a peak of 21 volts.
>Less say a volt for the diode drop & the fact that the mains sine wave is flattened a bit by all those switch mode power supplies, and you still have plenty in hand.

>This is why I use a 35V rating filter cap after the diode.
>A 25V one is likely having its voltage exceeded.

>Paul perry Melbourne Australia

Thanks Paul - that's excellent.

J