On Thursday, 6 June 2019 15:12:49 UTC+1, Harry Bloomfield wrote:
on 05/06/2019, tabbypurr supposed :

All Brian's points are incorrect except that they do often get stiff due to
limescale or corrosion.
A diode will give 240v x 0.707 rms volts, which is more than 120.

No, it will be 50% of the AC waveform, less a bit for the fraction of a
volt lost across the junction.

do you ever get anything right?

0.707 x the peak AC is the RMS voltage.

If you know the RMS, then multiplying by 1.41 will give you the peak
voltage. If you charged a cap via a bridge without any loading, that
would achieve 240v x 1.41 = 338.4v peak, less junction losses.