On 06/06/2019 15:12, Harry Bloomfield wrote:
on 05/06/2019, 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.

0.707 x the peak AC is the RMS voltage.

Of a sinewave, not a half-wave rectified sine wave.

Sinewave: 339V / sqrt(2) = 240V RMS

Half-wave rectified sinewave: 339V / 2 = 169.5V RMS

SteveW