[Amps] Equalising resistors with HV diodes

[DF3KV]

----- Original Message -----
From: <peter.chadwick at Zarlink.Com>
> >If that theory is solid, all fullwave bridge rectifiers should have
> >equalising resistors connected across the diodes, but no
manufacture
> >suggests that.
>
> I don't follow that argument. In a bridge, the 'off' diodes are
effectively
> in parallel, not series. Substitute bits of wire for the 'ON' diode
and
> analyse for one half cycle.

Hi Peter,

in the fullwave bridge at one 1/2 cycle, IMHO there always two diodes
series connected through the load and the other two are  "off"
Over a full cycle they act as parallel pairs of series connected
diodes

>
> Give me  a tube everytime!

thats my preference as well,
unfortunately there are no sources except old mercury vapor type  hv
rectifiers.
For that reason I use stacked  1N5408 and BY255 for more then 30 years
without any problem and without equalizing resistors but sometimes
with paralled MOVs.

73
Peter