"N Cook" wrote in message
...
I'm aware that in the days of overwind transformers for EHT in
'scopes very low current and high voltage rectifier diodes were used
rather
than cheaper higher current ones as they would fail open circuit
to protect the fine windings on the mains transformer.
Is anyone familiar with using diodes for more general
applications. Particularly what generic type or named series of diode
always fails open rather than closed circuit and rough idea
of rupture current with respect to normal use maximum
as of course never in the data sheets ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/





I think you're confused by the fact that early HV rectifiers had low current
ratings because the technology was in its infancy at that time. Modern HV
rectifiers have more robust ratings because the manufacturers understand the
processes a lot better now, and the manufacturing process is much more
refined.
Diodes/rectifiers have never, in my experience, been used as fuses. A fuse
is a device that has a predictable mode of failure in an overload condition;
a diode does not. In fact, most diodes that I have seen fail almost always
fail to a shorted condition. The PN junction fuses and becomes a conductor
rather than a semiconductor.

--
Dave M
MasonDG44 at comcast dot net (Just subsitute the appropriate characters in
the address)

Never take a laxative and a sleeping pill at the same time!!