29 Jul
2007
29 Jul
'07
1:02 p.m.
On Sunday 29 July 2007 15:13, Chuck Guzis wrote:
I still have the stink of hydrogen selenide from those
things etched
into my brain (when they went bad). Like hydrogen sulfide but more
pungent--and more toxic.
I'm not sure about the chemical involved, but that "toggle switch light
dimmer" mentioned in the other post started out with a small selenium
rectifier, until I overloaded it. No, there's no forgetting _that_ smell!
When you replaced them with silicon diodes in HV
supply applications
(IR used to offer complete clip-in cartridge diode assemblies), it
was customary to include a small-value series resistance.
This was also done when you'd take the base off an old tube and make a
rectifier using silicon. Sometimes. I did that in an old tube scope one
time, and didn't bother.
Older battery chargers used copper-oxide rectifiers as
well as Tungar
bulbs.
I remember lots of references to copper oxide rectifiers, but don't remember
actually ever seeing one. My grandfather had a battery charger that used a
Tungar bulb. As with a lot of other stuff he had, and elsewhere, I got
into it and took it apart to find out what I could. :-)
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin