On 2025-10-26 2:28 p.m., Paul Koning via cctalk wrote:
On Oct 26, 2025, at 2:52 PM, dwight via cctalk <[email protected]> wrote:
________________________________
From: Paul Koning via cctalk <[email protected]>
Sent: Saturday, October 25, 2025 1:31 PM
To: [email protected] <[email protected]>
Subject: [cctalk] Re: The transistor invention
On Oct 25, 2025, at 4:12 PM, ben via cctalk <[email protected]> wrote:
On 2025-10-25 2:01 p.m., Paul Koning via cctalk wrote:
...
"carborundum" is better known as silicon carbide. It has been a niche
semiconductor material for quite a while; I remember reading about its use for blue light
lasers, back around 1980. Nowadays it's mainstream for certain application areas, like
high power devices or high temperature operation.
There are also silicon carbide resistors, very nice for high power non-inductive
applications. Ham Radio people know of these for "dummy loads". I have one
that happily takes 100 watts for minutes on end, and if I were to dunk it into
transformer oil for cooling it could take a kilowatt.
paul
I think too that the same diodes are used as high voltage rectifiers in the
better hi-fi audio using valves.
Ben.
Could be, but I'm not sure why. Silicon diodes have been used in high voltage service
for many decades. It may be a case of using odd technology just because. That would fit
with stuff like using vacuum tubes, or using oversized copper wiring, or any number of
other weird things "high end audio" people do. It would not be quite as
strange as gold plated fiber optic connectors.
paul
Putting silicon carbide semiconductors in the same boat as silicon it missing
what is going on. They are both semiconductors but completely different. They
are about as different as sodium is from table salt.
Dwight
Well, yes, I am well aware of that. My point is that using SiC high voltage
rectifiers seems like an odd thing to do given that silicon rectifiers have
filled that role for decades.
paul
The ones I am thinking of have no switching noise when turning off.
Ben.
