26 Oct
2025
26 Oct
'25
1:45 p.m.
On 2025-10-26 2:28 p.m., Paul Koning via cctalk wrote:
The ones I am thinking of have no switching noise when turning off.
Ben.
On Oct 26, 2025, at 2:52 PM, dwight via cctalk
<cctalk(a)classiccmp.org> wrote:
________________________________
From: Paul Koning via cctalk <cctalk(a)classiccmp.org>
Sent: Saturday, October 25, 2025 1:31 PM
To: cctalk(a)classiccmp.org <cctalk(a)classiccmp.org>
Subject: [cctalk] Re: The transistor invention
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 On Oct 25, 2025, at 4:12 PM, ben via cctalk
<cctalk(a)classiccmp.org> 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