On 4/22/2021 9:21 AM, bitrex wrote:
On 4/22/2021 5:04 AM, piglet wrote:
On 22/04/2021 5:00 am, bitrex wrote:

There's this patent from '66 that describes a solid-state thyratron
replacement:

https://patentimages.storage.googleapis.com/42/6a/0d/6e35c415a3f0e0/US3293449.pdf


It uses a couple of SCRs. It's to replace high-power thyratrons but I
don't see why it couldn't be scaled-down.

Thanks Bitrex, that patent even mentions a tunnel diode and UJT which
are now very exotic devices. The struggle was to emulate the high
impedance thyratron grid. It seems to me (I have never seen a
thyratron) that a modern depletion mode mosfet would make a good
front-end to a SCR in that a negative grid bias is required to keep
the device non-conducting (if I understand thyratrons correctly).

Well Fig 2 in the patent doesn't look like it requires anything exotic,
the exotics look to be included in the "further embodiment of the
invention"

Oh okay I see what you're saying, instead of using a high-impedance SCR
as the first element in a two-SCR pair there are better devices to solve
that "struggle" of the inventor, now.