Chris Lewis wrote:
According to Tony Hwang :
You ought know then vacuum tube version of SCR, the Thyristor!
A thyristor is not a vacuum tube. Thyristors are semiconductors -


He meant thyratrons, I think the 2d21's were the smallest
ones and I don't remember the number of three huge ones that
controlled our Lepel 400KW 250KHz alloy bearing surface welders.

It gets hard to remember all these names when you're old
enough to remember real power control. Also, no one
mentioned carbon piles, another version of early "dimmers" ;-)

-- larry / dallas