Employing a unijunction and a triac of the era, this 1964 Electronic Design circuit uses a diac to trigger the Triac.
We found this circuit in documentation from the 1950s. The circuit basically applies to germanium...
The circuit shown, with the printed circuit board, was found in an article in the June 1990 issue...
We found this circuit in documentation from Ferranti from 1968. The circuit uses transistors from that...