This circuit was found in the 1969 RCA thyristor manual. The circuit has a limiter (clipping) with two 12 V zener diodes in opposition to cut power grid pulses that may influence the trigger.
This is the basic configuration of an operational amplifier sample & hold circuit. The FET and...
Microchip Continues Expansion of AVR Microcontroller Product Line with Addition of Three New...
The circuit shown, with the printed circuit board, was found in an article in the June 1990 issue...