This simple SCR trigger was found in a 1965 General Electric SCR manual. The circuit makes use of a diac, and the transistor supports an equivalent.
This circuit is from an American publication from 1975 and can use other operational amplifiers and...
This circuit generates audio signals for testing amplifiers and other equipment. The potentiometer R5...
This circuit was found in a 90s EDN. In it we have the use of LEDs and diodes to stabilize the supply...