The purpose of this circuit found in a 1967 GE SCR manual is to control a heating element. The SCR must have current according to the controlled load.
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime...