This circuit was found in a 1968 General Electric documentation. It has an input impedance of 2 M ohms and excites a load of 16 ohms. The integrated circuit of the time is the PA237.
The transistors of this amplifier for headphones with 8 to 200-ohm impedance can be BC548 or...
This circuit is from a Radio Electronics magazine from July 1979. It uses the well-known IC 7107, a...
This simple triac trigger switch with low current switch was found in the June 1970 Radio...