This circuit is from an American documentation from 1975. The single junction transistors can be 2N2646 and the signal must be applied to the input of a good amplifier.
This circuit was found in a 90s Popular Electronics. The circuit uses components from that time,...
Found in a 1966 General Electric manual, this circuit provides a delay in starting. The motor is...
The transistors can be the BC548 and BC558 and the operational can be a 741. The circuit is from...