Metal detector receiver (CB22457E)

Found at Popular Electronics this receiver is used with a transmitter for quadrature-coil signals.

Dimmer with filter (CB25027E)
The figure shows how to implement a filter against interference caused by the switching of a...
Stepper motor control (CB12763E)
The pulses applied to input C of the SAA1027 integrated circuit determine the engine speed. Each...
30 W Transistor Amplifier (CB23659E)
This circuit was obtained from an old publication from 1974 but can still be assembled with some...