Metal detector receiver (CB22457E)

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

Programmable Sequential (CB18156E)
This circuit works with small 5 V incandescent lamps but can be modified to operate with LEDs. The...
Game clock generator (CB7003E)
This circuit found in Radio Electronics can be used in games to produce a random pulse train. The...
Bridge photometer (CB12980E)
This photometer is based on a Wheatstone bridge that must be balanced by the linear potentiometer P1. The...