Metal detector receiver (CB22457E)

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

Even and odd counter (CB23780E)
This interesting digital counter with relays with complementary outputs was found in the Radio...
Socket control (CB24880E)
The idea of this circuit is that when the device in SO1 is turned on, the device connected to...
Battery Expander (CB12755E)
This interesting circuit allows to obtain symmetrical voltages from a simple battery. Among its...