Metal detector receiver (CB22457E)

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

INA240 – Zero Drift Sensors Amplifiers (COM167E)
January 2017 - Through Mouser Electronics Texas Instruments is launching its new zero-drift...
Multiprobe (CB16590E)
This circuit can be used to test continuity or even semiconductors. We found the configuration in a 1987...
Water Level Alarm (CB12215E)
I found this circuit in an Electronics Handbook from 1989. The circuit can be assembled with a...