Solid state relay (CB8518E)

This circuit was found in a 90s Popular Electronics. Both the coupler and the MOSFET can be of any type.

Tunnel Diode Mixer (CB22546E)
We found this circuit in the Radio Electronics magazine of November 1952. The circuit can be used...
Phase separator (CB8142E)
This circuit was found in a 1964 Electronic Design. It generates opposite phase signals from an...
Positive Power Line Current Sensor (CB5217E)
This circuit makes use of a Linear Technology LT6100 having been taken from the component...