Solid state relay (CB8518E)

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

Baxandall Tone Control (CB10829E)
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...
FET stage (CB6169E)
This input stage has unit gain but a high input impedance and low output impedance. The circuit is...
60 second relay delay (CB7233E)
Suggested by General Electric documentation from 1968, this circuit activates a relay after 60...