Equivalent optocouplers can be used in this relay or solid-state shield. The power of the load depends on the triac used.
This low power circuit for the FM band was found in a spy book from the 90s. The tunnel diode is...
This circuit was found in an old Motorola documentation from the 70s, as it uses one of its...
Suggested by General Electric in a 1970 documentation, this circuit makes use of some components of...