This 1967 Raytheon circuit uses a Raystor, an optical coupler with a lamp and an LDR. The circuit can be adapted to use another type of coupler.
This interesting circuit found in a European publication from the 1990s eliminates the voice that...
This simple circuit that interrupts the supply of a 12 V load in the event of an overvoltage was found in...
The radio presented was found in a 1980 documentation. It consists of 3 stages: the tuning circuit...