Found in a 1967 RCA documentation, this AC power grid contactor can be fitted with modern equivalent components. The SCR and the diodes must be according to the load current.
This ultra-simple receiver has in the tuning circuit a variable capacitor for AM and a coil,...
Presented as an electronic siren, this circuit was found in Radio Electronics magazine from June...
The circuit shown in the figure can be used to detect vibrations or to provide amplified acoustic...