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 circuit for VCR recording heads was found in the February 1990 issue of Radio Electronics magazine....
This very simple continuity tester uses a small 1.5 V lamp (type used in flashlights). Can be...
This commercial radio with 3 earphone listening transistors was manufactured in Japan in the...