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 is from American documentation from the 1980s. The transistors are general purpose...
This circuit was found in a Popular Electronics of the 1990s. The sensor is a rotating mechanical...
The purpose of this circuit is to sense the water level in the windshield wiper reservoir. The circuit...