This circuit can be used with motors or resistive loads, such as heaters and incandescent lamps. The circuit is from Popular Electronics from the 90s. All components used are common.
This alarm, found in a 2002 documentation, uses several sensors and has a 12 V supply, not...
This circuit uses a special 1950's RCA strobe tube. It can be built with equivalent components for the rest...
This circuit, which can act as a shield, was found in a 1970s American documentation. The...