Found in a 1967 General Electric SCR manual, this circuit triggers in case of excess current, causing the fuse to blow or a circuit breaker to open. The components are from the era.
With this circuit it is possible to use a common hair dryer as a hand dryer. The circuit is timed...
This circuit was obtained from an English magazine from 1979, but can be easily assembled today...
This circuit was obtained in a 1975 magazine, but it can be easily assembled using BC548...