Suggested by General Electric in a 1970 documentation, this circuit makes use of some components of the time, in the case of transistors. The circuit detects smoke by the transparency changing of the air.
This circuit is from 1980 documentation but can still be assembled today with BC548 transistors. The...
Found in a 90s Elektor, this circuit deactivates a source in case of excessive current. The relay...
This is the power step of the previous circuit. Output transistors must be mounted on good heat...