This circuit without sensors in series triggering an SCR was found in volume 5 of the 1995 Encyclopedia of Electronic Circuits. The circuit can have the number of sensors changed.
This circuit was found in a 1992 documentation and has excellent sensitivity, using components that...
This practical idea from a 1992 documentation shows how to count the turns of a winder using a...
In this circuit from the 60s, the power supply is made with 22.5 V, which is the voltage of the...