This trigger uses two switching transistors that can still be found with some ease. The circuit is from an old documentation and its purpose is to speed up the switching of logic circuits.
In the figure we have the photo-conductive way of using a photocell to control a small motor with...
Pressing S1 the LED glows by a time interval depending on the capacitor. Time intervals in the...
This is a protection circuit in which, under excess current in the load, the SCR trips by shorting the...