This constant current charger from 1997 Linear Technology Applications uses common components at the time. The transformer is the critical component, being designed according to the load voltage.
This 1995 circuit uses interruption sensors or NC connected in series in any quantity. With the...
This circuit, suggested by a 1975 documentation, detects an electrical discharge in a storm by...
Found in an old Electronic Design, this circuit provides an output voltage that is the absolute...