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 transistor source was found in a 1990 documentation. 2N3055 transistors must be equipped with...
This tube circuit is from an 80's documentation. The filter is of the selective type and the...
This general-purpose two-transistor circuit was found in the November 1993 issue of Electronics Now. The...