This circuit is from an American manual from 1975. The transistors are types of the time, but equivalents can be used, as well as the relay that can be according to the supply voltage.
This small automotive NiCad battery charger uses only passive components and has the number of...
This circuit is from a publication from the 50's. Inductive components are critical, and...
Found in documentation from the 1980s, this circuit can generate signals between 6 and 8 MHz. The...