Taken from a 1967 RCA publication, this circuit maintains a low current in the battery when it is charged. The components are from the era.
This commercial circuit is from a Japanese magazine from 1967. It uses germanium transistors, and...
This circuit can be used to drive relays, solenoids, motors and other loads according the...
This circuit is based on the small keychain that responded to the sound of a whistle and were...