Found in National Semiconductor documentation from the 90's, this circuit has an output current of 5 V. The integrated circuit must have a heat sink.
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...