This circuit was found in a 1967 US publication. In it we have the implementation of a ring counter using only relays. Relay free contacts can trigger indicator lamps or LEDs.
This old configuration of an audio amplifier has a push-pull two-transistor output stage. Output...
This is the traditional configuration of na Astable Multivibrator using two NPN ttransistor....
This circuit is from 1987 documentation. The operating system used is not common today, but two...