The circuit shown was found in an American documentation from 1964. The circuit uses transistors of the time and the indicators are small lamps.
This circuit triggers an alarm in the event of a power failure. The circuit is from an 80's...
We found this circuit in the April 1978 issue of Radio Electronics magazine. The 2-digit circuit uses...
This CMNOS crystal-based circuit generates a 2 Hz signal. It was found in the October 1994 issue of...