We found this circuit in the April 1978 issue of Radio Electronics magazine. The 2-digit circuit uses common TTL integrated circuits and must be powered by a voltage of 5 V.
This configuration is from a 1987 publication, but it can be easily assembled today, as the...
This circuit can be seen in several publications of the same time. The circuit is an application note...
A new version of the previous circuit triggered by the negative transition of the input signal is...