This is a typical 3 ½ digit TTL counter. We found it in the September 1973 issue of Radio Electronics magazine. The circuit is to be powered by 5 V. It can be expanded to more digits.
We found this circuit in an English documentation from 1979. It shows how you use a 100 uA...
This circuit was found in an EDN from the 90s. For the components indicated, the frequency is 10 kHz....
This is a very interesting automation that can be adapted for other types of applications. In...