This circuit was found in a 1966 General Electric documentation. The circuit makes use of PUTs that are uncommon components today. Counting direction depends on the programming in A and B.
This circuit uses a crystal phone and can be built with more modern transistors like the BC548. The...
This circuit was obtained from an American publication of the 80's. The integrated circuit is of the...
We found this circuit in a 1995 documentation. It includes several important features for a test...