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.
With this shield circuit it is possible to control several loads up to 500 mA from the parallel port...
This low power circuit was found in a 1986 documentation. It includes tone controls, mixer, and...
This circuit was sent by our longtime collaborator, Adriano Muniz Moura – Pirapora-MG. The...