This circuit was found in a 1967 US publication. In it we have the implementation of a ring counter using only relays. Relay free contacts can trigger indicator lamps or LEDs.
This circuit is for analog TV video signals and was found in the March 1988 issue of Radio...
The signal itself captured by the (long) antenna serves to feed this simple experimental circuit....
Although this project has only 3 digits, nothing prevents it from being modified to operate with a...