This circuit, which can serve as a reference for restorations, was found in the October 1989 issue of Radio Electronics magazine. The circuit uses a 5-digit display and a dedicated integrated circuit.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...