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.
This circuit is from an article in Radio Electronics magazine from August 1972. The circuit is...
Found in 1969 RCA documentation, this circuit maintains constant current in the filament of a lamp...
The integrated circuit used in this application is uncommon today. The circuit is from American...