This TTL circuit consists of a frequency divider or converter that has values selected by a switch. The circuit is from Radio Electronics from December 1980 and must be powered by a voltage of 5 V.
This circuit is given in two versions, having been found in a publication from the 90s. The second...
This circuit was found in an ancient American documentation. Used integrated circuits are uncommon...
This Texas Instruments circuit uses a phototransistor to fire a TTL trigger port. Other...