This TTL circuit has a well-known configuration, having been found in a Radio Electronics magazine from December 1980. The power supply must be 5 V.
We found this circuit at Modern Electronics in January 1991. The magazine no longer exists, but...
The circuit presented, from a 2005 documentation, can provide from 1 W to 2.5 W of output when...
This wired intercom circuit was found in a March 1965 Radio Electronics. The circuit uses two...