This simple TTL siren was found in a 1980s Electronics Today International. The power supply is 5 V and the integrated circuit can be the 7400.
Found in Popular Electronics this circuit will trigger a buzzer if the ignition key is removed...
Found in the July 1968 Supertena Bulletin of a Popular Electronics, this receiver makes use of the...
This common metronome configuration has already appeared in several of our articles and projects. This...