We found this circuit in the May 1972 issue of Radio Electronics magazine. Its purpose is to teach logic using integrated circuits of the TTL family. The 5 V power supply is included.
We found this circuit in a 1977 publication for radio amateurs. It serves to test general purpose...
This circuit is from a 1998 Poptronics. The circuit triggers a buzzer after a certain time, waking...
This circuit for electronic voltmeter was found in a publication by Gernsback from 1960. The...