This circuit is from an article that appeared in the June 1974 issue of Radio Electronics magazine. The circuit used integrated circuits and transistors of the time and included the power supply.
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...