We found this circuit in a Radio Electronics from October 1976. The components are still common, but the circuit applies to older car models with contact breaker ignition.
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...