This circuit was published in the July 1993 issue of Electronics Now magazine. It uses a sensor from the time and triggers a buzzer with a Sonalert-type oscillator.
This circuit is from a 1991 publication, but it can be assembled with more modern components. We...
This circuit provides a current given by the components calculated according to the formula next...
Published in Radio Electronics in October 1963, this circuit increases the audio output of a small...