This circuit was obtained in an Electronics Now from the 90s. The circuit uses operational amplifiers from the time and the indicator is of the Sonalert type with internal oscillator.
This simple voltage doubler provides a continuous voltage at its output that is twice the peak...
This simple 741 circuit was found in the August 1993 Electronics Now magazine. The source must be...
This circuit emits a sound at regular intervals to prevent you from falling asleep, for example. It...