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 oscillator circuit for sinusoidal audio signals with operational 741 requires a symmetrical power...
Found in a 1974 Radio Shack documentation. This circuit must have a connection to the ground of...
This sensitive circuit detects the live pole of a power grid or outlet. The circuit makes use of a high...