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.
May 2017 - The new 36V TLVx171 Series of General Purpose Operational Amplifiers from Texas...
This circuit was found in an American 1980s documentation. The transistorized step is the...
Using the 4001 integrated circuit, this latching relay can employ any general-purpose transistor. The...