This circuit was found in the July 1992 issue of Radio Electronics magazine. The circuit is based on a 741 that activates a buzzer with oscillator. R5 adjusts the sensitivity.
We found this circuit in a 1976 documentation. The circuit uses a double gate MOSFET. The circuit...
This circuit was obtained in an American documentation of 1964. The transistors are of the time....
August 2017 - STMicroelectronics' new DSL05 transient suppressors for 12 and 24 V voltages and...