Found in Electronics now from the 90s, this circuit uses a sensor from the time, which is difficult to find today. The circuit activates a sonalert-type buzzer.
This circuit was found in the June 1990 issue of Radio Electronics magazine. The maximum current is 1...
The critical components of this project from a 1978 publication are the transformers, which can be...
In the figure we have a simple configuration with a general-purpose transistor for a 3-input...