This circuit takes advantage of the noise generated at the reverse biased junction of a germanium diode. Other types of diodes can be used. The signal is weak.
With a touch of the push button the lamp is switched on. A new touch and the lamp go out, in this...
This circuit was obtained from Maxim documentation. The circuit has 4.5 and 5.5V thresholds for...
This circuit has a configuration very explored in our projects. The range can exceed 200 meters and...