R1 may be 10k and R2 100k. The transistor can be the BC548 and instead of the small lamp we can use a series LED with a 1k resistor. D1 is germanium and C1 is 10 nF. C2 can be 47 nF.
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...