This circuit is from a Radio Electronics from December 1964. The components are from the time and modern equivalents for transistors and diodes can be used.
This touch sensor, found in an American documentation on transistors, has gained 8 million times...
The block shown in the figure is a basic source with a configuration widely used in technical...
The output of this circuit must be connected to the input of an audio amplifier. The microphone is a small...