This traditional circuit generates a 200 Hz sinusoidal signal. The frequency depends on the capacitors and the transistor can be a BC548. We found this circuit in a 1979 documentation.
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...