Found in US documentation, this circuit changes the waveform and phase of a sine signal. The circuit is indicated for frequencies between 0.1 and 10 Hz. The power source must be symmetrical.
This basic Schmitt trigger was found in an American publication from 1968. The circuit uses...
This circuit is from an American 1964 documentation. Transistors of the time are used, but modern...
This simple circuit uses small speakers for both listening and speaking (microphone). The feeding is...