This simple bridge circuit can be used for impedance or resistance measurement using a high impedance earphone as an indicator. The circuit is from an American 80's documentation.
This circuit indicates the polarity of a voltage applied to the input. The circuit can make use of...
Yes, tunnel diodes can also be used in voltage regulators, as shown in this circuit from a Radio...
This rather sophisticated circuit does not recognize false tones, such as harmonics, and can be...