Tunnel Diodes - Has Errors, See Errata in the Description скачать в хорошем качестве

Tunnel Diodes - Has Errors, See Errata in the Description

Vocademy - Free Vocational Education - vocademy.net Errata: I misread the oscilloscope trace I used to show the voltages and currents of the charastic curve of a tunnel diode--I misread by a factor of 10, seeing 8 mA as 80 mA. This throws off my current and impedance numbers by the same factor. This doesn't affect the explanation and would be correct for a tunnel diode that operates at the currents I mentioned. However, it turns out that the curve I misread is typical, making my numbers unrealistic. While relating this video to a real tunnel diode, decrease the currents by a factor of 10 and increase the impedances/resistances by the same factor. The quantum tunneling effect causes a tunnel diode to act much like a fixed resistor of about five or six ohms when reverse-biased or below about 50 millivolts when forward-biased. Between about 50 millivolts and 300 millivolts (0.05 and 0.3 volts), assuming a germanium diode, the impedance of the tunnel diode increases exponentially as the voltage increases. This causes the current to decrease linearly as the voltage increases; the reverse of a fixed resistor. This is called the negative resistance region. Above 300 millivolts, the germanium tunnel diode acts like a regular germanium diode. The negative resistance region, along with the tunnel diode's low capacitance, can be exploited to create microwave-frequency oscillators. The tunnel diode acts like a voltage-sensitive variable resistor that provides a current inverse to the voltage of a ringing tank circuit. This current is, thus, fed into the tank circuit at the correct phase to compensate for the damping as energy is dissipated by the circuit's resistance. The "little green man" model used in this video is similar to the LGM model I use to explain the zener diode in the following video:    • Zener Diodes