Accuracy of The Thermistor Phase-Shifter Thermostat

概要

論文の詳細を見る
When an electric current higher than a certain intensity passes through a thermistor, the thermistor shows a negative differential resistance characteristic. If the thermistor is biased reasonably in this region and an alternating current of small amplitude is superimposed on the bias current, the phase and the amplitude of the resulting voltage variation depend on the frequency of the current. At extremely low frequencies, the voltage is 180° out of phase with the current. Since the thermistor has a thermal inertia, the phase difference between current and voltage is 90° at a certain frequency, and it exhibits an apparent inductance characteristic. Because the phase difference between current and voltage depends on the surrounding temperature, the temperature control can be realized as follows : a constant low frequency oscillator is employed as the alternating current generator. The variation of the surrounding temperature is detected by the variation of the phase difference, and the
茨城大学文理学部の論文