thermal oscillation
1.A low supply thermal shutdown circuit with hysteresis is presented in the paper, which can prevent thermal oscillation from occurring through simple feedback, without using Zener diode sand hysteresis comparators. The circuit can operate at a minimum supply voltage of 1.5V,the temperature of hysteresis is 20℃.
2.The main defects in CBO crystals were growth layers and the main cause of the growth defects were the shaky thermal convection and oscillation of temperatrue,which brought about the change of microcosmic growth rate with the time and the disarrangement of particles on the surface of crystals.
3.The oscillation mechanism of self-heating SnO2 sintered sensor in CO gas and air is discussed and the thermal equation of the sensor resistance is given. We have obtained the approximate expression of oscillation period for sensor resistance and the necessary condition of the cause of oscillation. We have also gotten the relationship between the frequency F,the CO concentration N and the working voltage V.
