Analysis of noise absorption characteristics of ceramic chip varistor according to the equivalent circuit model.

近来，各种发动机都由计算机控制。因此，对于电动机中出现的冲击噪声和高频噪声的对策对于防止机器的错误操作和破坏是重要的。压敏电阻器与齐纳二极管相比，具有电压-电流曲线极性对称、静电容量大、响应速度快等优点。因此，它不仅可用作防止静电的保护元件，还可用作防止便携式电话、摄像机、CD-ROM、DVD-ROM和直流电机的浪涌噪声的保护元件。特别是ZnO压敏电阻在大电流区具有很大的非线性系数，可用于噪声吸收。本文通过仿真分析了陶瓷压敏电阻器的噪声吸收特性，并为陶瓷压敏电阻器的设计提供了依据。 ...更多信息 陶瓷压敏电阻器的艾德等效电路。等效电路确定如下。在可变电阻器中，晶界层中的耗尽层引起了电压-电流的非线性，晶粒中表现出较小的电阻值。因此，晶界的等效电路表现为电阻与电容并联，而晶粒内部的等效电路表现为小电阻时的等效电路。在实际的压敏电阻器中，陶瓷晶体已经用编织物连接起来。在本研究中，将上述晶界和晶粒中的等效电路连接起来，构成等效电路的电阻和电容值的确定过程如下所示。首先，适当的电阻和电容的值，并通过电路模拟器（PSpice）计算的介电特性和电压-电流特性。确定了电阻和电容的取值，使计算的介电特性和伏安特性与实验结果吻合。少

Recently, various motors are being controlled by a computer. Therefore, a countermeasure toward surge noise which occurs in the motor and the high frequency noise is important to prevent faulty operation of the machine and destruction. Varistor has a lot of advantages in comparison with zener diode, such as the symmetry of electric polarity in the voltage-current curve, the large electrostatic capacity and the high responsibility. Therefore, it is used as a protective component against not only the static electricity but also the surge noise for the portable telephone, video camera, CD-ROM, DVD-ROM and DC motor. Especially, ZnO varistor is available for the noise absorption, since it has a large non-linear coefficient between applied voltage and current at the region of a large current. However, the noise absorption characteristics have been hardly investigated.In this study, simulations were made to analyze it and to present the data for designing a ceramic varistor using the determin … More ed equivalent circuit of ceramic varistor. The equivalent circuit was determined as follows. In the variable resistor, the non-linearity of the voltage-current is being brought about by depletion layer in grain boundary layer, and comparatively small resistance value is shown in the grain. Therefore, the equivalent circuit of grain boundary was shown in parallel connection of resistance and condenser, and the equivalent circuit in the grain was shown at small resistance. In actual varistor, the ceramic crystal has been connected with braided. In this study, the equivalent circuit which showed in above-mentioned grain boundary and in the grain were connected braided.The decision procedure of the value of the resistance and the condenser which constitute equivalent circuit is shown in the following. At the first, values which is appropriate for the resistance and condenser were let in, and dielectric characteristic and voltage-current characteristic were calculated by the circuit simulator(PSpice). The values of resistance and condenser were decided so that the calculated dielectric characteristic and voltage-current characteristic were agree with experimental one. Less