深度认识多用电表欧姆挡及其倍率转换原理

In-Depth Understanding on the Ohm Range of Multi-Meters and the Principle of Ratio Conversion

长期以来,由于高中物理教材给出的多用表电路图与实际情况存在较大的本质差异,致使教学过程中对多用表欧姆挡的理论与实践不相吻合.结合常用的指针式多用电表欧姆挡的一些实验现象和多用电表欧姆挡或欧姆表的实际电路进行分析,指出多用电表欧姆挡或欧姆表的倍率与表头电流的匹配关系是靠改变表头的分压电阻和分流电阻来实现.

For a long time, the circuit diagrams of multimeters given by high school physics textbooks are quite different from the actual situation, resulting in the inconsistency of the theory and practice of multimeter ohm files in the teaching process. This article analyzes some experimental phenomena of the ohm gear of the commonly used pointer multimeter and the actual circuit of the ohm gear of the multimeter or the actual circuit of the ohmmeter. The voltage divider resistance and shunt resistance are realized.