新编高中物理教材在学完交流电及二极管的单向导电性后的复习题中,选了一个定性分析的理论题——二极管限幅电路的题目于下: 图1是电子技术中用到的限幅电路,电池电动势都是ε,左端输入的是正弦交流电压u_1的最大值为2ε。试画出右端输出的电压u_2的图象,并分析说明理由。电池组的内电阻略去不计(甲种本第三册145页第7题)。该题从物理概念出发,学生是应该能够解决的。但因综合性较强,且学生感到抽象,独立完成该题普遍存在困难。在教学中先用演示实验让学生观察再进行原理分析,在有了感性认识的基础上,解决这一理论问题就容易多了。二极管限幅电路,元件经济、稳定可靠,且电路简 New high school physics textbooks in the review of AC and diode unidirectional conductivity after the review, selected a qualitative analysis of the theoretical problem - diode limiter circuit in the following: Figure 1 is the limit used in electronic technology Amplitude circuit, the battery electromotive force is ε, the left input is the maximum sinusoidal AC voltage u_1 2ε. Try to draw the image of the voltage u_2 output from the right end and analyze the reasons. The internal resistance of the battery is slightly negligible (Book 3, p. 145, p. 7). The question from the physical concept, students should be able to solve. However, due to its comprehensiveness and students' absurdity, it is difficult to complete this topic independently. In the teaching of demonstration experiments for students to observe and then carry out the principle analysis, on the basis of perceptual knowledge, to solve this theoretical problem is much easier. Diode limiting circuit, component economy, stable and reliable, and the circuit Jane