应该说,这个问题本人困惑了很长一段时间,近日,本人在分析正弦电压半波整流平均值时,得到了启发。我们设正弦交流电压的有效值为U2,其瞬时表达式如以零点作为坐际原点,则为U2(ut)=2~(1/2)Usinωt、输出平均电压Ud为: Ud=1/2πintegral from n=0 to π(2~(1/2)U2sinwtd(wt))=2~(1/2)/πU2=0.45U2 上式表明,正弦电压导通了半个周期,其平均值为0.45U2。现举例计算说明如下: It should be said that this issue I have been puzzled for a long time, recently, I am analyzing the half-wave sinusoidal voltage average rectification, have been inspired. We set the sinusoidal AC voltage RMS is U2, the instantaneous expression of zero as the inter-sectoral origin, then U2 (ut) = 2 ~ (1/2) Usinωt, the average output voltage Ud is: Ud = 1 / 2πintegral From n = 0 to π (2 ~ (1/2) U2sinwtd (wt)) = 2 ~ (1/2) /πU2=0.45U2 The above equation shows that the sinusoidal voltage turns on for half a cycle with an average value of 0.45 U2. The following is an example calculation as follows: