一 当被测量的物理量正比于某一非周期三角形脉冲的峰值时,为了读取被测量值,通常采用二极管峰值保持电路。非周期的三角形电压脉冲,记为u_1(t),如图1所示。U_m是脉冲的幅值,t_1和t_2分别是脉冲的前沿和后沿宽度,α_1和α_2是脉冲前沿和后沿的斜率,那么 α_1=U_m/t_1,α_2=U_m/t_2。 常用的二极管峰值保持电路,如图2所示,图中BG1是射极跟随器,D是开关二极管,C是存储电容器,BG2是源极跟随器。为了便于分析,用R_0表示前级的输出阻抗, Once the measured physical quantity is proportional to the peak value of a non-periodic triangular pulse, a diode peak hold circuit is usually used to read the measured value. Aperiodic triangular voltage pulse, denoted as u_1 (t), as shown in Figure 1. U_m is the amplitude of the pulse, t_1 and t_2 are the leading and trailing widths of the pulse, α_1 and α_2 are the slopes of the leading and trailing edges of the pulse, then α_1 = U_m / t_1 and α_2 = U_m / t_2. Commonly used diode peak hold circuit, shown in Figure 2, the figure BG1 emitter follower, D is the switching diode, C is the storage capacitor, BG2 is the source follower. In order to facilitate the analysis, with R_0 said the output impedance of the previous stage,