目前,对于模拟系统及数字系统来说,测量相位差通常采用置位复位触发器或者异或电路。经过合适的整形电路(1)以后获得的波形信号如图1中的A和B所示,这些信号当加到触发器的置位复位输入端或加到异或门的两个输入端时,这些电路的输出是一个脉冲宽度与两信号之间相位差成比例的脉冲序列信号。触发器和异或门通常可用集成电路构成。然而,这些电路需要一个合适的直流工作电源,且通常没有如图2所给出的电路简单、 At present, for analog systems and digital systems, the measurement phase difference is usually set reset flip-flop or XOR circuit. After the appropriate shaping circuit (1) obtained after the waveform signal shown in Figure 1, A and B, these signals when added to the flip-flop reset input or added to the two inputs XOR gate, The output of these circuits is a pulse train signal whose pulse width is proportional to the phase difference between the two signals. Flip-flop and XOR gate can usually be made of integrated circuits. However, these circuits require a suitable DC power supply and usually do not have the simple circuit shown in Figure 2,