基于ATmega128的低频正弦信号相位差测量系统

The Phase Difference Measurement System of Low Frequency Sine Signals Based on ATmega128

该系统由ATmega128单片机、多路模拟开关、放大整形电路、鉴相电路等组成。其电路具有较强的抗干扰能力,可精确的分辨出两路被测信号的相位差;利用信道交换技术消除了两个通道不严格匹配产生的测量误差;软件上采用简练的中断处理方式和多次采样取平均的方法减小了测量误差。

The system is composed of singlechip-ATmega 128, analog switch, rectifying circuit and phase discriminator circuit. The rectifying circuit has a strong capability of anti-jamming, which can catch the zero of sine precisely, so as to differentiate the phase difference of the two sine signals. The method of data channel exchanging eliminates the phase error caused by the delay of using different channels. Some correlative measures from soft, such as condensing interrupt subprogram, sampling several times and calculating average, are adopted to decrease the measurement error.