数字示波器测量RLC谐振特性

Measuring the resonant characteristics of RLCcircuit with digital oscilloscope

使用数字存储示波器测量RLC电路的幅频和相频特性,既能更清晰地观察信号相位变化及其物理含意,还可充分发挥其特色功能并采用离散傅里叶变换准确得到信号幅值和相位.由于使用比数字电桥更灵活的扫频设置可以消除测量频率点限制,而外置取样电阻则提高了理解I-V法测量原理的实在感.

Measuring the resonant characteristic of RLC circuit is a basic physics experiment,and LC circuit is a valuable electric unit for signal detection in experimental physics.It is important to understand the amplitude-frequency and phase-frequency characteristics of RLC circuit accurately in practical application of LC circuit unit.The phase change and its physical meaning of a circuit can be observed more clearly using digital storage oscilloscope,and the amplitude and phase of RLC circuit can be obtained accurately by discrete Fourier transform based on the waveform data.Because of the flexible scan frequency step with AC source can eliminate the limitation of the frequency settings with digital electric bridge,and the external sampling resistance improves the understanding on the principle of I-V method.