串联RLC谐振电路特性研究实验方案改进

IMPROVEMENT OF EXPERIMENTAL METHOD ABOUT THE RESONANT CHARACTERISTICS OF RLC SERIES CIRCUIT

RLC谐振电路实验中,电路中电流随信号频率改变及信号源存在输出阻抗,导致信号源输出电压随信号频率改变,对谐振曲线的通频带宽度及品质因数的测量结果产生影响。本文通过改进实验测量方法,同时测量RLC电路端压和电阻R两端电压,并根据欧姆定律,提出了修正RLC谐振电路实验中端压改变的理论公式,可以推算出谐振电路端电压为任意恒定值时的电流,解决了信号源输出改变对测量结果的影响,免去了实验中对信号源输出电压进行反复调整的步骤。验证实验结果表明修正公式及方法是正确的。

In the RLC resonant circuit experiment, because the current in the circuit changes with the signal frequency and the signal source has output impedance, the output voltage of the signal source changes with the signal frequency, which affects the passband width of the resonance curve and the measurement result of the quality factor. By improving the experimental measurement method, measuring the terminal voltage of RLC circuit and the voltage across the resistor at the same time, and based on Ohm’s law, this paper proposes a theoretical formula for modifying the terminal voltage change in the RLC resonant circuit experiment, which can calculate the current when the terminal voltage of resonant circuit is any constant value, and solve the influence of signal source output change on the measurement results. It eliminates the step of repeatedly adjusting the output voltage of the signal source in the experiment. The experimental results show that the modified formula and method are correct.