Overview

This experiment includes the study of transient process of RLC circuit and the study of RLC resonant circuit characteristics. The studied knowledge points are the characteristics of transient process of current and voltage in RL, RC and RLC circuits, the definition and measurement method of exponential decay time constant, the definition and measurement method of decay oscillation period and time constant, the usage and parameter selection of RC differential circuit, the usage and parameter selection of RC integral circuit and the characteristics of RLC circuit steady state, resonance, amplitude frequency characteristics, phase frequency characteristics, high pass circuit, low pass circuit, the upper limit frequency, lower limit frequency, cutoff frequency, passband width, resonant frequency, inductance, capacitance, quality factor, frequency selection, grounding, voltage resonance, current resonance, phase difference measurement, etc. The experimental device can realize the level teaching of RLC circuit experiment, and complete the basic content, advanced content, and high-level content.

Experimental content

1）Basic content

Amplitude-frequency/phase-frequency characteristics test of RC, RL, and RLC series circuits; quality factor Q test.

Observe the transient process of RC and RL series circuits, measure their exponential decay time constants, and study the effects of changes in component parameters on waveforms and time constants.

2) Enhance the content

Multi-method to find out the resonant frequency; amplitude-frequency characteristic test of RLC series circuit under different Q values; amplitude-frequency/phase-frequency characteristic test of RLC parallel circuit; RC low-pass filter circuit; RC high-pass filter circuit;

Change the magnitude of R, observe the transient process of RLC series circuit, and record the voltage waveform on C. Measure the period of decay oscillation and the waveform envelope decay time constant under undamped condition. Find the critical damping value. Observe the effect of R on the waveform in the over-damped case.

3）Advanced content

Second-order RC filter circuit.

Estimate the uncertainty of experimental measurements of the transient waveform time constants of RC and RL series circuits, the decay oscillation period and envelope decay time constants of undamped transient waveforms of RLC series circuits, and critical damping.

To study the transient behavior of RLC parallel circuits. Design the circuit and select appropriate parameters to integrate or differentiate the signal with the RC circuit. Determine the type of unknown components and roughly measure the parameters of unknown components by transient behavior.

4）High-level content

Design rectifier filter circuits, LC third-order low-pass filter circuits (square wave to sine), undamped oscillation circuits, etc.

Computer display of circuit transient processes, etc.

Features

1) Modular design

Independent module design, building-block combination, fully mobilize students' hands-on ability.

2）Visualized appearance

The bottom of the module is made of visualized transparent material, which is convenient to observe the components.

3）Detachable structure

The module adopts detachable structure, which is convenient to replace the components.

4）Digital experiment

It is very easy to measure the time constant using the voltage sensor. It is easy to verify whether the curve is exponential using the curve-fitting function of the software.

Typical experimental data

RC charging and discharging process

Voltage waveform in LC oscillation circuit (with damping)

Voltage waveform in LC oscillation circuit (undamped)

Parts List

Optional accessories

Function signal generator, digital oscilloscope, isolation transformer, resistor box.