Rlc circuit

RLC Circuits Objective Study a series RLC bandpass filter circuit.

Equipment List • • • •

Computer running Windows (NI ELVIS installed) National Instruments DAQ board (inside computer).

1kΩ resistor 0.22_F capacitor 12.4_H inductor Wires for connecting the previous equipment together.

Introcuction In this lab you will investigate a series RLC circuit. RLC series circuit is shown in figure 1.

Figure 1. RLC Circuit You will use Bode Analyzer in this lab. Bode Analyzer analysis the relationship of Gain (Vo/Vin) to frequency of the system. Vo here is the Voltage on the risistor R, Vin is the input signal given to the circuit. You may have not used it before. We will learn to use it today.

Procedure 1.Construct the circuit as shown in figure 2 on the NI ELVIS Prototyping board.. L is 12.4_H inductor, C is a 0.22_F capacitor, and R is a 1kΩ resistor. Connect point 1 to FUNC OUT, connect point 4 to AIGND. Also connect point 1 to ACH1+, and connect point 3 to ACH0+.

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Figure 2. Component Layout for RLC Circuit 2.Turn on the NI ELVIS Benchtop Workstation, select Start»Programs»National Instruments»NI ELVIS 1.0»NI ELVIS, or select NI ELVIS on the desktop. Turn on the Prototyping Board Power.

3.Open Bode Analyzer, set Start Frequency to 10.00 Hz, Set Steps to 5 and Stop Frequency to 35000.00 Hz. Also set Y Scale to Linear mode as shown in figure3.

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Figure 3. Bode Analyzer 4.Click the Run button on the Bode Analyzer; observe the Gain change with different frequency.

5.Close the Bode Analyzer. Open Function Generator and Oscilloscope. Set the parameters as shown in figure 4 and figure 5.

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Figure 4. Function Generator

Figure 5. Oscilloscope

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6.Click On at Function Generator; observe the waves on Oscilloscope.

7.Change the frequency from Function Generator, and observe the amplitude change of CHANNEL B on Oscilloscope. You may see this RLC circuit is a band pass filter, the Gain change with different frequency. Your observation from Oscilloscope is same as what you have seen from Bode Analyzer.

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