Record Your Results by Drawing the Waveform, Labeling Each Significant Point

MultiSIM – Lab #5

Student Name ______

1. Double-click on the Agilent Function Generator in Circuit A to open its window. You are observing the face of a real function generator. Depress the Power button. You will now set the function generator to generate a sine wave of frequency 100 Hz with an amplitude of 250 mVp-p and a positive offset of 50 mV. This will provide a DC offset that will shift the sine wave to oscillate above and below 50 mV instead of above and below zero.

2. Depress the sinewave symbol button, then the Freq. button. Set the frequency to 100 Hz by using the arrows at the right of the meter or clicking on the potentiometer at the top and "turning" it. Now press the Amplitude button and use the arrows or turn the potentiometer until 250 mVp-p is reached.

3. Press the Offset button and adjust the setting to 50 mV. You may need to use the right and left arrow keys to move the cursor from the "+" to the first digit. Run the simulation by depressing the Run Simulation switch or selecting Simulate/Run from the menu. Open the Oscilloscope by double-clicking on its face.

Record your results by drawing the waveform, labeling each significant point.

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4. Stop the simulation. Select Offset and adjust to zero. Depress the triangle wave button and run the simulation again. Note your results.

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5. In Circuit B, you will use the Amplitude Modulation feature that will produce an AM signal. Double-click on the Agilent Function Generator in Circuit B to open its window. Select Shift then AM. Select Freq. Set the carrier frequency to 100 kHz. Set the amplitude of the carrier signal to 700 mV by depressing the Ampl button. Set the frequency of the modulating signal to 500 Hz by depressing Shift then Freq. Select 90 % modulation by depressing Shift Ampl and adjusting to 0.9. Open the Oscilloscope window and run the simulation.

Record your results by drawing the waveform, labeling each significant point.

______

6. Now you will generate a square wave with an amplitude of 5 V and a duty cycle of 70 %. Depress the square wave button. Select Shift, then % duty. Set the duty cycle to 70 percent. Open the Oscilloscope then run the simulation.

Record your results. Comment on your results.

7. Circuit C is an AM detector. For this portion of the lab, we will generate an AM waveform with a 10 kHz carrier and a 1.5 kHz modulating signal. The carrier amplitude will be set to 1 V with a modulation index of 90 %.

Set the parameters as listed above for Circuit C. Refer to step 5 if you need assistance. Run the simulation. Open the Oscilloscope that is measuring the input signal. Full observation of the signal may take a minute.

Does the waveform represent your settings? ______.

8. Open the Oscilloscope to the right of the detector. The blue waveform represents the clipped AM waveform and the red waveform represents the fully detected output signal.

What do you expect the frequency of the output signal to be? ______

Measure it on the Oscilloscope and record the frequency of the de-modulated signal.

Comment ______