RC and Operational Amplifier Circuits - Pre Lab Experiment 3 | ECE 2274, Lab Reports of Electrical and Electronics Engineering

Download RC and Operational Amplifier Circuits - Pre Lab Experiment 3 | ECE 2274 and more Lab Reports Electrical and Electronics Engineering in PDF only on Docsity! EE 2274 Pre-Lab for Experiment # 3 RC and Op Amp Circuit Completed Prior to Coming to Lab Part I: RC Circuit 1. Design a high pass filter Fig. 1 which has a -3dB point at 1 kHz. Use a .1ufd capacitor. fb=1/2πRC V1 10v ac 0Vdc C1 .1uf d R1 1.5k VV Fig. 1 2. Use PSpice to perform an AC sweep of your designed circuit from 10Hz to 10kHz with 10 points per decade. You will need to use 10 VAC , 0 DC as your voltage source. Print out the AC sweep and label the -3dB point. (hint: After you do the AC Sweep then change graph and label to dB by “adding trace” and using the formula dB= 20 log 10V0 /Vin . V0 = V1..5kohm, Vin = V1) 3. Exchange C1 with R1 (Fig. 2) and measure the voltage across C1 and V1 as you did above. Do the sweep and change the graph to dB as in 2. What type of filter? ans: _________________ Label and turn in both graphs. V1 10v ac 0Vdc C1 .1uf d R1 1.5k VV Fig. 2 Part II: Op-Amp Circuit 1. Simulate an inverting amplifier circuit using a uA741 Op amp. a. The closed loop voltage gain (Av = vo/vi) should be designed to be -10. b. Choose resistor values for R1 and R2 between 500Ω-20kΩ from the list of 5% nominal resistor values. c. The positive and negative voltage supplies, V+ and V-, should be set to 12v and -12v, respectively. d. The input voltage source should be a part called VSIN. Set the DC offset voltage, VOFF, to 0V; the amplitude of the sinusoidal voltage source, VAPML, to 200mV, and the frequency of the voltage source, FREQ, to 1k (which is equal to 1000 Hz). e. Put two voltage markers into the circuit. One should be right after Vi and the other should be at the output of the uA741 Op Amp. Graphing both the input signal and the output signal allows comparison of what the circuit did to the input signal. f. Plot a transient analysis to confirm the gain of -10. Print out this transient to be turned in. g. Using the cursors, find the exact AC gain of the op amp. *NOTE: Pay close attention to the orientation of the op-amp in figure 3-1. The op- amp has been flipped vertically to make the wiring easier. The voltage source V3 has also been flipped. Figure 3-1: Inverting op-amp. Note that the op-amp has been vertically flipped as well as the DC source V3. 2. Run the following simulations: a. DC Sweep Lab Exercise Experiment # 3 RC and Op Amp Circuit Part I: 1. Build the high pass filter designed (Fig. 1) in the Pre-Lab 2. Run an AC sweep from 10Hz to 10,00Hz with a waveform amplitude of 10vac. Set the driving device to be the Agilent 33120A function generator and the reading device to be the Agilent 34401A multimeter. Use 20 steps per decade. a. Save the waveform to the buffer and go to the buffer menu. Select the waveform to save it, and then use the cursors to identify the -3dB point. How close is this from the design value? What could cause this error? b. Print out plot with log-x and dB-y axis c. Measure the exact value of the capacitor using the capacitance meter and measure the exact value of your resistance. d. Recalculate the -3dB point using the measured capacitance and resistance value. 3. Build the low pass filter designed (Fig. 2) in the Pre-Lab. 4. Run an AC sweep from 10Hz to 10,000Hz with a waveform amplitude of 10vac. Set the driving device to be the Agilent 33120A function generator and the reading device to be the Agilent 34401A multimeter. Use 20 steps per decade. a. Again, use the cursors to identify the -3dB point. b. Print out the plot with log-x and dB-y axis Part II: 1. DC Sweep: a. Build the inverting amplifier that you designed in the pre-lab. Select the DC sweep from the lab workbench software. Sweep parameters: Initial 0V, end voltage 2V, step voltage 50mv. Use the update parameters to set the values. Configure the multimeter for DC volts. Save your waveform to the buffer to be printed out and turn in with your lab data. 2. AC Sweep: a. Run an AC Sweep from 100Hz to 100,000Hz with a waveform amplitude of 200mV with 20 sweeps per decade. b. Print the plot with a log-x and dB-y axis. c. What frequency is the -3dB point? How does this compare to PSpice? 3. Transient: a. Using the function generator, select a sinusoid with an amplitude of 100mV (200mV peak to peak) and a frequency of 1kHz. b. Using the oscilloscope, measure the maximum output voltage in the positive and negative halves of is cycle. c. Adjust the amplitude of the function generator until you observe clipping of the wave form. d. Do a scope capture to be turned in with your lab to show clipping e. At what value does clipping occur? Why? f. How does this compare to PSpice? Data Sheet Experiment #3 RC and Op Amp Circuit Part I: 2. a. -3dB point of high pass filter. ____________ b. % error from PSpice ____________ c. What could have caused the error? 2. d. -3dB point recalculated ____________ 4. a. -3dB point of low pass filter ____________ b. % error from PSpice _____________ c. What could have caused error? Part II: 2. c. -3dB point of op-amp Measured: _____ PSpice: _____ % error from PSpice ____________ 3. b. Maximum output voltages ____________ ____________ 3. e. When does clipping occur? Vin = ____________ Vout = ____________ Why? 3. f. How does this compare with PSpice?