Objectives The purpose of this laboratory project is to introduce to equipment, measurement techniques, and simulations commonly used in C circuit analysis. In this laboratory session, each student will: 1. Learn how to use an LCR meter to make measurements 2. Learn how to measure phase differences within an C circuit. 3. Learn to input and analyze C circuits using SPICE in both the time and frequency domain. 4. Compare calculations, simulations, and experimental measurements. Pre-laboratory Work Must be completed and submitted prior to making measurements. Pre-laboratory nalysis for Circuit 1 3.3K C1 10n Fig. 1. Resistive-capacitive circuit for analysis. 1. Hand Calculations (in a manner suitable for submission) For the circuit in Fig. 1 with f = 5kHz and a source v ( in t ) 1.0cos 2 f t V applied at the circuit input (between points and ), calculate by hand the voltage v 1(t) at the input and the voltage v 2(t) at the output (between points and ). 2. Spice Time-omain nalysis 1) Enter the circuit from Fig. 1 into 2Sspice (labels,, and not required) a) Show node numbers. b) Save this circuit. 2) dd the following instruments: a) Function Generator at the circuit input, that is, between the node corresponding to point and ground (ref. node 0) with an amplitude of 1.0 (V), a sinusoidal frequency of f = 5kHz with no offset. b) Oscilloscope with two traces: Trace 1 across input (check show), Trace 2 across output (between the node corresponding to point and ground (ref. node 0)). Check Show. 3) Run Simulation (push ouble Green rrows to start a simulation) Note: if you need to make any changes to the simulation set-up first stop and reset the simulation. 4) Select Export under the Oscilloscope Set-up to create a plot to be saved. Page 1 of 6
a) Copy to Graph b) Use Edit xes to provide proper axis label with units (unclick selection title to allow change). c) Use Edit Plots to change trace colors and thickness. d) Use Horizontal Calipers to denote horizontal scale differences (here delta time measurements) 5) Use Export Graph under the file menu to save the desired figure in final form. 3. Repeat Steps 2 (1 5) for a frequency f = 10kHz. Pre-laboratory nalysis for Circuit 2 10 L1 0.1m Fig. 2. Resistive-inductive circuit for analysis 1. Hand Calculations (in a manner suitable for submission) For the circuit in Figure 1 with f = 5kHz and a source v ( in t ) 1.0cos 2 f t V applied at the circuit input (between points and ), calculate by hand the voltage v 1(t) at the input and the voltage v 2(t) at the output (between points and ) 2. Spice Time-omain nalysis 1) Enter the circuit from Fig. 1 into 2Spice (labels,, and not required) a) Show node numbers. b) Save this circuit. 2) dd the following instruments: a) Function Generator at the circuit input, that is, between the node corresponding to point and ground (ref. node 0) with an amplitude of 1.0 (V), a sinusoidal frequency of f = 5kHz with no offset. b) Oscilloscope with two traces: Trace 1 across input (check show), Trace 2 across output (between the node corresponding to point and ground (ref. node 0)). Check Show. 3) Run Simulation (push ouble Green rrows to start a simulation) Note: if you need to make any changes to the simulation set-up first stop and reset the simulation. 4) Select Export under the Oscilloscope Set-up to create a plot to be saved a) Copy to Graph. b) Use Edit xes to provide proper axis label with units (unclick selection title to allow change). c) Use Edit Plots to change trace colors and thickness. d) Use Horizontal Calipers to denote horizontal scale differences (here delta time measurements). 5) Use Export Graph under the file menu to save the desired figure in final form. Page 2 of 6
3. Repeat Steps 2 (1 5) for a frequency f = 10kHz. C. Operational mplifier Circuit esign 1. esign an inverting operational amplifier circuit with the following specifications: i. Input Impedance > 2kΩ ii. Power Supply: +/- 12VC iii. Vo/Vi = 10.0 +/- 5% for a sinusoidal input at 1 khz 2. Verify your design using 2Spice i. Enter the op-amp circuit you designed including power supplies into 2Spice. ii. Simulate using 2Spice.. Pre-laboratory Submission a. Pre-laboratory analysis of circuit 1 i. Hand calculations at 5 khz ii. Copy of your 2Spice time-domain results at 5 khz iii. Copy of 2Spice steady-state analysis results at 5 and 10 khz b. Pre-laboratory analysis of circuit 2 i. Hand Calculations at 5 khz ii. Copy of your 2Spice time-domain results at 5 khz iii. Copy of 2Spice steady-state analysis results at 5 and 10 khz c. Pre-laboratory analysis of operational amplifier circuit i. Schematic of op-amp circuit that you designed ii. 2Spice results that verify the specifications were satisfied for a sinusoidal input at 1 khz E. Preparation for Laboratory Measurements 1. Reading a) Oscilloscope: a. Read about how to use cursors to measure time differences.(find the manual on EE webpage https://www.uwplatt.edu/files/college-ofems/pfs/electrical_engineering_laboratory_manual.pdf). b. Read about how to convert time-shifts to phase-shifts. b) LCR meter: Read about how to use to make R, L, and C measurements. 2. Obtain the following items: 1. Resistors (values needed = 3.3kΩ and 10Ω) 2. readboard 3. Components needed to construct the op-amp that you designed in the pre-laboratory analysis. You will not receive credit for laboratory measurements unless your pre-laboratory analysis is submitted prior to the due date. Page 3 of 6
F. Phase ifference Measurement Suppose two sinusoids v 1(t) and v 2(t) have the waveforms shown in Fig. 3. Fig. 3 shows two sinusoidal signals phase-shifted relative to each other to illustrate the measurement procedure. The phase angle (in degrees) of v 2(t) relative to v 1(t), denoted as (V 2/V 1), can be calculated from the time difference (T d), assuming the frequency is f a: Td ( V2 / V1) 360 360T d fp, since period T p = 1/f a and v 2(t) lags v 1(t) (hence the T p negative sign). The value of T d shown in Fig. 3 can be measured with the cursors. Laboratory Procedure. Measuring Phase ifferences for RC circuits 3.3K C1 10n Fig. 4 shows the RC circuit for phase measurements. Page 4 of 6
1. Use the LCR meter to measure the actual resistor and capacitor values that will be used to construct the circuit in Fig. 4. 2. Construct the circuit in Fig. 4 on your breadboard. 3. Turn on your oscilloscope and verify proper operation of both scope probes. 4. ttach an oscilloscope probe to CH 1 with the probe tip located at point and the reference at point. 5. ttach another oscilloscope probe to CH 2 with the probe tip located at point and the reference at point. 6. djust your signal generator so that it provides a 5kHz input signal (CH 1) at 2V pp 7. Save a copy of the input and output waveforms from Channels 1 and 2 a. Use the computer to take a screen shot of the oscilloscope display: i. Log into the computer on the workbench. ii. Start the Wintek32 software by clicking on the wintek32 icon on the computer display or searching for Wintek32. iii. Select a name for the downloaded image file by clicking on File and then Target file. iv. Press the Run/Stop button on the oscilloscope. v. Press the Hardcopy key to download the image from the oscilloscope screen to the selected computer file. (This is a slow process; be patient.) 8. Measure the phase time shift between the waveforms using cursors. (Save an image of the scope trace used to determine phase time shift) 9. etermine the period of the waveforms. 10. etermine the phase shift from the period and the measured phase time shift. 11. Compare with the values obtained in your pre-laboratory analysis. 12. Repeat for a 10kHz input signal (CH 1) at 2V peak-to-peak.. Measuring Phase ifferences for RL circuits 10 L1 0.1m Fig. 5 shows the RL circuit for phase measurements. 1. Use the LCR meter to measure the actual resistor and inductor values that will be used to construct the circuit in Fig. 5. 2. Construct the circuit in Fig. 5 on your breadboard. 3. ttach an oscilloscope probe to CH 1 with the probe tip located at point and the reference at point. Page 5 of 6
4. ttach another oscilloscope probe to CH 2 with the probe tip located at point and the reference at point. 5. djust your signal generator so that it provides a 5kHz input signal at 2V peak-to-peak. 6. Save a copy of the input and output waveforms from Channels 1 and 2. 7. Measure the phase time shift between the waveforms using cursors. (Save an image of the scope trace used to determine phase time shift) 8. etermine the period of the waveforms. 9. etermine the phase shift from the period and the measured phase time shift. 10. Compare with the values obtained in your pre-laboratory analysis 11. Repeat for a 10kHz input signal (CH 1) at 2V peak-to-peak. C. esign and Construction of an Inverting Op-mp Circuit 1. uild the inverting operational amplifier circuit and document the gain (V o/v i) and phase at a source frequency of 1 khz (document with a scope image). 2. Experimentally determine the input voltage range for which the specification. a. V o/v i = 10.0 +/- 5% is valid (document with scope images). 3. Compare with your pre-laboratory analysis. Check off 1. Show your instructor the collected data. 2. Show the waveform of the op-amp circuit on the oscilloscope. 3. e prepared to answer laboratory related questions. 4. Submit data to the data dropbox for project 1 (single pdf only). Report Use the Informal Report template as shown in: https://www.uwplatt.edu/files/college-ofems/pfs/electrical_engineering_report_formats.pdf 1. Include all measured data. 2. Include the following sections: a. Header b. Summary c. Schematics d. Testing e. iscussion i. e sure to compare the simulated results to the measured results. f. References (if used) Page 6 of 6