# ATAT 105 Mandatory Project 105-2 EXAMPLE |Student Name|Student #|Section| Date |Sign|Stamp| |--|--|--|--|--|--| |$\qquad\qquad\qquad\qquad\qquad\qquad\qquad$|$\qquad\qquad\qquad$||$\qquad\qquad\qquad$||| >105-2 >Circuit calculations using laws and theorems associated with AC circuit analysis and demonstrate the proper use of test equipment to measure voltage, current, reactance and frequency in AC circuits, using an oscilloscope and other common measuring devices. --- ## Calculations ![[Pasted image 20211206110100.png|350]] Calculate the capacitive reactance, impedance and voltage drops across the resistor and capacitor of the circuit shown above and record your answers in Table A. Demonstrate that you know how to use the following formulas: $ X_C = \frac {1}{2 \pi fC}$ $ Z = \sqrt {R^2 + (X_L -X_C)^2} $ ![[Pasted image 20211206100824.png|Table A]] ## Measurements Enter all measurements in Table B. Turn on the waveform generator and set it up as follows: a) Sine wave output b) Output load ‘High Z’ c) Frequency 100 Hz d) Amplitude 10 V_PP Turn on the oscilloscope and set it up as follows: Channel = 1 Probe = x10 (10:1) Vertical Scale (Voltage range) = 2 V/div Horizontal Scale (Time Base) = 5 ms/div Trigger Channel = Ch. A Trigger = Auto Trigger Type = Edge Trigger Direction = Rising Trigger Threshold = 0V Measure resistor R1 using DMM to determine the actual resistance (Ω). Connect the 270 ohm resistor and the 2.2 µF capacitor in series with the waveform generator, as shown in the schematic diagram in Step 1 and the image below. ![[Pasted image 20211206101429.png|350]] Using a scope probe, connect the oscilloscope Channel 1 to the input of the circuit. Enable the output on the waveform generator and using the oscilloscope, verify that it is outputting the proper sine wave. What is the measured frequency of the input signal? <br> What is the measured V_RMS of the source signal? <br> Switch off the generator output. Remove connecting link ‘A’ from your circuit and connect the multimeter in series. Select ‘ACI’ function on the multimeter to measure the AC current. Enable the output from the waveform generator and record the current reading at point ‘A’. What is the measured current at "A"? <br> Switch off the generator output. Remove multimeter leads from the circuit. Replace link ‘A’. Move RED multimeter test lead to the socket marked ‘V’. Setup the multimeter to read AC voltages by pressing the ‘ACV’ button. Connect the multimeter leads across the resistor (parallel) to measure the voltage drop across the resistor. Enable the output from the generator and record the voltage drop across the resistor. What is the measured voltage over R₁? <br> Disconnect meter leads from the resistor and connect them across the capacitor. What is the measured voltage over C₁? <br> ![[Pasted image 20211206102519.png|Table B]] Change the waveform generator frequency to 1 kHz and repeat and record all measurements. --- Q1. Calculate the impedance of the circuit using your measured values for current and voltage using the following formula: $ Z = \frac {V_{RMS}}{I_T}$ Q2. Z@100Hz = Q3. Z@1KHz = Q4. How do your measured impedances compare to your calculated impedances? <br> Q5. Name two factors that could cause a discrepancy between calculated and measured values. <br> ---