Day Nineteen - Phasors: Passive RL Circuit Response 5/11/17

Hello guys, today we talked about Phasor. wow.
Phasor is usually used in AC analysis.
Phasor is usually represented by complex number (rectangular), polar form R(angle), and exponential form.

In our calculation, the phasors are always calculated through the rectangular and polar form.

Note that, when we are adding the phasors together, phasor with different frequency(or omega) can not add up together.

This cheatsheet is very important.

Lab:

Pre-Lab

The cutoff frequency for 1mH and 470Ohm resistor is 47000/2Pi = 7480Hz
The frequency with one tenth of cutoff frequency is 748Hz
The frequency with ten times of cutoff frequency is 74800Hz

With ten times the cutoff frequency, the phase difference is (3.102)/(13.5)*360 = -82.72degree,
and the gain is 2.155(mA)/223.2(mV) = 0.009655

With the cutoff frequency, the phase difference is (16.87)/(135)*360 = -44.9degree,
and the gain is 13.28/668.3 = 0.01987

With one tenth of cutoff frequency, the phase difference is (0.03)/1.45 = -7.448degree,
and the gain is 0.001675/1.013 = 0.0016535

Comparing our calculated values with measured values:

From the data, I can conclude that we successfully finished the lab, especially on the phase difference, we have an excellent data. However, things can improve, especially on the small angle. For the small angle, a more precise data can be achieved for analysis for less error.

Summary:
Today, we talked about phasor for AC circuit analysis, and we finished the lab which describe the nature of phasor. The phase difference occurs depend on the element in the circuit. and with different frequency, we may have different phase difference and gain.