Day 21

In this lab assignment, we will be concerned with the steady-state response of electrical to sinusoidal input. the input and output signals both have the same frequency, but the two signals can have different amplitudes and phase angles.

in the pre-lab, we going to derive formula, and use it.

the circuit is set up with 2 10KOhm, 1 1uF capacitor, and a op amp. 

Vin and Vout with frequency 100Hz

Vin and Vout with frequency 1KHz 

Vin and Vout with frequency 5KHz 

summary table,  

final table with gain and phase under the different frequency.

In this lab, build a oscillator on EveryCircuit.

during the building circuit, we are going to build a 99Hz. We calculate theoretical value for the pot, which is 8371Ohm.

the circuit is set up.

the picture is about Vout, the frequency is 99.8, its percent different is 1%.  

Day 20

In this lab assignment, we will be concerned with the stedy-state response of electrical circuits to sinusoidal inputs The input and output signals both have the same frequency, but the two signals can have different amplitudes and phase angles.

 

In the pre-lab, we have three dfferent frequency, Wc, Wc/10, and 10Wc, and Wc is 2.2*10^5 Hz.

We also find the cutoff frequency for the circuit:

                                 W:                  Wc                       Wc/10                   10Wc

                                              0.0321 /-45Ohm        0.0452/-5.711Ohm   4.52/-83.4 mOhm

A 22Ohm resistor and a 100uH inductor are used to set up circuit. 

f=35KHz, Vin=989.4mV, and I=31.25mA. we got 0.0316/-37.8 ohm.

 f=3.5k Ohm, Vin=973.4 mV, and I=38.55 mA. we got 0.0452/-6.3 Ohm.

  f=350k Ohm, Vin=994.8 mV, and I= 5.665 mA. we got 5.695/-78.12 mOhm.

Summary table. 

Day 19

Impedance

In this lab assignment, we measure impedes of resistors, capacitors, and inductors. The measured values will be compared with our expectations based on analyses. 

In the pre-lab, we calculate the impedance for RR, RL,and RC circuit.

The RR circuit is set up.

This picture is about the RR circuit with 1KHz. Vt= 1.354 V, I=13.2 mA. 

This picture is about the RR circuit with 5KHz. Vt= 1.354 V, I=13.2 mA.  

 This picture is about the RR circuit with 10KHz. Vt= 1.354 V, I=13.2 mA. 

The picture about resistor impedance = 47+ R, and the experiment value of resistors are 46.6Ohm and 99.9Ohm. so the experiment impedance is 146.5, its percent is 0.34%. 

The RC circuit is set up.

 This picture is about the RC circuit with 1KHz. Vt= 0.2652 V, I=40.05 mA.

  This picture is about the RC circuit with 5KHz. Vt= 1.0584 V, I=34.2 mA.

  This picture is about the RC circuit with 10KHz. Vt= 1.546 V, I=25.4 mA.

 A 2V sine wave  power is applied into a RL circuit.

 The RL circuit is set up

 This picture is about the RL circuit with 1KHz. Vt= 1.999 V, I=1.05 mA.

 This picture is about the RL circuit with 1KHz. Vt= 1.9774 V, I=4.955 mA.

  

This picture is about the RL circuit with 10KHz. Vt= 1.924 V, I=9.475 mA. 

When  different frequencies of 1kHz, 5kHz, and 10 kHz frequencies. In the capacitor circuit the current leads voltage by 90°

Summary:

Today, we learn that a resistor AC circuit has no phase change between the voltage and current.

And at the same time, the voltage lead the current by 90 degree with inductor. The current lead the voltage by 90 degree with capacitor.

Day 18

The oscilloscope is a tool, with can transfer the unable see sign to become able to see. it is helpful for most electric lab. The oscilloscope uses small and quick speed light, and put it to screen. Then this light can move on the screen. We can use this to observe how the light change on the screen, so we can use it to observe voltage, current, frequency, and amplitude.

Day 17

RLC Circuit Response

This lab will emphasize modeling and testing of a second order circuit containing two resistors, a capacitor, and a n inductor. In this assignment, the step response of the given circuit is analyzed and tested. The measured response of the circuit is compared with expectations based on the damping ratio and natural frequency of the circuit. 

In the pre-lab, we calculated the value depends on given value, R1=47, R2=1.1, C=10uF, L=1mH. and according the image of setting up, the R2 and L is series, and C is parallel with R2 and L, then R1 series with all of them.

The circuit is set up on breadboard. 

The picture is about input power, This is a square wave with 100Hz, its peak is 2V with offset 0. 

The picture is Vout.

                                 R1                      R2                       C                          L

experiment value       49Ohm                4.3Ohm              9.92uF                 cannot measure

In the lab, we calculated value of α is 3588.7, but the theoretical value is 1063.8. Its precent difference is -237.4%. 

Summary:

Today, we learned how to calculate the resistor, capactior and inductor in parallel.

Day 16

Series RLC Circuit Step Response

This lab will emphasize modeling and testing of a series RLC second order circuit. This lab assignment will consist of two parts:

In Part I of this assignment, the step response of a given circuit is analyzed and tested. The measured response of the circuit is compared with expectations based on the damping ratio and natural frequency of the circuit.

Part II of this assignment consists of a simple design problem: the circuit of Part I is to be re-designed to make it critically damped, without changing either the natural frequency or the DC gain. Again, the circuit step response is measured and compared to expectations.

 The image of circuit for setting up.

In the beginning of the lab, we are going to calculate the circuit belongs to overdamped, underdamped, or critically damped. 

In the pre-lab. we find a and w, then we find the circuit is underdamped

Then we use underdamped way to calculte.

The circuit is set up on breadboard,

 theoretical value:    the capacitor is 470 nF, the inductor is 1uH,             and the resistor is 1.1Ohm.

experiment value:    the capacitor is 420 nF, the inductor may be correct, and the resistor is 1.4Ohm.

 

The graph is about input voltage, the frequency is at 500Hz 

This is the graph about Vout

by the calculating, its w is 5.15*10^4. compare to our theoretical value 1.351*10^6, the percent different is 96.2%.

 put some data into excel, find the function is y=3.5006e^-8811x, the value a is 8811, but our theoretical value is 5.5*10^5., the experiment value is 1.6% of theoretical value.

Summary:

Today, we learned how to find solve source free RLC circuit and find boundary value. and we know there three different types of circuit, over damped, underdamped, and critically damped. 

Day 15

In this lab assignment, we will examine the forced response of a circuit which performs a differentiation  that is, the circuit output is derivative with respect to time of the input to the circuit. We will apply sinusoids of various frequencies to the circuit and compare the output with our expectations based on analysis.

In the pre-lab, we calculate Vout with different frequency 1KHz, 2KHz, and 500Hz.

Calculate the percent different about Vout with different frequency.

The circuit is set up on breadboard.

This picture shows the graph when the f=1KHz. 

In the picture, we know its peak voltage is 1.1544V, but our theoretical value is 1.388V, the percent different is 16.8%.

This picture shows the graph when the f=2KHz. 

In the picture, we know its peak voltage is 2.217V, but our theoretical value is 2.776V, the percent different is 20.1%.

This picture shows the graph when the f=500Hz. 

In the picture, we know its peak voltage is 0.603V, but our theoretical value is 0.649V, the percent different is 7.1%.

From the pictures, the percent different increase with frequency. so the error may be caused by frequency increasing.