Introduction:

Solar is one of the primary sources. Sun has almost unlimited energy source to supply our solar system. As the green house effect increases we are now start using renewable energy, and solar energy is one of them. This lab we are going to implement a series of testing on a solar panel, using a flash light to represent the sun to generate voltage. A solar panel has two different silicons, n type and p type, and between them we have a semiconductor. A solar panel will absorb sun light and separate positive and negative electron to create the current flow in order to create energy. During this lab we are going to present several test. We are going to use the flash light to light the solar cell at different height to test how much power it will create. Then we will use colored film filters to cover the light source. Then test with different color filter.

Equipment:

One solar cell

One voltage probe

One NXT adapter with NXT light sensor

Flash light

Ruler

Colored film filters

Procedure:

1. We will have the file, solarlab1.vi,  from backboard. Before we start we will need to understand how the program works, and how to record the measurement.

2. Then we start measuring how much voltage we can get from the solar cell. First we faced the solar cell to the desk, to measure the 0 light voltage. Then we will start using flash light to light the solar cell. We are going to measure five different heights, there are 0, 4, 8, 12, 16 cm.

3.Each measurement we will have 10 seconds for the program to run then we will have 10 data points. Each height we are able to find the average by using Excel.

4. Finally, we will have 4 different colored filters to cover the light source then take measurement at about 12 cm. Record all the data.

Data:

The above data shows that as the distance increase the voltage will decrease. And the graph below will have a better view of their inverse relationship.

The following table shows the voltage that we  generate with different colored filters.

This bar chart shows better view of voltage that we generate.

Conclusion:

This lab helped us to have a clear view of the future of solar energy. A single solar cell can only generate so much and the procedure of making the solar panel is also damaging the environment. Therefore I do not think that solar penal will be the solution of our current situation. Solar energy is on of the big part of our primary sources, but I think we need to find a better way to use that energy. Also this lab help us to understand different light will give us different result, brighter light gives us better result than the darker one.

Q: How long it takes to charge up a cellphone with a generator? (answer at the end.)

Introduction:

This lab we are going to generate power with a hand generator. Inside of a generator there is a magnet that moves back and forth inside a coil of wire. When we are shaking the generator the magnetic field will change as the magnet pass through the coil and the change of magnetic field will generate voltage. According to the Faraday’s Law that changing magnetic fluxes through coiled wires generate electricity also known as current and voltage. The greater it changes, the more power will generate. With NXT adapter we will be able to collect data to see how much power we have generated.

Equipment:

One generator

one voltage probe

one NXT adapter

NXT

labview VI

Excel sheet

Procedure:

1. We are provided a labview file, generator_lab.vi, to record our data. Before we start we need to understand how the file works. Once the program is running we will have 30 seconds to record the data. Each second the program will show the voltage that generated. Then VI will export the data to excel file.

2. After we connect the generator to NXT at the 1 terminal and connect the NXT to the computer we are now able to record the data. First we will shake the tube at a particular rate. As we shaking it we will also need to count the number of shake within 30 seconds.

3. After we run the program and record the data on VI there will be 30 data points each represent how much voltage you create in one second. Then We can export the data to excel, calculate the sum of the squares of the voltages (SSV). Repeat above steps 3 more times but each times with different rates of shakes.

4. After we find each SSV we are going make a plot to show our result with linear curve.

Data:

The above data table provide the proof of Faraday’s law. It shows that when the magnet inside the tube is moving forward (upward) the value we get it positive, but when the magnet is moving backward (downward) we will have negative result because the changing magnetic field can be negative. The coil in the tube did not change the direction of current flow therefore when the magnet is moving the opposite direction the data will have negative result. When we calculate the sum of squares of the voltages negative value will become positive. The table also shows us that with the number of shake increase are also increasing the generate energy.

This table will have a better view about when the number of shakes increase the sum of the output voltage increases.

The graph shows us the generated voltage is directly proportional to the number of shakes. As the number of shakes increases the more voltage we will generate, therefore the graph gives us linear relationship.

We are using about 80 mA and 110 v as input to charge up a cell phone. We need about 3 hours to get it fully charged, therefore 0.08 A*110 v = 8.8 W. With 3 hours 8.8 w *3 = 26.4 watt-hour, and it is about the same that supplying 50 watt light bulb for 30 minutes. As we can see we were be able to generate 8.423 v with 100 shakes in 30 second. So at this rate we will be able to charge a phone in 8.432 v*0.08 A=0.67456 w, and 26.4/0.67456 = 39.16 hours. So with in 40 hours with 200 shakes per minutes and no rest we will be able to charge our phone.

A: 40 hours.

Conclusion:

This lab is helpful to me to have a better view about green energy and also have a better idea how much work needed to provide certain amount of energy. It is interesting to see how much energy we will be able to produce in short amount of time. After this lab we are also be able to know the precious of energy.

During last class we were unable to connect the Robotic to the computer, therefore we moved the first experiment to this week.

Introduction:

In this experiment we are going to  present the relationship between velocity, distance and time.

We know the equation Distance  = Velocity * Time.

During the experiment we are going to connect the robot that we build from previous exercise to the computer with LabView, which contain the program that can move the robot. We can get the code from the Blackboard. In the code there are time, power, velocity, circumference, and the distance blocks. We are only be able to adjust the time, circumference and power blocks.

Procedure:

1. We have to measure the diameter of one of the wheels in order to calculate the circumference. In our case we have the diameter about 0.057 m. Following the equation we will be able to find the circumference. C = 2*pi*r=pi*d=0.057*pi=0.1790 m.

2. We set our time at 3 second. We do not want the time to be too short, because we want the robot to travel a certain distance in that case can help us to eliminate the error of the experiment.

3. The robot can only have the power range from 0 up to 75. We do not want to much power, because it will make the robot run out of the table. We picked 25, 50 and 65.

4. As we set up our constant time and power for three different trial. We hit the “run” program bottom on top of the windows. We are supposed to have 3 data for each power scale. Therefore we will have the average for each scale and total of 9 different trials.

5. We were doing the measurement on the table, so before we start we set the robot properly(make sure it will not run out of the edge of the table.). Then we mark the initial point, then we run the program. The robot will according to the power scale and time to move certain distance, then stop. We mark the final place for measurement by connecting two mark with a ruler, and record the data. On the screen, LabView will also gives us some data about the total distance and the velocity, we called it computer measurement since the calculation is doing by the instruments.

6. After we find all the data we are supposed to find the percentage error by using the following equation:

%error = [distance(measured)-distance(labview)/(measure+labview)/2] *100%

Table:

Conclusion:

This lab gives us a better idea about the relationship between time, velocity and distance. We were be able to confirm that distance is equal to time multiply by velocity. During this experiment we have some errors appeared in the table, compared to the computer’s data. The errors can comes from lots of places, such as the cable connecting between robot and the computer, or the mark that we put down for measuring. But in our group we were be able to control the error within 1.9 percent and some of them are with in 0.5 percent, which is pretty good.

During this lab, we are signed with a partner and each team gets a NXT robotics kit.

The robotic kit is from LEGO, which contain a Mindstorms NXT. A Mindstorm NXT is a programmable robotic kit.

For the first lab we did not get to the programming part, we only build the robot by following the Manuel and build the “2 Motor car.”

I am excited about the programming so we can tell the robot to do what we want.