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| PHY575 - Summer I |
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Course Grading
Each of the 20 daily reports will be graded on a 0 to 5 point scale resulting in a grade on a 100 point scale for the course. http://observe.phy.sfasu.edu/~ast305/Bruton/LectureSyllabus.doc All of the reports are due by 5:00 PM on July 14, 2008 (rather than July 3rd or 11th).
July 3, 2008 Finalize all of your daily reports.
Describe what future work can be done in your narrative for this day.
July 2, 2008
Modify the theoretical calculation for June 23, 2008 so that the magnet is rotating rather than moving along the z-axis.
Use this word document as a template for your work. Include a link to your word document in your report for this day.
July 1, 2008 Use Alt-Print screen to capture an image of your final equation from the July 23rd assignment.
Paste this image into your report for today.
[That's the EMF as a function of d, A, w, t, R, and the magnetic moment m.]
After this image, paste the following questions into your report. Answer each of the questions in your report for today.
Use the words "double", "trippled", "decreased by 1\4", etc. in your answers. You may have to approximate trends.
1. What happens to the EMF if the radius of the loop is doubled?
2. What happens to the EMF if the distance of the magnet is doubled?
3. What happens to the EMF if the amplitude of vibration of the magnet is doubled?
4. Based on your findings from question 3, is it better to have magnet in the middle of the belt or toward the fixed ends of the belts?
5. What happens to the EMF if the frequency of vibration is doubled?
6. In your opinion, changing which of the following will help us to best maximize the EMF: d, A, or, R?
[Dr. B thought question: Would an Excel surface plot help us find "peak" performance?]
June 30, 2008
Investigate the effects of low wind speeds on each of the following types of inexpensive belts:
1. Purple Ribbon
2. Clear Mylar
3. 35mm Film
4. Gray Duct Tape
5. Another of your choosing
Make sure that they are the same length during your testing.
Note that Dr. B has samples already prepared for items 1 thru 4 above in room 315A (back room).
Vary the tension during testing using the wing nuts.
Answer the following questions in narrative form in your report for this day.
1. Which type of belt performed best?
2. Did all of the belts work under all three fan speeds?
3. Which will work best in a mircowind environment?
4. What effect did magnet placement have on the frequency of oscillation?
June 26, 2008
Locate a battery powered magnetometer from the PHY242 storage area.
Measure the magnetic field at say 1 cm increments above the disc magnets
until the magnetic field goes to 0 or you have 20 or so measurements.
Include in your report a table with columns labeled z(cm), B(T), and m(A m^2)
where m is calculated using the magnetic field of a dipole is given here:
Hint: Note that the r vector just becomes a z vector for this experiment.
Remember to use 4 Pi and epsilon naught.
June 25, 2008
Use you theory results to complete the EMF column of this spead sheet.
Include a link to your spread sheet solution. June 24, 2008
Continue to work on the design and theory. Remember to take the time derivative.
Include a link to your word document solution.
June 23, 2008
Continue to work on the design and try to make the device as simple and small as possible.
Homework - Theory Development
Suppose that a magnetic dipole (magnet) is located at a distance of d from the center of a circular loop of wire of radius R. Assume that the dipole is oriented with its axis perpendicular to the plane of the loop and that it moves up and down along the z-axis as follows: zm(t) = d + A sin(wt). Find the voltage induced in the loop as a function of d, A, w, t, R, and the magnetic moment m.
The magnetic field of a dipole is given here:
You will need to use Faraday's Law to find the EMF (i.e. the voltage):
You can find the solutions to integrals here:
Type in your solution into a this word document and use Equation Editor for all equations.
Hint: See the engineering paper page taped to the chalkboard.
June 19, 2008
Analyze the circuit used for a solar cell battery charger provided by Dr. B.
Create the circuit in Electronics Workbench and include a link to this file.
Use Alt-Print-Screen to capture a JPEG image of your diagram and include it in today's report.
June 18, 2008
Build this real circuit: http://www.creative-science.org.uk/gensimple2.html
Also, create the circuit in Electronics Workbench and include a link to this file.
Use Alt-Print-Screen to capture a JPEG image of your diagram and include it in today's report.
June 17, 2008
* Look for web links showing circuit diagrams for that will rectify AC and charge a capacitor or rechargeable battery.
* Be prepared to build this circuit: http://www.creative-science.org.uk/gensimple2.html
* Will the circuit from a disposable 35mm camera work as far as charging a capacitor?
Add links to these YouTube videos to the appropriate logs/dates below:
Izzi's Windbelt
June 16, 2008
Connect an LED to your coils. Shake a magnet inside the coil.
Include a video demonstrating any successes. Also include this link in your report:
In your report mention that the magnets can be purchased from
www.rare-earth-magnets.com. What is the cost and dimensions of these magnets?
Discuss how moving the magnet in the center of the coil
might be different that moving the magnet just outside the coil.
Go back to all of your log entries so far and make the following modifications:
* Make sure that the all of the dates below appear in your report and that the requirements are met.
* Keep the entire report under one web page rather than have a new page for each day.
You may continue with your report style for you own use but email Dr. B
your new link for the non-paginated report.
June 12, 2008
* Begin to create the 2 coils for the button magnet wind belt. Include in your
report the estimated number of turns and the dimensions of the coil.
June 11, 2008
Continue soldering of the voice coil and begin to create the 2 coils for the button magnet wind belt.
June 10, 2008
Include in your online report a description of some of the difficulties experienced with you voice coil windbelt.
Describe the soldering process, etc.
This site says that there may need to be 500 to 1000 turns:
So, is the video here a result of the camera picking up infrared? We'll test with a camera.
June 9, 2008
Solder and LED to your voice coil using magnet wire.
Consider using 2 LED in parallel oriented in opposite directions
so that they pulse in an alternating fashion.
June 5, 2008 1. From this image estimate the number of coil layers from the coil drawing and then calculate the number of turns. Show your work on your website. 2. Continue working on the Windbelt that uses the voice coil.
June 4, 2008 Write a summary of your act ivies in the machine shop and include a link (or embed) this video in one of your daily reports.
June 3, 2008 Write a summary of today's activities (below) and include it on your website. Remember to include the date. 1. Use the ribbon provided (24 inches) and located some masses with mass hangers and a fan. For the three fan speeds determine the range of masses that result in aeroelastic flutter. Include a table with your results on your website and a description of this experiment. 2. Dismantle an old hard drive and construct this version of the wind belt based on your results above.
June 2, 2008 1. Who developed the “Wind Belt” device? Include in your answer the following: ÿ Where does he work?
ÿ A link to the Popular Mechanics movie on Wind Belts
ÿ A link to the wind belt developer’s website
ÿ A image of a Wind Belt
ÿ A diagram that shows how to construct a Wind Belt
2. What material is used for the black belt of the wind belt? What other components make up this device?
3. What is “aeroelastic flutter” and how is it related to the 1940 Tacoma Bridge collapse? Is it just wind generated resonance?
Include links to support your answer and include a movie of the bridge collapse.
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