Some nice videos demonstrating the huge effect of eddy currents and the benefits of statorlamination (or even rotor/magnet 'lamination'):
http://demoroom.phys.../demos/163.html
http://www.vuw.ac.nz/scps-demos/Demos/Pira...s/Aluminium.mp4
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eddy current effect videos
#2
Postat 18 January 2006 - 08:06 PM
Nice. There's another experiment I heard of. Never tried it myself but I guess they are related somehow.
Take a straight copper pipe. Then, get a cylindrical Neodymium magnet that loosely fits the inner diameter of the pipe. Hold the pipe vertically and slip the magnet inside the pipe hole. How long do you think it's going to take for the magnet to reach the bottom end of the pipe? Welll, the answer is "Longer than you might expect." I believe it's Eddy current related too.
Have fun,
Cirip
Take a straight copper pipe. Then, get a cylindrical Neodymium magnet that loosely fits the inner diameter of the pipe. Hold the pipe vertically and slip the magnet inside the pipe hole. How long do you think it's going to take for the magnet to reach the bottom end of the pipe? Welll, the answer is "Longer than you might expect." I believe it's Eddy current related too.
Have fun,
Cirip
Teorie este atunci cand stii totul, dar nu merge nimic.
Practica este cand toate merg, dar nu stii de ce.
Montajele mele imbina teoria cu practica: nu merge nimic si nu stiu de ce.
Practica este cand toate merg, dar nu stii de ce.
Montajele mele imbina teoria cu practica: nu merge nimic si nu stiu de ce.
#3
Postat 23 January 2006 - 02:11 AM
Yes it is true.
Basically your magnet creates a variable magnetic flux through the pipe's "flesh" and thus an electric field is created which in turn generates an electric current through the pipe's metal (flesh). This electric current (according to Faraday's induction law; particulary the consequence called Lenz law) generates an opposite magnetic field that will brake the magnet that falls through the pipe.
There was a problem given in a physics olympiad and many undergraduate classes in Physics (USA) use this problem to show the effects of the electromagnetic induction.
A good link about this: http://my.execpc.com...ey/magpipes.htm
Another link with a pdf file that shows some dimensional analysis on the phenomana: http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
One can deduce the analytical relation that expresses the law of motion of the magnet through the pipe.
Another application of these basic laws of electromagnetism is the flying non-supraconductor saucer. I tried it during the High School and one can find the description of these in many books that deals with physics applications. One can take a saucer shaped object built from aluminium (or other good conductor... I chose aluminium because it is a good conductor and it is light). Put this object on top of a coil (for details I can send e-mail) that creates a variable magnetic field. This generates Eddy (or so called Foucoult currents) in the flesh of the saucer and thus the saucer levitates if the strength of the inductor magnetic field is large enough...
Best regards,
MIG-29
Basically your magnet creates a variable magnetic flux through the pipe's "flesh" and thus an electric field is created which in turn generates an electric current through the pipe's metal (flesh). This electric current (according to Faraday's induction law; particulary the consequence called Lenz law) generates an opposite magnetic field that will brake the magnet that falls through the pipe.
There was a problem given in a physics olympiad and many undergraduate classes in Physics (USA) use this problem to show the effects of the electromagnetic induction.
A good link about this: http://my.execpc.com...ey/magpipes.htm
Another link with a pdf file that shows some dimensional analysis on the phenomana: http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
One can deduce the analytical relation that expresses the law of motion of the magnet through the pipe.
Another application of these basic laws of electromagnetism is the flying non-supraconductor saucer. I tried it during the High School and one can find the description of these in many books that deals with physics applications. One can take a saucer shaped object built from aluminium (or other good conductor... I chose aluminium because it is a good conductor and it is light). Put this object on top of a coil (for details I can send e-mail) that creates a variable magnetic field. This generates Eddy (or so called Foucoult currents) in the flesh of the saucer and thus the saucer levitates if the strength of the inductor magnetic field is large enough...
Best regards,
MIG-29
Aceasta postare a fost editata de MIG-29: 23 January 2006 - 02:17 AM
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