N52 Neodymium Magnet Wheel: Output Current Drops at High Speed in Copper Coil Experiment

Hi Experts,

   I'm doing an experiment of Electromagnetic Induction (producing current by changing magnetic field i.e. by circulating magnetic wheel of N52 Neodymium Magnets around copper coil),

but what i found

when the speed of wheel is HIGH, the Output Current is LOW (in range of .02 microAmp) &

when wheel is about to stop i.e. when its speed is LOW, the Output Current is HIGH (in range of .11 microAmp)

check the video once (https://www.youtube.com/watch?v=absyXy_KC1c),

 

Kindly suggest where i'm doing wrong or what i need to change in my experiment, because as per Faraday's law, more frequent change in magnetic field produces more current, but its not seen in my experiment


Kindly help

Thanks in Advance
Ashish
 

Hi,

First of all, in that setup of yours, you can see that the magnets are small and distant apart. The current if induced if there is a change in the magnetic flux of the coil. Like in this video, https://www.youtube.com/watch?v=gZpa7FYR_pw, the magnetic flux is cut faster. Look at this way, the direction of the flux is a bit weaker when done in that way. Review "right hand rule('')":https://www.khanacademy.org/test-prep/mcat/physical-processes/magnetism-mcat/a/using-the-right-hand-rule

Hi Kevin,

Thanks for such quick reply, & i like to add,

* Magnets are small but they are Neodymium N52 Magnets, which are having quite strong magnetism for such projects, what you say,

* So should i try to place them near, as you said "they are distant apart", in that case, i need to place them near with *opposite polarity*,
ok, i'll try & let you know the findings for the same.

but i like to know, if there any more changes, u think, i should do, as i need to generate current via magnets in the same setup i.e. via circular disc & copper coil.
(as in other video, which u shared, in that magnets are going up-down across the coil) that scenario i know, but i need to check this other scenario i.e. with circular magnetic disc.

Thanks in Advance
Ashish

Hi,

I tried putting multimeter at AC volts, but its showing zero reading, maybe because output voltage is too low, as output DC current was in microampere.

I tried with putting load (resistor) at the copper wire ends, to measure output voltage or current, but condition remains the same.

I also tried to put magnets close to each other with opposite polarity, but still condition is same.

Kindly suggest, if anything else i can do, to make experiment working properly.

Thanks in Advance
Ashish
lightenmyways.blogspot

How many turns in the coil ?

One good turn deserves another.

Faraday's law is all about a *changing* magnetic field. My guess is what your seeing is the greatest *change* of a magnetic field from when you go from a constant motion to stopping. In fact in you removed a bunch of the magnets from your wheel while maintaining the same angular frequency I'm guessing you'd probably see a larger current output. I'm guessing this would be due to the copper coil seeing a larger *change* in the magnetic field.

On another note I believe that the speed with which a coil cuts through the magnetic flux ( as in an AC generator) primarily affects the frequency output and not the magnitude of the waveform.