Design Efficient Permanent Magnet Flux Capture Inductor

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claudius2u

Joined Jul 16, 2011
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Does anyone have knowledge for or experience of permanent magnet flux maximized transference across a gap?

This project calls for maximum flux transfer from rotating magnets to a pick-up coil or other device.
 

Kermit2

Joined Feb 5, 2010
4,162
Maximum flux transfer occurs when one uses a ferromagnetic material, decreases the distance between magnet and ferromagnetic material(minimal air gap), and provides ample cross sectional area to conduct the flux.

On the other hand, larger masses of ferromagnetic material will increase the hysteresis and create a greater time lag between magnetization cycles.

You will find that 'maximum' flux transference, and high frequency of magnetization cycles are not mutually obtainable goals. Some trade-offs will have to accepted. lower maximums for higher frequency, etc.
 

Thread Starter

claudius2u

Joined Jul 16, 2011
0
Thank you, Kermit! [See below . . .]

Maximum flux transfer occurs when one uses a ferromagnetic material, decreases the distance between magnet and ferromagnetic material(minimal air gap), and provides ample cross sectional area to conduct the flux.

On the other hand, larger masses of ferromagnetic material will increase the hysteresis and create a greater time lag between magnetization cycles.

You will find that 'maximum' flux transference, and high frequency of magnetization cycles are not mutually obtainable goals. Some trade-offs will have to accepted. lower maximums for higher frequency, etc.

May I take it that you've some experience with magnetic flux transferring?

This application is on a bicycle. My aim is to design a minimum drag with spoke-mounted PMs that pass through one or more " C " shaped low reluctance cored inductors where one end picks up the "south" PM pole and the other the "North" pole.

Of course some physical properties, such as hinging to open for wheel removal are needed, but the main challenge is to maximize the flux transference.

From this pick up the idea is to excite a solid state Bedini oscillator that in turn excites a BiTT circuit that is running at its natural frequency. From that a regulator and storage setup.

I appreciate your response, Kermit.
 

wayneh

Joined Sep 9, 2010
17,498
Does anyone have knowledge for or experience of permanent magnet flux maximized transference across a gap?

This project calls for maximum flux transfer from rotating magnets to a pick-up coil or other device.
The power transfer will depend directly on the air gap, and so a large challenge is the machining tolerances required to pass the magnet thru the gap, especially since it is attracted to the core.

Another design consideration is your wire gauge. With a given core and target volume for the device, wire gauge of the coil is one of the few things you can control. Anyway, you get more emf with higher gauge (finer wire) but this adds both DC resistance and inductance, causing impedance rising with frequency. At low rpm, the inductance may not matter much but at higher rpm the impedance will be primarily from the inductance and the DC resistance will be insignificant in comparison. Choosing wire that is too large will limit the loops you can cram in, and thereby limit emf. And it can be hard to wind.
 

bertus

Joined Apr 5, 2008
22,278
Hello,

You can not have "free" energy.
As we do not allow ANY overunity circiuts ove here, I will close this thread.

Read the following thread why:
Perpetual motion
No more HHO, overunity, or Meyer

Also the ToS has somting to say about it:

6. Restricted topics. The following topics are regularly raised however are considered "off-topic" at all times and will result in Your thread being closed without question:

  • Any kind of over-unity devices and systems
  • Automotive modifications
  • Devices designed to electrocute or shock another person
  • LEDs to mains
  • Phone jammers
  • Rail guns and high-energy projectile devices
  • Transformer-less power supplies

If You come across a thread or post discussing any of the above topics please report the thread so We can close, and if necessary remove, the offending thread/posts.

Bertus
 
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