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Old 07-13-2012, 12:15 PM
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lamare lamare is offline
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Originally Posted by john_g View Post

Can you clarify the winding direction of the coils? A few of us are ready to wind up. Are the pairs of coils say wound both clockwise when viewed side-on, or is one clockwise and the other anticlockwise?

I presume the pattern shown in the picture is repeated by moving forward one slot, etc.
If I understand this correctly, the difference between this kind of winding and a traditional winding is that this is in essence a unidirectionally steered motor, in that sense that the coils are always excited in the same direction. In other words: there is no forced reversal of polarity.

What this does, is first of all establishes a closed magnetic loop trough the poles, which normally maintains itself nicely just as with a PM, as can be seen from Leedskalnin's perpetual motion holder:

Edward Leedskalnin's Perpetual Motion Holder

The magnetic force maintained in this loop is a dynamic force, much like a flowing waterfall, which in the static case exerts a force that is balanced across the poles, symmetric, and therefore no resulting force.

However, with a gentle unidirectional tickling of the coil, you can bend this already existing force, such that you create an imbalance in the system, and you get some asymmetry, which gives you a torque.

The problem with the normal way of winding is that because of the disruptive switching characteristics of the commutator, you use a lot of brute force to enforce sudden changes of the magnetic field trough your poles, which is expensive in terms of energy. With the overlapping way of winding AND uni-directional steering, you don't get these brute sudden changes in the magnetic field, but you allow it to change gradually.

In other words: with UFO's way of winding YOU only have to provide the energy needed to "bend" or "redirect" the already existing magnetic field, while with the normal way of winding YOU have to spend a lot of energy to kick the magnetic field back and forth between two extreme "redirection" positions for no reason at all.

Very, very interesting design.
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