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Old Nov 28, 2012, 11:30 AM
Alan Hahn is offline
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Joined May 2006
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You can look at this stuff in many different ways.

On the lowest level, you have the fundamental Lorentz Force.

However you can look at it also as the interaction of two magnetic fields that are trying to align themselves in an anti-parallel (e.g N-S, S-N) fashion.

Any moving current generates a magnetic field around the wire carrying the current. The vector sum of all these little current carrying segments produce the equivalent of a larger magnetic field.

The advantage of a coreless motor is less inertia to movement---it can accelerate faster. Also since there is no core (=iron type material) that is being magnetized by the current, you have no hysteresis or eddy current losses. However a core is like a magnifier of the field generated by the windings. In other words you get a stronger magnetic field with less current. So a coreless motor is likely to have more resistive losses than an equivalent core motor that is making the same torque.

So you win and you lose some!
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