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Discussion Starter #1 (Edited)
Most all DC (Direct Current) electric motors are either a "brush" or brushless" type.
(Permanent Magnet: type referenced)

Brush (communicator) Motors - +80% efficient
Most simply
External magnetic fields.
Surrounding an internal armature, wire wound to produce electromagnetic fields.
.
Armature
Electricity is supplied by brushes, through the communicator, to the wire windings to produce the electromagnetic fields.
These magnetic fields vary in polarity.
As the armature turns, the communicator is contacted by brushes of different electrical polarity (positive - negative) causing the electromagnetic fields to reverse.
The armature produced magnetic fields push and pull against the external fields causing the armature to turn.
educypedia.karadimov.info/library/Motor.swf
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educypedia.karadimov.info/library/Motor.swf

Advantages
Simplicity
Cost
Proven durability

Disadvantages

Efficiency loss - friction, arcing, "rough" transition of pos to neg
Wear- brushes (replaceable), and eventually the communicator, suffer wear

Brushless Motors - +90% efficiency
Brushless motors use a static circumference of electromagnets to push, and pull, an opposing circumference of permanent magnets.

Rather than using brushes and a communicator, the brushless motor uses multiple HALL sensors that detect rotational position and, using a controller, send precise pulses of electricity to power the motor.

The static (non-moving) electromagnets can be positioned around the outside circumference of the motor, causing the center shaft to spin. (1. link - below)

1. educypedia.karadimov.info/library/2-pole_bldc_motor.swf
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Or...

As is typically used in eBikes.
The static (non-moving) electromagnets can be positioned around the center shaft of the motor, causing the outer body of the motor to spin. (2. link - below)

2. bugman123.com/Engineering/Motor.m1v
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Advantages

1 moving part
No wear - (bearing only)
Whisper quiet

Disadvantages
Cost
Complexity - multiple circuits, complex controller
Requires a controller

Rambo mode! -I- January 15, 2012 - January 19, 2012 RIP

"To survive war, you must become war."
:cool: When I go ... I wanna go to eBike heaven :cool:
 

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