Brushless DC engines

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Brushless DC engines

Postby nikomaster on November 1st, 2007, 10:17 pm 

Past days I was looking for a DC motor that spins 25000 RPM average, i found these kind of motors at RC Models specially AIRCRAFTTS, so how this engines works?
nikomaster
 


Postby Sparky on November 1st, 2007, 11:12 pm 

Is English your native language?
Sparky
 


motors

Postby turbine on November 10th, 2007, 9:48 am 

These are universal motors. They can run on DC or AC, they use a commutator to transmit power to the coils. The commutator is located on the shaft and rotates, bushes ride on the commutator to transmit the electrical power to the rotating equipment. Any way there is a detail description here http://en.wikipedia.org/wiki/Electric_motor
turbine
 


Postby turbine on November 21st, 2007, 10:01 pm 

Sorry bushless DC, are also described in the link above.
turbine
 


Re: Brushless DC engines

Postby Luhan Monat on April 8th, 2008, 9:59 am 

nikomaster wrote:Past days I was looking for a DC motor that spins 25000 RPM average, i found these kind of motors at RC Models specially AIRCRAFTTS, so how this engines works?


I bought a couple of these. They are brushless dc motors. The 3 coils are located in the center of the unit and are mounted on the frame, the permanent magnet is on the outside and connects to the output shaft. A special circuit senses motion of the magnet and powers the coils in the proper sequence. These are as efficient as brush motors but do not have the problem of wearing out the brushes.
Luhan Monat
 


Postby pointloop on April 8th, 2008, 11:21 am 

The commutator on brush motors wear down and the motor looses its efficiency while a brushless motor doesn't. I wonder why they don't use a 3-phase motor for model air planes? Just convert the dc to 3-phase or would there be a weight problem?
pointloop
 


Postby Luhan Monat on April 8th, 2008, 3:58 pm 

pointloop wrote:The commutator on brush motors wear down and the motor looses its efficiency while a brushless motor doesn't. I wonder why they don't use a 3-phase motor for model air planes? Just convert the dc to 3-phase or would there be a weight problem?


That is basically what the electronics in a brushless motor does. It changes DC into 3 phases for powering the motor.
Luhan Monat
 



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