Mammoth Memory

Brushless D.C. motor

There is a way to deliver a powered spinning shaft without brushes. Brushes wear out, what we have below is a motor but you have to switch the direction of the electric current:

As soon as you switch on these two electromagnets they will repel the magnets and the magnet will start spinning.


Brushless D.C. motor diagram

The magnet will continue to spin as it is attracted to an opposite pole.


Magnet in brushless motor continues to spin

At the point where the magnet is in line with the electromagnet, it must switch the direction of the electrical current through the wires and change the polarity of the electromagnet and repel the opposing pole of the magnet. 


Current direct in brushless motor switches

The electromagnet can again attract the approaching opposite pole of the magnet.


Magnet in brushless motor continues to spin

Once level the electromagnet must again have the current changed to switch direction and the whole process can start again.


Current direction in brushless motor switches

Before the advent of cheap computers and power transistors (electronic switches), it was impossible to build up speed of the shaft.

Computers and transistors allowed accurate and fast switching to occur so much so that even more power can be generated by switching even more electromagnets around a magnet:

Brushless D.C. motor with many electromagnets

Switching accurately can make the magnet turn very powerfully.

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