Motor is not about electrons, it about magnetism

It does not matter how much knowledge is there around you. Unless you don’t understand it, it does not exist for you. For me its a new world. I am not writing it because there is something new… I am writing because I am enjoying this journey. 🙂

The topic today is building an electric motor. For a long time I thought it’s the electron that is pushing the motor. Ha Ha… never realized that its the magnetic force which is causing the motor to rotate.  But before that its important to understand an interesting feature of AC current- it pushes the electrons away in one cycle and then pulls them in next. How does it affect? Lets look into it.

Take case of a person waking straight in East direction. Is it possible that he is moving towards West. Yes and No

Yes when the surface he is walking on is flat but what if the surface itself is curved like earth? There will be a time when he will be walking towards west.

Does this phenomenon of changing direction has any consequence… after all  just the direction has changed. He is still moving forward only.

Yes, there are consequences and very deep consequences in the world of electromagnetism.

See the diagram below- it is a single metal wire  (its similar in a AC motor, just that there are many, but for our understanding lets take just one copper wire)

Even though the electrons do not change the motion (forward), they do change the direction because of the surface they are travelling on.

Now think of magnetism. The electromagnetic effect due to change in direction of current (the motion of electrons). This causes creation of North Pole where the current is moving anti-clockwise and a South Pole where motion is clockwise. The attraction and repulsion is in play. With more wiring, stronger the magnetic force and stronger the push and pull.

If you put a good conductor metal between the two poles, then metal itself will get polarized and due to the changing magnetic field, the like poles will repel and opposite poles will pull causing the metal to rotate.  Of course, the metal should be designed in a way that it keeps on rotating in the same direction during reversal of magnetic field, else your fan will also try to move clockwise and anti-clockwise. 🙂

So unlike a light bulb, where the motion of elections itself leads to emission of light, in case of a motor, it is the magnetic force that causes the motor the move. It took so long for me to understand this, but nonetheless I am happy, I got it.

Sometime I think, knowledge is like quantum. Till it hits your brain,  it is just a possibility. 🙂