Question about generators

Submitted by Rick on Wed, 12/11/2019 - 22:17

Not sure if this is the right place for this question but, I've been teaching myself about electronics and such for the past couple of weeks, and I am trying to understand how generators "create" electricity.  My understanding is this:

Electricity is generated by moving a coil through a magnetic field.  When this happens, the electrons in the coil become excited, and they repel each other, seeking a more positively-charged environment.  They move their way through the electrical circuit and eventually make their way to ground.  My question is this:

If the electrons are constantly moving through the circuit, eventually you would have no electrons in the copper any longer, right?  So the generator must be constantly forcing new electrons into it.  Where do they come from?  How does this happen?

Sorry if this is a very basic understanding, I'm new to the electronics world.  Thanks in advance for any help!

You asked the question at perfect place.
Your thinking is right but three assumptions are wrong.
Your wrong assumptions are -
1. Electricity is created by the genarator.
2. Electrons are created.
3. Electrons are destroyed in the circuit.

Lets get into the first assumption-

"Genarator" may genarate electricity but it is not actually a genarator. It is a converter. Genarator actually convert mechanical energies into electrical energy. Lots off people have this misconception. Energy, be it any thing, any kind of, can't be created or destroyed. It can oly be converted. Genrator convert mechanical energies into electrical energy.

Lets get into the second and third assumption-

Electrons flow through the copper coil. You are right that the electrons are coming from the copper coil but it is also present everywhere in the circuit, in the components, in this whole universe, everything. But it is also getting back. Few electrons converted into the heat in the associated circuit, and maximum is coming back. Especially if it is DC genaretor.

But for AC it is not true. An AC supply do not provide electrons in your circuit. They vibrate back and forth.

Think like a circular pipe filled with ping-pong balls and no space inbetween the balls. You move one ball, other balls also move. A circuit moves all the balls inside the circular pipe. The balls are present there, but you are applying force to move the balls.

Now if the pipe's diameter is larger than the balls diameter and you start to vibrate the balls, other balls also start vibrating. You can add a small plastic in any of the ball and could hear sound depending on the vibration. This is how you converting vibration into sound. This is alternating current.
Your hand is the force, the moving ball is the electrons, the circular pipe is circuit (circular kit, what you push comes back), the plastic is a speaker (coverts electrical energy to mechanical energy) and the vibration speed is the alternating frequency.

  Joined February 12, 2018      696
Monday at 02:11 PM

Thank you, that's a great explanation. 

So in the case of A/C current, electrons are pulled/pushed back and forth.  Let's talk about this for a moment.  When the coil is passing through one end of the magnetic field, electrons are pushed down the coil towards the other end of the circuit.  Does the coil draw electrons from the atmosphere around it to push them through the circuit?

Likewise, when the coil is passing through the other end of the magnetic field, electrons are pulled towards the coil; are they being drawn in from the grounded end of the circuit in that case?

Thanks again,

  Joined December 11, 2019      2
Wednesday at 10:08 PM

The world is a complex system and I have a simple answer. The world is a sea of electron. Just think how many attoms this world has. Now think how many electrons are present in this world. Even the wires of the genaretor has a sea of electron, not the infinity but it is uncountable object. The complete circuit which is connected with the genaretor is a just ignorable part of this world. Your genaretor, the circuit is the sea. What you are doing, by using some external things that is also a part of this world, taking a drop of a water from that sea of electrons (whole circuit, genretor, coils, wires, loads and all) from one end of the sea and again giving the same drop of water at the other one end of the sea of electrons. Does the water moves? NO! Is the sea of electron lossing water or electrons? NO. But some electrons or water gets converted in practical word. Why? Because when you are getting a drop of water and sending the same in the same sea, a very little bit of water converted due to other dependencies, may be it gets vaporised(the electrons that are converted into heat). So theoretically you are giving the same water taken from the same sea, but practically little bit of water is not going back to the sea.

Do you care about that amount of water or electrons? You are taking it from a sea of electron, ofcourse you will not care about it. But you should if you are getting the supply from a battery, it will convert chemical energy to the electrical energy, so the less will converted to the heat the back up time will be high. If you care about the converted small electrons, the mother nature will fulfill it, because due to the same reason your small electrons are converted into the heat, there are other process in the world that looses heat that are converted into the electrons. You need some thing that will convert chemical energies into electrical energies, a rechargable battery this time. So enjoy the world. You are also a colony of electrons resides in your whole body.

  Joined February 12, 2018      696
Monday at 02:11 PM

Thanks so much, that completely answers my question.  

  Joined December 11, 2019      2
Wednesday at 10:08 PM