## Generator Design

As you know, magnetic fields attract or repel each other depending on their poles.

Also, when you have electricity flowing through a wire, it generates a magnetic field. Conversely, in order to generate electricity, you move a magnetic field across a wire.

Well, it just so happens that when you try to generate electricity by moving a magnetic field across a wire, the very electricity that gets generated creates its own magnetic field, which opposes the one you are moving in order to create it.

It's the mechanism that keeps you from making energy out of nothing. You'll find that in this universe, there is always some such mechanism.

You can feel this by simply spinning a generator with no load, and then attaching a load to it (such as a light bulb). You'll find that the generator gets much harder to turn. I wish everybody tried this so that they would stop trying to to create energy by some "clever" arrangement of magnets.
 What is this counter electromotive force?

 Quote by sahil2309 What is this counter electromotive force?
http://en.wikipedia.org/wiki/Counter...romotive_force
 Hey I read the article but can someone just explain me how will this CEMF have an effect on the generator rotor when it's spinning
 Zero effect on rotor. CEMF will be induced in stator winding. Let's be straight: what are you thinking about ?
 So basically it won't have any effect on the rotor while its in motion? Yeah I've already mentioned about my intentions a few post earlier just have a look at it and youll know what I'm talking about
 Ok, so as I said it in one of my posts. Unless there is a real reason (like generator is drived by a very specific drive) there is no need to reduce rotor mass-> it's inertia. Inertia moment of rotor is not all bad, it is required to provide adequate dynamic properties to the machine. Plus: designing (and building) a rotor made of not-steel or so needs deep knowledge and can be extremly dangerous. Third thing: I'm sorry, but this is not about briliant ideas.. it needs some knowledge. EDIT: few mor words.. increasing generator efficinecy - this is your goal, right ? Well, this is very hard task even for people doing this for years. I won't elaborate on it. Please search for proper articles/books if you want. Then we can talk about important details in machines design.
 Recognitions: Gold Member Science Advisor You might find this article more instructive. http://www.reliance.com/mtr/mtrthrmn.htm