# Formula of generators

1. Jun 26, 2014

### amintanharpd

hi , i want to know that how calculate coil windings in the genarators,
i want make a small genarator with magnetic and copper coil for 12 volt but i couldn't find a formula for number of coil cycle please guide me about this , thank u.

2. Jun 26, 2014

### BOAS

The equation you're looking for is known as Faraday's law.

$$\xi =-N \frac{d \Phi}{dt}$$

What this says is that the average EMF induced in a coil of N loops depends upon the rate of change in magnetic flux through one loop.

$$\Phi = BA \cos \phi$$ is a general expression for magnetic flux that says magnetic flux is equal to the magnitude of the magnetic field, times the area of the surface the flux is passing through, times the cosine of the angle that the flux makes with the normal to the surface. i.e if the flux is perpendicular to the surface, $$\cos 0 = 1$$ so it disappears from the equation.

Do you have any further information regarding how you are going to make this generator?

You can do further reading here;

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/farlaw.html#c1

3. Jun 27, 2014

### amintanharpd

thank u very much , the link and your information about that was very useful for me thank u ;)