# Hi,I hope someone can help me. Looking at a magnetic generator,

1. Aug 27, 2011

### barendfaber

Hi,

I hope someone can help me. Looking at a magnetic generator, we will have a ring of magnets which will rotate, and then we have the copper wire static.

I understand that if I have a ring of alternating magnets, all placed right next to each other, thereby creating a solid magnet surface for the copper wire to rotate against, the formulation for calculating the induced EMF = 2 x length into paper x radius to wire x Radial Flux Density B from magnets x rotational speed.

Please see attached picture. The outer diameter is 300 mm and the height 50 mm. This design is different, as I have only 24 magnets, with a radial flux density of 1.4 Tesla. I think their size is approx length (29 mm) x width (14 mm) x height (50 mm). I then also have 18 copper wire coils.

Is there a formulation I can use to calculate the possible EMF I can expect from this design? Also, how do I calculate how many magnets

I need some help here, but I would like to be able to calculate how the EMF will change when I:

1) Increase or decrease the size of the magnets (I expect here that the surface area of the magnet that get in contact with copper will have an effect)
2) Increase or decrease the number of windings in one coil and thickness of the copper wire
3) Increase or decrease the amount of magnets
4) Increase or decrease the amount of coils
5) Increase or decrease the air space

Most of what I know by now I have learned on the internet or with other help, so please treat me kindly! I do not understand most of the symbols in formulations, so if you can help with a formulation with explanations of symbols, like with EMF above, that will be awesome!

#### Attached Files:

• ###### Magnetic Generator.jpg
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2. Aug 29, 2011

### Drakkith

Staff Emeritus
Re: Emf

I'd try the electrical engineering forums if you don't get any hits here. I'd help but I don't know enought to answer your questions!

3. Aug 30, 2011

### barendfaber

Re: Emf

Thanks, I will repost now.

4. Aug 30, 2011

### 121910marj

Re: Emf

2)increase the number of windings in one coil -- i think this will cause greater magnetic field
3) amount of magnets??
4)the same with #2
5) i don't know

read more about ELECTROMAGNETIC INDUCTION.. i think these are basics concepts under these topics but i forgot about it so, i might as well give wrong info if i would just recall. I really am not that sure.. hope you'll be patient reading :)