Orientation of coil in electric generator: Important?

AI Thread Summary
The orientation of the coil in an electric generator can impact the induced EMF, particularly when considering how it interacts with magnetic flux. For a windmill generator, using a radial array of coils and magnets is recommended, with stationary coils and rotating magnets for optimal efficiency. The design should focus on the number of magnetic poles and the coil configuration to achieve desired power output. Additionally, understanding the windmill blade diameter and expected wind power is crucial for effective design. Overall, proper coil orientation and configuration are key to enhancing the generator's performance.
Antic_Hay
Messages
5
Reaction score
0
Hi, I'm working with my granddad on a project to build a (simple!) electricity generating windmill. We're not trying to make the most efficient design possible, just a reasonably efficient design given the simple tools and materials we're using. It's mostly just a project for fun! :)

So, we have a setup as in the diagram below. What I'm wondering, is does it make a difference what way the coil of wire is oriented, i.e. if it is rotated 90 degrees in some direction in the design, will a greater EMF be induced in it each time it cuts the magnetic flux of the magnet.

(To clarify, the coil is currently oriented so that additional windings will make it grow along the Y axis, looking down at the XY plane, the cross section of the coil will be circular)

(Please go easy on me if I'm saying anything moronic, it's been a while since I studied Physics is school, and I did very little of it in college! ;) )

(Oh, the final design will have a full radial array of coils and magnets, if that's any confusion! But my main question is what shape the coil should be !

Thanks!
Mark.edit: yep, I know that should be 'propellor', not propeller!
nuLB7.jpg
 
Last edited:
Physics news on Phys.org
You have the best orientation for a windmill generator. Generally, the windmill generators have 8 to 12 magnetic poles (neodymium iron boron) in a circle, and as many coils for single phase output. But, unless you have a good way of getting the electric power off the rotor, you will want to have rotating magnets and stationary coils.

[Edit] I am not advertising this place, but here is a good detailed discussion of an axial field permanent magnet rotor construction for windmills. You should first decide on windmill blade diameter and expected windpower (watts and RPM)) and desired alternator power output.
http://www.otherpower.com/magnetrotors.shtml
 
Last edited by a moderator:
Hey, that's great, that cleared things up totally, and that link was full of useful detail, thanks a lot :-)

You're right about the stationary magnets too, makes much more sense!

Thanks :-)
 
Antic_Hay said:
yep, I know that should be 'propellor', not propeller!

In the USA, "propeller" is fine. Of course, some English-speakers claim that we Yanks speak/write a debased version of the language. :wink:
 
This is from Griffiths' Electrodynamics, 3rd edition, page 352. I am trying to calculate the divergence of the Maxwell stress tensor. The tensor is given as ##T_{ij} =\epsilon_0 (E_iE_j-\frac 1 2 \delta_{ij} E^2)+\frac 1 {\mu_0}(B_iB_j-\frac 1 2 \delta_{ij} B^2)##. To make things easier, I just want to focus on the part with the electrical field, i.e. I want to find the divergence of ##E_{ij}=E_iE_j-\frac 1 2 \delta_{ij}E^2##. In matrix form, this tensor should look like this...
Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'
Please can anyone either:- (1) point me to a derivation of the perpendicular force (Fy) between two very long parallel wires carrying steady currents utilising the formula of Gauss for the force F along the line r between 2 charges? Or alternatively (2) point out where I have gone wrong in my method? I am having problems with calculating the direction and magnitude of the force as expected from modern (Biot-Savart-Maxwell-Lorentz) formula. Here is my method and results so far:- This...
Back
Top