Neodymium Magnets
Neodymium Magnets
Find out more about neodymium magnets used in renewable applications
general | education | windNeodymium Magnets (aka
Neo,
NdFeB, or
rare earth magnets) are the strongest magnets in the world. They are made of a mixture of neodymium, iron, and boron. High levels of iron in neo magnets leave them vulnerable to rust and so they are usually plated with nickel. They used to be used primarily in computer hard drives (which still use up 50% of all neo magnets manufactured today), however they have also proved to be very useful in many
renewable energy applications.
Neo Magnets and Renewable Energy
Electricity is generated in an
alternator (used in
wind turbines and
hydro turbines) when magnets pass coils of wire. One of the factors which decides the amount of electricity generated is the strength of the magnets used. The stronger the magnets, the higher the current generated. (Other factors include the distance between the magnets and the coils, the size of the magnets, and the number of turns of wire in each coil). Therefore super-strong
neo magnets make for a better alternator.
Another advantage of the strength of
neo magnets is that they weigh far less than an equivalent ceramic magnet (the type used in old speakers) and are much smaller.
Neo Magnet Strength and Temperature Sensitivity
The
strength of neo magnets is given by a grading from N24 for the lowest strength magnets to N54 for the strongest. The stronger the magnet, the more mechically fragile it is and the lower the temperature at which
magnetism is lost. The weakest neos can be used in temperatures of over 200 degrees Celcius, however the strongest neo magnets will permanently lose their magnetism if exposed to temperatures over just 80 degrees celcius.
Gauss
The amount of
magnetism [at the centre] of a magnet is measured in
Gauss. This is a measure of the
penetration of a magnet. Below is a table of the Gauss ratings of the most popular neo magnets used in renewable energy applications:
| Grade | Gauss |
| N35 | 11,700-12,100 |
| N38 | 12,100-12,500 |
| N42 | 12,800-13,200 |
| N45 | 13,200-13,800 |
Buying Neodymium Magnets
Typically
N38 or
N42 neo magnets are used in renewable energy alternators since they give the optimal balance of magnet strength and durability for price. Prices of neo magnets have been consistently falling over recent years since the Chinese started manufacturing them and so more N42 neos are finding their way into DIY wind turbine alternators. Click here to find out some of the best places to
buy neodymium magnets in the UK.
Article Last Modified: 17:00, 21st Mar 2007Comment on this Article
If you have any comments on this article, please email them to
neil@reuk.co.uk.
Recommended Related Articles
People who read this article also enjoyed the following articles:
Buying Neodymium MagnetsBuying neodymium magnets in the UK
Article Last Modified: 10:15, 23rd Jul 2008general | wind | waveDIY 2kW Wind TurbineRead about a home built 2kW wind turbine constructed from scrap
Article Last Modified: 08:46, 4th Oct 2007wind | recyclingPermanent Magnet GeneratorBuild a wind or water power system with around a PM Generator
Article Last Modified: 11:44, 21st Jul 2008wind | hydroEnamelled Magnet WireFind out more about the wire used to wind coils for generators and alternators
Article Last Modified: 14:34, 5th Apr 2007general | shoppingHard Disk Drive Magnets For Wind TurbinesObtain super strong magnets from old hard disk drives to use in wind turbine alternators
Article Last Modified: 15:25, 14th Apr 2007windWhat is Wind Turbine FurlingUnderstand how Furling works to protect a wind turbine from high winds
Article Last Modified: 16:22, 19th Dec 2006wind | educationWind Turbine Alternator BasicsFind out how coils of wire and magnets are used to make electricity in a wind turbine alternator
Article Last Modified: 09:19, 11th Apr 2007wind | educationThree Phase BasicsGet an understanding of three phase wiring in wind turbine alternators
Article Last Modified: 15:13, 19th Aug 2008wind | electric circuit | websitesPVC Wind Turbine BladesLearn how to make your own PVC wind turbine blades
Article Last Modified: 15:16, 19th Aug 2008windWind Turbine Axial Flux AlternatorsLearn more about the design of an axial flux alternator - used in wind turbines and hyrdo power
Article Last Modified: 09:27, 7th May 2008wind
|
|
|
