Permanent Magnet Generator Rotor Plans

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Tamus

Tamus

Well-Known Member
Anyone got any advice and/or good links to plans and outputs of various designs of DIY permanent magnet generators?

I've read all the old Hugh Piggot books and pamphlets but maybe things have moved on by now... ?

Been in touch with these folk: http://www.first4magnets.com/wind-turbine--generator-magnets-131-c.asp but they really just supply neodymium magnets and not designs. :(

A suitable generator and self furling rotor design (wind turbine) for diy build with a rated output in the 2.5kw region would be what I'd like to build, for about 2/6d and stick of gum please (chewing helps me concentrate when I'm working)... or as close to as poss :D Thanks and Atb~Tom
 
Can you not gang rig auto alternators?
The latest versions on upper level vehicles are cooled from the engine coolant, check on the Bosch site.
Martin
 
Bavarianbrit said:
Can you not gang rig auto alternators?
The latest versions on upper level vehicles are cooled from the engine coolant, check on the Bosch site.
Martin
Click to expand...

Mr Piggot, the doyen of UK stand alone self buit wind turbines, would explain better than me... but... the trouble with auto alternators is that they require their initial electro magnetism to be derived from battery current ie. they don't have permanent magnets and the process of "magnetising" the coils in a little generator is not significantly a problem. In a wind turbine however, of any worthwhile output, I believe you would draw heavily on your batteries to create the initial magnetism, this would up the "cut in" speed and/or reduce the yield... I think... I may have got these technicalities wrong in detail but it's something like that.

Putting it another way, permanent magnets is definitely the way forward and all the other ideas do not hold up anywhere near so well, by comparison.

Cooling isn't really a problem either... so long as there is not excessive resistance in the circuitry. "Overspeed" control, on the otherhand, is an issue you must resolve.

My house is over 900ft above sea level, quite exposed and close to a ridge... we, all to frequently, see windspeeds here in excess of 100mph. Our ambient/mean wind speed is of the order of 8m/s. ... Many of our trees slant a bit... :-D

I look out on the largest concentration of commercial and private turbines to be seen anywhere in the world. From my sitting room windows alone we can see four major wind farms (at least partially) plus countless smaller turbine groups and stand alones. We can see for miles and miles here btw. The last attempted tally went to well in excess of 200 turbines visible on a clear day. Today I can actually only see 21. S'not a nice day. It is a very good place to catch the wind and make use of it though.
 
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Find a 'synchronous' servo motor and you will have a motor with a magnet rotor.
It will need to be re-wound for the low voltage you require or you may have to build a step-down regulator.
Re winding is the simplest option and a fairly crude shunt regulator would work for that.
Probably even a few knocking about the workshop!
Alternator has the correct voltage but unfortunately they need RPM (> 2krpm off top of head) which is hard to get from the wind.
The 'warning light' feed would not be much of a problem as it is only a few milliamps and when alternator is running does not draw any current.
Trick is a regulator that only switches the WL feed when needed!
 
why dont wind turbines have gears or some way of increasing load with increased wind speed?

seems a total waste to me
 
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