# Would a permanent magnet generator work?



## badlittlemonkey (Dec 28, 2010)

Would a permanent magnet generator work if I had a machine shop make a gearing unit, and where I could fit said unit.

*Permanent magnet generator* *(PMG)*

http://www.diytrade.com/china/4/pro...magnet_generator_1500rpm_3000rpm_4500rpm.html

http://www.alxion.com/bin/e_eoliennes.html


Then I need to work out where to fit the PMG (drive shaft or rear wheel) an inverter and linkage to a battery charger to recharge my main battery pack, any ideas?


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## EVfun (Mar 14, 2010)

A PM generator will require some type of controller to charge a battery pack. The voltage will vary directly with rpm complicating its use for regen braking. 

PM motors also tend to have rather high losses in no load operation because of the cogging caused by the permanent magnets attracting the iron in the poles.


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## algea07 (Oct 1, 2010)

i thought generators work like a current pump they ramp up the voltage until they get the current flowing. 

i got this from how stuff works 

"One simple way to think about a generator is to imagine it acting like a pump pushing water through a pipe. Only instead of pushing water, a generator uses a magnet to push electrons along. This is a slight oversimplification, but it paints a helpful picture of the properties at work in a generator. A water pump moves a certain number of water molecules and applies a certain amount of pressure to them. In the same way, the magnet in a generator pushes a certain number of electrons along and applies a certain amount of "pressure" to the electrons."

i was also under the impression that this is how an alternator worked (i know they're not the same thing). 

i thought that attaching a permanent magnet motor to an engine would produce the desired voltage, with a varied current.

i could be horribly wrong, so feel free to correct me.


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## EVfun (Mar 14, 2010)

A permanent magnet motor/generator (since they are really the same thing) has a set rpm per volt. If you apply more voltage than that it draws current and is a motor. If you connect it to a battery at a lower voltage it pushes current into the battery pack. If the voltage mismatch is very great, either way, a LOT of current will flow. 

Perhaps Major will come along and explain it much better than I am able.


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## badlittlemonkey (Dec 28, 2010)

Thanks guys was just a thought, since in a newbie to all this and would like to get a few answers I thought the guys and girls on here would have more of a idea than me. 

yet one other idea if anyone has tried it and wouldn't mind shearing, could I use something like a alternator or a series of them something like this.

http://www.youtube.com/watch?v=y3Dmwo-Pe0k

I have been told that I would have problems powering a unit like this and have been looking at the warp11/13 or k11/13 motors for this.

warp motors

http://www.ev-propulsion.com/motors.html

k11/13 motors

http://kostov-motors.com/tractionmotors/kostovevmotors-and-kits/seriesdcmotorsforelectricvehicles/

and to implant in a car like this Ford Mondeo zetec 2000

http://www.trademe.co.nz/Browse/Listing.aspx?id=341986069

any ideas of how it would work?


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## GerhardRP (Nov 17, 2009)

badlittlemonkey said:


> Would a permanent magnet generator work if I had a machine shop make a gearing unit, and where I could fit said unit.
> Then I need to work out where to fit the PMG (drive shaft or rear wheel) an inverter and linkage to a battery charger to recharge my main battery pack, any ideas?


Could you tell us what you are trying to accomplish. This looks like harvesting rotational energy to recharge batteries.. A perpetual motion scheme that will fail. If it is regenerative braking, then we can talk.
Gerhard


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## badlittlemonkey (Dec 28, 2010)

GerhardRP said:


> Could you tell us what you are trying to accomplish. This looks like harvesting rotational energy to recharge batteries.. A perpetual motion scheme that will fail. If it is regenerative braking, then we can talk.
> Gerhard


Guess we can't talk because nether of those links are what I have in mind, all good tho will go through trials with what I have in mind and see what comes of it, interesting that you only need 10 kw for a EV to travel 50 MPH so that would mean that you would need to generate somewhere around 15kws to do the speed limit of 62 mph, nice that's a very interesting find.

Thanks for the information that was a great help.


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