Author Topic: Voltage regulation  (Read 1544 times)

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(unknown)

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Voltage regulation
« on: July 30, 2006, 05:43:41 PM »
Hi their

Been thinking about building a wind turbine and was wondering how the voltage is controlled into my 12 volt battery, the max voltage needs to be the same as a car (14.1 volts maximum) has anyone used a voltage regulator from a car alternator ?

These should be easy to get hold of from a scrap yard and cheap but they are 3 phase, my wind turbine will be a single phase AC type so I was wondering if it is possible to just tap into part of the alternators regulator.


look forward to hearing from you.

Graeme

Great Britain

« Last Edit: July 30, 2006, 05:43:41 PM by (unknown) »

RogerAS

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Re: Voltage regulation
« Reply #1 on: July 30, 2006, 12:17:46 PM »
Graeme,


Sorry but that won't work and here's why.


The alternator in a car has a rotor that is an electro magnet. Your windturbine, I assume, will have permamnet magnets on the rotor. The automotive alternator's regulation is done by varying the current allowed into the electromagnetic rotor, and thus the stator output varies accordingly. As the need for more output from the alternator rises, like when the headlights are switched on, more current is fed to the rotor. The stator responds by producing more current. RPM and other factors are related to the final output as well. So in short, no the regulator would not work for your needs. It has nothing to do with the number of phases in the stator, or the coils of wire in the stator which are surrouding the rotor.


Hope this is of some help.

RogerAS

« Last Edit: July 30, 2006, 12:17:46 PM by (unknown) »

Flux

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Re: Voltage regulation
« Reply #2 on: July 30, 2006, 12:25:45 PM »
You don't need a voltage regulator, it can't be used with a permanent magnet alternator and even if you can use it with your alternator it will cause trouble.


The car type regulator works by reducing alternator output to keep the battery below 14v. If you do this with a wind generator it will run off load and will run at high speed which at best will be noisy and at worst dangerous.


Until the battery is fully charged, it will hold the alternator volts down to below 14v so you don't need to do anything until the battery is charged. The normal procedure is to use a dump load that loads the battery when it is fully charged and prevents the volts exceeding 14v.


Look up dump regulator or shunt regulator to find out what you need.

Flux

« Last Edit: July 30, 2006, 12:25:45 PM by (unknown) »

(unknown)

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Re: Voltage regulation
« Reply #3 on: July 30, 2006, 12:28:41 PM »
thanks for your reply Roger and Flux


Will carry out some more research, there is more to this than meets the eye.


Thanks again

Graeme

« Last Edit: July 30, 2006, 12:28:41 PM by (unknown) »

amiklic1

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Re: Voltage regulation
« Reply #4 on: July 30, 2006, 03:46:49 PM »
I think everyone that's looking into collecting some stuf or informations from this board should first read some old posts (google search is the best way to go), and to read FAQs (http://www.fieldlines.com/faq/re_faq#2003/11/4/122453/226).


Even if every one of us is going to explain the same thing many times, it's still better to read what's available, think about it, and that ask if something is still not clear.


Allmost all of us thought about car alternator regulator, but it's not aplicable to axial flux alt we're all building.

« Last Edit: July 30, 2006, 03:46:49 PM by (unknown) »

mattbrush

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Re: Voltage regulation
« Reply #5 on: August 08, 2006, 10:10:37 PM »
I would suggest something along the lines of this:

http://focus.ti.com/docs/prod/folders/print/pt5071.html


It's really efficient and can be adjusted to output the charging voltage for a normal battery.  The best part is, as long as your generator is putting out more than 7 volts, you can still get a useful amount of output voltage to trickle charge.


The only problem with that specific module is that it's only built for 1.5A, so maybe not too useful for most generators.  But in any case, you could no doubt find similar modules on goole that handle more current.  Or do what I do and build your own to suit your needs (not the easiest way, but much cheaper).


My $0.02


Cheers

Matthew Brush

« Last Edit: August 08, 2006, 10:10:37 PM by (unknown) »