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Using HDD motor as generator

Discussion in 'Renewable Energy' started by mygatt3, Feb 28, 2010.

  1. Grossel

    Grossel Member

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    The animation shown on the page linked to below review how:

    Motor Control Switched Reluctance Motor Solutions By Freescale.

    Just ask yourselv: Have you experienced that a harddrive spindle motor provided any voltage or current output when you aplies rotation speed? Don't think so. Not for any modern hardisk drive. Reason is as easy as this: No permanent magnets inside :D
     
  2. mygatt3

    mygatt3 New Member

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    so am i unable to use it?
     
  3. smanches

    smanches New Member

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    Put a meter on it. That's the only way to be sure.
     
  4. dave

    Dave New Member

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  5. tcmtech

    tcmtech Well-Known Member Most Helpful Member

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    I have an old hard drive motor in pieces right in front of me and it has magnets in it or more of a multi pole magnetic ring on the spindle to be exact. The odds are that there is more than one type of hard drive motor design in existence.

    Still I doubt it would put out much power as a generator.
     
  6. Grossel

    Grossel Member

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    Ok, it might just be me that haven't found any with permanent magnets. I guess I have pilled around ten disks to pieces.
     
    • Like Like x 1
  7. mazaldo

    mazaldo New Member

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    how fast does it turn with a table fan blowing on it?
     
  8. Vizier87

    Vizier87 Active Member

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    mazaldo, you're repeating my question already. Anyway use a meter and see the output, you'll save all the superfluous posts you can. Put an LED to the output terminals, it'll be good enough. If it can't even light up an LED, you'll never be able to charge the batteries unless you have a conversion circuitry, but that's another story.
     
  9. mygatt3

    mygatt3 New Member

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    alright well i tested it, and three of them read 5 ohms and one read 2.5ohms. (three phase)

    I think i am going to try and find a stepper motor instead. it doesnt seem logical to try this when i know that it will not be very effective.

    What kind of stepper motor should i look for that will be the most efficient and powerful for my application?

    Matt
     
  10. mygatt3

    mygatt3 New Member

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    [​IMG]

    [​IMG]

    Alright guys i also had this laying around what you think?


    its from a floppy drive i believe there are three terminals in the upper left corner in the pic with the cover off


    matt
     
  11. Grossel

    Grossel Member

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    Acording a paper I read some time ago (sorry to say I don't remember the title or source) said that reluctance motors was often used as generators in airplane engines. If that's true, I'm pretty sure it should be pretty efficient if you doing it right.


    It's probably a brushless DC-motor. It means that it has the controller circuit built in. You can always test with a screwdriver if it is permanent magnets inside.
     
    Last edited: Mar 3, 2010
  12. mygatt3

    mygatt3 New Member

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    so i should still test it yet? or would this motor be better?
     
  13. Vizier87

    Vizier87 Active Member

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    What I meant is the voltage, not resistance.
     
  14. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    OK - I just took an HDD to pieces, it's a Seagate 160Gb, and the spin motor is pretty well built in the casing, so you can't see anything of it apart from the three wires coming out.

    Connecting a scope to it, and spinning the motor with your fingers gives between 2 to 3 volts peak to peak between two of the three wires - so not a lot of voltage.

    If you short out the same two wires and spin the motor again, it stops after a second or so, with out the short it spins for probably 5 or 6 seconds, so it's not producing very much power.

    I think it would make a really useless generator.
     
  15. Vizier87

    Vizier87 Active Member

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    I made a generator just a bit bigger than a standard HDD, it generates 30V at 3500 rpm, no load. Probably a DIY is much better.
    [​IMG]

    ....and I used HDD neo-mags.. Well as the saying goes, when you can't eat lemons... make some lemonade out of 'em. :D
     
    Last edited: Mar 22, 2010
  16. eSilviu

    eSilviu New Member

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    do the rectifier upper proposed (6 diodes) and measure the output voltage.
    HDD motor IS a 3 phase AC motor, WITH permanent magnets, so it will work as 3 phase generator too. (but I'm afraid that voltage generated is too low for your needs)
     
  17. Hero999

    Hero999 Banned

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    You'll probably need to spin it near it's operating speed to get a reasonable voltage, which is about 7200 RPM for a typical modern hard drive.
     

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