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A Hand Cranked MagnetoGenerator

Discussion in 'General Electronics' started by default, Aug 14, 2005.

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  1. Randy Gross

    Randy Gross Guest

    You're right! Raising eathworms would be a lot less tiring;-)

  2. Randy Gross

    Randy Gross Guest

    Watson A.Name - "Watt Sun, the Dark Remover" wrote:

    I ran across a site a while back, can't remember where, whose author
    was selling used magnets he gleaned from hard drives and claimed they
    were Neo's. I was skeptical because of storage media in a computer but,
    it appears he may have been correct.

  3. Rich Grise

    Rich Grise Guest

    The part of the motor armature that's between the magnets and the
    media is soft iron and "shorts out" the magnetic field. Kinda like
    the E-core around a relay coil.

  4. I'd like to take exception to this number here. You produce almost 70
    watts just sitting there! (albeit, in the form of heat and not real

    When I was in HS physics, the class got around to the F+MA and all
    that stuff, and did an experiment to determine just how much power
    a person can generate. There was a 3-floor stairwell at this school,
    and what the physics class did was get a few boys to volunteer to
    run up the stairs as fast as they could, and be timed. Then, of
    course, the boy's mass times the height, with some gravity factor
    was the work done,divided by the time it took him to ascend 30 ft.
    (10 M) of stairs gives power, the rate of doing work. These guys
    were pushing a horsepower. But you were allowed to cheat - use
    the handrail, vault instead of turn the corner, whatever. I tried
    it and made about 300 watts, IIRC.

    But that's "fight or flight sprint" mode - nobody could keep that
    up for any extended period of time, obviously. So, maybe 70 watts
    would be a good comfortable pace on, say, an exercise bicycle.

    What somebody needs to invent is a movie of scenery going by, that
    moves by (on the big-screen projection TV next to the exercycle)
    at the same speed that you're pedaling. :)

    I also have an invention for a new type of recumbent pedal - but
    for a generator, you wouldn't need the gearshift. But I see I've
    gone over, and that's a topic shift...

  5. default

    default Guest

    Your analogy is correct about the shorting- but it takes effort (work)
    to move the iron armature (or pole pieces) through the magnetic force.
    Regardless of the structure (magnet flux). It may be easier to move
    through 360 degrees with a well designed armature/field but it would
    take the same effort to produce the same power (electrical energy) if
    it is produced in 90 degrees or 360 . . . (or with the bad design you
    could use a flywheel, or some other mechanical means to smooth the
    effort required)

    I have a 120 vdc generator (from the 40's) and if I add any kind of
    real field voltage (excitation) on it, it seems to lock up (as far as
    one's hands trying to turn it are concerned)

    No such thing as a free lunch. You want to generate electricity . .
    it takes work.

    Now, how much and how does it compare to the "grid' - a few years
    back I did the arithmetic, buying an alternator, buying fuel, buying
    the ancillary items (shed for the alternator, regular maintenance (air
    and fuel filters), radiator flushes, depreciation, lubricating oil,
    etc. etc).. I could just generate energy at the point where the power
    company is selling it to me . . .

    Now my opinion . . . the utility company probably tracks this stuff
    more closely than I do . . it will always be just a little tiny bit
    cheaper to buy power than make it (hydro, wind, solar cells,
    geothermal, tides, notwithstanding).
  6. default

    default Guest

    I'm not about to argue with you. A person "can" generate a horsepower
    of more for a (very) short period. (like how kenmore or craftsmen
    appliances are rated in the US)

    And when it comes to horsepower - The horse is walking in a circle -
    pulling a load, not lifting his/its weight - so I'd have to figure
    that in . . .

    I can generate over 300 watts for a few minutes - I can only generate
    100 watts for a few hours - and that's breathing hard - feeling like
    death is imminent - all out, do or die exertion - with very few
    people that can compete with me - except my neighbor. Hour long
    race, and he's 1000 yards ahead of me.

    True he's got that sweet carbon fiber bike, with the fancy alloy
    spokes, and he's six years younger - but dammit I want to beat him!
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