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New to forum! Have an idea and need help!

  1. Jul 23, 2012 #1

    I am new to the forum but figured I could ask some intelligent people about an idea that has been bugging me. Here goes...

    I am trying to make a generator that is run by an electric motor but the electric motor runs off the generator head at the same time.

    The way I see it is this... Run a battery bank with an inverter to start the initial spin of a high horsepower electric motor with proper pulley or gear sizing to get the desired rpms. Once the motor starts running and starts spinning the 10kw generator head, have a transfer switch kick the power from the generator head over to the electric motor to supply power to it, so it no longer is running off the battery bank and powers itself so to speak. Now I know there is the whole perpetual motion thing and the two laws and thermodynamics but if you have a generator head large enough to supply a sufficient amount of power to keep the motor running while still having enough room to power electronics you want to run off the head, would it work? Is this possible? If not please explain.
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  3. Jul 23, 2012 #2

    jim hardy

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  4. Jul 23, 2012 #3
    I somewhat understand that whole ordeal... but, does this really fall into that category? I'm no physics professor or engineer to an extent. I mean in reality is this really classified as perpetual motion? You have one item that runs on electricity and another item that produces electricity. You start with a power source and switch to another source to run your source. If the generator head is large enough to run your motor and have enough room left over to supply power,and your motor has enough hp to keep up with proper gearing, then technically it should work right? I am not trying to start an argument but I am new to this area and still learning basic physics I guess you could call it. I am great at engineering and designing things but the science part is still a learning process. So please,just in case anyone wants to criticize me, keep the comments to yourself.
    Last edited: Jul 23, 2012
  5. Jul 23, 2012 #4

    jim hardy

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    okay perhaps i shouldn't have snapped at you.

    Think about it logically for a few minutes. Physics is logical after all...

    If you built such a machine, started it, then wrapped it up in a sealed box,
    would the box not get warm from the electric machines whirring away inside?

    Is that not a machine that produces heat from nothing?

    Anything that leads to an impossible conclusion is , well, ,, er - be circumspect my friend .

    Always test your ideas against what you already know.
    That's what learning is, discovering what you already know.
  6. Jul 24, 2012 #5


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    Free energy and perpetual motion machines are banned topics on this Forum.

    Not that they are not interesting, but they waste a lot of time and space covering the same ground each time someone brings this up. They don't work and cannot work.

    Other fascinating subjects that are also banned are listed here:

    Just for your information, a generator that is under load requires a lot of force to rotate it, much more than one which is lightly loaded.
    If this has to come from a motor, this will require a lot of electrical power to drive it.

    Because motors and generators are not perfectly efficient, the power out of the generator will be less than the power needed to run the motor, even if you use all the generator power to do this.
  7. Jul 24, 2012 #6
    Thank you for your input Jim.

    As far as people saying perpetual motion will not and can not work.... That I beg to differ. It doesn't work because it hasn't been perfected. If you told someone we were going to have space travel, cell phones, or a micro processor 400 years ago they would have told you that it'll never work. It just hasn't been perfected yet. The earth used to be flat too.... science isn't always right and the laws of physics can be broken or bent.
  8. Jul 24, 2012 #7


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    There's so much wrong with this post it's hard to know where to begin. Regarding the flat earth statement read this. That sort of covers your argument about cell phones et al but to expand further on that: the fact that things thought to be impossible in the past were later achieved has no bearing on whether or not something thought to be impossible today will be possible in future. That's a non-argument that can be applied to anything (e.g. "In the future time travelling bannanas will be possible, don't agree? Well 500 years ago people wouldn't have believed cell phones"). Lastly assertions that observed physical laws for which a preponderance of evidence has been shown are possible to break are worthless without evidence.

    And as has been pointed out this thread is against our rules.
  9. Jul 24, 2012 #8


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    Adding my $.02 to a locked thread....

    You've made a very common (we get this question about once a month) but still very perplexing error in the first post (I'll deal with the last one later...): You're under the impression that a generator doesn't require input mechanical power; that it just free-spins. I suggest you buy a hand-crank generator to play with to prove it to yourself if logic doesn't convince you, but since you acknowledge conservation of energy (then summarily reject it, but still...), you should be able to figure out just how much power a 10kW generator takes to spin if you ignore losses due to friction and electrical resistance. 10kW of course! And a 10kW output mechanical power motor, how much electrical input does it require? Again, 10kW! Conservation of energy really is that simple.

    As for your last post, you jumped from inquisitive to full-throttle crackpot. You got answers you didn't like so you jumped straight to assuming science/scientists must be wrong (and you know better?), backing it up with factually wrong assertions about history. You're going to need to fix that attitude/belief if you ever want to learn science anywhere, much less learn it here.
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