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Battery that will run a dc motor

  1. Mar 25, 2010 #1
    hi i am new to this forum. i want to use a battery that will run a dc motor, dc motor will run three phase ac generator through mechanical coupling and the three phase ac generator will produce out put, now two phases of the ac generator will b utlilized by the load and 1 phase will recharge the battery. my question is wheather its possible or not?
     
  2. jcsd
  3. Mar 25, 2010 #2
    Re: hybrid power

    yes is possible. But you will need to separately and independently recharge the battery periodically since friction and electrical losses cannot be overcome.
    In other words its impractical.

    Try here for practical insights: http://en.wikipedia.org/wiki/Hybrid_car
     
  4. Mar 25, 2010 #3
    Re: hybrid power

    sir you mean its theoratically possible but practically impossible?
     
  5. Mar 25, 2010 #4
    Re: hybrid power

    no I mean it can be done but accomplishes nothing....except temporarily until the battery runs down....trying to recharge the battery from the output consumes more energy than it produces....
     
  6. Mar 25, 2010 #5

    Dale

    Staff: Mentor

    Re: hybrid power

    Even theoretically with 100% efficiency and no losses anywhere in the system the 1 phase used for recharging cannot recharge the battery faster than it is being drained if there is a load on the other 2 phases.

    It is certainly possible to build the device you describe, but it won't recharge the battery as fast as it is drained.
     
  7. Mar 25, 2010 #6
    Re: problem

    No, it is not possible. Violates conservation of energy.
     
  8. Mar 25, 2010 #7
    Re: problem

    how sir?
     
  9. Mar 25, 2010 #8
    Re: hybrid power

    is there any alternative?
     
  10. Mar 25, 2010 #9

    stewartcs

    User Avatar
    Science Advisor

    Re: problem

    If you use part of the converted a/c power to charge the battery there will still be a net loss of energy (due to irreversibilities in the conversion process). So strictly speaking you can "charge" the battery, but you can't fully recharge it such that it violates the conservation of energy.

    In other words you cannot create a perpetual motion machine. The battery will eventually drain completely.

    CS
     
  11. Mar 25, 2010 #10

    Dale

    Staff: Mentor

    Re: hybrid power

    Yes, charge it with an external power source.
     
  12. Mar 25, 2010 #11

    stewartcs

    User Avatar
    Science Advisor

    Re: hybrid power

    This is the third post of this exact topic by the same user...

    Do not multipost...

    CS
     
  13. Mar 25, 2010 #12
    Re: hybrid power

    can we eliminate all the losses?
     
  14. Mar 25, 2010 #13
    Re: problem

    is there any research on practical perpetual motion machine?
     
  15. Mar 25, 2010 #14

    berkeman

    User Avatar

    Staff: Mentor

    Re: problem

    We do not discuss perpetual motion machines here on the PF because it is a waste of time. Please re-read the Rules link at the top of the page.

    Thread closed.
     
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