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Alternator which is light in weight

  1. Oct 13, 2009 #1

    one urgent help ..

    i need an alternator which is light in weight and the shaft should be easy to rotate because we have a small impulse turbine as power source ... when i enquired a shop out here .. he is asking me some specs... like 12v * 25 amp or 200 *1.5amps .. the speed of rotation will be around 500 rpm...

    please tell me which of the above two specs are more suitable for my application ... it should not be heavy i.e moment of inertia should be less .. please also tell me the adv and dis-adv of both the specs .. thanks in advance :wink:
  2. jcsd
  3. Oct 13, 2009 #2
    Re: urgent help

    Hi darkprinz-
    You first need to estimate the amount of mechanical power you expect to get (as input) from the turbine. For example, 500 RPM at 1 Newton-meter of torque is 52 watts. Then you should look at possible alternators (or dc generators). There are a lot of small dc motors used in toys and other hobbies that make for good dc generators. The main difference between a small alternator (dynamo) and a dc brush motor is that one has a permanent magnet stator, and the other a permanent magnet rotor. For a steady RPM, the rotor inertia doesn't matter.

    Bob S
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