Anyone tried the presto wind alternator

Discussion in 'Windtura Generators' started by bigal1949, Sep 7, 2009.

  1. bigal1949

    bigal1949 WindyNation Engineer

    Has anyone on the board had any experience with the Presto wind line of alternators as yet? I like the heavy windings in the stator but is it a significant improvement over the other brands that have converted a auto alternator? Thanks for the help.
  2. murray2paddles

    murray2paddles WindyNation Engineer

    I am using the presto 80 rpm. with windy nation .35 in blades. So far it has been a good combination. What I did find was their advertisement on 12V at 80 rpm. seemed to be good to their word. I think the presto 40 might also be interesting in a low wind area.
  3. murray2paddles

    murray2paddles WindyNation Engineer

    Al, here is the update I had told you about. I copied a section from the update on Post Your Photos from the Presto 40 & 35in blades.
    "Murray wrote"
    Observing the actions of the unit in light wind as stated in the first report, it did pick up light wind very fast and as the alternator add stated it was producing cut in power very fast. BUT as many of us do not read all the fine print and we are lured by the adds that a generator can produce 12 V at relatively low rmp. we must learn to look into the rest of the formula.
    If you look at the Presto Power Curve advertisements the look impressive.
    As an example it states : 800 rpm - 97 V * 8 amps = 776 Watt, the rpm. volts and watts look pretty decent and appealing.
    But a first hint should have been the low amps reading.

    Now the formula, when the add states 97 V. this does not apply to most of us who are using a 12 V system.
    So now if you use the Oms formula, I will also give you a link so you can easily use this for your own calculations

    For us this should read : 800 rpm - 12 V * 8 amps = 96 Watt
    Yes that is right, only 96 watt and 800 rpm is a good spin for any generator.
    So my verdict is in due to this finding. Had I known this I would not have purchased the Presto !!!!!!

    Now the next part of the learning curve. We matched this alternator up with 35 in. blades and when in light to moderate winds the unit is able to hold itself facing the true wind. If the wind increases the unit continually tries to move and stall and then must seek true wind once again. We believe the blades may be overpowering the unit as there is very little load ( amps ) to put the blades under a work load. When there is a high wind condition this also creates an undesirable sound from the blades due to spinning so fast with no resistance.
    What did we learn, We believe we have matched the wrong generator to the right blades.

    Hope this info reached you in time to allow a more informed choice.


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