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  • Re: Generator, no. Alternator, close. It's a MAGNETO!

    by » 5 months ago


    From now on, I'm going with Permanent Magnet Alternator! (Just to drive everyone nuts ...).

    As a now-retired physicist, I'm very aware of common work usage being quite misleading when used to describe technology. "Work", for example is a word which everyone knows and intuitively understands, yet in physics/engineering it's (Force x Distance). So, walking, level, at constant speed, carrying a 50 lb sack of cement, you're doing zero work! "Generator" has a similar problem, common usage vs. its technical definition. Similarly, "magneto" in airplane circles brings to mind a hunk of metal sprouting spark plug wires which hangs at the back of a standard aircraft piston engine. More accurately, it's a magneto powered ignition system, a phrase which also applies to our Rotax engine ignition system. The power source is essentially the same, but the "ignition system" is quite different.

    While Rotax may wish to avoid the use of the word "magneto", I'm not so sure it reduces confusion because most of our instrument panels have switches labelled magneto (and alternator) anyway.

    Regardless, I'm glad to have a more clear understanding of the systems.

     

     

     

    37637_2_Screenshot 2023-09-29 210713.png (You do not have access to download this file.)

  • Re: Generator, no. Alternator, close. It's a MAGNETO!

    by » 5 months ago


    Hi Jeffry

    Best part we all had a good learning experience.  Thanks for the thread.

    Cheers


  • Re: Generator, no. Alternator, close. It's a MAGNETO!

    by » 5 months ago


    Jeffrey Stetson wrote: "...walking, level, at constant speed, carrying a 50 lb sack of cement, you're doing zero work!"

    Um... what?  You're going to have to explain that one.  Please type slowly; I don't have a physics degree, but I have carried sacks of cement.


  • Re: Generator, no. Alternator, close. It's a MAGNETO!

    by » 5 months ago


    Eric Page wrote:

    Jeffrey Stetson wrote: "...walking, level, at constant speed, carrying a 50 lb sack of cement, you're doing zero work!"

    Um... what?  You're going to have to explain that one.  Please type slowly; I don't have a physics degree, but I have carried sacks of cement.

    The point here is that physics (and good engineering) defines words to have a very precise meaning. With Work defined as Force x Distance, W = F x d = mass x acceleration x distance. Steady velocity (or standing still) means zero acceleration, hence zero "work". Yup, real life meaning it isn't, but reality, it is!


    Thank you said by: Eric Page

  • Re: Generator, no. Alternator, close. It's a MAGNETO!

    by » 5 months ago


    By that definition, a hovering helicopter is doing zero "work", but it sure requires a lot of "power".  ;)


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