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How Does an Electric Motor Know How Much Electricity Is Needed

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  How Does an Electric Motor Know How Much Electricity Is Needed "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-04-24 09:39 -0700
    How Does an Electric Motor Know How Much Electricity Is Needed HVAC <mr.hvac@gmail.com> - 2016-04-24 09:56 -0700
      Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-24 23:52 -0400
        Re: How Does an Electric Motor Know How Much Electricity Is Needed "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-04-25 11:49 -0700
          Re: How Does an Electric Motor Know How Much Electricity Is Needed Sam Wormley <swormley1@gmail.com> - 2016-04-25 14:37 -0500
            Re: How Does an Electric Motor Know How Much Electricity Is Needed Sergio <invalid@invalid.com> - 2016-04-25 21:14 -0500
    Re: How Does an Electric Motor Know How Much Electricity Is Needed Sergio <invalid@invalid.com> - 2016-04-24 12:17 -0500
    Re: How Does an Electric Motor Know How Much Electricity Is Needed Sam Wormley <swormley1@gmail.com> - 2016-04-24 14:14 -0500
    Re: How Does an Electric Motor Know How Much Electricity Is Needed Double-A <double-a3@hush.com> - 2016-04-24 13:41 -0700
      Re: How Does an Electric Motor Know How Much Electricity Is Needed "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-04-24 16:19 -0700
        Re: How Does an Electric Motor Know How Much Electricity Is Needed HVAC <mr.hvac@gmail.com> - 2016-04-24 16:45 -0700
        Re: How Does an Electric Motor Know How Much Electricity Is Needed "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-04-25 11:45 -0700
          Re: How Does an Electric Motor Know How Much Electricity Is Needed Sam Wormley <swormley1@gmail.com> - 2016-04-25 14:25 -0500
            Re: How Does an Electric Motor Know How Much Electricity Is Needed jimp@specsol.spam.sux.com - 2016-04-25 19:39 +0000
            Re: How Does an Electric Motor Know How Much Electricity Is Needed Double-A <double-a3@hush.com> - 2016-04-25 17:08 -0700
              Re: How Does an Electric Motor Know How Much Electricity Is Needed Sam Wormley <swormley1@gmail.com> - 2016-04-25 19:16 -0500
                Re: How Does an Electric Motor Know How Much Electricity Is Needed jimp@specsol.spam.sux.com - 2016-04-26 00:41 +0000
                Re: How Does an Electric Motor Know How Much Electricity Is Needed Wally W. <ww84wa@aim.com> - 2016-04-25 23:05 -0400
                  Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-26 03:11 -0400
                    Re: How Does an Electric Motor Know How Much Electricity Is Needed Sergio <invalid@invalid.com> - 2016-04-26 17:29 -0500
                  Re: How Does an Electric Motor Know How Much Electricity Is Needed Double-A <double-a3@hush.com> - 2016-04-26 13:11 -0700
                    Re: How Does an Electric Motor Know How Much Electricity Is Needed Sam Wormley <swormley1@gmail.com> - 2016-04-26 19:03 -0500
            Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-25 21:59 -0400
    Re: How Does an Electric Motor Know How Much Electricity Is Needed Sylvia Else <sylvia@not.at.this.address> - 2016-04-27 11:33 +1000
      Re: How Does an Electric Motor Know How Much Electricity Is Needed Wally W. <ww84wa@aim.com> - 2016-04-26 22:58 -0400
        Re: How Does an Electric Motor Know How Much Electricity Is Needed Sylvia Else <sylvia@not.at.this.address> - 2016-04-27 13:14 +1000
          Re: How Does an Electric Motor Know How Much Electricity Is Needed Wally W. <ww84wa@aim.com> - 2016-04-26 23:32 -0400
            Re: How Does an Electric Motor Know How Much Electricity Is Needed Sylvia Else <sylvia@not.at.this.address> - 2016-04-27 13:49 +1000
              Re: How Does an Electric Motor Know How Much Electricity Is Needed Wally W. <ww84wa@aim.com> - 2016-04-26 23:53 -0400
                Re: How Does an Electric Motor Know How Much Electricity Is Needed Wally W. <ww84wa@aim.com> - 2016-04-27 00:06 -0400
              Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-27 01:25 -0400
                Re: How Does an Electric Motor Know How Much Electricity Is Needed Sylvia Else <sylvia@not.at.this.address> - 2016-04-27 15:41 +1000
                  Re: How Does an Electric Motor Know How Much Electricity Is Needed Wally W. <ww84wa@aim.com> - 2016-04-27 07:06 -0400
                    Re: How Does an Electric Motor Know How Much Electricity Is Needed edprochak@gmail.com - 2016-04-27 05:31 -0700
                      Re: How Does an Electric Motor Know How Much Electricity Is Needed Wally W. <ww84wa@aim.com> - 2016-04-27 09:21 -0400
                        Re: How Does an Electric Motor Know How Much Electricity Is Needed edprochak@gmail.com - 2016-04-27 11:06 -0700
                  Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-27 11:22 -0400
                    Re: How Does an Electric Motor Know How Much Electricity Is Needed jimp@specsol.spam.sux.com - 2016-04-27 16:44 +0000
                  Re: How Does an Electric Motor Know How Much Electricity Is Needed "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-04-27 11:35 -0700
                    Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-27 18:44 -0400
                      Re: How Does an Electric Motor Know How Much Electricity Is Needed Wally W. <ww84wa@aim.com> - 2016-04-27 22:16 -0400
                        Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-27 23:09 -0400
        Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-26 23:34 -0400
    Re: How Does an Electric Motor Know How Much Electricity Is Needed "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-04-27 11:44 -0700
      Re: How Does an Electric Motor Know How Much Electricity Is Needed Sam Wormley <swormley1@gmail.com> - 2016-04-27 15:45 -0500
        Re: How Does an Electric Motor Know How Much Electricity Is Needed Sergio <invalid@invalid.com> - 2016-04-27 22:30 -0500
          Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-28 00:38 -0400
      Re: How Does an Electric Motor Know How Much Electricity Is Needed benj <nobodyxx@gmail> - 2016-04-27 18:43 -0400
    Re: How Does an Electric Motor Know How Much Electricity Is Needed gyansorova@gmail.com - 2016-04-27 11:58 -0700

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#573518

On Monday, April 25, 2016 at 8:05:42 PM UTC-7, Wally W. wrote:
> On Mon, 25 Apr 2016 19:16:29 -0500, Sam Wormley wrote:
> 
> >On 4/25/16 7:08 PM, Double-A wrote:
> >> On Monday, April 25, 2016 at 12:25:35 PM UTC-7, Sam Wormley wrote:
> >>> On 4/25/16 1:45 PM, reber g=emc^2 wrote:
> >>>> Electricity is by far our greatest energy.So clean.So quite
> >>>
> >>>
> >>>     You need to poke your head into the chimney of the coal power plant
> >>>     that generates the "clean", "quiet" energy, reber.  :-o
> >>>
> >>>
> >>
> >> Enough of this "war on coal"!  It heated my family home back in the day, and Bert has admitted it heated his too!
> >>
> >> Double-A
> >>
> >
> >   Coal (the burning of what's left in the ground) has the ability
> >   to assure the extinction of the human race.
> 
> Absolutely ludricrous.
> 
> Where is there any credible study that asserts the entire planet will
> become uninhabitable for humans if we spew more CO2?
> 
> You are claiming "climate change" will change *all* climates so
> drastically that humans will go extinct.
> 
> What rational justification for that claim can you possibly have?


Actually, CO2 is good for agriculture!

Double-A

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#573569

On 4/26/16 3:11 PM, Double-A wrote:
> On Monday, April 25, 2016 at 8:05:42 PM UTC-7, Wally W. wrote:
>> On Mon, 25 Apr 2016 19:16:29 -0500, Sam Wormley wrote:
>>
>>> On 4/25/16 7:08 PM, Double-A wrote:
>>>> On Monday, April 25, 2016 at 12:25:35 PM UTC-7, Sam Wormley wrote:
>>>>> On 4/25/16 1:45 PM, reber g=emc^2 wrote:
>>>>>> Electricity is by far our greatest energy.So clean.So quite
>>>>>
>>>>>
>>>>>      You need to poke your head into the chimney of the coal power plant
>>>>>      that generates the "clean", "quiet" energy, reber.  :-o
>>>>>
>>>>>
>>>>
>>>> Enough of this "war on coal"!  It heated my family home back in the day, and Bert has admitted it heated his too!
>>>>
>>>> Double-A
>>>>
>>>
>>>    Coal (the burning of what's left in the ground) has the ability
>>>    to assure the extinction of the human race.
>>
>> Absolutely ludricrous.
>>
>> Where is there any credible study that asserts the entire planet will
>> become uninhabitable for humans if we spew more CO2?
>>
>> You are claiming "climate change" will change *all* climates so
>> drastically that humans will go extinct.
>>
>> What rational justification for that claim can you possibly have?
>
>
> Actually, CO2 is good for agriculture!
>
> Double-A
>

   Not corn -- reduces yield because silking happens to early.
   If you want to know more, DuckDuckGo is your friend.

<HTML><BODY><BLOCKQUOTE><PRE>
<FORM action="https://duckduckgo.com" method=get name=f>
   <INPUT type=text name=q size=60 maxlength=256 value=""> <INPUT 
type=submit name=btnG value="DuckDuckGo">
</FORM>
</PRE></BLOCKQUOTE></BODY></HTML>

-- 

sci.physics is an unmoderated newsgroup dedicated
to the discussion of physics, news from the physics
community, and physics-related social issues.

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#573292

On 04/25/2016 03:25 PM, Sam Wormley wrote:
> On 4/25/16 1:45 PM, reber g=emc^2 wrote:
>> Electricity is by far our greatest energy.So clean.So quite
>
>
>    You need to poke your head into the chimney of the coal power plant
>    that generates the "clean", "quiet" energy, reber.  :-o
>
Come on Sammy, so long as the plant is far away, out of sight out of mind.

It's just like dumping trash in the Ocean. Once it floats away and you
don'tsee it anymore, then you don't have to worry about it!

Herb is an Imperial thinker. You are not.

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#573604

On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
> It even pulls in more electrons when doing moire work
> automatically.WOW  I can see why the thickness of a wire obeys the
> inverse square law.  I love electric motors,and I'm big on electron
> flow. Trebert
>

With increasing load, it slows down. As it does, the current has to 
increase so that the back EMF at the reduced speed still equals the 
applied voltage.

Sylvia.

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#573612

On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:

>On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>> It even pulls in more electrons when doing moire work
>> automatically.WOW  I can see why the thickness of a wire obeys the
>> inverse square law.  I love electric motors,and I'm big on electron
>> flow. Trebert
>>
>
>With increasing load, it slows down. As it does, the current has to 
>increase so that the back EMF at the reduced speed still equals the 
>applied voltage.

It's all describable, but it is still akin to magic. Stop the shaft,
and the current will increase to burn up the windings. Let the shaft
turn freely, and current will be just enough to both create and come
to equillibrium with an induced magnetic field; plus overcome
frictions of various kinds, temperature-varying resistive losses, etc.

And, supposedly, the Big Bang did it.

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#573615

On 27/04/2016 12:58 PM, Wally W. wrote:
> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>
>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>> It even pulls in more electrons when doing moire work
>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>> inverse square law.  I love electric motors,and I'm big on electron
>>> flow. Trebert
>>>
>>
>> With increasing load, it slows down. As it does, the current has to
>> increase so that the back EMF at the reduced speed still equals the
>> applied voltage.
>
> It's all describable, but it is still akin to magic.

It doesn't seem akin to magic to me.

Sylvia.

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#573618

On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:

>On 27/04/2016 12:58 PM, Wally W. wrote:
>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>
>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>> It even pulls in more electrons when doing moire work
>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>> flow. Trebert
>>>>
>>>
>>> With increasing load, it slows down. As it does, the current has to
>>> increase so that the back EMF at the reduced speed still equals the
>>> applied voltage.
>>
>> It's all describable, but it is still akin to magic.
>
>It doesn't seem akin to magic to me.
>
>Sylvia.

Lessee ... the generator in the next town knows just how many
electrons it should send to my motor. And that it should send a few
more of them if ... and only for as long as ... I apply some drag to
the shaft of the motor.

And it couldn't possibly be otherwise in another universe.

I share Trebert's sense of awe on dynamic, meticulous balance
maintained as a motor runs amid several interacting and dynamic
variables.

Not quite the definition I was looking for, but this concept may be
related:
https://en.wikipedia.org/wiki/Sense_of_wonder

Not a bad thing to look at the world once in a while and say,
"Really?! How does *that* happen?"

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#573620

On 27/04/2016 1:32 PM, Wally W. wrote:
> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
>
>> On 27/04/2016 12:58 PM, Wally W. wrote:
>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>>
>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>>> It even pulls in more electrons when doing moire work
>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>>> flow. Trebert
>>>>>
>>>>
>>>> With increasing load, it slows down. As it does, the current has to
>>>> increase so that the back EMF at the reduced speed still equals the
>>>> applied voltage.
>>>
>>> It's all describable, but it is still akin to magic.
>>
>> It doesn't seem akin to magic to me.
>>
>> Sylvia.
>
> Lessee ... the generator in the next town knows just how many
> electrons it should send to my motor.

Of course it doesn't. The electrons in the wire respond to the local 
voltage gradient in the wire. Increasing the load on your motor slows it 
down, and the reduced back EMF increases the voltage gradient at the 
input to the motor. So more electrons at that point. That changes the 
voltage gradient a bit upstream, and more electrons flow there. The 
change propagates along the wire, at a good fraction of the speed of 
light, until it eventually reaches the generator, which responds 
accordingly.

With an AC system, everything's cycling 50 or 60 times a second anyway, 
and the effect of the motor load is superimposed on that.

Sylvia.

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#573621

On Wed, 27 Apr 2016 13:49:12 +1000, Sylvia Else wrote:

>On 27/04/2016 1:32 PM, Wally W. wrote:
>> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
>>
>>> On 27/04/2016 12:58 PM, Wally W. wrote:
>>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>>>
>>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>>>> It even pulls in more electrons when doing moire work
>>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>>>> flow. Trebert
>>>>>>
>>>>>
>>>>> With increasing load, it slows down. As it does, the current has to
>>>>> increase so that the back EMF at the reduced speed still equals the
>>>>> applied voltage.
>>>>
>>>> It's all describable, but it is still akin to magic.
>>>
>>> It doesn't seem akin to magic to me.
>>>
>>> Sylvia.
>>
>> Lessee ... the generator in the next town knows just how many
>> electrons it should send to my motor.
>
>Of course it doesn't. The electrons in the wire respond to the local 
>voltage gradient in the wire. Increasing the load on your motor slows it 
>down, and the reduced back EMF increases the voltage gradient at the 
>input to the motor. So more electrons at that point. That changes the 
>voltage gradient a bit upstream, and more electrons flow there. The 
>change propagates along the wire, at a good fraction of the speed of 
>light, until it eventually reaches the generator, which responds 
>accordingly.
>
>With an AC system, everything's cycling 50 or 60 times a second anyway, 
>and the effect of the motor load is superimposed on that.
>
>Sylvia.

https://en.wikiquote.org/wiki/Star_Trek:_The_Original_Series
Spock: I've never stopped to look at clouds before. Or rainbows. You
know, I can tell you exactly why one appears in the sky, but
considering its beauty has always been out of the question.

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#573622

On Tue, 26 Apr 2016 23:53:41 -0400, Wally W. wrote:

>On Wed, 27 Apr 2016 13:49:12 +1000, Sylvia Else wrote:
>
>>On 27/04/2016 1:32 PM, Wally W. wrote:
>>> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
>>>
>>>> On 27/04/2016 12:58 PM, Wally W. wrote:
>>>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>>>>
>>>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>>>>> It even pulls in more electrons when doing moire work
>>>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>>>>> flow. Trebert
>>>>>>>
>>>>>>
>>>>>> With increasing load, it slows down. As it does, the current has to
>>>>>> increase so that the back EMF at the reduced speed still equals the
>>>>>> applied voltage.
>>>>>
>>>>> It's all describable, but it is still akin to magic.
>>>>
>>>> It doesn't seem akin to magic to me.
>>>>
>>>> Sylvia.
>>>
>>> Lessee ... the generator in the next town knows just how many
>>> electrons it should send to my motor.
>>
>>Of course it doesn't. The electrons in the wire respond to the local 
>>voltage gradient in the wire. Increasing the load on your motor slows it 
>>down, and the reduced back EMF increases the voltage gradient at the 
>>input to the motor. So more electrons at that point. That changes the 
>>voltage gradient a bit upstream, and more electrons flow there. The 
>>change propagates along the wire, at a good fraction of the speed of 
>>light, until it eventually reaches the generator, which responds 
>>accordingly.
>>
>>With an AC system, everything's cycling 50 or 60 times a second anyway, 
>>and the effect of the motor load is superimposed on that.
>>
>>Sylvia.
>
>https://en.wikiquote.org/wiki/Star_Trek:_The_Original_Series
>Spock: I've never stopped to look at clouds before. Or rainbows. You
>know, I can tell you exactly why one appears in the sky, but
>considering its beauty has always been out of the question.

http://www.imdb.com/title/tt0708440/quotes
Mr. Spock: Mr. Scott, there was no deity involved. It was my
cross-circuiting to B that recovered them.

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#573631

On 04/26/2016 11:49 PM, Sylvia Else wrote:
> On 27/04/2016 1:32 PM, Wally W. wrote:
>> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
>>
>>> On 27/04/2016 12:58 PM, Wally W. wrote:
>>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>>>
>>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>>>> It even pulls in more electrons when doing moire work
>>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>>>> flow. Trebert
>>>>>>
>>>>>
>>>>> With increasing load, it slows down. As it does, the current has to
>>>>> increase so that the back EMF at the reduced speed still equals the
>>>>> applied voltage.
>>>>
>>>> It's all describable, but it is still akin to magic.
>>>
>>> It doesn't seem akin to magic to me.
>>>
>>> Sylvia.
>>
>> Lessee ... the generator in the next town knows just how many
>> electrons it should send to my motor.
>
> Of course it doesn't. The electrons in the wire respond to the local
> voltage gradient in the wire. Increasing the load on your motor slows it
> down, and the reduced back EMF increases the voltage gradient at the
> input to the motor. So more electrons at that point. That changes the
> voltage gradient a bit upstream, and more electrons flow there. The
> change propagates along the wire, at a good fraction of the speed of
> light, until it eventually reaches the generator, which responds
> accordingly.
>
> With an AC system, everything's cycling 50 or 60 times a second anyway,
> and the effect of the motor load is superimposed on that.
>
> Sylvia.

Nice theory Sylvia, but generally speaking motors don't slow down when 
delivering power. So how does your theory work with synchronous motors?

I like the magic explanation better.

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#573635

On 27/04/2016 3:25 PM, benj wrote:
> On 04/26/2016 11:49 PM, Sylvia Else wrote:
>> On 27/04/2016 1:32 PM, Wally W. wrote:
>>> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
>>>
>>>> On 27/04/2016 12:58 PM, Wally W. wrote:
>>>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>>>>
>>>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>>>>> It even pulls in more electrons when doing moire work
>>>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>>>>> flow. Trebert
>>>>>>>
>>>>>>
>>>>>> With increasing load, it slows down. As it does, the current has to
>>>>>> increase so that the back EMF at the reduced speed still equals the
>>>>>> applied voltage.
>>>>>
>>>>> It's all describable, but it is still akin to magic.
>>>>
>>>> It doesn't seem akin to magic to me.
>>>>
>>>> Sylvia.
>>>
>>> Lessee ... the generator in the next town knows just how many
>>> electrons it should send to my motor.
>>
>> Of course it doesn't. The electrons in the wire respond to the local
>> voltage gradient in the wire. Increasing the load on your motor slows it
>> down, and the reduced back EMF increases the voltage gradient at the
>> input to the motor. So more electrons at that point. That changes the
>> voltage gradient a bit upstream, and more electrons flow there. The
>> change propagates along the wire, at a good fraction of the speed of
>> light, until it eventually reaches the generator, which responds
>> accordingly.
>>
>> With an AC system, everything's cycling 50 or 60 times a second anyway,
>> and the effect of the motor load is superimposed on that.
>>
>> Sylvia.
>
> Nice theory Sylvia, but generally speaking motors don't slow down when
> delivering power. So how does your theory work with synchronous motors?

In a synchronous motor, the current and the power factor, are a function 
of the angle between the rotor and the rotating field. When you load a 
synchronous motor there is indeed a temporary reduction in speed while 
the angle increases, which leads to an increase in current and power 
factor. The increased current, coupled with the angle, cause in increase 
in torque, which prevents further increase in the angle, and the speed 
returns to what it was originally.

Again, nothing magical, just a straight forward application of 
electromagnetism.

Sylvia.

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#573656

On Wed, 27 Apr 2016 15:41:10 +1000, Sylvia Else wrote:

>On 27/04/2016 3:25 PM, benj wrote:
>> On 04/26/2016 11:49 PM, Sylvia Else wrote:
>>> On 27/04/2016 1:32 PM, Wally W. wrote:
>>>> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
>>>>
>>>>> On 27/04/2016 12:58 PM, Wally W. wrote:
>>>>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>>>>>
>>>>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>>>>>> It even pulls in more electrons when doing moire work
>>>>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>>>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>>>>>> flow. Trebert
>>>>>>>>
>>>>>>>
>>>>>>> With increasing load, it slows down. As it does, the current has to
>>>>>>> increase so that the back EMF at the reduced speed still equals the
>>>>>>> applied voltage.
>>>>>>
>>>>>> It's all describable, but it is still akin to magic.
>>>>>
>>>>> It doesn't seem akin to magic to me.
>>>>>
>>>>> Sylvia.
>>>>
>>>> Lessee ... the generator in the next town knows just how many
>>>> electrons it should send to my motor.
>>>
>>> Of course it doesn't. The electrons in the wire respond to the local
>>> voltage gradient in the wire. Increasing the load on your motor slows it
>>> down, and the reduced back EMF increases the voltage gradient at the
>>> input to the motor. So more electrons at that point. That changes the
>>> voltage gradient a bit upstream, and more electrons flow there. The
>>> change propagates along the wire, at a good fraction of the speed of
>>> light, until it eventually reaches the generator, which responds
>>> accordingly.
>>>
>>> With an AC system, everything's cycling 50 or 60 times a second anyway,
>>> and the effect of the motor load is superimposed on that.
>>>
>>> Sylvia.
>>
>> Nice theory Sylvia, but generally speaking motors don't slow down when
>> delivering power. So how does your theory work with synchronous motors?
>
>In a synchronous motor, the current and the power factor, are a function 
>of the angle between the rotor and the rotating field. When you load a 
>synchronous motor there is indeed a temporary reduction in speed while 
>the angle increases, which leads to an increase in current and power 
>factor. The increased current, coupled with the angle, cause in increase 
>in torque, which prevents further increase in the angle, and the speed 
>returns to what it was originally.

All automatically, and without a control system. Only a complex
interaction of "natural laws," upon the reliability of which we can
bet our lives.

>Again, nothing magical, 

There is a difference between "akin to magic" and "magical."

>just a straight forward application of 
>electromagnetism.

Where waves travel without a medium. Simple. What is not to
understand? How could it be otherwise?

If it was all understood so well, second-order effects wouldn't bite
us in the ass when we try to predict the performance of a motor to 12
decimal places.

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#573671

On Wednesday, April 27, 2016 at 7:06:44 AM UTC-4, Wally W. wrote:
> On Wed, 27 Apr 2016 15:41:10 +1000, Sylvia Else wrote:
> 
[]snip
> >
> >In a synchronous motor, the current and the power factor, are a function 
> >of the angle between the rotor and the rotating field. When you load a 
> >synchronous motor there is indeed a temporary reduction in speed while 
> >the angle increases, which leads to an increase in current and power 
> >factor. The increased current, coupled with the angle, cause in increase 
> >in torque, which prevents further increase in the angle, and the speed 
> >returns to what it was originally.
> 
> All automatically, and without a control system. Only a complex
> interaction of "natural laws," upon the reliability of which we can
> bet our lives.

For simple applications, there is no computer control system.
Yes the control in that case is usually by design based on the
laws of electromagnetism. But it better be a simple system, like
a fan for example. A switch to turn it on or off is the only control.
> 
> >Again, nothing magical, 
> 
> There is a difference between "akin to magic" and "magical."

Physicists still get that "akin to magic" sense of wonder.
Just because we understand how it works doesn't mean we don't
appreciate it.
> 
> >just a straight forward application of 
> >electromagnetism.
> 
> Where waves travel without a medium. Simple. What is not to
> understand? How could it be otherwise?

(Ignoring the rhetorical crap)
> 
> If it was all understood so well, second-order effects wouldn't bite
> us in the ass when we try to predict the performance of a motor to 12
> decimal places.

By 12 decimal places we are well past second order effects. And usually
NOT getting bit in the ass.

Try running a motor with a 40:1 inertia mismatch. With the proper control
system, it still works. I have one where I do not have direct control
and we are still able to position that load within the required tolerance.

there are a lot of things in the universe we do not yet understand.
But motors are not one of them.

  ed

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#573682

On Wed, 27 Apr 2016 05:31:32 -0700 (PDT), edprochak@gmail.com wrote:

>On Wednesday, April 27, 2016 at 7:06:44 AM UTC-4, Wally W. wrote:
>> On Wed, 27 Apr 2016 15:41:10 +1000, Sylvia Else wrote:
>> 
>[]snip
>> >
>> >In a synchronous motor, the current and the power factor, are a function 
>> >of the angle between the rotor and the rotating field. When you load a 
>> >synchronous motor there is indeed a temporary reduction in speed while 
>> >the angle increases, which leads to an increase in current and power 
>> >factor. The increased current, coupled with the angle, cause in increase 
>> >in torque, which prevents further increase in the angle, and the speed 
>> >returns to what it was originally.
>> 
>> All automatically, and without a control system. Only a complex
>> interaction of "natural laws," upon the reliability of which we can
>> bet our lives.
>
>For simple applications, there is no computer control system.
>Yes the control in that case is usually by design based on the
>laws of electromagnetism. But it better be a simple system, like
>a fan for example. A switch to turn it on or off is the only control.
>> 
>> >Again, nothing magical, 
>> 
>> There is a difference between "akin to magic" and "magical."
>
>Physicists still get that "akin to magic" sense of wonder.
>Just because we understand how it works doesn't mean we don't
>appreciate it.
>> 
>> >just a straight forward application of 
>> >electromagnetism.
>> 
>> Where waves travel without a medium. Simple. What is not to
>> understand? How could it be otherwise?
>
>(Ignoring the rhetorical crap)
>> 
>> If it was all understood so well, second-order effects wouldn't bite
>> us in the ass when we try to predict the performance of a motor to 12
>> decimal places.
>
>By 12 decimal places we are well past second order effects. And usually
>NOT getting bit in the ass.

Could we predict the change in output power, to 12 decimal places, of
a motor operating at 1750 rpm and a room temperature of 20°C if we
keep "other things" (except the load) equal and increase the room
temperature to 25°C?

>Try running a motor with a 40:1 inertia mismatch. With the proper control
>system, it still works. I have one where I do not have direct control
>and we are still able to position that load within the required tolerance.
>
>there are a lot of things in the universe we do not yet understand.
>But motors are not one of them.
>
>  ed

We certainly understand motors enough to build them and to use them
effectively.

But research seems to be ongoing:
http://www.smma.org/emerf-overview.htm
EMERF Mission

To advance and promote the electric motor industry through education,
pre-competitive electric motor ***research*** and facilitation of
technology transfer within the industry and in cooperation with
academic, private ***research*** and governmental organizations.


I just appreciated Trebert's sense of awe at how conservation of
energy, etc., come together in an electric motor ... "automagically."

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#573752

On Wednesday, April 27, 2016 at 9:21:31 AM UTC-4, Wally W. wrote:
> On Wed, 27 Apr 2016 05:31:32 -0700 (PDT), edprochak@gmail.com wrote:
> 
[]
> >> If it was all understood so well, second-order effects wouldn't bite
> >> us in the ass when we try to predict the performance of a motor to 12
> >> decimal places.
> >
> >By 12 decimal places we are well past second order effects. And usually
> >NOT getting bit in the ass.
> 
> Could we predict the change in output power, to 12 decimal places, of
> a motor operating at 1750 rpm and a room temperature of 20°C if we
> keep "other things" (except the load) equal and increase the room
> temperature to 25°C?

Maybe as a graduate research thesis we might test the prediction.
In practice (Engineering) it isn't going to serve much purpose.
Let's see 1 part in 1000000000000. To get a 1 watt difference in
power used, the motor needs to be a 1 teraWatt motor (1000000000 KW)

let me know when you get one and we can test it.

(You have a real fixation on the number 12.)
[]
> 
> We certainly understand motors enough to build them and to use them
> effectively.
> 
> But research seems to be ongoing:
> http://www.smma.org/emerf-overview.htm
> EMERF Mission
> 
> To advance and promote the electric motor industry through education,
> pre-competitive electric motor ***research*** and facilitation of
> technology transfer within the industry and in cooperation with
> academic, private ***research*** and governmental organizations.
> 
I'm sure there is some basic research done by their academic
associates, but I assure you, the main focus and money is on
engineering research. There is not a lot to add to Maxwell's
equations.

> 
> I just appreciated Trebert's sense of awe at how conservation of
> energy, etc., come together in an electric motor ... "automagically."

Yes. A sense of awe is a real gift. My own awe of motors came when
I first realized how back EMF worked and affected motors and generators.

have a good day.
  ed

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#573704

On 04/27/2016 01:41 AM, Sylvia Else wrote:
> On 27/04/2016 3:25 PM, benj wrote:
>> On 04/26/2016 11:49 PM, Sylvia Else wrote:
>>> On 27/04/2016 1:32 PM, Wally W. wrote:
>>>> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
>>>>
>>>>> On 27/04/2016 12:58 PM, Wally W. wrote:
>>>>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>>>>>
>>>>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>>>>>> It even pulls in more electrons when doing moire work
>>>>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>>>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>>>>>> flow. Trebert
>>>>>>>>
>>>>>>>
>>>>>>> With increasing load, it slows down. As it does, the current has to
>>>>>>> increase so that the back EMF at the reduced speed still equals the
>>>>>>> applied voltage.
>>>>>>
>>>>>> It's all describable, but it is still akin to magic.
>>>>>
>>>>> It doesn't seem akin to magic to me.
>>>>>
>>>>> Sylvia.
>>>>
>>>> Lessee ... the generator in the next town knows just how many
>>>> electrons it should send to my motor.
>>>
>>> Of course it doesn't. The electrons in the wire respond to the local
>>> voltage gradient in the wire. Increasing the load on your motor slows it
>>> down, and the reduced back EMF increases the voltage gradient at the
>>> input to the motor. So more electrons at that point. That changes the
>>> voltage gradient a bit upstream, and more electrons flow there. The
>>> change propagates along the wire, at a good fraction of the speed of
>>> light, until it eventually reaches the generator, which responds
>>> accordingly.
>>>
>>> With an AC system, everything's cycling 50 or 60 times a second anyway,
>>> and the effect of the motor load is superimposed on that.
>>>
>>> Sylvia.
>>
>> Nice theory Sylvia, but generally speaking motors don't slow down when
>> delivering power. So how does your theory work with synchronous motors?
>
> In a synchronous motor, the current and the power factor, are a function
> of the angle between the rotor and the rotating field. When you load a
> synchronous motor there is indeed a temporary reduction in speed while
> the angle increases, which leads to an increase in current and power
> factor. The increased current, coupled with the angle, cause in increase
> in torque, which prevents further increase in the angle, and the speed
> returns to what it was originally.
>
> Again, nothing magical, just a straight forward application of
> electromagnetism.
>
> Sylvia.

A change of angle isn't "slowing down" so now you've got a second theory 
as to how motors know how much electricity to ask for!  So your first 
claim of slowing and "back EMF reduction" clearly is suddenly different! 
You can't have two different theories to explain the same events! That's 
no better than saying it's magic.

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#573717

benj <nobodyxx@gmail> wrote:
> On 04/27/2016 01:41 AM, Sylvia Else wrote:
>> On 27/04/2016 3:25 PM, benj wrote:
>>> On 04/26/2016 11:49 PM, Sylvia Else wrote:
>>>> On 27/04/2016 1:32 PM, Wally W. wrote:
>>>>> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
>>>>>
>>>>>> On 27/04/2016 12:58 PM, Wally W. wrote:
>>>>>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>>>>>>
>>>>>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>>>>>>> It even pulls in more electrons when doing moire work
>>>>>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>>>>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>>>>>>> flow. Trebert
>>>>>>>>>
>>>>>>>>
>>>>>>>> With increasing load, it slows down. As it does, the current has to
>>>>>>>> increase so that the back EMF at the reduced speed still equals the
>>>>>>>> applied voltage.
>>>>>>>
>>>>>>> It's all describable, but it is still akin to magic.
>>>>>>
>>>>>> It doesn't seem akin to magic to me.
>>>>>>
>>>>>> Sylvia.
>>>>>
>>>>> Lessee ... the generator in the next town knows just how many
>>>>> electrons it should send to my motor.
>>>>
>>>> Of course it doesn't. The electrons in the wire respond to the local
>>>> voltage gradient in the wire. Increasing the load on your motor slows it
>>>> down, and the reduced back EMF increases the voltage gradient at the
>>>> input to the motor. So more electrons at that point. That changes the
>>>> voltage gradient a bit upstream, and more electrons flow there. The
>>>> change propagates along the wire, at a good fraction of the speed of
>>>> light, until it eventually reaches the generator, which responds
>>>> accordingly.
>>>>
>>>> With an AC system, everything's cycling 50 or 60 times a second anyway,
>>>> and the effect of the motor load is superimposed on that.
>>>>
>>>> Sylvia.
>>>
>>> Nice theory Sylvia, but generally speaking motors don't slow down when
>>> delivering power. So how does your theory work with synchronous motors?
>>
>> In a synchronous motor, the current and the power factor, are a function
>> of the angle between the rotor and the rotating field. When you load a
>> synchronous motor there is indeed a temporary reduction in speed while
>> the angle increases, which leads to an increase in current and power
>> factor. The increased current, coupled with the angle, cause in increase
>> in torque, which prevents further increase in the angle, and the speed
>> returns to what it was originally.
>>
>> Again, nothing magical, just a straight forward application of
>> electromagnetism.
>>
>> Sylvia.
> 
> A change of angle isn't "slowing down" so now you've got a second theory 
> as to how motors know how much electricity to ask for!  So your first 
> claim of slowing and "back EMF reduction" clearly is suddenly different! 
> You can't have two different theories to explain the same events! That's 
> no better than saying it's magic.
 
Of course it is, otherwise how would the angle change?

 

-- 
Jim Pennino

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#573759

On Tuesday, April 26, 2016 at 10:41:16 PM UTC-7, Sylvia Else wrote:
> On 27/04/2016 3:25 PM, benj wrote:
> > On 04/26/2016 11:49 PM, Sylvia Else wrote:
> >> On 27/04/2016 1:32 PM, Wally W. wrote:
> >>> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
> >>>
> >>>> On 27/04/2016 12:58 PM, Wally W. wrote:
> >>>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
> >>>>>
> >>>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
> >>>>>>> It even pulls in more electrons when doing moire work
> >>>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
> >>>>>>> inverse square law.  I love electric motors,and I'm big on electron
> >>>>>>> flow. Trebert
> >>>>>>>
> >>>>>>
> >>>>>> With increasing load, it slows down. As it does, the current has to
> >>>>>> increase so that the back EMF at the reduced speed still equals the
> >>>>>> applied voltage.
> >>>>>
> >>>>> It's all describable, but it is still akin to magic.
> >>>>
> >>>> It doesn't seem akin to magic to me.
> >>>>
> >>>> Sylvia.
> >>>
> >>> Lessee ... the generator in the next town knows just how many
> >>> electrons it should send to my motor.
> >>
> >> Of course it doesn't. The electrons in the wire respond to the local
> >> voltage gradient in the wire. Increasing the load on your motor slows it
> >> down, and the reduced back EMF increases the voltage gradient at the
> >> input to the motor. So more electrons at that point. That changes the
> >> voltage gradient a bit upstream, and more electrons flow there. The
> >> change propagates along the wire, at a good fraction of the speed of
> >> light, until it eventually reaches the generator, which responds
> >> accordingly.
> >>
> >> With an AC system, everything's cycling 50 or 60 times a second anyway,
> >> and the effect of the motor load is superimposed on that.
> >>
> >> Sylvia.
> >
> > Nice theory Sylvia, but generally speaking motors don't slow down when
> > delivering power. So how does your theory work with synchronous motors?
> 
> In a synchronous motor, the current and the power factor, are a function 
> of the angle between the rotor and the rotating field. When you load a 
> synchronous motor there is indeed a temporary reduction in speed while 
> the angle increases, which leads to an increase in current and power 
> factor. The increased current, coupled with the angle, cause in increase 
> in torque, which prevents further increase in the angle, and the speed 
> returns to what it was originally.
> 
> Again, nothing magical, just a straight forward application of 
> electromagnetism.
> 
> Sylvia.

Sylvia You have it mostly right.Leave out the rotor slowing down.It can be made to slow down by overloading it with work.That will cause it to start to smoke,and burn up the amature in short time.  Trebert

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#573815

On 04/27/2016 02:35 PM, reber g=emc^2 wrote:
> On Tuesday, April 26, 2016 at 10:41:16 PM UTC-7, Sylvia Else wrote:
>> On 27/04/2016 3:25 PM, benj wrote:
>>> On 04/26/2016 11:49 PM, Sylvia Else wrote:
>>>> On 27/04/2016 1:32 PM, Wally W. wrote:
>>>>> On Wed, 27 Apr 2016 13:14:03 +1000, Sylvia Else wrote:
>>>>>
>>>>>> On 27/04/2016 12:58 PM, Wally W. wrote:
>>>>>>> On Wed, 27 Apr 2016 11:33:17 +1000, Sylvia Else wrote:
>>>>>>>
>>>>>>>> On 25/04/2016 2:39 AM, reber g=emc^2 wrote:
>>>>>>>>> It even pulls in more electrons when doing moire work
>>>>>>>>> automatically.WOW  I can see why the thickness of a wire obeys the
>>>>>>>>> inverse square law.  I love electric motors,and I'm big on electron
>>>>>>>>> flow. Trebert
>>>>>>>>>
>>>>>>>>
>>>>>>>> With increasing load, it slows down. As it does, the current has to
>>>>>>>> increase so that the back EMF at the reduced speed still equals the
>>>>>>>> applied voltage.
>>>>>>>
>>>>>>> It's all describable, but it is still akin to magic.
>>>>>>
>>>>>> It doesn't seem akin to magic to me.
>>>>>>
>>>>>> Sylvia.
>>>>>
>>>>> Lessee ... the generator in the next town knows just how many
>>>>> electrons it should send to my motor.
>>>>
>>>> Of course it doesn't. The electrons in the wire respond to the local
>>>> voltage gradient in the wire. Increasing the load on your motor slows it
>>>> down, and the reduced back EMF increases the voltage gradient at the
>>>> input to the motor. So more electrons at that point. That changes the
>>>> voltage gradient a bit upstream, and more electrons flow there. The
>>>> change propagates along the wire, at a good fraction of the speed of
>>>> light, until it eventually reaches the generator, which responds
>>>> accordingly.
>>>>
>>>> With an AC system, everything's cycling 50 or 60 times a second anyway,
>>>> and the effect of the motor load is superimposed on that.
>>>>
>>>> Sylvia.
>>>
>>> Nice theory Sylvia, but generally speaking motors don't slow down when
>>> delivering power. So how does your theory work with synchronous motors?
>>
>> In a synchronous motor, the current and the power factor, are a function
>> of the angle between the rotor and the rotating field. When you load a
>> synchronous motor there is indeed a temporary reduction in speed while
>> the angle increases, which leads to an increase in current and power
>> factor. The increased current, coupled with the angle, cause in increase
>> in torque, which prevents further increase in the angle, and the speed
>> returns to what it was originally.
>>
>> Again, nothing magical, just a straight forward application of
>> electromagnetism.
>>
>> Sylvia.
>
> Sylvia You have it mostly right.Leave out the rotor slowing down.It can be made to slow down by overloading it with work.That will cause it to start to smoke,and burn up the amature in short time.  Trebert
>
Sylvia, treeb knows how everything works. You had better listen to him 
or you'll get smoke! Imperial thought.

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