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Re: Question about power capacity of electrical motors.

From "Tim Williams" <tiwill@seventransistorlabs.com>
Newsgroups sci.physics.electromag, sci.electronics.design, sci.physics
Subject Re: Question about power capacity of electrical motors.
Date 2017-07-21 19:36 -0500
Organization A noiseless patient Spider
Message-ID <oku6ej$6ip$1@dont-email.me> (permalink)
References <okdk1a$426$1@dont-email.me> <oked4c$dj9$1@dont-email.me> <oksjee$qt5$1@dont-email.me>

Cross-posted to 3 groups.

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"Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> wrote in message 
news:oksjee$qt5$1@dont-email.me...
> However, I've heard of cases of high intensity magnetic fields where you 
> can get continuous, sustained fields significantly higher than this:
>
> Orders of magnitude (magnetic field).
> 11.7 T 117 kG Field strength of a 500 MHz NMR spectrometer
> 16 T 160 kG Strength used to levitate a frog[14]

About at this point, even the best superconductors, at LHe temperature, 
can't sustain operation.  These two cases, and many at lower intensities 
(including thousands of MRI machines in the 1-5T range), are all 
superconducting.

Superconductors are a big win, because the field isn't so high that it's 
impossible, and because most of these require tons of total energy (it's 
intense /over a large volume of space/, too).

It's impractical to try and charge one of these things every time you need 
to use it, let alone run steady-state, while burning a tremendous amount of 
power in a resistive material.  You'd have problems with mechanical 
expansion, thermal gradients, circulating fluids (I mean, you need LHe and 
LN2 otherwise, but not at the pressure and flow rate that you need for the 
cooling fluid to run a copper magnet this big) and so on.


> 23.5 T 235 kG Field strength of a 1 GHz NMR spectrometer[15]
> 36.2 T 362 kG Strongest continuous magnetic field produced by 
> non-superconductive resistive magnet.[16]
> 45 T 450 kG Strongest continuous magnetic field yet produced in a 
> laboratory (Florida State University's National High Magnetic Field 
> Laboratory in Tallahassee, USA).[17]
> https://en.wikipedia.org/wiki/Orders_of_magnitude_(magnetic_field)
>
> I imagine then these are using superconductors?

...These ones, however, may not be superconducting!  Or at least not wholly, 
AFAIK.

My familiarity with critical field is probably lacking as well; I just 
remember it's somewhere in that range.

You'd have to ask the designers of that particular NMR.  It might be 
feasible: after all, magnets can be stacked in a particular way so that 
their vectors add up (Halbach array and such).  They might be using a 
similar trick to optimize the use of superconductors.

The strongest are either fully resistive, or hybrid.  The ref shows how this 
one is built:
https://en.wikipedia.org/wiki/National_High_Magnetic_Field_Laboratory#/media/File:National_High_Magnetic_Field_Lab00.png
A metric shitton of current, and water, is supplied to a perforated copper 
sheet, wound into a helix.  Around that, superconductors supply as much 
field as they can (evidently, around 20T), which superimposes with the 
resistive magnet's field.  It has to be done this way, and not the other way 
around (superconductor inside), because superconduction is not linear at 
this level.

And note that boosting a 20.0T superconducting magnet, up to 21T as a hybrid 
magnet, takes exactly as much additional effort as making a 1T air core 
magnet does (not easy!).  So, to achieve another 20-some T extra from that 
resistive magnet is no small feat!

Tim

-- 
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com

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Question about power capacity of electrical motors. "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2017-07-15 13:43 -0400
  Re: Question about power capacity of electrical motors. Cursitor Doom <curd@notformail.com> - 2017-07-15 18:39 +0000
  Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-15 18:31 +0000
    Re: Question about power capacity of electrical motors. Piglet <erichpwagner@hotmail.com> - 2017-07-15 20:09 +0100
      Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-15 19:19 +0000
        Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 05:44 -0400
          Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 15:24 +0000
            Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 12:17 -0400
              Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 17:07 +0000
                Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 13:42 -0400
                Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 18:05 +0000
                Re: Question about power capacity of electrical motors. John S <Sophi.2@invalid.org> - 2017-07-21 13:46 -0500
                Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 15:07 -0400
                Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 19:30 +0000
                Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 17:31 -0400
                Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 22:11 +0000
                Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 19:04 -0400
                Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-22 00:22 +0000
    Re: Question about power capacity of electrical motors. krw@notreal.com - 2017-07-15 18:46 -0400
      Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-16 02:00 +0000
        Re: Question about power capacity of electrical motors. krw@notreal.com - 2017-07-15 22:38 -0400
          Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-16 03:07 +0000
            Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-16 09:20 +0200
    Re: Question about power capacity of electrical motors. "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2017-07-15 21:46 -0400
      Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-16 02:13 +0000
        Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 05:49 -0400
          Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 15:26 +0000
            Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 12:45 -0400
              Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-21 12:08 -0500
              Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 17:10 +0000
                Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 13:43 -0400
                Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 18:07 +0000
                Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 15:10 -0400
                Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 19:32 +0000
                Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 17:32 -0400
                Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 22:11 +0000
              Re: Question about power capacity of electrical motors. "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2017-07-22 10:51 -0400
                Re: Question about power capacity of electrical motors. Lofty Goat <rlwatkins@gmail.com> - 2017-07-22 17:55 -0500
                Re: Question about power capacity of electrical motors. Lofty Goat <rlwatkins@gmail.com> - 2017-07-22 17:58 -0500
                Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-22 18:56 -0500
                Re: Question about power capacity of electrical motors. benj <benj@nobody.net> - 2017-07-22 21:25 -0400
                Re: Question about power capacity of electrical motors. Lofty Goat <rlwatkins@gmail.com> - 2017-07-23 20:01 -0500
                Re: Question about power capacity of electrical motors. "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2017-07-24 05:35 -0400
                Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-24 08:39 -0500
                Re: Question about power capacity of electrical motors. Lofty Goat <rlwatkins@gmail.com> - 2017-07-24 20:15 -0500
                Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-25 11:56 +0200
                Re: Question about power capacity of electrical motors. Lofty Goat <rlwatkins@gmail.com> - 2017-07-25 20:23 -0500
                Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-26 20:28 -0500
                Re: Question about power capacity of electrical motors. Lofty Goat <rlwatkins@gmail.com> - 2017-07-29 18:47 -0500
                Re: Question about power capacity of electrical motors. benj <benj@nobody.net> - 2017-07-29 21:18 -0400
                Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-29 23:59 -0500
                Re: Question about power capacity of electrical motors. benj <benj@nobody.net> - 2017-07-31 17:05 -0400
                Re: Question about power capacity of electrical motors. Lofty Goat <rlwatkins@gmail.com> - 2017-07-24 20:13 -0500
    Re: Question about power capacity of electrical motors. David Lesher <wb8foz@panix.com> - 2017-07-17 22:29 +0000
    Re: Question about power capacity of electrical motors. "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2017-07-21 04:18 -0400
      Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 15:29 +0000
  Re: Question about power capacity of electrical motors. John Larkin <jjlarkin@highlandtechnology.com> - 2017-07-15 12:51 -0700
    Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-15 23:47 -0500
      Re: Question about power capacity of electrical motors. benj <nobody@gmail.com> - 2017-07-16 00:58 -0400
        Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-16 09:22 +0200
          Re: Question about power capacity of electrical motors. benj <nobody@gmail.com> - 2017-07-17 01:13 -0400
            Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-17 08:46 -0500
      Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 06:26 -0400
        Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 15:32 +0000
          Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-21 11:09 -0500
            Re: Question about power capacity of electrical motors. benj <benj@nobody.net> - 2017-07-21 21:44 -0400
              Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-21 22:17 -0500
                Re: Question about power capacity of electrical motors. benj <nobody@yahoo.com> - 2017-07-22 02:16 -0400
                Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-23 10:33 +0200
                Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-23 16:34 -0500
                Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-24 12:10 +0200
                Re: Question about power capacity of electrical motors. John S <Sophi.2@invalid.org> - 2017-07-24 05:19 -0500
                Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-24 12:32 +0200
                Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-24 08:52 -0500
                Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-24 16:56 +0200
                Re: Question about power capacity of electrical motors. Serg io <invaalid@invalid.com> - 2017-07-24 12:02 -0500
                Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-24 23:51 +0200
                Re: Question about power capacity of electrical motors. John S <Sophi.2@invalid.org> - 2017-07-24 17:16 -0500
                Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-25 01:12 +0200
                Re: Question about power capacity of electrical motors. John S <Sophi.2@invalid.org> - 2017-07-24 18:25 -0500
                Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-25 11:54 +0200
                Re: Question about power capacity of electrical motors. benj <benj@nobody.net> - 2017-07-24 17:19 -0400
                Re: Question about power capacity of electrical motors. benj <benj@nobody.net> - 2017-07-24 17:10 -0400
                Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-24 23:33 +0200
                Re: Question about power capacity of electrical motors. benj <benj@nobody.net> - 2017-07-24 21:02 -0400
          Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 13:12 -0400
            Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 17:25 +0000
              Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 13:45 -0400
                Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-21 18:08 +0000
              Re: Question about power capacity of electrical motors. benj <benj@nobody.net> - 2017-07-21 18:53 -0400
                Re: Question about power capacity of electrical motors. jimp@specsol.spam.sux.com - 2017-07-22 00:23 +0000
    Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 06:00 -0400
      Re: Question about power capacity of electrical motors. Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-07-21 09:48 -0400
        Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 13:30 -0400
      Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-21 17:30 +0200
        Re: Question about power capacity of electrical motors. rickman <gnuarm@gmail.com> - 2017-07-21 13:34 -0400
          Re: Question about power capacity of electrical motors. John S <Sophi.2@invalid.org> - 2017-07-21 13:08 -0500
  Re: Question about power capacity of electrical motors. "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-07-15 19:51 -0500
    Re: Question about power capacity of electrical motors. "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2017-07-21 06:05 -0400
      Re: Question about power capacity of electrical motors. "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-07-21 19:36 -0500
        Re: Question about power capacity of electrical motors. Jos Bergervoet <jos.bergervoet@xs4all.nl> - 2017-07-22 10:39 +0200
          Re: Question about power capacity of electrical motors. "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2017-07-22 12:47 -0400
            Re: Question about power capacity of electrical motors. "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2017-07-26 18:18 -0400
              Re: Question about power capacity of electrical motors. "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-07-26 18:27 -0500
        Re: Question about power capacity of electrical motors. "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2017-07-22 11:40 -0400
          Re: Question about power capacity of electrical motors. "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-07-23 14:32 -0500

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