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Groups > sci.physics.electromag > #20113
| 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 | 2017-07-26 18:27 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <olb8af$juf$1@dont-email.me> (permalink) |
| References | (2 earlier) <oksjee$qt5$1@dont-email.me> <oku6ej$6ip$1@dont-email.me> <59730f26$0$792$e4fe514c@news.xs4all.nl> <okvvbi$qns$1@dont-email.me> <olb481$9mo$1@dont-email.me> |
Cross-posted to 3 groups.
"Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> wrote in message news:olb481$9mo$1@dont-email.me... > The question in regards to magnetic field strength in electric motors is > whether increasing the power by increasing the current is limited by > magnetic saturation of the core material. Ah, I get it -- to a certain extent, no. But for practical purposes, yes, I think. The reason is the same as why transformers can deliver far more current than the magnetizing current required to saturate their cores. This applies to induction motors, which are little more than transformers where the secondary is a shorted turn, allowed to spin. Flux density in the rotor is proportional to slip. Um, it probably applies to series wound / universal motors as well, but I can't quite intuit whether that should be the case or not. It also depends on load, because RPM/EMF and current are interdependent. A PM motor is limited by the coercive force of the magnets, and whether that [magnetomotive] force can be transmitted by the laminated core. (For laminated iron and NdFeB, it might not be possible, dunno.) Transmitted force (mechanical and MMF kinds) is limited by air gap, so you have that to fight. Whether that means you can destroy an NdFeB based motor, or demagnetize it, by thrashing the winding current and/or rotor velocity, I'm not sure. Under pulse conditions, even if you saturate the core around the winding, you can always deliver more and more flux density, and eventually the motor looks more like an air core one (these exist, for low inertia applications, like old timey computer tape drives that had to reverse on a dime; and probably similar with some aerospace synchro or LVDT applications, too), and yeah, the force will continue to rise, but not as quickly as it did before saturation, because the effective air gap is now vastly higher. So, no, the force isn't limited, but yeah, it's only going to go so far. Whereas an ideal diode looks like a limited voltage (with current rising exponentially), a real diode has series resistance; same with saturation, where it gets much harder to put in that extra flux, but you're fighting an increasing amount of air gap in the process. 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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