Groups > sci.physics.electromag > #20089

Re: Question about power capacity of electrical motors.

From	Serg io <invaalid@invalid.com>
Newsgroups	sci.physics.electromag, sci.electronics.design, sci.physics
Subject	Re: Question about power capacity of electrical motors.
Date	2017-07-23 16:34 -0500
Organization	Aioe.org NNTP Server
Message-ID	<ol34pd$svk$1@gioia.aioe.org> (permalink)
References	(5 earlier) <okt8vb$gli$1@gioia.aioe.org> <5972adf6$0$31177$c3e8da3$a9097924@news.astraweb.com> <okug4l$14j7$1@gioia.aioe.org> <5972edd2$0$43785$b1db1813$2411a48f@news.astraweb.com> <59745f4c$0$721$e4fe514c@news.xs4all.nl>

Cross-posted to 3 groups.

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On 7/23/2017 3:33 AM, Jos Bergervoet wrote:
> On 7/22/2017 8:16 AM, benj wrote:
>> On 07/21/2017 11:17 PM, Serg io wrote:
>>> On 7/21/2017 8:44 PM, benj wrote:
>>>> On 7/21/2017 12:09 PM, Serg io wrote:
>>>>> On 7/21/2017 10:32 AM, jimp@specsol.spam.sux.com wrote:
>>>>>> In sci.physics.electromag rickman <gnuarm@gmail.com> wrote:
>>>>>>> Serg io wrote on 7/16/2017 12:47 AM:
>>>>>>>> On 7/15/2017 2:51 PM, John Larkin wrote:
>>>>>>>>> On Sat, 15 Jul 2017 13:43:55 -0400, "Robert Clark"
>>>>>>>>> <rgregoryclark@gmSPAMBLOACKail.com> wrote:
>      ...
>   ..
>>>>> the Magamp is also 99% effecient.  there are some switching power
>>>>> supplies based upon magamps, and they are 99% effecient.
>>>>
>>>> Magamps are certainly radiation resistant and EMP hardened, but 99%
>>>> efficiency? Doubtful. It takes some energy to saturate a magnetize
>>>> core even of the best materials. Core losses are significant.
>>>> Resistive losses are significant (you have to keep core saturated in
>>>> spite of output currents). Sure switchers have lots of currents
>>>> flowing that can be used but 99% seems rather high to me for a magamp
>>>> control unless you are going super conducting or something.
>>>>
>>>
>>> 99% is right, look at transistor switchers, they run 70 to 83% or so
>>> efficient, and they have loss due to Vbe, they cannot get to the rails.
>>
>> Actually they do get to "rails" In switching mode they go from full
>> "off" to low impedance "on" where losses are very small.
> 
> And there is no "Vbe" restricting the voltage drop, first
> of all because you can use a MOSFET if you want, but even
> for a BJT the driving circuit can lift the base voltage
> above the rail.
> 
>>  All the loss
>> takes place during the switching transition.
> 
> Now you exaggerate to the other extreme! There certainly
> is loss during conduction. Not Vbe, but still a finite Vce
> due to the internal collector resistance.
> 
>> The switching time is not
>> zero plus there is a delay factor due to sweeping carriers out of
>> junction.
> 
> That *is* mainly the switching time in many cases! The other
> part is (re)charging the parasitic capacitances on the different
> circuit nodes.
> 
>> The actual percentage dissipation depends upon the structure
>> of the device which is not only the type of device but the kind of
>> structures used in fabrication.
> 
> And Sergeio is of course completely wrong to claim that it is
> "70 to 83% or so" for transistors. They also can reach 99%, if
> the switching is done at relatively low frequency (or even
> up to a few MHz with resonant drive). A value of 70% would be
> typical only if you use GHz frequencies, and nobody in his right
> mind would do that purely for power conversion purposes.

got a URL for your 99% effecient transistor power supply ?

typical cheap transistor power supplies run 70 to 83% or so.

https://en.wikipedia.org/wiki/80_Plus

your turn.

> 
>>    Of course above I'm especially talking
>> about junction structures, though principles still apply to other
>> structures. Yeah, I've measured this crap.
> 
> Actually measuring the precise losses if you are around 99%
> efficiency is not so simple! For instance you'd need the small 
> difference between large AC input power and DC output power,
> by necessity measured in not exactly the same way.. Probably 
> calorimetric measurement (how much heat does the converter
> produce) will be the best way. Is that how you did it?

no, output power/input power  that is it.

> 
>>> magamps do not have that limitation, (they do have some distortion for
>>> audio) I have not designed with them that much.
>>
>> Yes, but you are still driving a core to saturation and current in coils
>> of wire. I mean transformers (and motors) do pretty well, but 99% seems
>> really pushing the edge to me.
> 
> They are said to use materials with small hysteresis losses.
> Of course if the loop area in those BH curves becomes almost
> zero then those losses will vanish. But the magamp will need
> to drive the field into complete saturation (as opposed to
> ordinary transformers, where hysteresis losses are a problem
> already, so it does sound difficult! I cannot disagree with
> you this time..)

easier to measure input I and V then measure output I and V.

mag amps used at lower power are no problem.

this was a well known field of engineering and technology in the 50's 
and 60's

https://www.google.com/patents/US3122701

I found another reference that says a mag amplifier can get up to 90% 
effeciency....

http://www.tpub.com/neets/book8/32l.htm

Thread

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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