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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 2017-07-24 08:52 -0500
Organization Aioe.org NNTP Server
Message-ID <ol4u34$1m7d$1@gioia.aioe.org> (permalink)
References (9 earlier) <59745f4c$0$721$e4fe514c@news.xs4all.nl> <ol34pd$svk$1@gioia.aioe.org> <5975c794$0$742$e4fe514c@news.xs4all.nl> <ol4hbf$vcl$2@dont-email.me> <5975ccdb$0$833$e4fe514c@news.xs4all.nl>

Cross-posted to 3 groups.

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On 7/24/2017 5:32 AM, Jos Bergervoet wrote:
> On 7/24/2017 12:19 PM, John S wrote:
>> On 7/24/2017 5:10 AM, Jos Bergervoet wrote:
>>> On 7/23/2017 11:34 PM, Serg io wrote:
>>>> 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 ?
>>>
>>> Why would I need one? I know how to compute those things
>>> and how to build them. I knew it even when the web did not
>>> yet exist, and URLs likewise.

>> Mainly because your claim seems unreasonable.
> 
> Why is it unreasonable? Working with voltages in the order of
> a few hundred volt (as for instance a converter for a mains-fed
> fluorescent lamp) and transistor saturation voltages of a few
> tenths of a volt, you have conduction losses in the order of
> 0.1%. The other switching losses scale with frequency so staying
> at low f (e.g. 35 kHz) keeps them low as well (and of course
> zero-current switching will help, like in a correctly tuned
> half-bridge converters). The passive-component losses are mainly
> in the inductors, which can have a Q-factor of e few hundred at
> those frequencies, so no need for more than 1% losses.
> 
> So based on those facts, it is not unreasonable at all. On the
> contrary, your claim that the losses should be much higher is
> unreasonable! Can you give a mechanism that would make those
> high losses probable?!
> 

those are design goals, not facts.  if you find a URL that points to an 
existing 99% power supply in production, that would be fact.

remember during your switching time when transistor goes from off to on, 
you have a power spike too, V and I cross over, so bandwidth of the 
transistor/mosfet must be high.

http://xppower.com/pdfs/95_High_Efficiency.pdf

getting above 90% effeciency with transistors/mosfets is quite difficult

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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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