Groups > sci.physics.electromag > #20098

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 12:02 -0500
Organization	Aioe.org NNTP Server
Message-ID	<ol597v$c3c$1@gioia.aioe.org> (permalink)
References	(11 earlier) <5975c794$0$742$e4fe514c@news.xs4all.nl> <ol4hbf$vcl$2@dont-email.me> <5975ccdb$0$833$e4fe514c@news.xs4all.nl> <ol4u34$1m7d$1@gioia.aioe.org> <59760a9e$0$759$e4fe514c@news.xs4all.nl>

Cross-posted to 3 groups.

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On 7/24/2017 9:56 AM, Jos Bergervoet wrote:
> On 7/24/2017 3:52 PM, Serg io wrote:
>> 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.
> 
> The question was why they are *unreasonable!* And they
> are based on clear enough reasoning for you to understand,
> so it would be *your* burden of proof to convince us that
> they are "unreasonable".

bullshit.  your working design demonstrating it meets 99% effeciency is 
the proof.  OR, if you got a URL to an in production unit.

> 
>>  ..  if you find a URL that points to an
>> existing 99% power supply in production, that would be fact.
> 
> Lots of URLs point there:
>    http://www.google.com/search?hl=en&as_q=99%25+efficiency+half-bridge
> 
> Do your own work if you want to sort them out!
> 

that is only a half rectifying bridge. not an entire power supply. and 
the bridge is made of SiC

so...  the 99% limitation is the front end rectifiers, from ac to 
dc-ish, the diode drop.

one has to go to SiC

and you can buy 90% eff supplies, LRS-150-24 etc. Cant buy 95% that much

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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