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Question about power capacity of electrical motors.

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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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#20109

On 7/25/2017 1:25 AM, John S wrote:
> On 7/24/2017 6:12 PM, Jos Bergervoet wrote:
>> On 7/25/2017 12:16 AM, John S wrote:
>>> On 7/24/2017 4:51 PM, Jos Bergervoet wrote:
>>>> On 7/24/2017 7:02 PM, Serg io wrote:
>>>>> 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:
>>>>    ...
>>>>   ..
>>>>>>>>>>>> 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.
>>>>
>>>> Why should it be? The Magamp examples that were claimed here
>>>> to be 99% efficient were also not an entire power supply. In
>>>> fact it was completely unspecified what exactly they converted
>>>> into what! Fact is, for a half-bridge converting DC into some
>>>> AC frequency the efficiency can 99% plus.
>>>>
>>>>>    and
>>>>> the bridge is made of SiC
>>>>
>>>> Irrelevant. Si can do the same. You need SiC to make the paper
>>>> accepted. (The 99% is no big deal, it's "novel" because of SiC!)
>>>>
>>>>> so...  the 99% limitation is the front end rectifiers, from ac to
>>>>> dc-ish, the diode drop.
>>>>
>>>> There you might have a full diode bridge, with say 2*0.8V drop
>>>> for a 300V DC output voltage (for 240V mains), so that's 99.5%
>>>> efficient as an additional step. Not really spoiling it!
>>>>
>>>> You might even use a synchronous rectifier with MOS switches
>>>> where you can make the drop as low as you want by using very
>>>> big ones (50/60Hz AC really will not give you large capacitive
>>>> losses!) But of course no-one will do that since it is not
>>>> cost-effective to get rid of just this 0.5% loss.
>>>>
>>>> So really, you should stop nit-picking. The claim "70 to 83%
>>>> or so" may be true for cheap small battery loaders, but for
>>>> large power conversion units (like the solid state units in
>>>> power distribution) it may even be closer to 99.9% than 99%.
>>>> There they have to compete with copper-iron transformers,
>>>> which definitely (as opposed, or perhaps not, to Magamps)
>>>> can beat 99%.
>>>
>>> Please provide a link to these "large power conversion units (like the
>>> solid state units in power distribution)".
>>
>> May I suggest you use a "search engine"? Look for:
>>    "SST solid state transformer"
>> or similar terms.
>
> May I suggest you stop being a troll?

So you can't win a scientific discussion and now
you resort to name calling?

Your kind of typical construction engineers only
can reproduce what is presented to them in a "link"
or a "URL". You will soon be replaced by computers.

-- 
Jos

-- 
Jos

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#20100

On 7/23/2017 5:34 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 ?
> 
> typical cheap transistor power supplies run 70 to 83% or so.
> 
> https://en.wikipedia.org/wiki/80_Plus
> 
> your turn.

Hey, Sergio, I spot 96% in that table! Hmmm. 96% seems close enough to 
99% for Jos' imagination to take over and fill in the missing part.

>>
>>>    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

Well yeah, but that's not using Jos'"zero hysteresis" fantasy magnetic 
materials.

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#20099

On 7/23/2017 4:33 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.

No exaggeration. But obviously "it depends" because while Vce is finite, 
and losses therefore low, it's all a matter how long you are "on". If 
you are switching on and off at fast rates I assure you majority of loss 
is during transition. No exaggeration.

>> 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.

I already noted that switching rate matters.

>>    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. Actually was done with high speed high accuracy multipliers. Looked 
at the product of current through the device and voltage across it. You 
get a large (and very interesting) power spike as the device switches.

>>> 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..)

Cannot Disagree? Jos? Jos, is that really you or some sock puppet 
pretending to be you?

[toc] | [prev] | [next] | [standalone]

#20101

On 7/24/2017 11:10 PM, benj wrote:
> On 7/23/2017 4:33 AM, Jos Bergervoet wrote:
>> On 7/22/2017 8:16 AM, benj wrote:
  ...
>>>  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.
>
> No exaggeration. But obviously "it depends" because while Vce is finite,
> and losses therefore low, it's all a matter how long you are "on". If
> you are switching on and off at fast rates I assure you majority of loss
> is during transition.

That is true but the "majority of loss" should not be replaced
by "all the loss" (as you did). That is an exaggeration.

> No exaggeration.

Yes it is! It is!

  ...
>>>    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. Actually was done with high speed high accuracy multipliers. Looked
> at the product of current through the device and voltage across it.

OK, the multipliers might be high-accuracy but the current
sensors and the voltage probes should then be completely
phase error free, and with perfectly matching delay too.

>  You
> get a large (and very interesting) power spike as the device switches.

But it's size is very sensitive to probe errors..

>>>> 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..)
>
> Cannot Disagree? Jos? Jos, is that really you or some sock puppet
> pretending to be you?

Your current post is already a lot better!

-- 
Jos

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#20106

On 7/24/2017 5:33 PM, Jos Bergervoet wrote:
> On 7/24/2017 11:10 PM, benj wrote:
>> On 7/23/2017 4:33 AM, Jos Bergervoet wrote:
>>> On 7/22/2017 8:16 AM, benj wrote:
>   ...
>>>>  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.
>>
>> No exaggeration. But obviously "it depends" because while Vce is finite,
>> and losses therefore low, it's all a matter how long you are "on". If
>> you are switching on and off at fast rates I assure you majority of loss
>> is during transition.
> 
> That is true but the "majority of loss" should not be replaced
> by "all the loss" (as you did). That is an exaggeration.
> 
>> No exaggeration.
> 
> Yes it is! It is!

No it's not! It's not!

Recess over yet?

>   ...
>>>>    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. Actually was done with high speed high accuracy multipliers. Looked
>> at the product of current through the device and voltage across it.
> 
> OK, the multipliers might be high-accuracy but the current
> sensors and the voltage probes should then be completely
> phase error free, and with perfectly matching delay too.

Well duh.

>>  You
>> get a large (and very interesting) power spike as the device switches.
> 
> But it's size is very sensitive to probe errors..

Well duh.

>>>>> 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..)
>>
>> Cannot Disagree? Jos? Jos, is that really you or some sock puppet
>> pretending to be you?
> 
> Your current post is already a lot better!

I know. I didn't even mention Jefimenko once!

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#20040

jimp@specsol.spam.sux.com wrote on 7/21/2017 11:32 AM:
> 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:
>>>>
>>>>> I read that the Tesla electric motor is able to achieve its remarkable power
>>>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical gasoline
>>>>> engine, because it tightly winds its copper wires in its coils therefore
>>>>> being able to carry more current in the same space. If so, then we should be
>>>>> able to produce more power if we have a material that can carry more
>>>>> current.
>>>
>>>
>>> motor design is very mature, there are other things in the chain that you
>>> can optomize
>>
>> Why do you feel electric motors can't be improved with new materials?
>
> The current state of the art for electric motors is over 95% efficiency,
> which does not leave a lot of room for any improvements of any kind.

You really can't stay on topic can you?  We were discussing size and weight 
reduction vs. power output, not efficiency.

-- 

Rick C

[toc] | [prev] | [next] | [standalone]

#20044

In sci.physics.electromag rickman <gnuarm@gmail.com> wrote:
> jimp@specsol.spam.sux.com wrote on 7/21/2017 11:32 AM:
>> 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:
>>>>>
>>>>>> I read that the Tesla electric motor is able to achieve its remarkable power
>>>>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical gasoline
>>>>>> engine, because it tightly winds its copper wires in its coils therefore
>>>>>> being able to carry more current in the same space. If so, then we should be
>>>>>> able to produce more power if we have a material that can carry more
>>>>>> current.
>>>>
>>>>
>>>> motor design is very mature, there are other things in the chain that you
>>>> can optomize
>>>
>>> Why do you feel electric motors can't be improved with new materials?
>>
>> The current state of the art for electric motors is over 95% efficiency,
>> which does not leave a lot of room for any improvements of any kind.
> 
> You really can't stay on topic can you?  We were discussing size and weight 
> reduction vs. power output, not efficiency.

Blow it out your ass, stalker. 

-- 
Jim Pennino

[toc] | [prev] | [next] | [standalone]

#20048

jimp@specsol.spam.sux.com wrote on 7/21/2017 1:25 PM:
> In sci.physics.electromag rickman <gnuarm@gmail.com> wrote:
>> jimp@specsol.spam.sux.com wrote on 7/21/2017 11:32 AM:
>>> 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:
>>>>>>
>>>>>>> I read that the Tesla electric motor is able to achieve its remarkable power
>>>>>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical gasoline
>>>>>>> engine, because it tightly winds its copper wires in its coils therefore
>>>>>>> being able to carry more current in the same space. If so, then we should be
>>>>>>> able to produce more power if we have a material that can carry more
>>>>>>> current.
>>>>>
>>>>>
>>>>> motor design is very mature, there are other things in the chain that you
>>>>> can optomize
>>>>
>>>> Why do you feel electric motors can't be improved with new materials?
>>>
>>> The current state of the art for electric motors is over 95% efficiency,
>>> which does not leave a lot of room for any improvements of any kind.
>>
>> You really can't stay on topic can you?  We were discussing size and weight
>> reduction vs. power output, not efficiency.
>
> Blow it out your ass, stalker.

I didn't remember you for sure as I haven't seen you post lately.  Now I 
recognize your signature, profanity and anger.  I thought I had you 
killfiled...  Later.

-- 

Rick C

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#20052

In sci.physics.electromag rickman <gnuarm@gmail.com> wrote:
> jimp@specsol.spam.sux.com wrote on 7/21/2017 1:25 PM:
>> In sci.physics.electromag rickman <gnuarm@gmail.com> wrote:
>>> jimp@specsol.spam.sux.com wrote on 7/21/2017 11:32 AM:
>>>> 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:
>>>>>>>
>>>>>>>> I read that the Tesla electric motor is able to achieve its remarkable power
>>>>>>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical gasoline
>>>>>>>> engine, because it tightly winds its copper wires in its coils therefore
>>>>>>>> being able to carry more current in the same space. If so, then we should be
>>>>>>>> able to produce more power if we have a material that can carry more
>>>>>>>> current.
>>>>>>
>>>>>>
>>>>>> motor design is very mature, there are other things in the chain that you
>>>>>> can optomize
>>>>>
>>>>> Why do you feel electric motors can't be improved with new materials?
>>>>
>>>> The current state of the art for electric motors is over 95% efficiency,
>>>> which does not leave a lot of room for any improvements of any kind.
>>>
>>> You really can't stay on topic can you?  We were discussing size and weight
>>> reduction vs. power output, not efficiency.
>>
>> Blow it out your ass, stalker.
> 
> I didn't remember you for sure as I haven't seen you post lately.  Now I 
> recognize your signature, profanity and anger.  I thought I had you 
> killfiled...  Later.

Yeah, I don't well tolerate puerile stalkers. 

-- 
Jim Pennino

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#20063

On 7/21/2017 1:25 PM, jimp@specsol.spam.sux.com wrote:
> In sci.physics.electromag rickman <gnuarm@gmail.com> wrote:
>> jimp@specsol.spam.sux.com wrote on 7/21/2017 11:32 AM:
>>> 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:
>>>>>>
>>>>>>> I read that the Tesla electric motor is able to achieve its remarkable power
>>>>>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical gasoline
>>>>>>> engine, because it tightly winds its copper wires in its coils therefore
>>>>>>> being able to carry more current in the same space. If so, then we should be
>>>>>>> able to produce more power if we have a material that can carry more
>>>>>>> current.
>>>>>
>>>>>
>>>>> motor design is very mature, there are other things in the chain that you
>>>>> can optomize
>>>>
>>>> Why do you feel electric motors can't be improved with new materials?
>>>
>>> The current state of the art for electric motors is over 95% efficiency,
>>> which does not leave a lot of room for any improvements of any kind.
>>
>> You really can't stay on topic can you?  We were discussing size and weight
>> reduction vs. power output, not efficiency.
> 
> Blow it out your ass, stalker.
> 
This is a demonstration of Chimp's level of scientific understanding.

[toc] | [prev] | [next] | [standalone]

#20066

In sci.physics.electromag benj <benj@nobody.net> wrote:
> On 7/21/2017 1:25 PM, jimp@specsol.spam.sux.com wrote:
>> In sci.physics.electromag rickman <gnuarm@gmail.com> wrote:
>>> jimp@specsol.spam.sux.com wrote on 7/21/2017 11:32 AM:
>>>> 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:
>>>>>>>
>>>>>>>> I read that the Tesla electric motor is able to achieve its remarkable power
>>>>>>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical gasoline
>>>>>>>> engine, because it tightly winds its copper wires in its coils therefore
>>>>>>>> being able to carry more current in the same space. If so, then we should be
>>>>>>>> able to produce more power if we have a material that can carry more
>>>>>>>> current.
>>>>>>
>>>>>>
>>>>>> motor design is very mature, there are other things in the chain that you
>>>>>> can optomize
>>>>>
>>>>> Why do you feel electric motors can't be improved with new materials?
>>>>
>>>> The current state of the art for electric motors is over 95% efficiency,
>>>> which does not leave a lot of room for any improvements of any kind.
>>>
>>> You really can't stay on topic can you?  We were discussing size and weight
>>> reduction vs. power output, not efficiency.
>> 
>> Blow it out your ass, stalker.
>> 
> This is a demonstration of Chimp's <snip troll drool>

At least this troll admits to being a lier and troll.

-- 
Jim Pennino

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#20024

John Larkin wrote on 7/15/2017 3:51 PM:
> On Sat, 15 Jul 2017 13:43:55 -0400, "Robert Clark"
> <rgregoryclark@gmSPAMBLOACKail.com> wrote:
>
>> I read that the Tesla electric motor is able to achieve its remarkable power
>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical gasoline
>> engine, because it tightly winds its copper wires in its coils therefore
>> being able to carry more current in the same space. If so, then we should be
>> able to produce more power if we have a material that can carry more
>> current.
>
> Teslas accelerate in short manic bursts. The motor would fry if it ran
> steady-state at full power.

Of course, you only need to accelerate for short periods, like a few 
seconds.  After that you are running illegal speeds anywhere in the US.  Why 
design it to run full power beyond all use cases?  Your Audi will melt down 
if you hold the pedal to the metal all day long too.


> And the power/weight ratio drops a lot if you include the batteries.

That's a pointless number.  The car runs 300+ miles on a charge and 
recharges while you have a cup of coffee.  Who cares about pointless 
numbers?  You just like to whine.

-- 

Rick C

[toc] | [prev] | [next] | [standalone]

#20030

On 07/21/2017 06:00 AM, rickman wrote:
> John Larkin wrote on 7/15/2017 3:51 PM:
>> On Sat, 15 Jul 2017 13:43:55 -0400, "Robert Clark"
>> <rgregoryclark@gmSPAMBLOACKail.com> wrote:
>>
>>> I read that the Tesla electric motor is able to achieve its
>>> remarkable power
>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical
>>> gasoline
>>> engine, because it tightly winds its copper wires in its coils therefore
>>> being able to carry more current in the same space. If so, then we
>>> should be
>>> able to produce more power if we have a material that can carry more
>>> current.
>>
>> Teslas accelerate in short manic bursts. The motor would fry if it ran
>> steady-state at full power.
>
> Of course, you only need to accelerate for short periods, like a few
> seconds.  After that you are running illegal speeds anywhere in the US.
> Why design it to run full power beyond all use cases?  Your Audi will
> melt down if you hold the pedal to the metal all day long too.

Towing a boat up a mountain takes a lot longer than a few seconds.  Gas 
engines do that just fine.

>
>
>> And the power/weight ratio drops a lot if you include the batteries.
>
> That's a pointless number.  The car runs 300+ miles on a charge and
> recharges while you have a cup of coffee.  Who cares about pointless
> numbers?  You just like to whine.

Power to weight ratio is important if you care about acceleration.

Cheers

Phil Hobbs


-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

[toc] | [prev] | [next] | [standalone]

#20043

Phil Hobbs wrote on 7/21/2017 9:48 AM:
> On 07/21/2017 06:00 AM, rickman wrote:
>> John Larkin wrote on 7/15/2017 3:51 PM:
>>> On Sat, 15 Jul 2017 13:43:55 -0400, "Robert Clark"
>>> <rgregoryclark@gmSPAMBLOACKail.com> wrote:
>>>
>>>> I read that the Tesla electric motor is able to achieve its
>>>> remarkable power
>>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical
>>>> gasoline
>>>> engine, because it tightly winds its copper wires in its coils therefore
>>>> being able to carry more current in the same space. If so, then we
>>>> should be
>>>> able to produce more power if we have a material that can carry more
>>>> current.
>>>
>>> Teslas accelerate in short manic bursts. The motor would fry if it ran
>>> steady-state at full power.
>>
>> Of course, you only need to accelerate for short periods, like a few
>> seconds.  After that you are running illegal speeds anywhere in the US.
>> Why design it to run full power beyond all use cases?  Your Audi will
>> melt down if you hold the pedal to the metal all day long too.
>
> Towing a boat up a mountain takes a lot longer than a few seconds.  Gas
> engines do that just fine.

Are you saying the Tesla won't pull a boat?  The car didn't melt down or 
implode.  It continued to pull a very respectable time.  Actually I don't 
think the model S will pull a boat as it has no trailer hitch.  The model X 
has a trailer hitch option for 5,000 pounds.  Do you think it dies when you 
actually connect a trailer?


>>> And the power/weight ratio drops a lot if you include the batteries.
>>
>> That's a pointless number.  The car runs 300+ miles on a charge and
>> recharges while you have a cup of coffee.  Who cares about pointless
>> numbers?  You just like to whine.
>
> Power to weight ratio is important if you care about acceleration.

So is the Tesla lacking in acceleration?  Check it out.  The model S has the 
fastest 0 to 60 time in the world according to Road and Track, 2.3 seconds. 
All those heavy batteries really slow it down!

Too bad the car sucks so bad in all other regards.  Oh, wait, it's really a 
great car in other regards!  I guess you like to join JL in whining.

BTW, power to weight doesn't determine acceleration.  Torque vs. weight 
does, and *THAT* is why the Tesla model S is the fastest production 0 to 60 
car in the world.

-- 

Rick C

[toc] | [prev] | [next] | [standalone]

#20031

On 7/21/2017 12:00 PM, rickman wrote:
> John Larkin wrote on 7/15/2017 3:51 PM:
>> On Sat, 15 Jul 2017 13:43:55 -0400, "Robert Clark"
>> <rgregoryclark@gmSPAMBLOACKail.com> wrote:
>>
>>> I read that the Tesla electric motor is able to achieve its
>>> remarkable power
>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical
>>> gasoline
>>> engine, because it tightly winds its copper wires in its coils therefore
>>> being able to carry more current in the same space. If so, then we
>>> should be
>>> able to produce more power if we have a material that can carry more
>>> current.
>>
>> Teslas accelerate in short manic bursts. The motor would fry if it ran
>> steady-state at full power.
>
> Of course, you only need to accelerate for short periods, like a few
> seconds.  After that you are running illegal speeds

No, not if you're going up-hill. (Gasoline engines are of
course much more suitable in that case.)

> Why design it to run full power beyond all use cases?  Your Audi will
> melt down if you hold the pedal to the metal all day long too.

No, not unless you block the airflow through the radiator.

>> And the power/weight ratio drops a lot if you include the batteries.
>
> That's a pointless number.

Why did anyone bring it up, then?

>    The car runs 300+ miles on a charge and
> recharges while you have a cup of coffee.

But what if you don't want to have coffee but just want to
proceed without waiting one hour?

>    Who cares about pointless
> numbers?

If they are truly pointless nobody cares. If anyone does care, I
think you shouldn't be so sure that they are pointless numbers..
(But then again, people care about astrological predictions as
well.)

-- 
Jos

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#20045

Jos Bergervoet wrote on 7/21/2017 11:30 AM:
> On 7/21/2017 12:00 PM, rickman wrote:
>> John Larkin wrote on 7/15/2017 3:51 PM:
>>> On Sat, 15 Jul 2017 13:43:55 -0400, "Robert Clark"
>>> <rgregoryclark@gmSPAMBLOACKail.com> wrote:
>>>
>>>> I read that the Tesla electric motor is able to achieve its
>>>> remarkable power
>>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical
>>>> gasoline
>>>> engine, because it tightly winds its copper wires in its coils therefore
>>>> being able to carry more current in the same space. If so, then we
>>>> should be
>>>> able to produce more power if we have a material that can carry more
>>>> current.
>>>
>>> Teslas accelerate in short manic bursts. The motor would fry if it ran
>>> steady-state at full power.
>>
>> Of course, you only need to accelerate for short periods, like a few
>> seconds.  After that you are running illegal speeds
>
> No, not if you're going up-hill. (Gasoline engines are of
> course much more suitable in that case.)
>
>> Why design it to run full power beyond all use cases?  Your Audi will
>> melt down if you hold the pedal to the metal all day long too.
>
> No, not unless you block the airflow through the radiator.
>
>>> And the power/weight ratio drops a lot if you include the batteries.
>>
>> That's a pointless number.
>
> Why did anyone bring it up, then?

Because they don't understand basic Newtonian mechanics, rather they listen 
to everyone else who spouts nonsense.


>>    The car runs 300+ miles on a charge and
>> recharges while you have a cup of coffee.
>
> But what if you don't want to have coffee but just want to
> proceed without waiting one hour?

You mean 20 minutes and you don't need to empty your bladder after driving 
for four hours?  I guess you pee into Gatorade bottles while you drive?  I 
never developed that skill.


>>    Who cares about pointless
>> numbers?
>
> If they are truly pointless nobody cares. If anyone does care, I
> think you shouldn't be so sure that they are pointless numbers..
> (But then again, people care about astrological predictions as
> well.)

I don't duplicate my other post about acceleration and 0 to 60 times.

-- 

Rick C

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#20049

On 7/21/2017 12:34 PM, rickman wrote:
> Jos Bergervoet wrote on 7/21/2017 11:30 AM:
>> On 7/21/2017 12:00 PM, rickman wrote:
>>> John Larkin wrote on 7/15/2017 3:51 PM:
>>>> On Sat, 15 Jul 2017 13:43:55 -0400, "Robert Clark"
>>>> <rgregoryclark@gmSPAMBLOACKail.com> wrote:
>>>>
>>>>> I read that the Tesla electric motor is able to achieve its
>>>>> remarkable power
>>>>> to weight ratio of 8.5 kW/kg, about 10 times better than a typical
>>>>> gasoline
>>>>> engine, because it tightly winds its copper wires in its coils 
>>>>> therefore
>>>>> being able to carry more current in the same space. If so, then we
>>>>> should be
>>>>> able to produce more power if we have a material that can carry more
>>>>> current.
>>>>
>>>> Teslas accelerate in short manic bursts. The motor would fry if it ran
>>>> steady-state at full power.
>>>
>>> Of course, you only need to accelerate for short periods, like a few
>>> seconds.  After that you are running illegal speeds
>>
>> No, not if you're going up-hill. (Gasoline engines are of
>> course much more suitable in that case.)
>>
>>> Why design it to run full power beyond all use cases?  Your Audi will
>>> melt down if you hold the pedal to the metal all day long too.
>>
>> No, not unless you block the airflow through the radiator.
>>
>>>> And the power/weight ratio drops a lot if you include the batteries.
>>>
>>> That's a pointless number.
>>
>> Why did anyone bring it up, then?
> 
> Because they don't understand basic Newtonian mechanics, rather they 
> listen to everyone else who spouts nonsense.
> 
> 
>>>    The car runs 300+ miles on a charge and
>>> recharges while you have a cup of coffee.
>>
>> But what if you don't want to have coffee but just want to
>> proceed without waiting one hour?
> 
> You mean 20 minutes and you don't need to empty your bladder after 
> driving for four hours?  I guess you pee into Gatorade bottles while you 
> drive?  I never developed that skill.
> 
> 
>>>    Who cares about pointless
>>> numbers?
>>
>> If they are truly pointless nobody cares. If anyone does care, I
>> think you shouldn't be so sure that they are pointless numbers..
>> (But then again, people care about astrological predictions as
>> well.)
> 
> I don't duplicate my other post about acceleration and 0 to 60 times.
> 

Ya know, rickman, you really are a pimple on the ass of mankind. Try to 
find a different group to hassle.

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#19990

You can build one with superconductors, but you have to be careful of three 
things:
1. Type 2 superconductors have AC losses.  Preferably, this would be done 
with type 1, at LHe temperatures.
2. You can't use magnetic materials very well.  Well, you could -- but you'd 
only be gaining a paltry ~tesla before saturation, when you have several 
tesla available with the superconductor.  They'd also be lossy, putting out 
heat that you don't need.
3. The cryocooler is going to set you back more, in space and power, than 
doing it with copper in the first place, not to mention the expense (and 
making slip rings, and low resistance connections, and..).

Although one neat thing is, you can avoid slip rings by using a 
superconducting loop for the rotor (thus you get a superconducting BLDC 
machine).  Much stronger than NdFeB, and as long as the cryocooler never 
shuts down, it never demagnetizes.

Tim

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

"Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> wrote in message 
news:okdk1a$426$1@dont-email.me...
>I read that the Tesla electric motor is able to achieve its remarkable 
>power to weight ratio of 8.5 kW/kg, about 10 times better than a typical 
>gasoline engine, because it tightly winds its copper wires in its coils 
>therefore being able to carry more current in the same space. If so, then 
>we should be able to produce more power if we have a material that can 
>carry more current.
>
> Carbon nanotubes are such a material. In tests they can carry orders of 
> magnitude more current than ordinary conductors such as copper, aluminum, 
> or gold. The problem is they've only be able to be produced for short 
> lengths, a few centimeters at most.
>
> But an interesting research on nanotube-copper composites showed they can 
> carry a 100 times more current than standard copper. So for the same size 
> electric motor we could produce 100 times more power than currently:
>
> Posted: Aug 06, 2013
> Novel CNT-copper nanocomposite delivers a 100-fold increase in current 
> density
> http://www.nanowerk.com/spotlight/spotid=31710.php
>
> For the Tesla that would not be as major a deal because of the small size 
> of the motor at only about 32 kilos for the Tesla S, a vehicle that weighs 
> thousands of kilos.
>
> But that would be major for large scale motors used in other scenarios. 
> These can weigh thousands of kilos, and could then be reduced to only tens 
> of kilos. It would also be especially important for proposed electric 
> aircraft that many groups are working towards.
>
> So is it really true we can increase electric motor power levels simply by 
> using wire of higher current capacity?
>
>
> Bob Clark
>
> ----------------------------------------------------------------------------------------------------------------------------------
> Finally, nanotechnology can now fulfill its potential to revolutionize 
> 21st-century technology, from the space elevator, to private, orbital 
> launchers, to 'flying cars'.
> This crowdfunding campaign is to prove it:
>
> Nanotech: from air to space.
> https://www.indiegogo.com/projects/nanotech-from-air-to-space/x/13319568/
> ----------------------------------------------------------------------------------------------------------------------------------
> 

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#20025

>You can build one with superconductors, but you have to be careful of three 
>things:
>1. Type 2 superconductors have AC losses.  Preferably, this would be done 
>with type 1, at LHe temperatures.
>2. You can't use magnetic materials very well.  Well, you could -- but 
>you'd only be gaining a paltry ~tesla before saturation, when you have 
>several tesla available with the superconductor.  They'd also be lossy, 
>putting out heat that you don't need.
>3. The cryocooler is going to set you back more, in space and power, than 
>doing it with copper in the first place, not to mention the expense (and 
>making slip rings, and low resistance connections, and..).
>
>Although one neat thing is, you can avoid slip rings by using a 
>superconducting loop for the rotor (thus you get a superconducting BLDC 
>machine).  Much stronger than NdFeB, and as long as the cryocooler never 
>shuts down, it never demagnetizes.
>
>Tim
>

Thanks for that info that even with high current you run into the problem of 
magnetic saturation, where the magnetic field produced levels off:

Saturation(magnetic).
https://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/Magnetization_curves.svg/418px-Magnetization_curves.svg.png
https://en.wikipedia.org/wiki/Saturation_(magnetic)

According to this wiki article the best you can get is with iron alloys at 
2.2 T (Tesla).

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]
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?

  Bob Clark

-- 

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#20067

"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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