> On Fri, 12 May 2017 13:56:50 -0500, Tim Wescott
> <tim@seemywebsite.really> wrote:
>
>> On Fri, 12 May 2017 11:09:26 -0400, Randy Yates wrote:
>>
>>> Tim Wescott <seemywebsite@myfooter.really> writes:
>>>> [...]
>>>> I think that itty bitty brushed motors will be around for a while, at
>>>> least until people figure out how to make itty bitty controllers that
>>>> are cheaper than itty bitty brushes and commutators.
>>>
>>> Too funny! Tim, was the term "itty bitty" used in your graduate
>>> textbooks?
>>
>> No. But it should have been.
>>
>> I couple of decades ago I realized, thanks to a colleague with a PhD,
>> that "bazzilion", "ginormous", "teeny", etc., are all valid technical
>> terms (meaning, in order, roughly, and in most contexcts, "so many that
>> it's not cost effective to enumerate", "so big that it's not cost
>> effective to consider the size", and "so small that it's not cost
>> effective to consider the size").
>>
>
> There are measurement units that are commonly used to convey similar
> meaning, .e.g., "buttloads", "shit-ton", etc. I've accepted these,
> and many other, as legitimate technical terms or units of measurement
> for a long time. They seem to be nearly universally accepted, so it
> has been neither problematic nor controversial in my experience.
Remember Mars Climate Orbiter and the Gimli Glider. You have to specify
if it's a metric buttload or an avordupois buttload.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.nethttp://hobbs-eo.com
Reply by ●July 18, 20172017-07-18
On Tuesday, May 9, 2017 at 12:19:18 PM UTC-7, gyans...@gmail.com wrote:
> Talked to a motor manufacturer in Germany.
> They don't even do DC motors any more, no call for
> them at all. Just ac and brushless DC which is really
> ac under a different name. Apparently with a good ac
> controller you can get an induction motor to have the
> same torque as a DC motor and you get max torque at
> zero speed - all down to flux vectoring. So do we throw
> out our brushed motors.
There is a light rail system, a few years old now, in Seattle.
If you are anywhere near the train, with an AM radio, you
know that the train is running. The power converter puts
out enough harmonics within the AM band, which then go down
the overhead wires to any nearby radios (usually in cars).
We also have some electric trolley (two overhead wire) buses
in Seattle, with different converter technology, that also
goes into the AM band.
As far as I know AC/DC motors (series wound) are still used in
many household appliances, still cheaper than the appropriate
power converter. For tiny motors, like for battery powered
toys, I believe that they are usual DC brush motors.
Reply by robert bristow-johnson●May 15, 20172017-05-15
On Friday, May 12, 2017 at 5:23:34 PM UTC-4, eric.j...@ieee.org wrote:
> On Fri, 12 May 2017 13:56:50 -0500, Tim Wescott
> <tim@seemywebsite.really> wrote:
>
> >On Fri, 12 May 2017 11:09:26 -0400, Randy Yates wrote:
> >
> >> Tim Wescott <seemywebsite@myfooter.really> writes:
> >>> [...]
> >>> I think that itty bitty brushed motors will be around for a while, at
> >>> least until people figure out how to make itty bitty controllers that
> >>> are cheaper than itty bitty brushes and commutators.
> >>
> >> Too funny! Tim, was the term "itty bitty" used in your graduate
> >> textbooks?
> >
> >No. But it should have been.
> >
> >I couple of decades ago I realized, thanks to a colleague with a PhD,
> >that "bazzilion", "ginormous", "teeny", etc., are all valid technical
> >terms (meaning, in order, roughly, and in most contexcts, "so many that
> >it's not cost effective to enumerate", "so big that it's not cost
> >effective to consider the size", and "so small that it's not cost
> >effective to consider the size").
> >
>
> There are measurement units that are commonly used to convey similar
> meaning, .e.g., "buttloads", "shit-ton", etc. I've accepted these,
> and many other, as legitimate technical terms or units of measurement
> for a long time. They seem to be nearly universally accepted, so it
> has been neither problematic nor controversial in my experience.
milli-smidgen .
Reply by rickman●May 13, 20172017-05-13
On 5/12/2017 5:23 PM, eric.jacobsen@ieee.org wrote:
> On Fri, 12 May 2017 13:56:50 -0500, Tim Wescott
> <tim@seemywebsite.really> wrote:
>
>> On Fri, 12 May 2017 11:09:26 -0400, Randy Yates wrote:
>>
>>> Tim Wescott <seemywebsite@myfooter.really> writes:
>>>> [...]
>>>> I think that itty bitty brushed motors will be around for a while, at
>>>> least until people figure out how to make itty bitty controllers that
>>>> are cheaper than itty bitty brushes and commutators.
>>>
>>> Too funny! Tim, was the term "itty bitty" used in your graduate
>>> textbooks?
>>
>> No. But it should have been.
>>
>> I couple of decades ago I realized, thanks to a colleague with a PhD,
>> that "bazzilion", "ginormous", "teeny", etc., are all valid technical
>> terms (meaning, in order, roughly, and in most contexcts, "so many that
>> it's not cost effective to enumerate", "so big that it's not cost
>> effective to consider the size", and "so small that it's not cost
>> effective to consider the size").
>>
>
> There are measurement units that are commonly used to convey similar
> meaning, .e.g., "buttloads", "shit-ton", etc. I've accepted these,
> and many other, as legitimate technical terms or units of measurement
> for a long time. They seem to be nearly universally accepted, so it
> has been neither problematic nor controversial in my experience.
You need to be more specific. Is that an imperial "shit-ton" or a
metric "shit-ton". The imperial "shit-ton" is an informal unit with a
definition that varies with the speaker much like the inch being related
to the distance between the user's knuckles.
--
Rick C
Reply by ●May 12, 20172017-05-12
On Fri, 12 May 2017 13:56:50 -0500, Tim Wescott
<tim@seemywebsite.really> wrote:
>On Fri, 12 May 2017 11:09:26 -0400, Randy Yates wrote:
>
>> Tim Wescott <seemywebsite@myfooter.really> writes:
>>> [...]
>>> I think that itty bitty brushed motors will be around for a while, at
>>> least until people figure out how to make itty bitty controllers that
>>> are cheaper than itty bitty brushes and commutators.
>>
>> Too funny! Tim, was the term "itty bitty" used in your graduate
>> textbooks?
>
>No. But it should have been.
>
>I couple of decades ago I realized, thanks to a colleague with a PhD,
>that "bazzilion", "ginormous", "teeny", etc., are all valid technical
>terms (meaning, in order, roughly, and in most contexcts, "so many that
>it's not cost effective to enumerate", "so big that it's not cost
>effective to consider the size", and "so small that it's not cost
>effective to consider the size").
>
There are measurement units that are commonly used to convey similar
meaning, .e.g., "buttloads", "shit-ton", etc. I've accepted these,
and many other, as legitimate technical terms or units of measurement
for a long time. They seem to be nearly universally accepted, so it
has been neither problematic nor controversial in my experience.
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
Reply by Tim Wescott●May 12, 20172017-05-12
On Fri, 12 May 2017 11:09:26 -0400, Randy Yates wrote:
> Tim Wescott <seemywebsite@myfooter.really> writes:
>> [...]
>> I think that itty bitty brushed motors will be around for a while, at
>> least until people figure out how to make itty bitty controllers that
>> are cheaper than itty bitty brushes and commutators.
>
> Too funny! Tim, was the term "itty bitty" used in your graduate
> textbooks?
No. But it should have been.
I couple of decades ago I realized, thanks to a colleague with a PhD,
that "bazzilion", "ginormous", "teeny", etc., are all valid technical
terms (meaning, in order, roughly, and in most contexcts, "so many that
it's not cost effective to enumerate", "so big that it's not cost
effective to consider the size", and "so small that it's not cost
effective to consider the size").
--
www.wescottdesign.com
Reply by Randy Yates●May 12, 20172017-05-12
Tim Wescott <seemywebsite@myfooter.really> writes:
> [...]
> I think that itty bitty brushed motors will be around for a while, at
> least until people figure out how to make itty bitty controllers that
> are cheaper than itty bitty brushes and commutators.
Too funny! Tim, was the term "itty bitty" used in your graduate
textbooks?
--
Randy Yates, Embedded Firmware Developer
Garner Underground, Inc.
866-260-9040, x3901
http://www.garnerundergroundinc.com
Reply by Frank Miles●May 10, 20172017-05-10
On Tue, 09 May 2017 12:19:15 -0700, gyansorova wrote:
> Talked to a motor manufacturer in Germany. They don't even do DC motors any more, no call for them at all. Just ac and brushless DC which is really ac under a different name. Apparently with a good ac controller you can get an induction motor to have the same torque as a DC motor and you get max torque at zero speed - all down to flux vectoring. So do we throw out our brushed motors.
We use some specialty "zero-cogging" motors to generate precision
torque-systems - "manipulanda". These are grasped by the hand, and
the user attempts to move the device while following a kind of video
game. Unfortunately variations in torque - particularly at higher
frequencies - excite certain proprioceptors in a bad way. We need
super-smoothness as well as being able to deliver high torque
perturbations.
So yes, it's a _real_ niche application, but the loss of these motors
is gonna be hard. There is at least one maker of a fractional-turn
motor that is close to working (we haven't had to go there yet).
Reply by Steve Underwood●May 10, 20172017-05-10
On 05/10/2017 03:19 AM, gyansorova@gmail.com wrote:
> Talked to a motor manufacturer in Germany. They don't even do DC motors any more, no call for them at all. Just ac and brushless DC which is really ac under a different name. Apparently with a good ac controller you can get an induction motor to have the same torque as a DC motor and you get max torque at zero speed - all down to flux vectoring. So do we throw out our brushed motors.
>
Brushed motors are still being used in massive numbers in new product
designs. For example, most new power tools and kitchen appliances still
use them. It isn't high cost German manufacturers who produce those low
end motors, though.
Steve
Reply by Tim Wescott●May 9, 20172017-05-09
On Tue, 09 May 2017 12:19:15 -0700, gyansorova wrote:
> Talked to a motor manufacturer in Germany. They don't even do DC motors
> any more, no call for them at all. Just ac and brushless DC which is
> really ac under a different name. Apparently with a good ac controller
> you can get an induction motor to have the same torque as a DC motor and
> you get max torque at zero speed - all down to flux vectoring. So do we
> throw out our brushed motors.
Keep what you have, at least. They'll work as well as they ever did. I
think that itty bitty brushed motors will be around for a while, at least
until people figure out how to make itty bitty controllers that are
cheaper than itty bitty brushes and commutators.
Industrial brushless motors with built-in controllers are getting more
common -- one box with a shaft on one end and a cord on the other. Give
it power and commands, and it does what it's told.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
I'm looking for work -- see my website!