Prev: cmos latchup in mcu
Next: Built-in audio playback module
From: JosephKK on 27 Apr 2010 21:35
On Sat, 24 Apr 2010 07:56:35 -0700, John Larkin
<jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:

>On Sat, 24 Apr 2010 03:50:50 -0700,
>"JosephKK"<quiettechblue(a)yahoo.com> wrote:
>
>>On Tue, 20 Apr 2010 04:11:50 -0700, John Larkin
>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:
>>
>>>On Mon, 19 Apr 2010 20:50:35 -0700, Tim Wescott <tim(a)seemywebsite.now>
>>>wrote:
>>>
>>>>John Larkin wrote:
>>>>> Can anybody suggest a good one?
>>>>
>>>>Ha ha ha ha ha he he he he he ho ho ho ho ho aaaaaaaaaaaaaaaaagh!
>>>>
>>>>(I'm not making fun of you here, that's hysterical laughter).
>>>
>>>There seems to be some stuff from, say, 1955 or so. I don't suppose
>>>much has changed.
>>>
>>>>
>>>>Call Renco Encoders and see if you can sweet-talk them out of a copy of
>>>>"Feedback Devices in Motion Control Systems", by Robert M. Setbacken.
>>>>
>>>>Then call Moog Components -- wade through the Moog website and find the
>>>>guys that sell the precision industrial and aerospace encoders. Sweet
>>>>talk them, too.
>>>>
>>>>Be aware that all the electronics whizzes who worked on encoders have
>>>>died of old age -- it's all mechanical engineers; they know bearings,
>>>>they know winding machines, and they know how to test things, but when
>>>>you start asking questions about impedance vs. frequency and other
>>>>seemingly obvious things the best you'll get is a friendly shrug.
>>>
>>>Seems that way. A lot of the books and lit seem cartoonish.
>>>
>>>>
>>>>They're variable transformers. They're really inefficient. Their
>>>>impedance is pretty close to the wiring resistance plus the inductance
>>>>times radian frequency (no surprise there). They work over an
>>>>astonishingly large frequency range, although they are traditionally
>>>>only specified at the frequency that the first customer wanted to use.
>>>>The drive amplitude is specified in voltage, although if you read
>>>>between the lines they're limiting the I^2R losses in the primary. Try
>>>>to ask the guys who design them these days and at best you'll get a
>>>>friendly shrug...
>>>>
>>>>You can order them specified for other frequencies, or sizes, for "some"
>>>>NRE. "Some" is relative, and Moog is an aerospace company...
>>>>
>>>>How tightly are you gonna simulate the resolvers? Just behavioral?
>>>>1st-order with inductances and winding resistance? Parallel
>>>>capacitance? Electrical nonlinear effects? Spatial nonlinear effects?
>>>> Are you gonna simulate multi-speed resolvers?
>>>
>>>My gadget is going to be transformers, adcs, dacs, and an FPGA.
>>>Whatever I can do with that. I'll be generating low-power signals into
>>>an electronics box that thinks it's connected to an LVDT or a synchro.
>>>It's representing mechanical positions of things like flaps or bits of
>>>engines, so it doesn't need arc-second accuracy. Stuff like
>>>multi-speed would be easy.
>>>
>>Multispeed easy?? Not going to happen. Do you know how to
>>elecromechanically zero a multispeed synchro?
>>>>
>>>>There's probably a market for a general-purpose resolver simulator, and
>>>>possibly even more so for a general-purpose resolver _meter_ (I recall
>>>>looking and not finding one, at a time that one was desperately needed).
>>>
>>>The meters are around.
>>>
>>>http://www.naii.com/Angle-Position-Indicators/PSC8
>>>
>>>http://www.controlsciences.com/
>>>
>>>http://peakelectronics.com/index.php?option=com_content&task=view&id=36&Itemid=62
>>>
>>I can see where you think you can break into a lucrative, but niche,
>>market.
>
>I don't have to break into a market. A pretty big aerospace company is
>asking me to do this to replace a board that they designed themselves
>and don't want to/can't make any more.
>
>A lot of big aerospace companies and national labs used to design
>their own electronics. Sometimes it was good, but often not. The trend
>is now towards outsourcing, for several reasons.
>
>John

Your last hint, to do multispeed right you also need to be at least a
jackleg mechanical or industrial engineer.
From: John Larkin on 27 Apr 2010 22:46
On Tue, 27 Apr 2010 18:35:56 -0700,
"JosephKK"<quiettechblue(a)yahoo.com> wrote:

>On Sat, 24 Apr 2010 07:56:35 -0700, John Larkin
><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Sat, 24 Apr 2010 03:50:50 -0700,
>>"JosephKK"<quiettechblue(a)yahoo.com> wrote:
>>
>>>On Tue, 20 Apr 2010 04:11:50 -0700, John Larkin
>>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:
>>>
>>>>On Mon, 19 Apr 2010 20:50:35 -0700, Tim Wescott <tim(a)seemywebsite.now>
>>>>wrote:
>>>>
>>>>>John Larkin wrote:
>>>>>> Can anybody suggest a good one?
>>>>>
>>>>>Ha ha ha ha ha he he he he he ho ho ho ho ho aaaaaaaaaaaaaaaaagh!
>>>>>
>>>>>(I'm not making fun of you here, that's hysterical laughter).
>>>>
>>>>There seems to be some stuff from, say, 1955 or so. I don't suppose
>>>>much has changed.
>>>>
>>>>>
>>>>>Call Renco Encoders and see if you can sweet-talk them out of a copy of
>>>>>"Feedback Devices in Motion Control Systems", by Robert M. Setbacken.
>>>>>
>>>>>Then call Moog Components -- wade through the Moog website and find the
>>>>>guys that sell the precision industrial and aerospace encoders. Sweet
>>>>>talk them, too.
>>>>>
>>>>>Be aware that all the electronics whizzes who worked on encoders have
>>>>>died of old age -- it's all mechanical engineers; they know bearings,
>>>>>they know winding machines, and they know how to test things, but when
>>>>>you start asking questions about impedance vs. frequency and other
>>>>>seemingly obvious things the best you'll get is a friendly shrug.
>>>>
>>>>Seems that way. A lot of the books and lit seem cartoonish.
>>>>
>>>>>
>>>>>They're variable transformers. They're really inefficient. Their
>>>>>impedance is pretty close to the wiring resistance plus the inductance
>>>>>times radian frequency (no surprise there). They work over an
>>>>>astonishingly large frequency range, although they are traditionally
>>>>>only specified at the frequency that the first customer wanted to use.
>>>>>The drive amplitude is specified in voltage, although if you read
>>>>>between the lines they're limiting the I^2R losses in the primary. Try
>>>>>to ask the guys who design them these days and at best you'll get a
>>>>>friendly shrug...
>>>>>
>>>>>You can order them specified for other frequencies, or sizes, for "some"
>>>>>NRE. "Some" is relative, and Moog is an aerospace company...
>>>>>
>>>>>How tightly are you gonna simulate the resolvers? Just behavioral?
>>>>>1st-order with inductances and winding resistance? Parallel
>>>>>capacitance? Electrical nonlinear effects? Spatial nonlinear effects?
>>>>> Are you gonna simulate multi-speed resolvers?
>>>>
>>>>My gadget is going to be transformers, adcs, dacs, and an FPGA.
>>>>Whatever I can do with that. I'll be generating low-power signals into
>>>>an electronics box that thinks it's connected to an LVDT or a synchro.
>>>>It's representing mechanical positions of things like flaps or bits of
>>>>engines, so it doesn't need arc-second accuracy. Stuff like
>>>>multi-speed would be easy.
>>>>
>>>Multispeed easy?? Not going to happen. Do you know how to
>>>elecromechanically zero a multispeed synchro?
>>>>>
>>>>>There's probably a market for a general-purpose resolver simulator, and
>>>>>possibly even more so for a general-purpose resolver _meter_ (I recall
>>>>>looking and not finding one, at a time that one was desperately needed).
>>>>
>>>>The meters are around.
>>>>
>>>>http://www.naii.com/Angle-Position-Indicators/PSC8
>>>>
>>>>http://www.controlsciences.com/
>>>>
>>>>http://peakelectronics.com/index.php?option=com_content&task=view&id=36&Itemid=62
>>>>
>>>I can see where you think you can break into a lucrative, but niche,
>>>market.
>>
>>I don't have to break into a market. A pretty big aerospace company is
>>asking me to do this to replace a board that they designed themselves
>>and don't want to/can't make any more.
>>
>>A lot of big aerospace companies and national labs used to design
>>their own electronics. Sometimes it was good, but often not. The trend
>>is now towards outsourcing, for several reasons.
>>
>>John
>
>Your last hint, to do multispeed right you also need to be at least a
>jackleg mechanical or industrial engineer.

And how is a jackleg industrial engineer going to program trig into an
ARM processor driving an FPGA full of math, connected to a bunch of
ADCs and DACs?

Multispeed looks pretty simple to me. In fact, the whole thing looks
pretty simple.

John


From: JosephKK on 28 Apr 2010 00:11
On Tue, 27 Apr 2010 19:46:36 -0700, John Larkin
<jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:

>On Tue, 27 Apr 2010 18:35:56 -0700,
>"JosephKK"<quiettechblue(a)yahoo.com> wrote:
>
>>On Sat, 24 Apr 2010 07:56:35 -0700, John Larkin
>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:
>>
>>>On Sat, 24 Apr 2010 03:50:50 -0700,
>>>"JosephKK"<quiettechblue(a)yahoo.com> wrote:
>>>
>>>>On Tue, 20 Apr 2010 04:11:50 -0700, John Larkin
>>>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:
>>>>
>>>>>On Mon, 19 Apr 2010 20:50:35 -0700, Tim Wescott <tim(a)seemywebsite.now>
>>>>>wrote:
>>>>>
>>>>>>John Larkin wrote:
>>>>>>> Can anybody suggest a good one?
>>>>>>
>>>>>>Ha ha ha ha ha he he he he he ho ho ho ho ho aaaaaaaaaaaaaaaaagh!
>>>>>>
>>>>>>(I'm not making fun of you here, that's hysterical laughter).
>>>>>
>>>>>There seems to be some stuff from, say, 1955 or so. I don't suppose
>>>>>much has changed.
>>>>>
>>>>>>
>>>>>>Call Renco Encoders and see if you can sweet-talk them out of a copy of
>>>>>>"Feedback Devices in Motion Control Systems", by Robert M. Setbacken.
>>>>>>
>>>>>>Then call Moog Components -- wade through the Moog website and find the
>>>>>>guys that sell the precision industrial and aerospace encoders. Sweet
>>>>>>talk them, too.
>>>>>>
>>>>>>Be aware that all the electronics whizzes who worked on encoders have
>>>>>>died of old age -- it's all mechanical engineers; they know bearings,
>>>>>>they know winding machines, and they know how to test things, but when
>>>>>>you start asking questions about impedance vs. frequency and other
>>>>>>seemingly obvious things the best you'll get is a friendly shrug.
>>>>>
>>>>>Seems that way. A lot of the books and lit seem cartoonish.
>>>>>
>>>>>>
>>>>>>They're variable transformers. They're really inefficient. Their
>>>>>>impedance is pretty close to the wiring resistance plus the inductance
>>>>>>times radian frequency (no surprise there). They work over an
>>>>>>astonishingly large frequency range, although they are traditionally
>>>>>>only specified at the frequency that the first customer wanted to use.
>>>>>>The drive amplitude is specified in voltage, although if you read
>>>>>>between the lines they're limiting the I^2R losses in the primary. Try
>>>>>>to ask the guys who design them these days and at best you'll get a
>>>>>>friendly shrug...
>>>>>>
>>>>>>You can order them specified for other frequencies, or sizes, for "some"
>>>>>>NRE. "Some" is relative, and Moog is an aerospace company...
>>>>>>
>>>>>>How tightly are you gonna simulate the resolvers? Just behavioral?
>>>>>>1st-order with inductances and winding resistance? Parallel
>>>>>>capacitance? Electrical nonlinear effects? Spatial nonlinear effects?
>>>>>> Are you gonna simulate multi-speed resolvers?
>>>>>
>>>>>My gadget is going to be transformers, adcs, dacs, and an FPGA.
>>>>>Whatever I can do with that. I'll be generating low-power signals into
>>>>>an electronics box that thinks it's connected to an LVDT or a synchro.
>>>>>It's representing mechanical positions of things like flaps or bits of
>>>>>engines, so it doesn't need arc-second accuracy. Stuff like
>>>>>multi-speed would be easy.
>>>>>
>>>>Multispeed easy?? Not going to happen. Do you know how to
>>>>elecromechanically zero a multispeed synchro?
>>>>>>
>>>>>>There's probably a market for a general-purpose resolver simulator, and
>>>>>>possibly even more so for a general-purpose resolver _meter_ (I recall
>>>>>>looking and not finding one, at a time that one was desperately needed).
>>>>>
>>>>>The meters are around.
>>>>>
>>>>>http://www.naii.com/Angle-Position-Indicators/PSC8
>>>>>
>>>>>http://www.controlsciences.com/
>>>>>
>>>>>http://peakelectronics.com/index.php?option=com_content&task=view&id=36&Itemid=62
>>>>>
>>>>I can see where you think you can break into a lucrative, but niche,
>>>>market.
>>>
>>>I don't have to break into a market. A pretty big aerospace company is
>>>asking me to do this to replace a board that they designed themselves
>>>and don't want to/can't make any more.
>>>
>>>A lot of big aerospace companies and national labs used to design
>>>their own electronics. Sometimes it was good, but often not. The trend
>>>is now towards outsourcing, for several reasons.
>>>
>>>John
>>
>>Your last hint, to do multispeed right you also need to be at least a
>>jackleg mechanical or industrial engineer.
>
>And how is a jackleg industrial engineer going to program trig into an
>ARM processor driving an FPGA full of math, connected to a bunch of
>ADCs and DACs?
>
>Multispeed looks pretty simple to me. In fact, the whole thing looks
>pretty simple.
>
>John
>
The trig is NOT the problem.
From: Tim Wescott on 28 Apr 2010 00:30
JosephKK wrote:
> On Sat, 24 Apr 2010 07:56:35 -0700, John Larkin
> <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:
>
>> On Sat, 24 Apr 2010 03:50:50 -0700,
>> "JosephKK"<quiettechblue(a)yahoo.com> wrote:
>>
>>> On Tue, 20 Apr 2010 04:11:50 -0700, John Larkin
>>> <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:
>>>
>>>> On Mon, 19 Apr 2010 20:50:35 -0700, Tim Wescott <tim(a)seemywebsite.now>
>>>> wrote:
>>>>
>>>>> John Larkin wrote:
>>>>>> Can anybody suggest a good one?
>>>>> Ha ha ha ha ha he he he he he ho ho ho ho ho aaaaaaaaaaaaaaaaagh!
>>>>>
>>>>> (I'm not making fun of you here, that's hysterical laughter).
>>>> There seems to be some stuff from, say, 1955 or so. I don't suppose
>>>> much has changed.
>>>>
>>>>> Call Renco Encoders and see if you can sweet-talk them out of a copy of
>>>>> "Feedback Devices in Motion Control Systems", by Robert M. Setbacken.
>>>>>
>>>>> Then call Moog Components -- wade through the Moog website and find the
>>>>> guys that sell the precision industrial and aerospace encoders. Sweet
>>>>> talk them, too.
>>>>>
>>>>> Be aware that all the electronics whizzes who worked on encoders have
>>>>> died of old age -- it's all mechanical engineers; they know bearings,
>>>>> they know winding machines, and they know how to test things, but when
>>>>> you start asking questions about impedance vs. frequency and other
>>>>> seemingly obvious things the best you'll get is a friendly shrug.
>>>> Seems that way. A lot of the books and lit seem cartoonish.
>>>>
>>>>> They're variable transformers. They're really inefficient. Their
>>>>> impedance is pretty close to the wiring resistance plus the inductance
>>>>> times radian frequency (no surprise there). They work over an
>>>>> astonishingly large frequency range, although they are traditionally
>>>>> only specified at the frequency that the first customer wanted to use.
>>>>> The drive amplitude is specified in voltage, although if you read
>>>>> between the lines they're limiting the I^2R losses in the primary. Try
>>>>> to ask the guys who design them these days and at best you'll get a
>>>>> friendly shrug...
>>>>>
>>>>> You can order them specified for other frequencies, or sizes, for "some"
>>>>> NRE. "Some" is relative, and Moog is an aerospace company...
>>>>>
>>>>> How tightly are you gonna simulate the resolvers? Just behavioral?
>>>>> 1st-order with inductances and winding resistance? Parallel
>>>>> capacitance? Electrical nonlinear effects? Spatial nonlinear effects?
>>>>> Are you gonna simulate multi-speed resolvers?
>>>> My gadget is going to be transformers, adcs, dacs, and an FPGA.
>>>> Whatever I can do with that. I'll be generating low-power signals into
>>>> an electronics box that thinks it's connected to an LVDT or a synchro.
>>>> It's representing mechanical positions of things like flaps or bits of
>>>> engines, so it doesn't need arc-second accuracy. Stuff like
>>>> multi-speed would be easy.
>>>>
>>> Multispeed easy?? Not going to happen. Do you know how to
>>> elecromechanically zero a multispeed synchro?
>>>>> There's probably a market for a general-purpose resolver simulator, and
>>>>> possibly even more so for a general-purpose resolver _meter_ (I recall
>>>>> looking and not finding one, at a time that one was desperately needed).
>>>> The meters are around.
>>>>
>>>> http://www.naii.com/Angle-Position-Indicators/PSC8
>>>>
>>>> http://www.controlsciences.com/
>>>>
>>>> http://peakelectronics.com/index.php?option=com_content&task=view&id=36&Itemid=62
>>>>
>>> I can see where you think you can break into a lucrative, but niche,
>>> market.
>> I don't have to break into a market. A pretty big aerospace company is
>> asking me to do this to replace a board that they designed themselves
>> and don't want to/can't make any more.
>>
>> A lot of big aerospace companies and national labs used to design
>> their own electronics. Sometimes it was good, but often not. The trend
>> is now towards outsourcing, for several reasons.
>>
>> John
>
> Your last hint, to do multispeed right you also need to be at least a
> jackleg mechanical or industrial engineer.

I don't see how that's necessary at all, particularly since he's
planning on doing an all-electronic simulation of a multispeed resolver.

Perhaps you could say what you have to say, instead of winking and
grinning and hinting.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
From: John Larkin on 28 Apr 2010 10:19
On Tue, 27 Apr 2010 21:30:34 -0700, Tim Wescott <tim(a)seemywebsite.now>
wrote:

>JosephKK wrote:
>> On Sat, 24 Apr 2010 07:56:35 -0700, John Larkin
>> <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:
>>
>>> On Sat, 24 Apr 2010 03:50:50 -0700,
>>> "JosephKK"<quiettechblue(a)yahoo.com> wrote:
>>>
>>>> On Tue, 20 Apr 2010 04:11:50 -0700, John Larkin
>>>> <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote:
>>>>
>>>>> On Mon, 19 Apr 2010 20:50:35 -0700, Tim Wescott <tim(a)seemywebsite.now>
>>>>> wrote:
>>>>>
>>>>>> John Larkin wrote:
>>>>>>> Can anybody suggest a good one?
>>>>>> Ha ha ha ha ha he he he he he ho ho ho ho ho aaaaaaaaaaaaaaaaagh!
>>>>>>
>>>>>> (I'm not making fun of you here, that's hysterical laughter).
>>>>> There seems to be some stuff from, say, 1955 or so. I don't suppose
>>>>> much has changed.
>>>>>
>>>>>> Call Renco Encoders and see if you can sweet-talk them out of a copy of
>>>>>> "Feedback Devices in Motion Control Systems", by Robert M. Setbacken.
>>>>>>
>>>>>> Then call Moog Components -- wade through the Moog website and find the
>>>>>> guys that sell the precision industrial and aerospace encoders. Sweet
>>>>>> talk them, too.
>>>>>>
>>>>>> Be aware that all the electronics whizzes who worked on encoders have
>>>>>> died of old age -- it's all mechanical engineers; they know bearings,
>>>>>> they know winding machines, and they know how to test things, but when
>>>>>> you start asking questions about impedance vs. frequency and other
>>>>>> seemingly obvious things the best you'll get is a friendly shrug.
>>>>> Seems that way. A lot of the books and lit seem cartoonish.
>>>>>
>>>>>> They're variable transformers. They're really inefficient. Their
>>>>>> impedance is pretty close to the wiring resistance plus the inductance
>>>>>> times radian frequency (no surprise there). They work over an
>>>>>> astonishingly large frequency range, although they are traditionally
>>>>>> only specified at the frequency that the first customer wanted to use.
>>>>>> The drive amplitude is specified in voltage, although if you read
>>>>>> between the lines they're limiting the I^2R losses in the primary. Try
>>>>>> to ask the guys who design them these days and at best you'll get a
>>>>>> friendly shrug...
>>>>>>
>>>>>> You can order them specified for other frequencies, or sizes, for "some"
>>>>>> NRE. "Some" is relative, and Moog is an aerospace company...
>>>>>>
>>>>>> How tightly are you gonna simulate the resolvers? Just behavioral?
>>>>>> 1st-order with inductances and winding resistance? Parallel
>>>>>> capacitance? Electrical nonlinear effects? Spatial nonlinear effects?
>>>>>> Are you gonna simulate multi-speed resolvers?
>>>>> My gadget is going to be transformers, adcs, dacs, and an FPGA.
>>>>> Whatever I can do with that. I'll be generating low-power signals into
>>>>> an electronics box that thinks it's connected to an LVDT or a synchro.
>>>>> It's representing mechanical positions of things like flaps or bits of
>>>>> engines, so it doesn't need arc-second accuracy. Stuff like
>>>>> multi-speed would be easy.
>>>>>
>>>> Multispeed easy?? Not going to happen. Do you know how to
>>>> elecromechanically zero a multispeed synchro?
>>>>>> There's probably a market for a general-purpose resolver simulator, and
>>>>>> possibly even more so for a general-purpose resolver _meter_ (I recall
>>>>>> looking and not finding one, at a time that one was desperately needed).
>>>>> The meters are around.
>>>>>
>>>>> http://www.naii.com/Angle-Position-Indicators/PSC8
>>>>>
>>>>> http://www.controlsciences.com/
>>>>>
>>>>> http://peakelectronics.com/index.php?option=com_content&task=view&id=36&Itemid=62
>>>>>
>>>> I can see where you think you can break into a lucrative, but niche,
>>>> market.
>>> I don't have to break into a market. A pretty big aerospace company is
>>> asking me to do this to replace a board that they designed themselves
>>> and don't want to/can't make any more.
>>>
>>> A lot of big aerospace companies and national labs used to design
>>> their own electronics. Sometimes it was good, but often not. The trend
>>> is now towards outsourcing, for several reasons.
>>>
>>> John
>>
>> Your last hint, to do multispeed right you also need to be at least a
>> jackleg mechanical or industrial engineer.
>
>I don't see how that's necessary at all, particularly since he's
>planning on doing an all-electronic simulation of a multispeed resolver.

I hadn't planned to do multispeed, but there's no reason we couldn't.
My first customer is mostly concerned about simulating LVDTs.

>Perhaps you could say what you have to say, instead of winking and
>grinning and hinting.

Exactly. He's being way too coy. His record for being actually right
about stuff is right up there with YouKnowWho. [1]

John

[1] and I don't mean Voldemort.


First  |  Prev  |  Next  |  Last
Pages: 1 2 3 4 5
Prev: cmos latchup in mcu
Next: Built-in audio playback module