REQ: major electronics analysis project help needed TIA

[JB2]

thanks John, I'll look into Ethernet.

On Sat, 04 Jun 2005 21:21:43 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 05 Jun 2005 02:28:30 GMT, Fred Bloggs <nospam@nospam.com
wrote:



John Larkin wrote:
On Sat, 04 Jun 2005 23:25:54 GMT, Fred Bloggs <nospam@nospam.com
wrote:



John Larkin wrote:


Here's one of our AC acquisition modules...

http://www.highlandtechnology.com/DSS/V180DS.html

And from which competitor did you illegally pirate the algorithms?



I don't know of any competitor for this module - do you? - much less
one that publishes his algorithms. I just sat down and wrote the code.
I've been doing AC power meters for almost 20 years, and things have
just sort of evolved. I did a few thousand end-use survey meters (back
when that sort of thing was popular+funded) and over 1700 apartment
submeters for Battery Park City, right across the street from the
ex-World Trade Center buildings.

Well, you did ask.

John

All those applications have been converted to smart networked nodes-


Yeah, Ethernet - especially PoE - is the ultimate expansion bus. I
can't see why anybody would want to use IEEE-488 or RS-232 for
instrumentation any more.

John

 

[Fred Bloggs]

John Larkin wrote:

On Sun, 05 Jun 2005 02:28:30 GMT, Fred Bloggs <nospam@nospam.com
wrote:



John Larkin wrote:

On Sat, 04 Jun 2005 23:25:54 GMT, Fred Bloggs <nospam@nospam.com
wrote:



John Larkin wrote:



Here's one of our AC acquisition modules...

http://www.highlandtechnology.com/DSS/V180DS.html

And from which competitor did you illegally pirate the algorithms?



I don't know of any competitor for this module - do you? - much less
one that publishes his algorithms. I just sat down and wrote the code.
I've been doing AC power meters for almost 20 years, and things have
just sort of evolved. I did a few thousand end-use survey meters (back
when that sort of thing was popular+funded) and over 1700 apartment
submeters for Battery Park City, right across the street from the
ex-World Trade Center buildings.

Well, you did ask.

John

All those applications have been converted to smart networked nodes-



Yeah, Ethernet - especially PoE - is the ultimate expansion bus. I
can't see why anybody would want to use IEEE-488 or RS-232 for
instrumentation any more.

John

Energy use monitoring is big business. Even the power companies have
taken to marketing third-party widgets into which you plug an appliance
for data logging various primary power use parameters with download
capability to a PC. It's only a matter of time before the energy
intensive appliances themselves contain this feature with connectivity
to a home automation standard, reporting not only the dull and drab
energy consumption, but other more fascinating status information like
the freezer temperature, washing machine cycle state, or dryer
temperature, maybe component failure, warranty status, and automatic
connection to whomever the consumer has decided is appropriate- this
will make for an easy high profit margin option for the sellers.

 

JB2 <none@none.com> wrote:

mroberds@worldnet.att.net wrote:
Do you need analog measurements for everything, or is
digital OK for some of the inputs?
[...] All the sources are analog, but how those samples are
obtained, I don't think will make a difference. I thought simple
inductive pickups that feed analog to dig conv for recording.

I wasn't completely clear. What I meant was, do all your inputs need to
be of the form "bus B is at exactly 27.3 volts" (analog) or can some of
them be of the form "bus B is on" or "bus B is off" (digital). It sounds
like all or nearly all of your inputs will be analog.

How accurate does each analog reading need to be?
Big question! I would want at most _+2%. I suspect any more
deviation may make modeling too inaccurate.

To a zeroth approximation, this helps define your system architecture.
If you require high precision, it might make sense to buy one or a few
really good A to D converter(s), and then use it (them) to make several
dozen measurements in turn. If your requirements are not so strict (and
yours seem to not be very strict), it might make sense to buy lots of
cheaper A to D converters and let each one do a handful of measurements.

I have a crew on board, flight crew, trechnicians, engineers (me) 707
A/C

Since you mentioned elsewhere it's DoD, maybe you could just throw
people at it. Buy 150 $20 digital multimeters, open up a couple of
fresh cans of soldiers/sailors/airmen/marines, put them on the aircraft,
and tell them "at the sound of the tone, write down the readings on the
five meters that have been assigned to you". After you land, have each
one key his/her readings into a computer for you, then buy him/her a
beer. Ebay most of the meters at $10. Total cost $1500 + beer. OK,
the aircraft might not seat 30 extra personnel and/or it might affect
the flight manuevers you want to do.

Matt Roberds

 

[JB2]

I found the folks with the specific test gear, and we have a plan.
I'm going to have to take multiple samples, as the test gear only
handles so much info in one shot. (I forgot the company
name)...Drantis or somthing but they are supposed to be the
industry leaders in power testing. Although, I do like your last idea
the best!! LOL ....I can see it now.... Ok everyone 1..2...3....NOW
ok, time to go home and drink. outstanding


On Mon, 06 Jun 2005 08:58:41 GMT, mroberds@worldnet.att.net wrote:

JB2 <none@none.com> wrote:
mroberds@worldnet.att.net wrote:
Do you need analog measurements for everything, or is
digital OK for some of the inputs?
[...] All the sources are analog, but how those samples are
obtained, I don't think will make a difference. I thought simple
inductive pickups that feed analog to dig conv for recording.

I wasn't completely clear. What I meant was, do all your inputs need to
be of the form "bus B is at exactly 27.3 volts" (analog) or can some of
them be of the form "bus B is on" or "bus B is off" (digital). It sounds
like all or nearly all of your inputs will be analog.

How accurate does each analog reading need to be?
Big question! I would want at most _+2%. I suspect any more
deviation may make modeling too inaccurate.

To a zeroth approximation, this helps define your system architecture.
If you require high precision, it might make sense to buy one or a few
really good A to D converter(s), and then use it (them) to make several
dozen measurements in turn. If your requirements are not so strict (and
yours seem to not be very strict), it might make sense to buy lots of
cheaper A to D converters and let each one do a handful of measurements.

I have a crew on board, flight crew, trechnicians, engineers (me) 707
A/C

Since you mentioned elsewhere it's DoD, maybe you could just throw
people at it. Buy 150 $20 digital multimeters, open up a couple of
fresh cans of soldiers/sailors/airmen/marines, put them on the aircraft,
and tell them "at the sound of the tone, write down the readings on the
five meters that have been assigned to you". After you land, have each
one key his/her readings into a computer for you, then buy him/her a
beer. Ebay most of the meters at $10. Total cost $1500 + beer. OK,
the aircraft might not seat 30 extra personnel and/or it might affect
the flight manuevers you want to do.

Matt Roberds

 

[JB2]

FYI I'm going to be using a Dranetz pp1 and plain 'ol current pickups.

On Mon, 06 Jun 2005 08:58:41 GMT, mroberds@worldnet.att.net wrote:

JB2 <none@none.com> wrote:
mroberds@worldnet.att.net wrote:
Do you need analog measurements for everything, or is
digital OK for some of the inputs?
[...] All the sources are analog, but how those samples are
obtained, I don't think will make a difference. I thought simple
inductive pickups that feed analog to dig conv for recording.

I wasn't completely clear. What I meant was, do all your inputs need to
be of the form "bus B is at exactly 27.3 volts" (analog) or can some of
them be of the form "bus B is on" or "bus B is off" (digital). It sounds
like all or nearly all of your inputs will be analog.

How accurate does each analog reading need to be?
Big question! I would want at most _+2%. I suspect any more
deviation may make modeling too inaccurate.

To a zeroth approximation, this helps define your system architecture.
If you require high precision, it might make sense to buy one or a few
really good A to D converter(s), and then use it (them) to make several
dozen measurements in turn. If your requirements are not so strict (and
yours seem to not be very strict), it might make sense to buy lots of
cheaper A to D converters and let each one do a handful of measurements.

I have a crew on board, flight crew, trechnicians, engineers (me) 707
A/C

Since you mentioned elsewhere it's DoD, maybe you could just throw
people at it. Buy 150 $20 digital multimeters, open up a couple of
fresh cans of soldiers/sailors/airmen/marines, put them on the aircraft,
and tell them "at the sound of the tone, write down the readings on the
five meters that have been assigned to you". After you land, have each
one key his/her readings into a computer for you, then buy him/her a
beer. Ebay most of the meters at $10. Total cost $1500 + beer. OK,
the aircraft might not seat 30 extra personnel and/or it might affect
the flight manuevers you want to do.

Matt Roberds