Driver to drive?

[Francesco Poderico]

On Sunday, 10 March 2013 16:35:29 UTC, Nico Coesel wrote:

Francesco Poderico wrote:



On Sunday, 10 March 2013 00:16:57 UTC, Bruce Varley wrote:

wrote in message



news:c1ad2481-696a-4257-8242-a8c92169124b@googlegroups.com...



Hi all,



I've started designing a 200 MSPS Oscilloscope with a 25 MHz analog



bandwidth, 3Ksample/channel buffer.



The oscilloscope can be connected to a PC via USB, and eventually via



Ethernet and WiFi.



The trigger is ( at moment) rising, falling... auto, normal.







I would appreciate suggestions and or comment for possible improvement



and functionality that could make this oscilloscope interesting.







Thanks,



Francesco







Been there done that. Spent many weeks putting together a box that I was



very proud of, then purchased a Rigol that does everything it does plus a



lot more and a lot better. Is this really a good use of your time and



energy?



I get the point... and your are not the first one to tell me that.

but I believe that an oscilloscope is still an instruments a lot of electronic enthusiastic would love to have it if priced correctly.

Marketing will be the biggest challenge in a market so competitive.



Did you look what a Siglent scope costs on Ebay? IIRC its about US

$180 including shipping from China. How do you expect to beat that?

BTW Lecroy sells the exact same scope for a lot more.



--

Failure does not prove something is impossible, failure simply

indicates you are not using the right tools...

nico@nctdevpuntnl (punt=.)

--------------------------------------------------------------

it's challenging but not impossible.
I agree...It is very difficult to compete with China, but not impossible if we point on quality.

 

[Joerg]

John Larkin wrote:

On Sun, 10 Mar 2013 10:05:34 -0700, Joerg <invalid@invalid.invalid> wrote:

John Larkin wrote:
On Wed, 06 Mar 2013 14:48:39 -0800, Joerg <invalid@invalid.invalid> wrote:

Jamie wrote:
[...]

I think you'll find if you don't have a latency problem with the
serial link to the chip, you should be able to do all the FMing you
want..

The problem with the uC on these little boards is not the serial link.
Well, at least not if 100Hz sweeps suffice. The problem is that they are
too small to calculate the numbers on the fly and usually have to little
flash left to store them in a LUT. Plus that would be a major
time-consuming hack.
Fancy ramped, modulated DDS sinewave generation at 200K samples/sec would be no
sweat for a $4 ARM, and you get a mux'd ADC and a DAC for free. But yes, it
would take some code slinging.

And I'll probably do that if this becomes a product, with whatever
processor the local SW folks can handle without a major learning curve.
Just not right now, got to watch work load, expenses and time line. So
it'll be analog for now.

If you do go ARM, let me know if you'd like some example C code to butcher. We
have an app that uses an ADC interrupt to do a filtering + PID algorithm, ADC in
to DAC out, on an LPC1754. The algorithm is pretty fancy, and we run it at 100
KHz with the internal uP clock throttled down to 50 MHz. We pay $3.55 each,
pre-programmed by a distributor.

Bring your programmer and we'll go to Zeitgeist and we'll explain our code and
the DDS theory. Your treat, of course.

That sounds good. Although this project would fit much nicer into a
Cypress PSoC because that has lots of useful analog functions in there.
Like S/C filters that can be pressed into service as mixers.

Today I'm writing a PowerBasic program to graph a bunch of thermocouple
temperature controller params vs time. It's slow, graphing coffee cups of hot
water cooling off. Thermal stuff is always tedious.

You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.

I'd try to gauge the thermal effects of foam recombination on an Anchor
Steam OBA. Problem is, with me it won't stay in the glass for too long.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Phil Hobbs]

On 3/10/2013 2:44 PM, John Devereux wrote:

nico@puntnl.niks (Nico Coesel) writes:

Francesco Poderico <francescopoderico@googlemail.com> wrote:

On Sunday, 10 March 2013 00:16:57 UTC, Bruce Varley wrote:
francescopoderico@googlemail.com> wrote in message

news:c1ad2481-696a-4257-8242-a8c92169124b@googlegroups.com...

Hi all,

I've started designing a 200 MSPS Oscilloscope with a 25 MHz analog

bandwidth, 3Ksample/channel buffer.

The oscilloscope can be connected to a PC via USB, and eventually via

Ethernet and WiFi.

The trigger is ( at moment) rising, falling... auto, normal.



I would appreciate suggestions and or comment for possible improvement

and functionality that could make this oscilloscope interesting.



Thanks,

Francesco



Been there done that. Spent many weeks putting together a box that I was

very proud of, then purchased a Rigol that does everything it does plus a

lot more and a lot better. Is this really a good use of your time and

energy?

I get the point... and your are not the first one to tell me that.
but I believe that an oscilloscope is still an instruments a lot of electronic enthusiastic would love to have it if priced correctly.
Marketing will be the biggest challenge in a market so competitive.

Did you look what a Siglent scope costs on Ebay? IIRC its about US
$180 including shipping from China. How do you expect to beat that?
BTW Lecroy sells the exact same scope for a lot more.

I've wanted to make something like a "dynamic signal analyser" that goes
up to 1 or 10 MHz, instead of 100kHz like they all seem to.

You and me both. I'm fond of my HP 35665A, but like the rest it only
goes up to 100 kHz. (It also uses a somewhat wimpy digitizer--13 bits
or something--but a bit of the old HP magic makes it work very well anyway.)

There have been a few FFT spectrum analyzers where you could use the IF
section as poor man's DSA, but it would sure be nice to have all the
features of a real one, at 100 times wider BW. (Of course I'm way too
cheap to actually buy one, unless I had a real genuine customer
requirement.)

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 USA
+1 845 480 2058

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

 

[rickman]

On 3/9/2013 7:23 PM, Joerg wrote:

rickman wrote:
On 3/3/2013 11:56 AM, Joerg wrote:

If one can program them in a reasonaable time frame which I can't (yet).


If I can find an appropriate eval board for an FPGA, I can gen up a
solution that should do everything you need. How much are you willing
to spend? Unfortunately the FPGA boards tend to be a bit more than MCU
boards. Nearly anyone should be able to do this on an MCU board, but
that isn't my forte.


Thanks for the offer, that was nice. But meantime I already did it the
old analog way.

Too bad. Last night when I was reading some of your other posts in this
thread I realized you were looking for a module you could put on your
board. I have a module that would suit your needs with a little
programming of the FPGA. It has a small FPGA, a 24 bit stereo CODEC, op
amps and could do just what you seem to need. The programming would not
be a big deal. The job it was designed for is similar and mostly I
would just need to rearrange the code pieces a bit.

Heck, I have an old sig gen that I need to repair. I just got a Renesas
MCU eval board for free. I'm sure it has the analog I/O needed. I'll
take a look to see if it will do this. When you are done can I get it
back so I don't have to repair my sig gen? I was just starting to take
a look at it today and got called away. Too fine detail and too hard to
get into... damn old eyes!


Tell me about it, I just designed a board full of 0402 parts and I'll
get to debug it later :-(

So, a few months ago I caved in and bought one of those Donegan Optical
head goggle thingies. Took the 5x version because some of my work is now
much finer pitch than 0402. I can keep my reading glasses on while
soldering that. I was at the point where I occasionally wore two reading
glasses stacked.

Yeah, I had a very nice one and someone walked off with it. I really
should break down and get another. They are worth their price. In the
mean time I have gone to using two pair of reading glasses. If I set
them on each other just right they give me three different
magnifications, tri-focals!

BTW, I dug into my sig gen this morning and I don't like what I found.
What I mean by that is I don't understand it. I'll post some details in
the thread I started about it a couple of weeks ago.

--

Rick

 

[Roberto Waltman]

Jeff Liebermann wrote:

6. Presumably, it's dual channel. If so, make it stackable via a
common bus or preferably via ethernet, so that multiple units can be
conglomerated into a 4,6,8, etc channel scope.

From my (rather narrow) point of view, where the main use of an
oscilloscope is in debugging embedded software, this would make it
stand out above the competition.
--
Roberto Waltman

[ Please reply to the group,
return address is invalid ]

 

[Joerg]

rickman wrote:

On 3/9/2013 7:23 PM, Joerg wrote:
rickman wrote:
On 3/3/2013 11:56 AM, Joerg wrote:

If one can program them in a reasonaable time frame which I can't
(yet).


If I can find an appropriate eval board for an FPGA, I can gen up a
solution that should do everything you need. How much are you willing
to spend? Unfortunately the FPGA boards tend to be a bit more than MCU
boards. Nearly anyone should be able to do this on an MCU board, but
that isn't my forte.


Thanks for the offer, that was nice. But meantime I already did it the
old analog way.

Too bad. Last night when I was reading some of your other posts in this
thread I realized you were looking for a module you could put on your
board. I have a module that would suit your needs with a little
programming of the FPGA. It has a small FPGA, a 24 bit stereo CODEC, op
amps and could do just what you seem to need. The programming would not
be a big deal. The job it was designed for is similar and mostly I
would just need to rearrange the code pieces a bit.

Maybe next time. Nico had also offered to built one, which was nice.

Heck, I have an old sig gen that I need to repair. I just got a Renesas
MCU eval board for free. I'm sure it has the analog I/O needed. I'll
take a look to see if it will do this. When you are done can I get it
back so I don't have to repair my sig gen? I was just starting to take
a look at it today and got called away. Too fine detail and too hard to
get into... damn old eyes!


Tell me about it, I just designed a board full of 0402 parts and I'll
get to debug it later :-(

So, a few months ago I caved in and bought one of those Donegan Optical
head goggle thingies. Took the 5x version because some of my work is now
much finer pitch than 0402. I can keep my reading glasses on while
soldering that. I was at the point where I occasionally wore two reading
glasses stacked.

Yeah, I had a very nice one and someone walked off with it. I really
should break down and get another. They are worth their price. In the
mean time I have gone to using two pair of reading glasses. If I set
them on each other just right they give me three different
magnifications, tri-focals!

http://www.mpja.com

Their site is currently not working properly but article numbers 17653TL
and 17654TL would be the head-worn magnifiers. Not very expensive. I'd
tell them not to ship UPS, they crushed the first one by tossing the
package over the backyard fence. The next one came via US mail, because
I insisted.

BTW, I dug into my sig gen this morning and I don't like what I found.
What I mean by that is I don't understand it. I'll post some details in
the thread I started about it a couple of weeks ago.

Hmm, I only remember George Herold's thread about function generators.
What's the subject line of the thread?

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Joerg]

langwadt@fonz.dk wrote:

On Mar 10, 9:14 pm, Joerg <inva...@invalid.invalid> wrote:
John Larkin wrote:
On Sun, 10 Mar 2013 10:05:34 -0700, Joerg <inva...@invalid.invalid> wrote:
John Larkin wrote:
On Wed, 06 Mar 2013 14:48:39 -0800, Joerg <inva...@invalid.invalid> wrote:
Jamie wrote:
[...]
I think you'll find if you don't have a latency problem with the
serial link to the chip, you should be able to do all the FMing you
want..
The problem with the uC on these little boards is not the serial link.
Well, at least not if 100Hz sweeps suffice. The problem is that they are
too small to calculate the numbers on the fly and usually have to little
flash left to store them in a LUT. Plus that would be a major
time-consuming hack.
Fancy ramped, modulated DDS sinewave generation at 200K samples/sec would be no
sweat for a $4 ARM, and you get a mux'd ADC and a DAC for free. But yes, it
would take some code slinging.
And I'll probably do that if this becomes a product, with whatever
processor the local SW folks can handle without a major learning curve.
Just not right now, got to watch work load, expenses and time line. So
it'll be analog for now.
If you do go ARM, let me know if you'd like some example C code to butcher. We
have an app that uses an ADC interrupt to do a filtering + PID algorithm, ADC in
to DAC out, on an LPC1754. The algorithm is pretty fancy, and we run it at 100
KHz with the internal uP clock throttled down to 50 MHz. We pay $3.55 each,
pre-programmed by a distributor.
Bring your programmer and we'll go to Zeitgeist and we'll explain our code and
the DDS theory. Your treat, of course.
That sounds good. Although this project would fit much nicer into a
Cypress PSoC because that has lots of useful analog functions in there.
Like S/C filters that can be pressed into service as mixers.


I just saw the new STM32F3xx, cortexM4 with all the usual interfaces
and up to four opamps/PGAs and seven comparators

That would be nice. But ST is not on my most favored list, mostly
because of their IMHO strongly lacking customer service and screwed up
web site.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[langwadt@fonz.dk]

On Mar 10, 9:14 pm, Joerg <inva...@invalid.invalid> wrote:

John Larkin wrote:
On Sun, 10 Mar 2013 10:05:34 -0700, Joerg <inva...@invalid.invalid> wrote:

John Larkin wrote:
On Wed, 06 Mar 2013 14:48:39 -0800, Joerg <inva...@invalid.invalid> wrote:

Jamie wrote:
[...]

 I think you'll find if you don't have a latency problem with the
serial link to the chip, you should be able to do all the FMing you
want..

The problem with the uC on these little boards is not the serial link.
Well, at least not if 100Hz sweeps suffice. The problem is that they are
too small to calculate the numbers on the fly and usually have to little
flash left to store them in a LUT. Plus that would be a major
time-consuming hack.
Fancy ramped, modulated DDS sinewave generation at 200K samples/sec would be no
sweat for a $4 ARM, and you get a mux'd ADC and a DAC for free. But yes, it
would take some code slinging.

And I'll probably do that if this becomes a product, with whatever
processor the local SW folks can handle without a major learning curve..
Just not right now, got to watch work load, expenses and time line. So
it'll be analog for now.

If you do go ARM, let me know if you'd like some example C code to butcher. We
have an app that uses an ADC interrupt to do a filtering + PID algorithm, ADC in
to DAC out, on an LPC1754. The algorithm is pretty fancy, and we run it at 100
KHz with the internal uP clock throttled down to 50 MHz. We pay $3.55 each,
pre-programmed by a distributor.

Bring your programmer and we'll go to Zeitgeist and we'll explain our code and
the DDS theory. Your treat, of course.

That sounds good. Although this project would fit much nicer into a
Cypress PSoC because that has lots of useful analog functions in there.
Like S/C filters that can be pressed into service as mixers.

I just saw the new STM32F3xx, cortexM4 with all the usual interfaces
and up to four opamps/PGAs and seven comparators

-Lasse

 

[Bill Sloman]

On Mar 11, 8:16 am, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 10 Mar 2013 15:00:24 -0400, Spehro Pefhany









speffS...@interlogDOTyou.knowwhat> wrote:
On Sun, 10 Mar 2013 11:34:49 -0700, the renowned John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.

Pro tip: Remove thermocouple element from Inconel 600 thermowell
before attempting.

http://www.tantaline.com/files/billeder/Thermowell_Series385S.jpg

I wonder what's the temperature of a well-stirred mixture of crushed ice, rum,
and Coke. That deserves further research.

A well-stirred ice bath, made with distilled water and pure ice, sits
at 0C (273.15K) to about +/-0.001K, if the US NBS is to be believed.
Adding anti-freeze is going to make it cooler and less predictable,
and there's a risk that your measurments will become less reliable as
the experiment progresses, not that anybody prepared to drink either
rum or Coke is to be trusted in the first place.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Mar 11, 9:14 am, Joerg <inva...@invalid.invalid> wrote:

John Larkin wrote:
On Sun, 10 Mar 2013 10:05:34 -0700, Joerg <inva...@invalid.invalid> wrote:

John Larkin wrote:
On Wed, 06 Mar 2013 14:48:39 -0800, Joerg <inva...@invalid.invalid> wrote:

Jamie wrote:
[...]

 I think you'll find if you don't have a latency problem with the
serial link to the chip, you should be able to do all the FMing you
want..

The problem with the uC on these little boards is not the serial link.
Well, at least not if 100Hz sweeps suffice. The problem is that they are
too small to calculate the numbers on the fly and usually have to little
flash left to store them in a LUT. Plus that would be a major
time-consuming hack.
Fancy ramped, modulated DDS sinewave generation at 200K samples/sec would be no
sweat for a $4 ARM, and you get a mux'd ADC and a DAC for free. But yes, it
would take some code slinging.

And I'll probably do that if this becomes a product, with whatever
processor the local SW folks can handle without a major learning curve..
Just not right now, got to watch work load, expenses and time line. So
it'll be analog for now.

If you do go ARM, let me know if you'd like some example C code to butcher. We
have an app that uses an ADC interrupt to do a filtering + PID algorithm, ADC in
to DAC out, on an LPC1754. The algorithm is pretty fancy, and we run it at 100
KHz with the internal uP clock throttled down to 50 MHz. We pay $3.55 each,
pre-programmed by a distributor.

Bring your programmer and we'll go to Zeitgeist and we'll explain our code and
the DDS theory. Your treat, of course.

That sounds good. Although this project would fit much nicer into a
Cypress PSoC because that has lots of useful analog functions in there.
Like S/C filters that can be pressed into service as mixers.

Today I'm writing a PowerBasic program to graph a bunch of thermocouple
temperature controller params vs time. It's slow, graphing coffee cups of hot
water cooling off. Thermal stuff is always tedious.

You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.

I'd try to gauge the thermal effects of foam recombination on an Anchor
Steam OBA. Problem is, with me it won't stay in the glass for too long.

Beer foam collapses because the CO2 inside the bubbles diffuses out a
lot faster than O2 and N2 diffuse in - the latter two are much less
soluble in the water film than the CO2.

The thermodynamics might be interesting, but are probably too
dominated by the evaporation of water and ethanol justify any serious
measurement effort.

--
Bill Sloman, Sydney

 

[hamilton]

On 3/10/2013 3:43 PM, Francesco Poderico wrote:

Thanks Roberto,
I'm not sure what do you mean with a stackable oscilloscope, do you mean... e.g. 4 oscilloscopes... 2 channel each that makes a 8 channel oscilloscope?
The only problem I see with that is that between each scope you can have 20 ns max. of time offset.

Wouldn't it be easier to pass the trigger between modules ??

Getting one signal right would be easier then getting 4-8-12 signals right.

My $0.02

 

[Spehro Pefhany]

On Sun, 10 Mar 2013 12:16:50 -0700, the renowned John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 10 Mar 2013 15:00:24 -0400, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Sun, 10 Mar 2013 11:34:49 -0700, the renowned John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:


You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.


Pro tip: Remove thermocouple element from Inconel 600 thermowell
before attempting.

http://www.tantaline.com/files/billeder/Thermowell_Series385S.jpg



I wonder what's the temperature of a well-stirred mixture of crushed ice, rum,
and Coke. That deserves further research.

With a Type K thermocouple immersed in a similar ice-liquid mixture, I
get close to 0°C, but the experiment needs to be repeated with better
instrumentation.

http://www.speff.com/Dalwhinnie_test.jpg


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Michael A. Terrell]

Nico Coesel wrote:

An 8051 compares to ARM like a model T Ford compares to a Volkswagen
Golf / Rabbit. IMHO finding a second source for parts is becoming more
and more impossible. Just like the XR2206 8051 microcontrollers may
become extinct real soon as well.

And the sun will go nova tomorrow.

 

[Phil Hobbs]

On 3/10/2013 6:10 PM, Spehro Pefhany wrote:

On Sun, 10 Mar 2013 12:16:50 -0700, the renowned John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 10 Mar 2013 15:00:24 -0400, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Sun, 10 Mar 2013 11:34:49 -0700, the renowned John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:


You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.


Pro tip: Remove thermocouple element from Inconel 600 thermowell
before attempting.

http://www.tantaline.com/files/billeder/Thermowell_Series385S.jpg



I wonder what's the temperature of a well-stirred mixture of crushed ice, rum,
and Coke. That deserves further research.

With a Type K thermocouple immersed in a similar ice-liquid mixture, I
get close to 0°C, but the experiment needs to be repeated with better
instrumentation.

http://www.speff.com/Dalwhinnie_test.jpg

And of course repeated many times to get better statistics.

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 USA
+1 845 480 2058

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

 

[Francesco Poderico]

On Sunday, 10 March 2013 21:25:43 UTC, Roberto Waltman wrote:

Jeff Liebermann wrote:

6. Presumably, it's dual channel. If so, make it stackable via a

common bus or preferably via ethernet, so that multiple units can be

conglomerated into a 4,6,8, etc channel scope.



From my (rather narrow) point of view, where the main use of an

oscilloscope is in debugging embedded software, this would make it

stand out above the competition.

--

Roberto Waltman



[ Please reply to the group,

return address is invalid ]

Thanks Roberto,
I'm not sure what do you mean with a stackable oscilloscope, do you mean... e.g. 4 oscilloscopes... 2 channel each that makes a 8 channel oscilloscope?
The only problem I see with that is that between each scope you can have 20 ns max. of time offset.

 

[Roberto Waltman]

Francesco Poderico wrote:

Roberto Waltman wrote:
Jeff Liebermann wrote:

6. ... so that multiple units can be
conglomerated into a 4,6,8, etc channel scope.

... this would make it
stand out above the competition.

I'm not sure what do you mean with a stackable oscilloscope, do you mean... e.g. 4 oscilloscopes... 2 channel each that makes a 8 channel oscilloscope?
That is what I understood from Jeff's post.

The only problem I see with that is that between each scope you can have 20 ns max. of time offset.
That could be unacceptable in some scenarios, and not important at all

in others. May be you can add a common clock or some other HW trick to
synchronize several units?
--
Roberto Waltman

[ Please reply to the group,
return address is invalid ]

 

[John Larkin]

On Sun, 10 Mar 2013 13:39:34 -0700 (PDT), Bill Sloman <bill.sloman@ieee.org>
wrote:

On Mar 11, 8:16 am, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 10 Mar 2013 15:00:24 -0400, Spehro Pefhany









speffS...@interlogDOTyou.knowwhat> wrote:
On Sun, 10 Mar 2013 11:34:49 -0700, the renowned John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.

Pro tip: Remove thermocouple element from Inconel 600 thermowell
before attempting.

http://www.tantaline.com/files/billeder/Thermowell_Series385S.jpg

I wonder what's the temperature of a well-stirred mixture of crushed ice, rum,
and Coke. That deserves further research.

A well-stirred ice bath, made with distilled water and pure ice, sits
at 0C (273.15K) to about +/-0.001K, if the US NBS is to be believed.
Adding anti-freeze is going to make it cooler and less predictable,
and there's a risk that your measurments will become less reliable as
the experiment progresses, not that anybody prepared to drink either
rum or Coke is to be trusted in the first place.

Try some Ron Zacapa 23, straight of course. It makes cognac obsolete.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[Nico Coesel]

Francesco Poderico <francescopoderico@googlemail.com> wrote:

On Sunday, 10 March 2013 21:25:43 UTC, Roberto Waltman wrote:
Jeff Liebermann wrote:

6. Presumably, it's dual channel. If so, make it stackable via a

common bus or preferably via ethernet, so that multiple units can be

conglomerated into a 4,6,8, etc channel scope.



From my (rather narrow) point of view, where the main use of an

oscilloscope is in debugging embedded software, this would make it

stand out above the competition.

return address is invalid ]

Thanks Roberto,
I'm not sure what do you mean with a stackable oscilloscope, do you mean... e.g. 4 oscilloscopes... 2 channel each that makes a 8 channel oscilloscope?
The only problem I see with that is that between each scope you can have 20 ns max. of time offset.

If you distribute the trigger and use a global reference clock to
which all the ADCs are synchronised it will work. At least that is how
I planned it for my own USB scope design about 9 years ago. But then
Rigol emerged so I stopped the project.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

 

[Tim Williams]

"Nico Coesel" <nico@puntnl.niks> wrote in message
news:513d21d9.4118857421@news.kpn.nl...

If you distribute the trigger and use a global reference clock to
which all the ADCs are synchronised it will work. At least that is how
I planned it for my own USB scope design about 9 years ago. But then
Rigol emerged so I stopped the project.

You still have the propagation delay of the clock (and trigger if shared)
cascading between modules. You could characterize each unit's delay and
adjust in the DLL, perhaps, or perform a round-trip self-calibration, or
ask the user to run a BNC cable from the "probe test" connector on the
master unit down to each successive input; assuming the cable remains
constant during the test, this would allow the inputs to be adjusted for
zero time difference.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://seventransistorlabs.com

 

[langwadt@fonz.dk]

On Mar 10, 11:54 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 10 Mar 2013 13:39:34 -0700 (PDT), Bill Sloman <bill.slo...@ieee.org
wrote:









On Mar 11, 8:16 am, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 10 Mar 2013 15:00:24 -0400, Spehro Pefhany

speffS...@interlogDOTyou.knowwhat> wrote:
On Sun, 10 Mar 2013 11:34:49 -0700, the renowned John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

You can keep a thermocouple to within a tenth degree of 25C by holding the lead
in your mouth, roughly 6" from the junction, sliding it a bit left or right to
keep the temp on target, varying the thermal conduction. You can even do it
hands-off with a bit of practice.

Pro tip: Remove thermocouple element from Inconel 600 thermowell
before attempting.

http://www.tantaline.com/files/billeder/Thermowell_Series385S.jpg

I wonder what's the temperature of a well-stirred mixture of crushed ice, rum,
and Coke. That deserves further research.

A well-stirred ice bath, made with distilled water and pure ice, sits
at 0C (273.15K) to about +/-0.001K, if the US NBS is to be believed.
Adding anti-freeze is going to make it cooler and less predictable,
and there's a risk that your measurments will become less reliable as
the experiment progresses, not that anybody prepared to drink either
rum or Coke is to be trusted in the first place.

Try some Ron Zacapa 23, straight of course. It makes cognac obsolete.

Indeed, I've always hated rum, especially rum and coke
then I tried a Ron Zacapa and that is damn nice


-Lasse