Driver to drive?

Jan Panteltje · Nov 17, 2014

On a sunny day (Sun, 16 Nov 2014 17:29:05 -0800) it happened John Larkin
<jlarkin@highlandtechnology.com> wrote in
<ehii6ah50jlugm6298o2n3dp5kba22c8hk@4ax.com>:

This is awful:

http://www.analog.com/static/imported-files/data_sheets/ADCMP567.pdf

It's still Rev 0, from 2003.

The only associated appnote is from 1989!

Yes, I recently (or not so recently) had very bad plans for the AD datasheet
writer...
Probably good enough for a war ciminal trial.

After reading their datasheet about 10 or more times,
and trying their example that made no sense to me,
but thinking 'I must be missing sometthing so let me try this,
but it makes no sense whatsover' I dumped their idea and did it my way.
My way works better, is simpler too.

Then the next chip, that fractional 2.4 GHz divider / oscillator where their
PLL design software did not run... in Linux wine.
Probably the same app writer

Maybe I will still try that chip, ADF4360-1.pdf,
anybody used it? Any good?

--

John Larkin Highland Technology, Inc
picosecond timing laser drivers and controllers

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

Nov 17, 2014

If they actually squatted, they should not win the case. No disagreement there. Now if they stopped paying rent because the roof caved in or something...

And some people are that much of an asshole to sue in a case like that.

Nov 17, 2014

On Monday, November 17, 2014 8:13:27 AM UTC-8, jurb...@gmail.com wrote:

If they actually squatted, they should not win the case. No disagreement there. Now if they stopped paying rent because the roof caved in or something...

In my case, the root leaked for one day, did not cave in. I spent thousands to repair it afterward. But he seems entitled to living free forever because it leaked one day. It never leaked again. This is just an excuse, if not for this, there are others. He even stated in his answer that he is withholding rent because there are missing shelfs in the fridge. Any sane judge would see that he is just gaming the system.

> And some people are that much of an asshole to sue in a case like that.

I am pretty sure to get a net judgment against the defendant, but probably unable to collect from the deadbeat. I am angry at the court to allow such non-sense. After the eviction, will take it to the federal court to sue the state.

RobertMacy · Nov 17, 2014

On Sun, 16 Nov 2014 15:31:16 -0700, Clifford Heath <no.spam@please.net>
wrote:

On 17/11/14 08:22, RobertMacy wrote:
but you still haven't posted schematic or models ? Everybody could help
a lot more given that and the Rx field assumptions etc.

Robert, the original post has both the LTSpice file and the model.

thanks, Wow. did I MISS that! luckily this browser will open a thread of
deleted emails, bringing all back into existance.

Was the Rx field strength assumed to be 60uA/m ??? In Tesla isn't that
epsilon*A? so that would be 75.4 pT
earth's magnetic field noise is less than 0.1pT/rtHz in that range so even
with a BW of 10Hz should be fine, except for noise from manmade sources.

for what it's worth, a 100T 2 inch diameter coil inside our electronics
lab had a 'measured' noise floor of around 56pVrms/rtHz.

in a field of 75pT at 60kHz that coil would generate 5.7uV!! more than
enough! and this was broadband reception, too. And way above background
noise in a 'standard' lab. uh, ok, all 'old' monitors turned off in the
room. The tones from Tektronix scope's SMPS's showed up, but you can work
around them.

checking numbers
ev = N*B*2pif*Area:
100*75e-12*2*pi()*60000*(pi()*.0254*.0254) = 5.7uV

Did I miss something here? This was NOT even a 'tuned' coil, simply 100
turns made up on FR4 six layer PCB, we're talking veyr poor Q.

Seems there is oodles of margins to work with.

Is that field assumption too high?

From memory the 'preamp' was simply a fixed gain of 50 using an ?? the
whole Rx circuit ate 2mA at 3.3Vdc, but this was a broadband preamp
operating DC to 100kHz...no tuned coil. Using a tuned coil and FET
follower should yield beaucoup volts!

Q of 90 and only a buffer means around 50uV, that's enough to operate an
accumulator function straight in and make a decision as to what's going
on. Aren't most ADC's in the audio range exhibit less than 10-20nV/rtHz
input noise?

Nov 17, 2014

Well, My NDA expired on the subject from 6 years ago. 400-1000 Watt Co2 in a inert atmosphere. Fiber lasers can be used with some metals.

The trick is not the laser, its the specialized lensing.

Steve

Jolly Roger · Nov 17, 2014

On 2014-11-17, David Howard <dshoward@microsoft.com> wrote:

On Sun, 16 Nov 2014 05:23:09 +0000, Jolly Roger wrote:

You'd have to be pretty naive to think that all of them are unnamed.

Let's just re-iterate your point and mine.

You already tried and failed to do that once. No need to repeat
yourself.

--
E-mail sent to this address may be devoured by my ravenous SPAM filter.
I often ignore posts from Google. Use a real news client instead.

JR

Jim Thompson · Nov 17, 2014

On Sun, 16 Nov 2014 17:29:05 -0800, John Larkin
<jlarkin@highlandtechnology.com> wrote:

This is awful:

http://www.analog.com/static/imported-files/data_sheets/ADCMP567.pdf

It's still Rev 0, from 2003.

The only associated appnote is from 1989!

John Larkin · Nov 17, 2014

On Mon, 17 Nov 2014 08:49:58 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sun, 16 Nov 2014 17:29:05 -0800, John Larkin
jlarkin@highlandtechnology.com> wrote:

This is awful:

http://www.analog.com/static/imported-files/data_sheets/ADCMP567.pdf

It's still Rev 0, from 2003.

The only associated appnote is from 1989!

What's to understand? Looks to be simply a modernized version of my
1960's design "MC1650/51 High Speed Comparators", PDF on the home page
of my website.

...Jim Thompson

Gosh, did you invent the comparator?

--

John Larkin Highland Technology, Inc
picosecond timing laser drivers and controllers

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

Phil Hobbs · Nov 17, 2014

On 11/16/2014 01:54 PM, John Larkin wrote:

On Sun, 16 Nov 2014 08:14:11 -0800, Joerg <news@analogconsultants.com
wrote:

rickman wrote:
On 11/4/2014 6:29 PM, rickman wrote:
I am working on a project for receiving a very narrow bandwidth signal
at 60 kHz. One of the design goals is to keep the power consumption to
an absolute minimum. I'm trying to figure out how to run a
pre-amplifier on less than 100 uW. So far I have found nothing. Any
suggestions?

I had found one op amp that might get me in the ballpark of power
consumption and I did some spice simulation on it. The current ends up
being in the 50 uA range which is more than I would like and the gain is
only around 100 before the bandwidth limits are felt which is less than
I would like. At 50 uA there is not the power to add a second stage.

Instead I was looking at some JFETs and found one I like, BF862 made by
NXP. I can construct a stage that gives a gain of 40 dB at only a
handful of uA. But when I try to cascade a second stage I have trouble.

The input capacitance is stated in the data sheet to be in the range of
10 pF. If I add a 10 pF cap to the output of the first stage I get
close to 40 dB of gain at the frequency of interest, 60 kHz. But when a
second stage is added with capacitive coupling the gain of the first
stage drops to 19 dB at 60 kHz while maintaining 40 dB at 1 kHz.

You need a FET with an input capacitance an order of magnitude lower.
Got to run now and can't find it so quickly but ask John Larkin. He
suggested a FET a while ago that is IIRC under 1pF.

NE3509 maybe... a bit under 1 pF. Phemts have high 1/f noise corners,
so I don't know how well they might work at 60 KHz and low current.
Phil probably has lf noise data on a Skyworks part.

The key to low-noise, low-power gain in narrowband amps is proper
input network tuning. A tuned circuit makes voltage gain for zero
power consumption. Ditto interstage coupling. This problem may not
actually need a super-low-capacitance part.

My data are pretty limited--a few examples of the SKY65050 had flatband
1-Hz noise of about 0.4 nV and a 1/f corner of about 50 MHz. (!)

The Avago ATF38143s I tested were quieter, 0.35 nV and 10 MHz, which is
still pretty high--JFETs usually come in at about 1 kHz and good
bipolars, 10 Hz.

Besides the 1/f noise, the main down side of pHEMTs is that they have
pathetically low drain impedances, down in the hundreds of ohms. That
makes them useless for followers, for instance, and seriously limits the
voltage gain you can get out of them. Cascoding them helps a lot.

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

Jim Thompson · Nov 17, 2014

On Mon, 17 Nov 2014 07:53:52 -0800, John Larkin
<jlarkin@highlandtechnology.com> wrote:

On Mon, 17 Nov 2014 08:49:58 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sun, 16 Nov 2014 17:29:05 -0800, John Larkin
jlarkin@highlandtechnology.com> wrote:

This is awful:

http://www.analog.com/static/imported-files/data_sheets/ADCMP567.pdf

It's still Rev 0, from 2003.

The only associated appnote is from 1989!

What's to understand? Looks to be simply a modernized version of my
1960's design "MC1650/51 High Speed Comparators", PDF on the home page
of my website.

...Jim Thompson

Gosh, did you invent the comparator?

Tim Wescott · Nov 17, 2014

On Sun, 16 Nov 2014 21:45:14 -0800, Jamie M wrote:

Hi,

Here is an upcoming metal 3D printer that uses a laser for melting metal
powder layer by layer:

http://techcrunch.com/2014/07/18/matterfab/

Any idea on what type or even part# of laser this uses? There are a
couple spots in the video with a close up of it, 5minutes in.

I suspect CO2. I think that's mostly what's used for cutting metal &
such, because it's easy & powerful.

--
www.wescottdesign.com

whit3rd · Nov 17, 2014

On Sunday, November 16, 2014 5:01:35 PM UTC-8, rickman wrote:

On 11/16/2014 5:47 PM, whit3rd wrote:
On Saturday, November 15, 2014 7:18:17 PM UTC-8, rickman wrote:
On 11/4/2014 6:29 PM, rickman wrote:
I am working on a project for receiving a very narrow bandwidth signal
at 60 kHz [and] keep the power consumption to
an absolute minimum

How about a programmable-bias-current op amp? LM4250 is easily
available, there used to be lots of others. OTAs like LM13700 have similar
low-power specifications, with the additional feature that output loads
don't change the power requirement.

The LM4250 has too low a GBP to work at 60 kHz. The max GBW is about
300 kHz and the setting I would need brings it closer to 60,000 kHz
where it would have a gain of about 1.

Not completely relevant; remember, an amplifier performs three functions,
and voltage gain is only one. The other two, power gain (because the output
impedance is lower than input impedance) and input/output isolation,
are enough to make this chip useful. There have been suggestions
already to use positive-feedback circuitry, and isolation REALLY helps
there.

I don't know much about OTAs in general and the LM13700 specifically.
It has a 2 MHz open loop bandwidth so that might work if I limit the
gain. I don't see much on power consumption and I only see mention of
ą15 volt supplies. Doesn't sound good.

LM13700 OTAs are good down to 4V or so, and current draw is under three times
the program current (fully specified, down to 3 uA). More important, the
OTA multiplies the differential input signal by the program current; it's
also a MIXER, not just another amplifier. Don't read too much into the
'open loop bandwidth' number, that depends too much on external
loading (you can push it up or down with output load choices). Older
datasheets mentioned '50V/us' typical output swing, which was also
nearly meaningless.

Nov 18, 2014

On Monday, November 17, 2014 10:21:20 PM UTC, rickman wrote:

On 11/17/2014 4:56 PM, whit3rd wrote:
On Sunday, November 16, 2014 5:01:35 PM UTC-8, rickman wrote:

The LM4250 has too low a GBP to work at 60 kHz. The max GBW is about
300 kHz and the setting I would need brings it closer to 60,000 kHz
where it would have a gain of about 1.

Not completely relevant; remember, an amplifier performs three functions,
and voltage gain is only one. The other two, power gain (because the output
impedance is lower than input impedance) and input/output isolation,
are enough to make this chip useful. There have been suggestions
already to use positive-feedback circuitry, and isolation REALLY helps
there.

I usually can figure out what people mean when they post something new
to me. But I can't grasp how an amp with a gain of 1 would be able to
do anything useful for positive feedback. But maybe I'm just not
getting it.

For pfb to generate high q the amp's output can be just 1x the power of the input. Whit3rd was suggesting IIUC that Vgain=1 Pgain>1 could do this - indeed it can.

NT

Nov 18, 2014

On the systems I saw, beam positioning was galvanometer scanner based with a F-Theta lens for focal plane correction. The object to be made sat in a tank of argon, and a metal dust tornado" was swirled around the object to be sintered.
The lab I was in was making turbine blade prototypes from high temperature materials. As well as other rapid prototypes. These were later annealed in some fashion to become "single Crystal" metals. After SLS, they went into a conventional oven to consolidate the sintering before further treatment. No oxygen is allowed in, for obvious reasons.

I worked in a university laser lab at the time. We were given their castoffs as worn but usable gear when they upgraded to better lasers. It kept us running another two years. Most fun I ever had loading a truck. As a treat(ment) I was given a tour of the SLS labs on site.

Syd,
Flame spraying is used for very course deposition, and usually a plasma torch running inert gas is the source these days. Flam spraying is usually for placing a hardening layer on a structural object or for building back up worn spots on a shaft. It is very crude, resolution wise, and the target

Nov 18, 2014

>"He even stated in his answer that he is withholding rent because there are >missing shelfs in the fridge. "

You might not believe this, but after he moves out I would make a very concerted effort to find out where he went and make damn sure he has a run of very bad luck.

In fact, however he gets to court or the mailbox, it has pneumatic tires no ?

Other people don't s it that way, oh revenge is bad and all this shit, but I call it helping karma along. Seriously, when I gt into discussions over people killing thugs who try to rob them and they say "judge, jury and executionaer" I say "Damn right !, and it should happen EVERY TIME until motherfuckers get the idea to be straight uip with people, or are all dead.

When people get like that, I consider them animals.

George Herold · Nov 18, 2014

On Monday, November 17, 2014 12:45:19 AM UTC-5, Jamie M wrote:

Hi,

Here is an upcoming metal 3D printer that uses a laser for melting
metal powder layer by layer:

http://techcrunch.com/2014/07/18/matterfab/

Any idea on what type or even part# of laser this uses? There are a
couple spots in the video with a close up of it, 5minutes in.

cheers,
Jamie

Having no idea, I would guess a diode laser. I think you want a really small spot size. A lot of heat in a small volume and something has to melt.

George H.

Syd Rumpo · Nov 18, 2014

On 17/11/2014 18:39, sroberts6328@gmail.com wrote:

Well, My NDA expired on the subject from 6 years ago. 400-1000 Watt Co2 in a inert atmosphere. Fiber lasers can be used with some metals.

The trick is not the laser, its the specialized lensing.

Steve

Would it be possible to use a small flame? Much cruder and slower, I
suppose, but probably cheaper. Just musing. How small can you make
ox-acetylene anyway? Or CO and O2 perhaps to avoid making water.

Cheers
--
Syd

Nov 18, 2014

On Monday, November 17, 2014 3:54:59 PM UTC-8, jurb...@gmail.com wrote:

"He even stated in his answer that he is withholding rent because there are >missing shelfs in the fridge. "

You might not believe this, but after he moves out I would make a very concerted effort to find out where he went and make damn sure he has a run of very bad luck.

In fact, however he gets to court or the mailbox, it has pneumatic tires no ?

Other people don't s it that way, oh revenge is bad and all this shit, but I call it helping karma along. Seriously, when I gt into discussions over people killing thugs who try to rob them and they say "judge, jury and executionaer" I say "Damn right !, and it should happen EVERY TIME until motherfuckers get the idea to be straight uip with people, or are all dead.

When people get like that, I consider them animals.

I would not do anything stupid. I have more to lose than he does. But i would do everything i can legally to get at him, and the Stupid Court. Without the In-Justice Court harbouring such deadbeat, it would not turn out this way. I expect the Nevada State Supreme Court to reject my claim, then i start over in federal court.

He will have cases filed against him in Justice Court, District Court and Federal Court. Regardless of outcome, no future sane landlord will touch him.

rickman · Nov 18, 2014

On 11/17/2014 1:39 PM, sroberts6328@gmail.com wrote:

Well, My NDA expired on the subject from 6 years ago. 400-1000 Watt Co2 in a inert atmosphere. Fiber lasers can be used with some metals.

The trick is not the laser, its the specialized lensing.

I haven't looked at the video. I assume the beam is invisible as CO2
lasers work in the infrared range.

--

Rick

rickman · Nov 18, 2014

On 11/17/2014 7:53 AM, RobertMacy wrote:

On Sun, 16 Nov 2014 15:31:16 -0700, Clifford Heath <no.spam@please.net
wrote:

On 17/11/14 08:22, RobertMacy wrote:
but you still haven't posted schematic or models ? Everybody could help
a lot more given that and the Rx field assumptions etc.

Robert, the original post has both the LTSpice file and the model.

thanks, Wow. did I MISS that! luckily this browser will open a thread of
deleted emails, bringing all back into existance.

Was the Rx field strength assumed to be 60uA/m ??? In Tesla isn't that
epsilon*A? so that would be 75.4 pT
earth's magnetic field noise is less than 0.1pT/rtHz in that range so
even with a BW of 10Hz should be fine, except for noise from manmade
sources.

Got it in one! Everything I have read says man made sources are the
problem. Another reason to use a loop antenna as the null can be
pointed to the noise source if you can identify it... and there is just
one.

for what it's worth, a 100T 2 inch diameter coil inside our electronics
lab had a 'measured' noise floor of around 56pVrms/rtHz.

in a field of 75pT at 60kHz that coil would generate 5.7uV!! more than
enough! and this was broadband reception, too. And way above background
noise in a 'standard' lab. uh, ok, all 'old' monitors turned off in the
room. The tones from Tektronix scope's SMPS's showed up, but you can
work around them.

checking numbers
ev = N*B*2pif*Area:
100*75e-12*2*pi()*60000*(pi()*.0254*.0254) = 5.7uV

Some of your short hand escapes me but I think 100T is 100 turns? I
used the following formula and started with 100 uV/m field strength.
The 100 uV/m is the approx value for WWVB given for Gaithersburg, MD
which is not far from my location and also not far from the worst case
reception for CONUS.

V = (2 * pi * A * N * E * cos(theta)) / lambda

Using your numbers I get 25.5 uV which is about the same as the result
from my coil... after tuning.

Your coil though is not electrostatically shielded. The reading I have
done indicates the noise sources generate a more significant E field
which can be shielded. So my starting point was a shielded antenna.
Boosting the signal is just one part of the problem. Digging the signal
out of the noise is the other. I supposed it could be shielded easily
enough. If I go with a small coil with more turns I would use a ferrite
core. With a two inch diameter that would be a lot of ferrite.

Did I miss something here? This was NOT even a 'tuned' coil, simply 100
turns made up on FR4 six layer PCB, we're talking veyr poor Q.

Seems there is oodles of margins to work with.

Why is a few uV "oodles of margin"?

Is that field assumption too high?

From memory the 'preamp' was simply a fixed gain of 50 using an ?? the
whole Rx circuit ate 2mA at 3.3Vdc, but this was a broadband preamp
operating DC to 100kHz...no tuned coil. Using a tuned coil and FET
follower should yield beaucoup volts!

Not looking for beaucoup volts. I'm looking for a low power consumption
and enough volts. How would a follower give voltage gain? I have only
seen followers in a current amplification stage with no voltage gain.

Q of 90 and only a buffer means around 50uV, that's enough to operate an
accumulator function straight in and make a decision as to what's going
on. Aren't most ADC's in the audio range exhibit less than 10-20nV/rtHz
input noise?

What? How do you get 50 uV into an accumulator? Using an ADC at 240
kSPS would totally blow the power budget.

My concept is to get the signal level high enough that it can make a
statistical difference in the state of the input. With the huge
processing gain from a very narrow bandpass filter I expect to see
several 10's of dB improvement in SNR. Rather like the way they recover
a direct sequence spread spectrum signal or more accurately very much
like a lock-in amplifier.

But I have started to doubt the ability of this circuit to work behind
the digital input on the chip. If the signal and noise are too small to
overcome any latent hysteresis in the input circuit there might be no
signal to improve. I was just trying to explore the possibility of
adding a low power consumption amplifier. As usual many people take the
discussion on many tangents. That is how I learn.

--

Rick

Driver to drive?

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