Driver to drive?

[Klaus Vestergaard Kragelu]

"Anders F" <af-spam@hi5.dk> wrote in message
news:2urkdaF2bqlusU1@uni-berlin.de...

"Joel Kolstad" <JKolstad71HatesSpam@Yahoo.Com> wrote in message
Interesting... at Tek they spend a LOT of time (literally man-months,
maybe
even years!) worrying about things like menu layout. This might be a
case
of where 'design by committee' ends up being less user-friendly than if
just
one or a few engineers had gotten together to do the design.

I find that kind of hard to believe! Not that I think the menus are bad -
'cause they are not. But my TDS3032 have definitely not been tested by
real
people. The lag when pushing the rubbery (with poor tactile feedback)
buttons is unbearable. Every time I haven't used it for a while I keep
pressing them twice.
Besides that it's a great scope!

/Anders

PS: I /think/ they fixed it in the B versions...
PPS: The FFT key is also vastly expensive (FFT is not that hard to do is
it
;-) - one actually thinks about hacking it ;-)

The TDS22x and the one I tested TPS20xx has fast menues. BUT - often
pressing a key just changes the text next to the key. So if one presses too
fast one misses the wanted menu point and have to try again. The TDS3000
series has most of the times a round-robin menu. So due to the increased
screen resolution one can see what the next menu-point is if the button is
pressed

Cheers

Klaus

>

 

[Joel Kolstad]

"Anders F" <af-spam@hi5.dk> wrote in message
news:2urkdaF2bqlusU1@uni-berlin.de...

I find that kind of hard to believe! Not that I think the menus are bad -
'cause they are not. But my TDS3032 have definitely not been tested by
real
people. The lag when pushing the rubbery (with poor tactile feedback)
buttons is unbearable.

The requirements list probably went something like this:

Keys respond in <250ms: Must have
Key respond in <25ms: Would be nice

I'm just making up the numbers here, but I've seen more than one
manufacturer where it seems clear the 'keys respond more or less
instantaneously' requirement was deemed very much to be in the 'would be
nie' category rather than requisite. Strange (to me) but true.

Tek typically does field test most if not all of their products before
releasing them to the general public. In fact my understanding is that the
new(er) management has made it more of a priority than in prior years.

PS: I /think/ they fixed it in the B versions...

That's good to hear!

PPS: The FFT key is also vastly expensive (FFT is not that hard to do is
it
;-) - one actually thinks about hacking it ;-)

As you're probably aware, all the software to do everything the scope can do
is already in the scope -- the various purchasable options merely enable its
usage. I have no idea how sophisticated their authetication scheme is
though.

---Joel

 

[Rich Grise]

On Wed, 03 Nov 2004 08:48:28 +0000, Scott Stephens wrote:

xray wrote:

I think during their lifetimes all the religious leaders had pretty much
the same message. Now we are dealing with hundreds or thousands of years
of interpretation.

Not really. Checkout
http://www.wunderland.com/WTS/Ginohn/cetera/hankisms.html

Crude, amusing, sad but true. We need some new isms. Or some more brains
and soul to figure out some better isms.

Spooky! Look at the first one:

"Ancient Judaism - If you are nice to one of Hank's close personal
friends, they will kiss Hank's ass for you, and you'll get some money
right away. If you get the shit kicked out of you instead, it's your
own damn fault. Keep trying."

You could replace "Judaism" with "Cheneyism" or "Rovism" and it wouldn't
change the meaning a bit.

I think I like this guy's 'tude. ;-)

Cheers!
Rich

 

[Rich Grise]

On Wed, 03 Nov 2004 08:48:28 +0000, Scott Stephens wrote:

xray wrote:

I think during their lifetimes all the religious leaders had pretty much
the same message. Now we are dealing with hundreds or thousands of years
of interpretation.

Not really. Checkout
http://www.wunderland.com/WTS/Ginohn/cetera/hankisms.html

Crude, amusing, sad but true. We need some new isms. Or some more brains
and soul to figure out some better isms.

Man, that guy's thorough! When I got to "SubGenius," I almost split
a gut!

http://www.subgenius.com/

And, interestingly, I'm a Slacker!

Cheers!
Rich

 

[Rich Grise]

On Wed, 03 Nov 2004 08:52:05 +0000, Scott Stephens wrote:

Rich Grise wrote:

On Wed, 03 Nov 2004 01:19:23 +0000, Scott Stephens wrote:

Would you complain as vehemently if Clinton used force in his policy of
regime change, rather than merely advocating it?


I don't care who, or what his idology is.

Some of us discriminate about whos sins we condemn for ulterior purposes.

Using force to override another
person's will is evil. It's that simple.

Its not that simple. What about overriding the will of children?

That's the most insidious evil of all, perpetrated, of course, in
the name of "god".

The
criminally insane?

Who defines "criminally insane?" These days, apparently, the punishment
for the criminally insane is to elect them to office.

You have a very simplistic outlook that indicates you
don't understand the complexity of the world you live in. That is a bad
thing.

If you say so.

Did you bitch and moan
about Clinton's Jihad in Serbia?

I wasn't paying any attention.

Because you find the sins of hippy-bashing Repugs more offensive than
the sins of socialist, communist and even national-socialist (fascist)
Democrats? At least bash them some of the time.

No, I had other things going on in my immediate sphere of influence
than agonizing about who the politicos were killing that week.

Are you being a good little hippie and stopped using your petro-dollars,
burning gasoline, and smoking imported weed that fuels our fascist
military-industrial complex?


When did I ever claim to be a "good little hippie?"

I think peacenicks should refrain from burning or using petroleum
products, which means they should be living like Amish, to not be
hypocrites.

Well, OK, that's what you think "they" "should" do.

Well, I'm not going to live by your limitations, and if you want
to force me to, you're going to have to have the courage to come
over here and physically use force on me. That's the way your
religion works, isn't it? You're gonna save their souls if you
have to burn them at the stake?

Our culture is based on technology, and that technology is mostly
powered by petroleum, and half of that (IIRC) is coming from the middle
east, which is why our countrymen are being wounded and killed there,
and not in Africa or Antarctica. Let the Democrats run energy policy and
see what happens. They just complain because they can't and wont do
anything better or different.

I see Alaska passed a pot referendum! I'll bet some good weed is going
to be growing their soon. I hear its a great place to vacation. Big fish
in all the rivers. Beautiful countryside.

And so, in your little speech here, you have completely evaded my
question as to when I ever claimed to be a "good little hippy."

But you didn't pass up the opportunity to spew forth your personal
ideology, did you?

Thanks for another demonstration of how clockwork dupes operate.

Cheers!
Rich

 

[John Larkin]

On Wed, 03 Nov 2004 17:34:24 GMT, Rich Grise <rich@example.net> wrote:

Using force to override another
person's will is evil. It's that simple.

Its not that simple. What about overriding the will of children?

That's the most insidious evil of all, perpetrated, of course, in
the name of "god".

I overrode the will of my children to protect them, civilize them, and
because I love them. To do less would be evil.

John

 

[Rich Grise]

On Wed, 03 Nov 2004 12:56:43 +0000, Kevin Aylward wrote:
[about FET current sources]

Vt\Vp can vary several hundred percent so this one off batch means
nothing. You can expect huge variations. Your "design" is an accident
waiting to happen.

So, in other words, are you saying, as was I, that coming off the

line, even with care in the production process, there is still so much
variation in the cutoff current that makes it such that you'd have
to individually test each unit? (which, of course, jacks the price
up a bunch)

Thanks,
Rich

 

[Ken Smith]

In article <j1vdo0lamg06fkhruiv8tup4l1ndc34h11@4ax.com>,
Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote:
[...]

Of course this is about as useful a statistic as the one that the
average human has one breast and one testicle.

What got me was that no-one quoting it seemed to notice that it wasn't
posible.

Most people have more than the average number of arms.

--
--
kensmith@rahul.net forging knowledge

 

[Ken Smith]

In article <lhqdo05hcapn7te2icbciu0trnagu9v7kh@4ax.com>,
John Larkin <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote:

On Mon, 1 Nov 2004 21:57:23 +0000 (UTC), kensmith@green.rahul.net (Ken
Smith) wrote:

In article <sk0do09pe0qn0o00rihkj3p8dhnenf0uu6@4ax.com>,
John Larkin <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:
[...]
Without meaning to offend, I have noticed that more liberal people
tend to be innumerate. Something in my brain just automatically
sanity-checks any numbers I see (habit developed from engineering, of
course) and I'm astounded by how much of the stuff in the press makes
no sense, orders of magnitude off from reality. I guess they don't
teach much math in journalism school.

Some years back there was one "statistic" that was widely reported that
just floored me. They claimed that straight men had on the average twice
as many sex partners as straight women. A lot of people repeated that
without realizing that it simply can't be true.


Of course it can be true.

Are you counting sheep or something?

--
--
kensmith@rahul.net forging knowledge

 

[Ken Smith]

In article <7316f5e2.0411030846.24782fd6@posting.google.com>,
Alessandro Convertino <convertino@deemail.poliba.it> wrote:

Hi to all,
I would like to know some informations about bandpass filtering on
frequency range between 0.05-30 Hz. In the past I've used a Sallen-key
active filter, and I would like to find a more performing solution.
What IC can I use to implement it?

How good does it have to be and are you making one or a million?

Making a low noise high performance analog filter near 0.05 is next to
imposible. The capacitors you need to use are large and costly. If this
is just a one-off or cost is no object, There are 2 and 3 op-amp circuits
you may want to consider.

If the cost is an object, I'd suggest you try to find a way to not need
the filter. A micro controller with an ADC and DAC could implement a very
sharp filter, but there you have the LSB rattling issue to deal with.

If I was going with the micro method I'd do this:

If needed add some high frequency noise to the signal to ensure that the
noise is at least 2 LSBs RMS. Run the ADC circuit at as high of a
frequency as you can. Construct a multi-stage IIR filter in software.
Pump the output values to the DAC much faster than the Nyquist. Add a
high frequency dithering (PWM to fake more bits) to the data for the DAC
that is large enough to blur out the dif-nonlinearities. Follow the DAC
with a low pass filter to remove the dithering.

--
--
kensmith@rahul.net forging knowledge

 

[Ban]

Alessandro Convertino wrote:

Hi to all,
I would like to know some informations about bandpass filtering on
frequency range between 0.05-30 Hz. In the past I've used a Sallen-key
active filter, and I would like to find a more performing solution.
What IC can I use to implement it?

Thanks for your attention.

Alessandro

With this broad range you can only cascade a highpass with a lowpass filter.
With two filters of second order with maybe Bessel-characteristic you will
get a very good performance with very small overshoot and constant delay in
the passband.
It doesn't matter which topology you implement the filters, because the
performance will be the same. Sallen-Key is indeed the most suitable
topology, but keep resistors low and (unfortunately) capacitors high. If you
need steeper filter characteristic, you will have to increase the filter
order.
It is very important to choose the right opamps for this low frequency task.
I recommend the AD797 or if it has to be cheap the NE5532. Fet- and CMos
opamps are unsuitable because of their low-frequency unstability. Use caps
of at least 1000uF for the high-pass. I think the noise performance will be
the most important issue, as well as THD. But it all depends on your
application.
--
ciao Ban
Bordighera, Italy

 

[Joerg]

Hello Alessandro,

This could be nicely done with a DSP. ADC and DAC for data conversion
are cheap and plentiful, and so are DSP.

A microcontroller solution might work as well if it has to be rock
bottom in cost. Some MSP430 versions contain a 16 bit multiplier.
However, it can be a hassle to pipe the data in and out through the ports.

Ciao, Joerg

http://www.analogconsultants.com

 

[Ken Taylor]

"Jim Thompson" <thegreatone@example.com> wrote in message
news:l0ngo09p77dn8bpib0irt45ibcknmqe1pi@4ax.com...

On 2 Nov 2004 19:25:45 -0800, soar2morrow@yahoo.com (Tom Seim) wrote:

Barack is a very welcome addition to the Dems.

Agreed!

...Jim Thompson
--
Congratulations also to Lyn Allison for becoming leader in the Senate.

Ken

 

[Joerg]

Hi Rich,

Vt\Vp can vary several hundred percent so this one off batch means
nothing. You can expect huge variations. Your "design" is an accident
waiting to happen.



So, in other words, are you saying, as was I, that coming off the
line, even with care in the production process, there is still so much
variation in the cutoff current that makes it such that you'd have
to individually test each unit? (which, of course, jacks the price
up a bunch)


As Kevin said it is the lot to lot tolerance that really spoils the

broth here. If you take all the FETs from one lot you may be ok. But
that is not a viable concept for long term production.

Processes may be a bit better controlled than 20 years ago but when you
look at the data sheet of, say, ye olde BF245 there should be some goose
pimples on the designer's skin when it is used in a single-FET current
source.

Regards, Joerg

http://www.analogconsultants.com

 

[Jim Thompson]

On Wed, 03 Nov 2004 20:24:15 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Hi Rich,

Vt\Vp can vary several hundred percent so this one off batch means
nothing. You can expect huge variations. Your "design" is an accident
waiting to happen.



So, in other words, are you saying, as was I, that coming off the
line, even with care in the production process, there is still so much
variation in the cutoff current that makes it such that you'd have
to individually test each unit? (which, of course, jacks the price
up a bunch)


As Kevin said it is the lot to lot tolerance that really spoils the
broth here. If you take all the FETs from one lot you may be ok. But
that is not a viable concept for long term production.

Processes may be a bit better controlled than 20 years ago but when you
look at the data sheet of, say, ye olde BF245 there should be some goose
pimples on the designer's skin when it is used in a single-FET current
source.

Regards, Joerg

http://www.analogconsultants.com

I don't know the OP's desired current range, but why not an LM317 plus
a resistor? Quite accurate.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Joerg]

Hi Jim,

I don't know the OP's desired current range, but why not an LM317 plus
a resistor? Quite accurate.


Yes. Or use a TL431/TLV431. My favorite because of its low cost. The

extra transistor only adds two cents or so.

Regards, Joerg

http://www.analogconsultants.com

 

[Joerg]

Hi Terry,

ps yay the Red Sox!

Aren't you located in New Zealand? If so, how come you are a Red Sox fan?

Regards, Joerg

http://www.analogconsultants.com

 

[Paul Burridge]

On Wed, 03 Nov 2004 19:23:19 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Hi Paul,

So what is cheap plonk? The category "mise en bouteille dans notre garage"?



Shouldn't that be *une* bouteille? ;-)


Don't think so but I am no expert in French. With 'en' they mean 'into
the'. The Dutch have a different saying, something like: "Du pain - du
vin - du hoofdpijn". The last one means 'headache', a.k.a hangover.

Ah: wine/hangover. That's the kind of grammar that makes sense in any
language. It also accounts for a lot of what Jim Thompson posts.
--

"What is now proved was once only imagin'd." - William Blake, 1793.

 

[Winfield Hill]

Terry Given wrote...

ps yay the Red Sox!

Hear! Hear! (Except for Kurt Shilling of course.)


--
Thanks,
- Win

 

[John Larkin]

On Wed, 03 Nov 2004 09:58:23 -0700, Jim Thompson
<thegreatone@example.com> wrote:

On 3 Nov 2004 08:46:17 -0800, convertino@deemail.poliba.it (Alessandro
Convertino) wrote:

Hi to all,
I would like to know some informations about bandpass filtering on
frequency range between 0.05-30 Hz. In the past I've used a Sallen-key
active filter, and I would like to find a more performing solution.
What IC can I use to implement it?

Thanks for your attention.

Alessandro

VERY LOW FREQUENCY filters are difficult since the dissipation factor
of typical capacitors dominates (and deteriorates) the performance,
particularly in a production environment where repeatability is
important.

How so? I'd suspect a polycarb or something decent would have a very
low df in the sub-Hz range. Numbers like 1 uF and 10 megohms seem
perfectly nice to me, with fet opamps.

John