USB microscopes for very small SMT

[Joerg]

It seems the eeePC 701 will do over 5 hours with WiFi off and a 6600 mAh battery pack:
http://www.eeeuser.com/

At a $100 or so premium AFAIR. In the Samsung that performance is
standard and it supposedly reaches >7h. Probably longer with WLAN turned
off.

scroll to bottom page.
The 100 0seris will do up to 7.5 hours and have Xp home or Linux.
http://en.wikipedia.org/wiki/ASUS_Eee_PC#Eee_1000_Series

Well, the Samsung clocked in under $500 and has a 160GB drive which
comes in handy.

 

[Joerg]

I'm told that the main reason those netbooks have a 1024x600 LCD is that --
unlike the older HP Mini 2133 -- Microsoft will only sell XP for "low end"
machines that have no higher resolution nor more than 60? GB of storage and
1GB of RAM; everything with better specs has to run Vista.

@#$#@$%#$%

Guess Samsung found a back road then because the HD on there is 160GB.
Resolution probably has to do with the form factor. I am not too
thrilled about the 600 vertical pixels either because it might mean I
can't easily run Linux in VirtualBox on there. Oh well, can't help it,
the netbooks are pretty much all like that.

(This is also the reason that most manufacturers advertise their Atom
CPU-based netbooks as being available with "up to 1GB of RAM" even though in
general they'll all happily accept a 2GB DIMM -- the maximum the hardware
supports.)

I found 1GB under XP to be plenty for the typical EE-tasks on the road.

You know how much we encourage all of you and Jim and John to write books.

When we retire

But seriously, there won't be much of an audience. I can't cater much to
folks that run a uC to perform the job of a one-shot and stuff like
that, and somehow that seems to become the majority these days. Those
guys won't buy the book because it'll mostly contain <gasp> non-digital
stuff.

So maybe it'll be a web site and self-publication, free to the public.
There comes a point where one has to give back to society. And still,
this will pale compared to what volunteers at Hospice do. We were at
their yearly memorial event yesterday and it amazed me what they do.

 

[krw]

Laptop designers seemed to have "un-learned" that as well. Until
recently when the Intel Atom came out and (some) laptop designers
"re-learned" the art. When Howard here in the NG mentioned the Samsung
NC-10 and I saw it gets >6h, like my old Compaq Contura used to, I
honored that laptop performance with an order. Seems others have done
the same since I initially received a backorder notice despite the fact
that "in stock" was mentioned. Should arrive in a few days

6hr batter life isn't the only design point for laptops. Many/most
are being used as desktop replacements, so battery life is *maybe*
a secondary parameter. In my case, two hours is good enough but I
need high resolution, external display capability, large disk(s),
and all the other stuff that used to be the sole domain of
desktops. Sure, I'd like a three day battery, but I'm not going to
give up any other aspects of my laptop to get it. In fact, newer
laptops *are* better than those of five or six years ago, taking
all of the parameters into account.

I often encounter folks who are quite unfamiliar with the scheme of
saving battery power via pulse action instead of high impedance.

The designers of these devices are well aware of these power-saving
schemes, and far more. It's a matter of design (and that
necessarily means marketing) priorities.

Students need to re-learn the old art of obtaining some of their wisdom
from non-academic sources. I'd venture to say that >50% of the knowledge
I use in my practice is from non-academic sources. App notes, Internet,
ARRL books and such.

This stuff is standard design practice. There aren't any secrets
here. The processor datasheets lay it all out. Do not, however
that a given computation has a minimum power requirement. If you
draw that time out (your "pulse action") you only waste more
energy.

 

[Joerg]

6hr batter life isn't the only design point for laptops. Many/most
are being used as desktop replacements, so battery life is *maybe*
a secondary parameter. In my case, two hours is good enough but I
need high resolution, external display capability, large disk(s),
and all the other stuff that used to be the sole domain of
desktops. Sure, I'd like a three day battery, but I'm not going to
give up any other aspects of my laptop to get it. In fact, newer
laptops *are* better than those of five or six years ago, taking
all of the parameters into account.

Well, for desktop jobs in the office I use ... a desktop.

The designers of these devices are well aware of these power-saving
schemes, and far more. ...

When I see a fan and hot air coming out of a laptop no matter what you
set in the "energy management" tab I do have my doubts here. For
example, the old Compaq could throttle the uP down to a few MHz. That's
how they got 6h out of a standard old-tech NiCd. For years. Until all
the rough flights and nail-it-to-the-runway landings caused the frame of
this laptop to fracture :-(

... It's a matter of design (and that
necessarily means marketing) priorities.

Sometimes it's necessary that engineers question decisions by marketing.
Got to be careful here, since I married a marketeer ;-)

This stuff is standard design practice. There aren't any secrets
here. The processor datasheets lay it all out. Do not, however
that a given computation has a minimum power requirement. If you
draw that time out (your "pulse action") you only waste more
energy.

That's what I thought as well, that folks know this. But, example:
"Don't you have to keep the bridge current running until you are sure
the uC code has finished and can read the ADC?" ... "No, the value is
being stored." ... "But it can't be, the code may not have gotten to
that point." ... "See that 74HC4051 there? It's set up as track-and-hold
so the value will be stored in the film cap over there." ... "Oh."

 

[Rich the Newsgroup Wacko]

...Until you get hungry or thirsty.

That's simple - just get one who's lactating. ;-)

Cheers!
Rich

 

[krw]

Well, for desktop jobs in the office I use ... a desktop.

Don't know about you, but mine is difficult to carry. Trust me,
you are the oddity. ;-)

When I see a fan and hot air coming out of a laptop no matter what you
set in the "energy management" tab I do have my doubts here. For
example, the old Compaq could throttle the uP down to a few MHz. That's
how they got 6h out of a standard old-tech NiCd. For years. Until all
the rough flights and nail-it-to-the-runway landings caused the frame of
this laptop to fracture :-(

I don't have any doubts. People *use* laptops and demand desktop
performance from them. Guess what, that takes power no matter how
you (time) slice it.

Sometimes it's necessary that engineers question decisions by marketing.
Got to be careful here, since I married a marketeer ;-)

Question all you want, the answer is the same. Customers demand
performance. Laptops aren't toys anymore. Few use both laptops
and desktops anymore. They take their work with them. Licensing
agreements don't help but data isn't all that portable either.

That's what I thought as well, that folks know this. But, example:
"Don't you have to keep the bridge current running until you are sure
the uC code has finished and can read the ADC?" ... "No, the value is
being stored." ... "But it can't be, the code may not have gotten to
that point." ... "See that 74HC4051 there? It's set up as track-and-hold
so the value will be stored in the film cap over there." ... "Oh."

How much of that is going on inside your laptop?

 

[Joerg]

Guess Samsung found a back road then because the HD on there is 160GB.

The full story turns out to be, "...it used to be 80GB [not the 60GB I
guessed/wrote], and MS recently doubled it to 160GB."

Don't forget, MS is also seeing some pressure from the industry. Along
the lines of "Look, you guys have badly screwed up with Vista and we are
simply not buying this piece of #%@&!" I don't think Gates or whoever
runs the place now was very enthused last month when the Dell flyer with
the rock-bottom priced Mini-9 and Ubuntu on there came out.

Personally the hard drive size is the least of my worries... I'd be quite
happy with 40GB for a netbook; the screen resolution limitation is much more
irksome.


Agreed, I just find it annoying that manufacturers go so far as to
misrepresent their hardware's capabilities so as to make Microsquish happy.

It's like minimum advertized prices, there's ways around it

That's OK... contact Newnes, they'll publish anything.

And at least PDF stick around forever. Hopefully those old books by the likes
of Terman and Guillemin will be scanned before all the printed copies are
gone!

As a last resort there'll always be the Library of Congress, hopefully.

Yeah, but it doesn't seem like you really need much of a market. Check out,
"Intuitive Analog Circuit Design" by Marc Thompson
(http://www.amazon.com/Intuitive-Analog-Circuit-Design-Thompson/dp/0750677864)...
it's been around for two-and-a-half years, and has all of 3 reviews: A good
one, one where the guy gripes the title is inaccurate (OK, fine, "intuitive"
is a very subjective thing), and another where the guy completely misses the
point of the book, saying:

"...it walks the reader through formulas a circuit designer would hardly ever
use, except when in school..." (Well, actually, no, people doing more
advanced circuit design still run through those time constant calculations and
lots of basic algebra... check out Jim's web site...)
"If you need to learn how to design analog circuits, there are many "cook
books" out there to get the job done fast." (Ah, now we see what he's really
after -- not wanting to learn how to actually *design* at all, but wanting a
cookbook...)

(And who the heck is Marc Thompson anyway? Turns out he's a professor at WPI,
went to MIT...)

I doubt he's getting rich off of book royalties.

You can see that trend in many appnotes these days. Scant data, swaths
of it plain missing, followed by cookbook style layout and part lists.
Take this, that and the other thing, hit enter, and voila, there's the
complete XYZ gizmo. I find more and more that engineers become really
lost the instant they need to deviate from the app note ever so
slightly. But oh well, that's part of my income now 8-D

Cool, that's great.


Volunteering to work at a hospice clearly has very direct benefits, which is
great... but don't sell yourself short on the good that, e.g., your work on
ultrasound machines over the years has done as well: The indirect benefit
could easily be plenty of babies' lives saved, tumors discovered early enough
for successful treatment, etc.

The best was an experimental device (not at liberty to tell, yet) where
a guy in Europe signed his life away on the usual waiver because there
was nothing else medicine could do for him anymore until imminent death
would strike. Pretty much 100% disabled and failing, fast. Afterwards he
did something he'd never dream of, dusted off his racing bike and got
back into the swing of things.

Still this is nothing compared to personal care for the dying. My wife
and I do that as lay caregivers for church (my wife a lot more than me).
It is very taxing emotionally. Some of the hospice caregivers yesterday
broke into tears when they read out the name of one they had cared for.

 

[Joerg]

Don't know about you, but mine is difficult to carry. Trust me,
you are the oddity. ;-)

Why would I ever want to schlepp it around in the office?

I don't have any doubts. People *use* laptops and demand desktop
performance from them. Guess what, that takes power no matter how
you (time) slice it.

Depends on the job. Once this little Samsung arrives it'll probably
accompany me on 80-90% of trips. The remainder will have to be handled
by the big laptop because it has more horsepower.

Question all you want, the answer is the same. Customers demand
performance. Laptops aren't toys anymore. Few use both laptops
and desktops anymore. They take their work with them. Licensing
agreements don't help but data isn't all that portable either.

I do not have much faith in many marketeers. Just like the big three
auto makers blundered so much in that domain resulting in people buying
imports. They assumed people wanted certain products. The minor issue
was that people didn't want them.

How much of that is going on inside your laptop?

It was an example from the analog world. Want one from the world of
laptops? Ok:

There is absolutely no reason, zero, nada, zilch, why a processor has to
keep idling at close to a gigahertz while the user is sitting in front
of a laptop, pondering a text entry for a long time or answering a call
on their cell phone. Yet they do. Almost 20 years ago the old engineers
at Compaq understood that, the designers of most "modern" laptops
obviously do not understand that. Ok, back then it wasn't fully
automatic but I knew when I had to write a module spec on a flight
across an ocean I'd better switch it to low speed. Made no difference
while entering text but it stretched the battery life all the way to the
coast of Ireland. I still remember a guy next to me getting really
pissed when his super-expensive Thinkpad shut down and I kept tapping
away another three hours. Especially after he saw that mine was an old
economy-class Contura. While I had my document completed he had the
privilege to do a jet-lagged late night typing session once he got to
the hotel. I went to the bar and had a couple of cold ones.

Intel's Atom is a step in the right direction. Here's hoping that they
don't screw it up again like they did with the divestiture or
cancellation of product line such as their CPLD in the 90's. Their stock
price indicates that they really need a killer app and product, and soon.

 

[Joerg]

I've been surprised that the lower limit on many-an-Intel-CPU is 1GHz... seems
like 100MHz would be plenty for an idling PC. (I realize that modern CPUs
often have the registers implemented as dynamic memory, so you can't go down
to DC... but still... 100MHz should be plenty...)

Back then the good ones would go down to DC. But the RAM didn't and
that's why they either had to have an extra arbiter or keep them running
at a few MHz. AFAIK the Contura didn't have an arbiter. But hey, 6h out
of legacy NiCd ain't bad. With today's LiIon it would probably run for
two days. And this wasn't even the Aero version (kind of the first
netbook back when netbooks weren't "invented" yet).

Was that coach, business, or 1st class? Are you tall or short or inbetween?
I've always found that in coach you're packed in tightly enough that it's
kinda difficult to get productive work done... although I do see people
trying.

Those were the golden days. International business class and sometimes
first. Blini, caviar and champagne. So comfy that once I did not wake up
until the flight attendants tapped me on the shoulder and the whole
cabin was empty. I am over 6ft and some coach class seat arrangements
give me a back pain.

At least a netbook is a good size for a computer if you are going to try to
get work done...

Yep. Much bigger than my first laptop. A Wang with 200 vertical pixels,
no backlight, no mouse, yet I did large designs on it using OrCad SDT.
Almost until the arrow keys fell off. This thing had a built-in modem
and printer (!).

 

[Joerg]

Although that is true, the real question is:
How much current does it save to clock down the processor?

A lot. I measured it back then but that data is gone by now. The biggest
difference was turning off the hard drive which was easy. They already
had hibernate and suspend modes back then so you really only needed it
shortly before turn-off (if hibernate was chosen) and then it came on
automatically. I didn't care because DOS stuff just didn't crash. Data
was either stored on a PCMCIA memory card or 3-1/4 floppy. Because I
didn't trust hard drives for good reason, lost three in that laptop alone.

Next was the backlight IIRC, third was the processor clock. Now,
backlight is easy to handle. The designers of this laptops were very
smart, they put some programmable extra buttons on there. So if, say, I
got stuck and had to think hard about some equation while writing a
module spec I hit a button and the display would blitz off. Later
another press of the button and it was back instantly. This feature and
the turned-off HD made the processor the number one consumer and that
was fixed by their nifty under-clock scheme. A marvelous machine. And
then, later, came Carly ...

I have never seen a laptop this nifty during the whole 15 years until a
few weeks ago with the latest generation netbooks.

There is a test from some guy for the eeePC, clocked down all the way to 160MHz
IIRC or there about, and it hardly made any difference in power consumption.
I installed the clock mod (very simple: unload a module and run something),
and the thing became unstable at those low clock speeds.
Makes you wonder if the Celeron can be static clocked anyways...
So, because of that instability (I like my data) I removed the clock mod again.
It had no real advantage, maybe because it is already under clocked at 630MHz..
There are other big power guzzlers in the thing, display, WiFi,
switching WiFi off adds an hour or so? And the USB GPRS-HSDPA modem.

Camera people sometimes wear a belt with batteries, maybe some idea?

Try to get that past the security guys at the airport ;-)

 

[Joerg]

Interesting that the whole netbook movement came from Asus, a Taiwanese
company.

A lot of innovative stuff comes from Asia. I remember when the
traditional watchmakers laughed and scoffed at the first Japanese quartz
wrist watches. They no longer laugh. I would not be surprised if some
former execs of the Europa Uhrenwerk in Ulm are now wearing Seiko
watches. I was in that building after it became a mini ghost town
because a client rented rooms there, dirt cheap. Spooky. My car plus a
dozen others in a parking lot designed for several hundred. A humongous
array of buildings, 99% empty.

I always knew there was a market for netbooks but the industry slept.
Now they'll have their lunch eaten. Reminds me of certain auto
manufacturers ...

One company I called about the Samsung told me they can't keep up
because these things fly off the shelves like hotcakes. And Samsung
knows how to do proper production ramp-up. The only mistake they may
have made is to build too many white ones.

Although HP was relatively fast to jump on the bandwagon with the 2133...
which wasn't very competitive, although the newer 1000 series are. Try one
out at Costco next time you visit... very similar to your NC10... somewhat
thinner and lighter, although in part that comes from not having a standard
VGA connector, only 2 USB ports rather than 3, a 1.8" drive rather than 2.5",
and a 3-cell battery rather than six. (Six-cell batteries and regular VGA
cables supposedly show up in January...)

3-cell? <yawn> What were they thinking? The smaller drive and less USB
is ok but not having a standard VGA is going to cost them. Those things
will be used by presentation jockeys left and right.

Advice to HP and others: Talk to potential _customers_, _not_ your own
marketeers. That's how we do it in medical (and caused HP-IVUS to throw
in the towel ...) Get some better web designers. Oh, and the Costco web
site doesn't even show it under netbooks. That ain't the way S&M works.

If there is no VGA at all via some cheap adapter then the product might
fizzle in the marketplace altogether. Anyhow, January they'll have
missed two major milestones, section 179 tax year sales and the whole
Christmas shopping period. Not that I like the fact that Christmas is
being commercialized but it's unfortunately a fact.

Sometimes I wish I could be VP of sales just for a year or so. In many
companies that'll probably feel more like a salvage job.

 

[Joerg]

Apparently their marketing guys decided it was, "Less than one inch thick or
bust!" -- it's 0.99" thick, and you apparently can't get a regular VGA
connector into a case than thin after allowing for some reasonable thickness
for the "top" (the LCD panel). Actually, while this is what I've read, I'm
not sure it's correct, since it does still have a regular RJ-45 Ethernet
socket, which seems about as thick... I suppose the difference is that
Ethernet cables fit within the RJ-45 socket completely, whereas VGA cable
connectors are larger than the connector.

Heck, even if it comes out the top with a small lid that's better than
not having VGA at all.

Anyway, HP chose to use a "DisplayPort" connector instead, so one can have a
short pig-tail lead to a regular VGA connector... once they're available,
supposedly in January. (I guess they took a page from Apple's playbook
here -- their ultra-thin MacBook Air requires a pig-tailed RJ-45 Ethernet
connector...) Purportedly the upside of DisplayPort is that -- since it's
actually more of a general-purpose high-speed bus and not just a video
connection standard -- they'll have docking stations as well that have USB,
Ethernet, etc., all going through the same connector as the video. This is
something I'll only believe when I see it though, since DisplayPort is still
awfully new.

Personally I don't like proprietary solutions. This is also why I would
never buy a netbook with a promise that a 6-cell battery will come out
next month or so. Because most likely it will carry premium pricing. I
hope they at least furnish a VGA pigtail with the netbook.

I had a Sony laptop once that had a pig-tailed lead to a VGA connector... I
always lived in fear that one day I'd lose it and be completely unable to
connect a regular monitor, as this was somewhat before eBay became so
well-known and made it easy to obtain such obscure replacement parts in many
cases.

That'll be a real pain when you get to the client, all the suits are
lined up in the board room to see your solution and you can't find that
VGA adapter thang. Then you'd start spooling the PPT file onto somebody
else's laptop while the suits with income levels of $10 per minute or
more are twiddling their thumbs ;-)

I swear that the Costco web site tends to have less than half of what you find
in the actual stores on-line... Here's Newegg's link:
http://www.newegg.com/Product/Product.aspx?Item=N82E16834147824

Oh man. So S&M asleep at the wheels again? Our guys sure as hell watched
all the major sales outfits that our products were advertized properly.
If not it costs maybe 15 minutes to alert a vendor that a link is
missing or broken. In pre-Christmas times this is paramount for any
computer gear. The return on investment for those 15 minutes spent by a
S&M assistant can easily exceed 1000:1. Uncle Leroy looks for a netbook
for lil' Jeremy. Oh, they don't have HP. Ah, the MSI Wind looks good as
well. Click, click, click, confirm order, done.

 

[JosephKK]

I've been surprised that the lower limit on many-an-Intel-CPU is 1GHz... seems
like 100MHz would be plenty for an idling PC. (I realize that modern CPUs
often have the registers implemented as dynamic memory, so you can't go down
to DC... but still... 100MHz should be plenty...)


Was that coach, business, or 1st class? Are you tall or short or inbetween?
I've always found that in coach you're packed in tightly enough that it's
kinda difficult to get productive work done... although I do see people
trying.

At least a netbook is a good size for a computer if you are going to try to
get work done...

---Joel

Leveraging some insider information part of the issue is the balance
between leakage current and switching current. They seem to need to
keep enough switching going to keep leakage from corrupting the
processor state. Appropriately mobile rated parts do better.

 

[Greegor]

Often it does boil down to this. In my line of work I often talk with
cardiologists and one told me that his gross income was well north of
$200k. But liability insurance costs him >$100k/year. And that's exactly
one of the two main problems with our health "system": Ambulance chasers.

"iatrogenia dirty hospital", "god complex doctor", "confirmation bias"

It is not hot coffee suits.

 

[krw]

Why would I ever want to schlepp it around in the office?



Depends on the job. Once this little Samsung arrives it'll probably
accompany me on 80-90% of trips. The remainder will have to be handled
by the big laptop because it has more horsepower.

Which is precisely my point.

People don't want to have to decide which computer to use based on
what they think they might be doing. They want it all. What
happens if the job changes *after* you've left home? Do you buy
multiple copies of all your tools? Keep multiple copies of all
your documentation? ...up to date? No thanks (decided not to buy
an eeePC for this reason), I'll carry my one full size laptop with
me even though I'm limited to 2-3 hours on the battery.

I do not have much faith in many marketeers. Just like the big three
auto makers blundered so much in that domain resulting in people buying
imports. They assumed people wanted certain products. The minor issue
was that people didn't want them.

You're going to let engineers in the back room make SKU and
inventory decisions?

It was an example from the analog world. Want one from the world of
laptops? Ok:

There is absolutely no reason, zero, nada, zilch, why a processor has to
keep idling at close to a gigahertz while the user is sitting in front
of a laptop, pondering a text entry for a long time or answering a call
on their cell phone. Yet they do.

There is very good reason. It doesn't save much to have it running
at half that. If you want to save significant power you have to
turn things *OFF*. Then it takes time to get them back.

Almost 20 years ago the old engineers
at Compaq understood that, the designers of most "modern" laptops
obviously do not understand that.

Utter nonsense.

Ok, back then it wasn't fully
automatic but I knew when I had to write a module spec on a flight
across an ocean I'd better switch it to low speed. Made no difference
while entering text but it stretched the battery life all the way to the
coast of Ireland. I still remember a guy next to me getting really
pissed when his super-expensive Thinkpad shut down and I kept tapping
away another three hours. Especially after he saw that mine was an old
economy-class Contura. While I had my document completed he had the
privilege to do a jet-lagged late night typing session once he got to
the hotel. I went to the bar and had a couple of cold ones.

His was a desktop, with legs. Yours a "lite". Different design
point.

Intel's Atom is a step in the right direction. Here's hoping that they
don't screw it up again like they did with the divestiture or
cancellation of product line such as their CPLD in the 90's. Their stock
price indicates that they really need a killer app and product, and soon.

Intel will screw up a wet dream.

--

 

[Joerg]

krw wrote:

[...]

Depends on the job. Once this little Samsung arrives it'll probably
accompany me on 80-90% of trips. The remainder will have to be handled
by the big laptop because it has more horsepower.

Which is precisely my point.

People don't want to have to decide which computer to use based on
what they think they might be doing. They want it all. What
happens if the job changes *after* you've left home? ...

They never do. An EMI job remains an EMI job. If any hardcore sims need
to be done I always know when that could happen. Plus there is always a
client PC.

... Do you buy
multiple copies of all your tools? ...

I make sure the license agreement allows multiple PC and sole user. If
not I don't buy it.

... Keep multiple copies of all
your documentation? ...up to date? ...

Yes, and yes. But not all _on_ the laptop. That would really get me into
a pickle if someone steals it. I consider it dangerous to have all my
sensitive data on a laptop and I don't work this way. Just what's needed
for the job plus the rest one separate secured media.

... No thanks (decided not to buy
an eeePC for this reason), I'll carry my one full size laptop with
me even though I'm limited to 2-3 hours on the battery.


You're going to let engineers in the back room make SKU and
inventory decisions?

I have made inventory decisions myself. A lot.

There is very good reason. It doesn't save much to have it running
at half that. If you want to save significant power you have to
turn things *OFF*. Then it takes time to get them back.

The engineers who designed the Compaq Contura have proven the contrary.

Utter nonsense.

So? Then why did they get 6h out of NiCd? To me this is very simple:
Bloat happens (unfortunately), but so do battery performance increases.
If battery performance divided by bloat is declining then we do not have
progress. With devices like the little Samsung we have (some) progress
again.

His was a desktop, with legs. Yours a "lite". Different design
point.

Nope, not at all. We had a longer chat later and his machine wasn't all
that different. Also, we both typed text docs, same job. Except his
croaked 3h earlier.

Intel will screw up a wet dream.

Unfortunately, sometimes they make bizarre business decisions IMHO.

 

[Charlie E.]

It used to not be that way, back when more engineers knew about analog.
For example, one classic mistake I find in my consulting practice is the
use of too high impedances in low-energy sensing circuits. A little
moisture, a little dirt, and it'll be on the fritz. The right way is to
use low impedances and then pulse-measure. But it seems universities
don't teach that stuff anymore.

Yesterday a friend told me a sad story: They have a double oven, friggin
expensive, IIRC it's a GE. The controller up top is, unfortunately,
electronic and expensive, In ten years the third one has died so now
they consider this oven a total loss. That is pathetic.

Our double oven is over 35 years old. When it dies I will go to great
lengths to find a replacement that is controlled via bi-metal thermostat
switches. I don't want any PWM or whatever in there. Just relays,
bi-metal and switches.

Well, our new house came with a nice, Whirlpool Gold slide in range.
We soon noticed that there was a fan that got very, very noisy while
the oven was on, so had them come and repair it. Took them two trips,
one to verify that, yes, that fan was very noisy, and then come back
after the part was in. (Took two weeks to get the part.) Found out
that the purpose of the fan (which, when quiet, is still pretty
noisy!) was to keep the electronics cool! Electronics are in the
front, the fan is in the back... Your logic may resemble mine when
contemplating this arrangement.

Then, a few months later (but, after the warranty period!) the touch
pad quit working. No warning, no deterioration, it just stopped one
day. Found out that the fan doesn't do that good a job of keeping the
electronics cool, and this is a very common failure! Two months
later, we finally had that fixed. So, last year we did no Christmas
baking!

Now, it is a year later, and suddenly the broiler quits. It won't
light, although you can hear the zap! zap! zap! of the ignitor.
Research on the web says it is either the actual ignitor going out.
($14 part...) or the electronics aren't giving it enough drive for it
to operate ($85 part.) So, since we don't do that much broiling, and
it usually just small stuff, we did the easy thing - bought a toaster
oven for $35! Saved myself a world of hassles.

Charlie

 

[[email protected]]

People don't want to have to decide which computer to use based on
what they think they might be doing.  They want it all.  What
happens if the job changes *after* you've left home?  Do you buy
multiple copies of all your tools?  Keep multiple copies of all
your documentation? ...up to date?  No thanks (decided not to buy
aneeePCfor this reason), I'll carry my one full size laptop with
me even though I'm limited to 2-3 hours on the battery.

One thing the eeePC can do (after all it is a 'netbook' ) is connect
to
'the internet.
I was somewhere and needed a file, a script actually, and it was on
the home server.
Just used the GPRS modem to connect to my home server, downloaded the
script
with scp (secure copy), and things worked.
Now on a small bandwidth connection like GPRS it will not work
to do a ssh -Y [email protected] and have a graphical user interface
to the home server, but you can run the Xilinx FPGA programs in text
mode too.
Given the correct scripts (that I once made), you can even synthesize
remotely.
So what I am saying is: not always needed to carry the application on
the notebook,
just do it remotely.

 

[Joerg]

Well, our new house came with a nice, Whirlpool Gold slide in range.
We soon noticed that there was a fan that got very, very noisy while
the oven was on, so had them come and repair it. Took them two trips,
one to verify that, yes, that fan was very noisy, and then come back
after the part was in. (Took two weeks to get the part.) Found out
that the purpose of the fan (which, when quiet, is still pretty
noisy!) was to keep the electronics cool! Electronics are in the
front, the fan is in the back... Your logic may resemble mine when
contemplating this arrangement.

Then, a few months later (but, after the warranty period!) the touch
pad quit working. No warning, no deterioration, it just stopped one
day. Found out that the fan doesn't do that good a job of keeping the
electronics cool, and this is a very common failure! Two months
later, we finally had that fixed. So, last year we did no Christmas
baking!

Now, it is a year later, and suddenly the broiler quits. It won't
light, although you can hear the zap! zap! zap! of the ignitor.
Research on the web says it is either the actual ignitor going out.
($14 part...) or the electronics aren't giving it enough drive for it
to operate ($85 part.) So, since we don't do that much broiling, and
it usually just small stuff, we did the easy thing - bought a toaster
oven for $35! Saved myself a world of hassles.

I remember friends who kind of snickered when I bought my car. "What? It
doesn't even have electric windows and keyless entry?" Long story short
most have now gone through 2-3 more cars, at times because the
electronics stuff kept breaking and repairs became uneconomical. I still
drive the same car and all the snickering has stopped.

Our double-oven is one of those extra skinny ones. 35 years old and
mechanically wearing out. I dread that day when I have to find a
replacement with the least amount of electronics, ideally zero electronics.

Too many engineers remain blissfully unaware of flash retention curves
for elevated temperatures. It can easily drop down to low single-digit
years. I just hope they never design ovens and cars.

 

[Joerg]

Ah, so YOU'RE the reason that the "big three" are going bankrupt! Sheesh,
would you just go out and CONSUME some already? Buy unreliable products,
always get the latest and greatest widgets! Help the economy thrive!

Not me, the real reason is an elderly lady who is the worst nightmare of
automakers. I marveled at an Austin Healey in front of a Costco. A lady
came and said she bought it used in 1961, her first car. It'll also
probably be her last car since she might just let her driving license
lapse a few years from now. Just imagine, half a century of driving and
never having bought a new car, and only once a used car.