Driver to drive?

[Ban]

Mark Jones wrote:

By Mark Jones 1N4001 1N5189 1N4148
1) Vforward @ 5v, z=100M 0.29v 0.01v 0.46v
1) Vforward @ 5v, z=10M 0.32v 0.02v 0.48v
1) Vforward @ 5v, z=1M 0.38v 0.05v 0.55v
1) Vforward @ 5v, z=100k 0.45v 0.10v 0.62v
1) Vforward @ 5v, z=10k 0.56v 0.18v 0.70v
1) Vforward @ 5v, z=1k 0.75v 0.37v 0.90v
----------------------------------------------------
2) Ireverse @ 5v, z=0.1R 66fA 1.1uA 2.75mA
----------------------------------------------------
3) Vreverse @ 5v, z=100M 6.6mV 4.99v 2.75v
3) Vreverse @ 5v, z=10M 2.1mv *4.10v 2.65v
3) Vreverse @ 5v, z=1M -0.3mV *1.00v *2.24v
3) Vreverse @ 5v, z=100k -0.7mV *0.12v *1.67v
3) Vreverse @ 5v, z=10k -0.8mV 0.01v *1.06v
3) Vreverse @ 5v, z=1k -0.9mV 300uV 0.48v
* 1N5189 showed extreme tempco in the volt range
* 1N4148 showed measurable tempco in the mV range
* Vr measured across dropping resistor to ground.

---
That looks pretty fishy to me; especially the part about a reverse
current of 2.75mA through a 1N4148. How did you make the
measurements and what did you use to make them with? In
particular, what's the resistance of your voltmeter?



Why? Do you mean 20Kohm/Volt isn't adequate ?

...Jim Thompson



Oh crap... that 1N4148 ended up actually being a 1N5231, which is a
5.1v zener! It looks damn identical to a 1N4148, no wonder the results
were askew... sorry about the misleading data there. :0

-M

Mark, be aware that you not only measure the DUT, but at the same time the
effect of the input current of your voltmeter. Try to find out what comes
from what and if with these values the whole thing really makes sense to
measure.
--
ciao Ban
Bordighera, Italy

 

[Paul Burke]

Charles Edmondson wrote:

I call BS. I am married to a visually impaired woman, and the easiest
way to get her dander up is to call her blind! She still has a little
sight, and goes crazy every day because people assume that since she
can't see, she is incapable of anything else! And, this applies to most
of her friends, as well in the VI community!

That's probably a UK/US cultural difference. And yes, I know several
partially sighted people, of whom one is a headmaster, one MD of a
customer firm. The headmaster doesn't mind blind (though he can see
enough to ride a bike in good light), but he's albino, has a bushy beard
and HATES being called Father Christmas. But euphemisms make his flesh
crawl.

Paul Burke

 

[Rene Tschaggelar]

Joerg wrote:

Hi Rene,

As to the file, I made a webpage (not to be released) where
I can view the list of parts, with links to the sorted datasheets.



Interesting. Can that web page sort? For example, if you wanted to know
which different types of Schmitt trigger chips you have on hand, or what
kinds of FETs in SOT23 package, could it list that for you?

Joerg,
I'm just a small developer and cannot have too many parts. So
the list FETs is less than a page, the list of OpAmps is a bit longer
and therfore split into manufacturers and sorted alphabetically each.
However to each part, the specifications are listed.

The html-file is handeditable with notepad.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

 

[CBarn24050]

Subject: What do you think of this design?
From: Guy Macon http://www.guymacon.com
Date: 28/11/2004 13:44 GMT Standard Time
Message-id: <10qjlhl62bs6o98@corp.supernews.com


One of the fellows working for me designed this:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3856393230

It's a simple product, but any comments on the design of it
would be most appreciated.

I thought we had allready established to uselessnes of this product. If you
want to use this newsgroup as a marketing tool then you should put the letters
AD in the title so people can save themselves the bother of reading even more
spam.

 

[mojoman]

Rattus P. Phunk wrote:

Looking for these Schematics.

Say, so am I. Did you finally get them and would you be so kind as to
share them.
Mojoman

 

[mojoman]

Rattus P. Phunk wrote:

Looking for these Schematics.

Say, so am I. Did you finally get them and would you be so kind as to
share them.
Mojoman

 

[Jonathan Kirwan]

On Thu, 2 Dec 2004 03:59:07 -0500, Active8 <reply2group@ndbbm.net> wrote:

How about Vce << Va ?

Sure, then it's not so significant. But I thought I read you saying that it
*improved* things to remove it. That shouldn't be the case, as it should make
it slightly worse even if Vce << va. It just doesn't make sense for it to make
things better unless there is something else going on that such removal blindly
adjusts for.

Jon

 

[Dirk Bruere at Neopax]

Paul Burke wrote:

Charles Edmondson wrote:


I call BS. I am married to a visually impaired woman, and the easiest
way to get her dander up is to call her blind! She still has a little
sight, and goes crazy every day because people assume that since she
can't see, she is incapable of anything else! And, this applies to
most of her friends, as well in the VI community!


That's probably a UK/US cultural difference. And yes, I know several
partially sighted people, of whom one is a headmaster, one MD of a
customer firm. The headmaster doesn't mind blind (though he can see
enough to ride a bike in good light), but he's albino, has a bushy beard
and HATES being called Father Christmas. But euphemisms make his flesh
crawl.

Optically challenged? Visually otherabled?

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org

 

[Watson A.Name - \"Watt Su]

"Terry Given" <my_name@ieee.org> wrote in message
news:0ZNpd.11872$9A.264964@news.xtra.co.nz...

Marc H.Popek wrote:

Here are some nice "little" RF transistors.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3855097381&ssPag

eNam

e=STRK:MESE:IT


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3855292125&ssPag

eNam

e=STRK:MESE:IT


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3856043724&ssPag

eNam

e=STRK:MESE:IT


No, THIS is a transistor


http://www.eupec.com/gb/2_PRODUCTS/2_1_ProductRange/pdf/db_fz600r65kf1.p

df

How about the transistor Rthetajc = 0.011C/W

tha case Rthetacs = 0.006C/W

So for a 50C junction temperature rise above ambient this can
dissipate
3kW - which is about 600A when ON (Vce = 5V).

Oh yeah, it weighs 1.4kg

Yeah! But what's in them suckers? I've seen single junction
transistors with more than a kV breakdown voltage, but do they use more
than one junction in series in these beasties to get more than 6kV
breakdown?

Cheers
Terry

 

[Joerg]

Hi Winfield,

Not that I want to sound too critical here but in the old days
(early 90's) you could get by with a lot less RAM than the 16MB
that they proudly announced after the 'Retro Hardware Party'.



Yes, I remember very well. But those machines didn't support USB,
high-density graphics displays, multitasking, etc., etc.

That is true. But with a (manually) switched parallel port I did pretty
much the same stuff as with USB. Ok, they didn't make memory sticks back
then. Graphics was pretty good, 600*800 or so wasn't a big deal. Even
more but monitors over 15" were very expensive. I was pretty content
with the performance of Tseng Labs chips. Even did a real time
ultrasound display with one although it blew the monitor flyback
transformer when I tried higher resolution.

Multitasking with Windows is often a joke. I am using two PCs or more
simultaneously because one alone is too slow for me. You switch to
another window and then nothing happens for many seconds until a task in
the other one is finished. There were routines for DOS which let you do
the same and also went past the 1MB extender limit. Except that it
didn't crash when I became impatient ;-)

I admit that there has been progress. Just by far not as much as the
marketeers claim there has been. It reminds me of 'modern' cars. A
vehicle containing several dozen micro controllers is not something I'd
trust for a trip across a desert range. There is a reason Bob Pease
stuck with VW Bugs.

On a side note, it would be nice if you set your news agent to
post at or less than the standard 80 characters width.



I have no control over my newsgroup posting host, but I generally
manually edit the line length. For example about 70 charactes max
for that post. What happened when you read it? Did I miss a line?

Jim meant my post. It's just that I can't do anything about it right
now. I tried four newsreaders and kept the one with the lowest
percentage of posts with messed up line breaks (Mozilla).

Regards, Joerg

http://www.analogconsultants.com

 

[Paul Burke]

Rune Allnor wrote:

so the common denominator of trolls, is that they are stupid,
malicious, and don't survive getting exposed to scrutiny in
bright sunlight.

Have you read Terry Pratchett's 'Discworld' series? The trolls in that
are stupid and lumbering but sometimes amiable. But when it gets REALLY
cold... well, they are a silicon-based life form- the noise level goes
down- they become intelligent and quick. Getting dangerously on-topic here!

Paul Burke

 

[Fred Bloggs]

Rune Allnor wrote:

so the common denominator of trolls, is that they are stupid,
malicious, and don't survive getting exposed to scrutiny in
bright sunlight.

Rune

Don't forget to add that they post lengthy off topic messages...

 

[Ian]

"Winfield Hill" <hill_a@t_rowland-dotties-harvard-dot.s-edu> wrote in
message news:com1kb013iq@drn.newsguy.com...

Mark Jones wrote...


Oh crap... that 1N4148 ended up actually being a 1N5231, which is
a 5.1v zener! It looks damn identical to a 1N4148, no wonder the
results were askew... sorry about the misleading data there. :0

No, actually that's quite interesting. Relabel that column, and
measure a proper 1n4148 for a fourth column, then add a fifth red
LED column, and you'll have something pretty cool indeed.


If you do measure an LED, make sure it is in the dark.

Regards
Ian

 

[John Smith]

"Terry Given" <my_name@ieee.org> wrote in message
news:e20qd.14186$9A.271659@news.xtra.co.nz...

Arie de Muynck wrote:
"Neil Preston" ...

So, how would typical resistors react to such a pulse? (In this

application,

it might occur as often as once per second.) Would a 1 watt resistor be
sufficient?
Would it be subject to internal arcing or other degradation?
Would there be any performance/reliability difference in various types

such

as carbon comp, carbon film, metal film, MOX flame proof, wirewound, etc?
Is there a rule of thumb for the ratio of the power rating to the

intensity

of the energy pulse?


I've once made the mistake of just calculating the power dissipation and
using a film resistor (triac, inductive load, snubber use). They showed
beautiful little sparks after a year of 1 Hz switching. Replacing them
with
(cheaper) carbon composite resistors solved the problem.
Lesson: never ignore the PEAK dissipation and current that may occur, and
check the datasheet of even a simple item like a $0.03 resistor.

Regards,
Arie de Muynck

Hell yes. I learned this very early on, when placing damping resistors in
series with Y caps in big EMI filters. One day we noticed a flash of light
when we switched the prototype on. We switched it off, pronto. A thorough
set of diagnostics found no problem, but we weren't hallucinating so kept
looking. And the 1R 2W PR02 resistor I had in series with the 100nF Y cap
was open circuit. As were ALL of them, in all of the prototypes. We then
asked the peak-power question, which was something like (400V*1.41)^2/1R =
oh fuck, 314kW. And a carbon-composition resistor solved the problem. HVR
make some real good ones

Cheers
Terry

Our three-phase, 460VAC, thyristor-controlled, DC and AC motor speed
controllers had snubbers and MOV transient suppressors. All our controllers
used the same snubber values. In two different sites (Denver and Puerto
Rico), one of the MOVs would explode and the customer would send the unit
back for repair. After noticing that the same unit had been returned more
than once for the same problem, we got to looking into the cause more
closely.

It turns out that the firing of the thyristors in conjunction with the
snubber values and line inductance can _create_ a transient, and repetitive
transients will destroy MOVs eventually. The controllers would operate fine
for a day or three, then fail. Simulation showed that we needed to change
the snubber values based on the controller model current rating.

We had no hard data showing that the line impedance in Denver and Puerto
Rico was higher than in other places, but, as I recall, simulation showed
that it most certainly could be the cause.

Pardon me for posting a little off-topic, but I thought it might be useful
information.

John

 

[robert bristow-johnson]

in article f56893ae.0412020400.3b9213f6@posting.google.com, Rune Allnor at
allnor@tele.ntnu.no wrote on 12/02/2004 07:00:

Talking about word usage, Trolling is a hot topic in some of the other
threads. I always thought that Trolls were monsters that lived under
bridges in Scandinavia and who gobbled up travelers.
....
so the common denominator of trolls, is that they are stupid,
malicious, and don't survive getting exposed to scrutiny in
bright sunlight.

like a lot of terms on the internet, "troll" has a multifaceted etymology.
another root has to do with fishing, particularly "trolling". the troll or
"troller" has cast a line or a net and is just seeing what kinds of and how
many "fish" in the vast sea he'll pick up.

r b-j

 

[Mark Zenier]

In article <6c71b322.0411302043.19838b67@posting.google.com>,
Tom Seim <soar2morrow@yahoo.com> wrote:

"Nicholas O. Lindan" <see@sig.com> wrote in message
news:<A45rd.10847$Ua.6352@newsread3.news.atl.earthlink.net>...
US military establishment ... need their own engineering and
manufacturing capability. That would solve a lot of their
contracting problems with missles as well.

As in Rocky Flats, Fernauld, Savanna River, Hanford, Oak Ridge ...

In general, the fastest way to make a really expensive mess is to
put the (anybody's) govm't in charge.

All those places were actually run by contractors. If you got pulled over
in Richland, Wa, you showed the officer your General Electric company ID,
because the town cops were actually GE Plant Security.

Ever notice where those really big onions come from: Walla-Walla
Washington - just downwind from Hanford; Vidalia - around the
corner from Savannah River. Monster Mutant Onions. I wonder if
they grow around Chernobyl.

Not so. Walla Walla is WSW from Hanford -- prevailing winds here are
from the SW. That means they are heading NE.

Huh? West Southwest of the Tri-Cities is a frigging big ridge of
mountains. Eventally Goldendale, Wishram, and Bingen. Walla Walla
is due East of the Tri-Cities (Richland, Kennewick, Pasco).

Now, there are plenty of crops that are REALLY downwind from Hanford,
like the mint crops (do you chew gum?).

Just east of there is a huge (100 sq miles or so.) California sytle
agro-industrial farm growing just about anything. A lot of fruit
orchards, potoato fields, an a lot of signs saying Private Property
don't come here.

Further east are a bunch of empty Aspargus fields. It seems that
there was an agreement with Peru to replace Coca with other crops.
So the Peruvians found an area, far away from the Coca growing areas,
that could yield three crops of Aspargus a year. The drugs still grow
and one of Washington State's major crops gets screwed.

Mark Zenier mzenier@eskimo.com Washington State resident

 

[Mark Zenier]

In article <3tvpq05e53oi14uk1r407r2r6asgcr661r@4ax.com>,
Jim Thompson <thegreatone@example.com> wrote:

It's Bemelman, what else can you say ?

Maybe somebody should report that guy in Arizona who was trying to
get a system that picked up aircraft ID transponders. You never
know what somebody who wants to know that is REALLY going to do?

Mark Zenier mzenier@eskimo.com Washington State resident

 

[Mark Zenier]

In article <%89rd.26977$zx1.4559@newssvr13.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:

A downside with physical cards is
ambiguity. For example, you may think that you are short of 2N2907
because the card says there are two left but your prototype needs five.
Then, way at the other end of the rolodex there is a card showing dozens
of PMBT2907. Same thing, different manufacturer. A database would find
those.

For my hobby parts inventory, I use a 4x6 card for each generic part,
listing a line for each full number, quantity, and location. That way
you can design with what's in your parts boxes, with the substitutes
already listed.

Mark Zenier mzenier@eskimo.com Washington State resident

 

[Guy Macon]

Arie de Muynck wrote:

I knew, but was still speculating if it was also the reason for the negative
voltage on telephone lines. The dampness on the old telegraph isolators
would cause a small current - and galvanic corrosion. After an industry
switches to a certain polarity, they would stick to it.

Most telegraphs had a different system: a battery on each end.
This resulted in negative ground at one end and positive ground
at the other end, and ground halfway between positive and negative
somewhere in-between.

--
http://www.guymacon.com/

 

[Jonathan Kirwan]

On 2 Dec 2004 06:16:28 -0800, "lemonjuice" <exskimos@anonymous.to> wrote:

Base or source resistance can also affect the result. Also the size of
the signal can affect results. ie Ic = Is exp Vbe + input signal /Vt

I'm assuming that (Vbe2 - Vbe1) is close to zero. Which is the usual case, I
believe where these are used (I've examined their use in all-BJT power supply
feedback circuits, for example, where at times both collectors can feed to the
next similar stage.) Absolute size of signal should be close to zero, what it
usually being sought is the gain near that point. And that's how I proceeded in
my own analysis.

Jon