Driver to drive?

[Fred Bloggs]

John S. Dyson wrote:

It is amazing that the human mind is so very complex, that otherwise
very intelligent people can have their emotional immaturity and
weaknesses be so easily manipulated by people like Soros, Michael Moore,
and Kerry.

John

There you go again with that friggin *mind* crap! The reason you are so
ignorant is that you are scared of your own shadow. I pity the
individual who has so little belief in his own sanity that he is
actually terrified of the slightest exposure to any ideas or information
that might contradict his beliefs. You are definitely *shattered*- the
best thing for you to do is get absorbed in your electronics and stay
away from everything else.

 

[Bob Stephens]

On Thu, 07 Oct 2004 14:01:45 +0100, Paul Burke wrote:

Don Pearce wrote:


Well, it will certainly turn a fruit cake into a cabbage - if you
consider that to be working. I don't consider it to be much of an
advance over the blade-up-behind-the-eye-socket lobotomy.


It may be an urban myth, but I have heard of a British hospital that
used an ECT machine for years, no one noticing that it was broken.
Apparently the results were exactly as though the machine had functioned
normally.

Paul Burke

I've heard of people faking convulsions, but it would be a pretty good
trick to fake inducing them...

 

[Bob Stephens]

On Thu, 07 Oct 2004 08:04:34 +0100, Paul Burke wrote:

IEEE symbols, which were an attempt to sort all this out, never really
took off,

Thank God!

Designed around the
computer and plotter capabilities of the 70s, and profoundly anti-
intuitive,

Hear Hear!

Bob

 

[Winfield Hill]

Winfield Hill wrote...

They also say,

V_MAX = Maximum voltage device can withstand without damage at
its rated current.

This is 60V, but the maximum rated current is 3A, and that's for
continuous operation.

OK, sorry, I misread that spec. For "maximum current" it says,
"IT = Trip current - minimum current at which the device will
always trip at 23℃ still air." So that's the maximum current
to insure tripping at room temp, that could ever be observed for
one of these parts.

The curves on page 3 show a trip time of 1 second at 3A for the
FRH160-600, the largest 600V PTC. Clearly it can handle much
higher currents, and will then trip much faster. I seem to have
misunderstood when assuming that the "maximum current" spec was
related to the V-max spec.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Al]

In article <hjaam0dehtfp1avu8ush5ogdtpojjgtcg6@4ax.com>,
Glen Walpert <gwalpert@notaxs.com> wrote:

On Wed, 6 Oct 2004 18:18:03 -0400, "Robert Morein"
nowhere@nowhere.com> wrote:

"Glen Walpert" <gwalpert@notaxs.com> wrote in message
newsrn7m0tf82a2rjcj13sscuh7occ8f5m1k5@4ax.com...
On Wed, 6 Oct 2004 01:49:11 -0400, "Robert Morein"
nowhere@nowhere.com> wrote:

"John Woodgate" <jmw@jmwa.demon.contraspam.yuk> wrote in message
news:mFfMHMBKz3YBFwq3@jmwa.demon.co.uk...
clip
On the other hand,
explosive rupture of a battery pack close to the abdomen could,
concievably, be lethal.

Yes, but the probability is probably lower than that of being fatally
kicked by a horse.
--
The two probabilities are not in the same universe of discourse because I
don't ride horses. OTOH, I am in close proximity with lithium packs.

I am pretty sure John assumed you don't ride horses when he assigned
the lower probability to the exploding battery pack. All computer
lithium battery packs include a thermal fuse in direct contact with
one or more cells, so a cell explosion requires multiple simultaneous
failures including at least a low impedance short across the battery
and thermal fuse failure.

The above is not true. Thermal runaway is possible within a single cell.
See:
http://www.ewh.ieee.org/cmte/PES-SBC/Downloads/sWM04_LithiumBatTech-Valence.p
df

OK, this article claims that it is a myth that protective devices will
prevent all battery explosions, and they are probably right. But they
only provide 2 examples of battery "explosions" including a single
laptop computer, and these incidents resulted only in minor burns.
Presumably the designed in cell overpressure venting features worked,
and these "explosions" consisted primarily of the venting of hot
gasses, which are not nearly as dangerous (or likely) as being kicked
by a horse. Even if the vent failed, the case of a lithium battery is
too thin to allow enough pressure to develop to cause penetration of
the laptop case when the cell ruptures. "Possible" is quite different
than "probable", and the "explosion" of a lithium cell is quite
different than the explosion of a roadside bomb in Iraq! But if you
are really concerned about the slight possibility of second degree
burns, how about a nomex lap pad?

Great, execpt in the USA, two is two too many. We ban items when 6
people get hurt over a 5 year period even though millions have used them
safely.

Al

 

[Fred Bloggs]

Tom Seim wrote:

fred,

you have just invented a substitute for Valium. Suggest you patent it
immediately. Must go to slee.....

You're way too dumb to see it- but you're witnessing the beginning of
the end. You are not so old that you will escape experiencing the
horrific chaos about to unfold. The upside for you is that you will not
last three days- you're not tough enough to survive.

 

[Rich Grise]

On Thursday 07 October 2004 06:05 am, John S. Dyson did deign to grace us
with the following:

Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> writes:
(John S. Dyson) wrote:
[everybody's nuts]
Why stop there?

Letter from Dr. Wurm, of the Wuerttemberg Evangelical Provincial
Church, to Reich Minister of interior Dr. Frick, September 5, 1940

Dear Reich Minister,

On July 19th I sent you a letter about the systematic extermination of
lunatics, feeble-minded and epileptic persons.

I am CERTAINLY not suggesting that the feeble minded pro-Democrat hate
mongers be 'exterminated!!!' However, it is true that their own
vehement attitudes could extend to exterminating those who don't think
just like them. The ongoing attacks against GOP establishments seems
to be the start of such a movement. There have already been some
organized movements against GOP representative (multiple attacks on the
same day, apparently coordinated at higher levels in the Dem party.)

My own interest is in HELPING those who are so very consumed by hatred,
and NOT trying to totally redirect or modify their general position. The
'hatred' is an overly strong manifestation of partisanship, and seems
to result from very immature personalities.

So, you're gonna save their soul if you have to burn them at the stake
to do it, huh?

Opposition and for/against any given party is an OKAY thing. Hatred
is problematic.

Ever looked in a mirror?

Thanks,
Rich

 

[Rich Grise]

On Thursday 07 October 2004 05:47 am, Fred Bloggs did deign to grace us with
the following:

Rich Grise wrote:


It is not ranting,


It comes off as ranting, Fred. When you get into tirade mode, it's so
easy to dismiss you as lunatic fringe.

I am not concerned in the slightest about your opinion. You are so
simple, so ignorant, and lacking so much background information that it
makes no difference what you think. Your political posts are an endless
stream of superficial and non-informational pseudo-philosophical
garbage- absolutely worthless drivel.

OK.

 

[Paul Burridge]

On Thu, 07 Oct 2004 14:01:45 +0100, Paul Burke <paul@scazon.com>
wrote:

It may be an urban myth,

It is.

but I have heard of a British hospital that
used an ECT machine for years, no one noticing that it was broken.
Apparently the results were exactly as though the machine had functioned
normally.

Your recollection is faulty. There was such a case, certainly, but it
didn't involve ECT. It must have been some other costly piece of junk
but I can't remember quite what it might have been after so long.
--

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

 

[Winfield Hill]

Fred Bloggs wrote...

You're way too dumb to see it- but you're witnessing the beginning
of the end. You are not so old that you will escape experiencing the
horrific chaos about to unfold. The upside for you is that you will
not last three days- you're not tough enough to survive.

Whatever are you talking about, Fred?


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Paul Burridge]

On 7 Oct 2004 03:49:24 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:

Fwliw There are limited ways round some of those issues for some
cases, but theyre unsatisfactory for most things. I'm thinking there
of ebay for very low volume production specialist items - not relevant
for ampman.

I wonder if it's the same bloke who posted the same request here last
year?
--

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

 

[Rich Grise]

On Thursday 07 October 2004 05:12 am, Matt Strandberg did deign to grace us
with the following:

I am still in college but I can tell you I took a class that was centered
around this microcontroller. We used it for data acquisition (i.e.
interfacing it with a pressure sensor and embedding a program that can
determine if a filter is operational). Toward the end of the course, we
used it in combination with a PC to implement a digital voltmeter. Since
I am a student, our possible uses for this microcontroller were limited
due to
lack of experience. I can tell you, however, the HC11 language is pretty
easy to pick up and when you combine it with a cross assembler, you can
build and embed some pretty powerful programs.

Hope this helps

I've worked with them before. It's a very nice architecture. Having been
raised on intel, the counter took a little getting used to, but after I
figured it out, I prefer it.

Be sure and get the full development system, or at least a simulator/IDE.
I wouldn't want to try to design it in without one.

Have Fun!
Rich

 

[John Larkin]

On 7 Oct 2004 04:26:38 -0700, Winfield Hill
<Winfield_member@newsguy.com> wrote:

Kevin Aylward wrote...

James Cheung wrote:

I am studying transimpedance amplifier (TIA) circuit for photodiodes
with bit rate approaching 2Gbps.

So far I have seen in the literature, Op Amp like TIA IC are used
to amplifier the current signals to voltage signals.

No chance. This is way to high for op-amp based designs on the front
end.

I have seen data sheets for opamp-style transimpedance amplifiers
with built-in feedback resistors having bandwidths exceeding 2GHz.
Offered for example by Agilent. Lately Agilent has withdrawn many
of these parts, offering them only in optical receiver components.

I think one of the Maxim parts will go that fast. To get speeds like
that, people usually wire-bond the TIA chip right next to the pin
diode to keep the critical node capacitance down.

John

 

[Phil Hobbs]

John Larkin wrote:

On 7 Oct 2004 04:26:38 -0700, Winfield Hill
Winfield_member@newsguy.com> wrote:



Kevin Aylward wrote...


James Cheung wrote:


I am studying transimpedance amplifier (TIA) circuit for photodiodes
with bit rate approaching 2Gbps.


So far I have seen in the literature, Op Amp like TIA IC are used
to amplifier the current signals to voltage signals.


No chance. This is way to high for op-amp based designs on the front
end.


I have seen data sheets for opamp-style transimpedance amplifiers
with built-in feedback resistors having bandwidths exceeding 2GHz.
Offered for example by Agilent. Lately Agilent has withdrawn many
of these parts, offering them only in optical receiver components.



I think one of the Maxim parts will go that fast. To get speeds like
that, people usually wire-bond the TIA chip right next to the pin
diode to keep the critical node capacitance down.

John



Yes, or bump-bond the PD to the TIA chip to go even faster. Guys in my

building are making 40 GB/s TIAs in silicon-germanium that work like
that. Using silicon-carrier packaging, you can get connections shorter
than a wirebond, and with controlled impedance yet.

Cheers,

Phil Hobbs

 

[John Larkin]

On Wed, 06 Oct 2004 22:31:58 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

On Wed, 06 Oct 2004 09:46:57 -0700, the renowned John Larkin
jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:

You can do the reverse: feed back a bit of the ramp voltage into the
guts of the current source such as to increase the current as the ramp
runs. This adds a t-squared term to the curve, nearly compensating
shunt resistance or any other effects that bow the ramp down. I've
done this with 25 ns ramps.

Nice trick.

Reminds me of the old RTD linearization trick. Well, sort of.
John

Sort of.


Best regards,
Spehro Pefhany

Oh, arcane tidbit: you can linearize an RTD by putting a negative
resistor across it. It's some number of kohms... can't recall the
exact value.

John

 

[Don Taylor]

"Daniel Kelly \(AKA Jack\)" <d.kellyNOSPAM@NOSPAM.ucl.ac.uk> writes:

Incidentally, there already exists an "electronic brain stimulator". And
it's used frequently for cognitive neuroscience research. It's called TMS
(transcranial magnetic stimulation). I'm a bit scared of it so I've never
had it done... the idea is that you place a large coil close to the head,
then you pump 8000Amps through the coil in a short burst, this creates a 2
tesla magnetic field which induces current in the brain.

There are published results in the journals out now that show much
lower levels of magnetic fields, thousands of times lower or even
smaller, have observable effects on the brain.

Things on the order of little reed-relay coils with an iron core
being driven by perhaps a dozen volts with frequencies in the low
tens or hundreds of hz appear to be enough to observe effects.

Apparently nobody tried these low level varying frequency stimuli
in the past, that is the only explanation I can imagine why this
wasn't discovered earlier.

 

[Kevin Aylward]

Winfield Hill wrote:

Kevin Aylward wrote...

James Cheung wrote:

I am studying transimpedance amplifier (TIA) circuit for photodiodes
with bit rate approaching 2Gbps.

So far I have seen in the literature, Op Amp like TIA IC are used
to amplifier the current signals to voltage signals.

No chance. This is way to high for op-amp based designs on the front
end.

I have seen data sheets for opamp-style transimpedance amplifiers
with built-in feedback resistors having bandwidths exceeding 2GHz.

I cant see that they act much like op-amp feedback amps, not with around
a loop gain of say, 1 or 2. The FB resister can hardly steal all the
current as it should. Noise is probably going to be a bit of an issue,
and thank the lord its only small signals, otherwise with no loop gain,
it would be volts on the diff input pair!


Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[CBarn24050]

Subject: Compact fluorescent light failures
From: "Peter E. Orban" peter.orban@nrc.ca
Date: 07/10/2004 15:52 GMT Standard Time
Message-id: <41655831.86B224A1@nrc.ca

Hi Everyone,

We replaced most of our incandescent light bulbs with compact
fluorescent bulbs about a year and a half ago (it was before the NA
blackout last year). The bulbs are holding up fine, except in the
bathrooms, and I am wondering what could be the reason.

These lamps do not like being turned on, in situations where they are on for
short periods during the day they will fail quicker than lamps left on for long
periods.

 

[Joerg]

Hello George,

That filter is gonna be tough to do in the tens of MHz without a DSP, I
think.

Not really if you check other markets that need wider filters with good

group delay flatness yet steep slopes, such as television.

I'm dealing with channels about 15 kHz center-to-center (only about
5 kHz guard bands) at 200 MHz. That's a pretty small percentage bandwidth,
and the filter has to have good group delay too. The receiver also has to
be able to tune to all the channels. So putting a detector up front and a
good filter in front of that, might be as difficult as using a DSP that does
both jobs. Will have to look hard at all the alternatives.


As Tim already mentioned, detecting the onset of a transmission in that

small bandwidth is going to be very tough and requires an SNR that you
might not be able to reach over longer distances. A correlation scheme
via comparing a code to a matched filter has a higher chance here but
that certainly needs a DSP or some digital hardware.

Prices have come down big time, mostly because of the advent of DSL and
cable modems. Check out TI. Yes, these DSP can do all the math you want
to perform afterwards on the same chip that does the detection. Also,
you may be able to pull routines from a library if the manufacturer
provides them. But in this application a DSP may still be overkill.



Thanks for the pointer, I would not have thought to look at components for
cable modems. The DSP I used a few years ago was an Analog Devices part,
but I am not up to date on what has become available since then.


It's not just modems. The craze to cram every conceivable gizmo into a

cell phone (for reasons that escape my consciousness) has also fueled
the DSP market. Prices really are only a fraction of what they used to
be in the early 90's. I remember the shoe horn strategies to squish
enough performance out of a 2105 because we only had a $10 max budget
for the DSP. Now you get a Rolls Royce chip for that amount.

Vielen dank


Gern geschehen. (did it with pleasure)

Regards, Joerg

http://www.analogconsultants.com

 

[CFoley1064]

Subject: 68hc11 What can I build with it?
From: john_20_28_2000@yahoo.com (jm)
Date: 10/6/2004 8:59 PM Central Daylight Time
Message-id: <c67e4bdd.0410061759.24451bd4@posting.google.com

I was given a 68hC11 and was wondering if it is possible to use it for
a "newbie" type project or is it way too complex? I am a computer
programmer and am not afraid of assembler. Some electronics
experience. Thanks for any ideas or links.

A plain MCU chip by itself isn't going to do you a whole lot of good. If
you're interested in learning about 68HC11 processors on the cheap, try the
following website:

http://www.technologicalarts.com/myfiles/mc11.html

In concert with Motorola/Freescale, Technological Arts is offering a 68HC11
Stamp with lots of goodies (including ASM, SBASIC, and trialware/shareware for
BASIC11 and C, along with a diskful of goodies, for $68 (USD) and up. They
even give you a serial cable. Pretty tough to beat this.

Good luck
Chris