HDTenEightyP/NetNews huggingface dataset:
From: HSANCHEZ@UCRVM2.BITNET (Harold Sanchez)
Newsgroups: sci.electronics
Subject: High quality PCs for control
Date: 15 Apr 92 19:35:30 GMT
Article-I.D.: nettlera.9204151936.AA07282
X-Unparsable-Date: Tue, 14 Apr 92 21:01:47 UCR


We are trying to upgrade the electromechanical public telephone exchanges in
Costa Rica by substituting their control parts.

The control parts are being changed by PC's or compatibles + I/O interfaces +
programming. Comercial PC's and compatibles are used.

The substitutes work very well due to the simple tasks they have to perform.
This gives us plenty of scope for improvements.

Prototipe modules have being tried with real telephone traffic.

Now we need highly reliable parts for prototipes to be tried during long
periods. Where can we get these (PC motherboards, power supplies, disk drives
and controlers, I/O interface cards, modems, etc.) ? Any military grade PC's?

Is this the proper list for this subject? Should I try another one?
Please e-mail directly to me.
Thanks in advance for any help.

Harold Sanchez          hsanchez@ucrvm2.bitnet

Unidad de Investigacion y Desarrollo
Instituto Costarricense de Electricidad
Costa Rica
From: edhall@rand.org (Ed Hall)
Newsgroups: sci.electronics
Subject: Re: Jacob's Ladder
Date: 14 Apr 92 02:29:19 GMT
Distribution: na
Organization: The RAND Corporation

>> rdi@cci632.cci.com (Rick Inzero) writes:
>>>Note that there exist some big neon sign transformers.  Mine
>>>is rated 15,000 volts at *3000* ma.  This most certainly would
>In article <1992Apr8.161347.3926@ole.uucp>, ray@ole.uucp (Ray Berry) writes:
>>      Must be a real honker- 15 KV * 3 A = 45 KVA :-)..
In article <1992Apr13.093036.425@cmkrnl.com> jeh@cmkrnl.com writes:
>For that matter, what do you power it with?  That's more power than an entire
>house is typically supplied with (residential 100-amp service).

Yup, but 120V at 3A is about right for 15,000V at 24mA.  Perhaps that is
the primary and not the secondary current...

Or maybe it is a 3000 uA secondary. :-)

		-Ed Hall
		edhall@rand.org

Newsgroups: sci.electronics
From: nustad@lightning.med.ge.com (Tim Nustad  x7-4361)
Subject: Re: micro-stepping
Summary: Sources for micro-stepping drive
Keywords:  stepper motors drives	
Organization: G.E. Medical Systems - Ultrasound
Date: Fri, 17 Apr 92 12:56:46 GMT


A couple of people have asked for vendors on drives capable
of microstepping stepper motors:	

Parker Compumotor has a couple of microstepper drives that	
we had  good luck with.  I believe they start at less that $200.
They used to have both "stand alone" and PC card versions.  

The only phone number I have for Parker is (800) 358-9068.  



--
==============================================================
   
   Opinions are, of course, my own and not GE's

   Tim Nustad - nustad@mrsvr.ge.com

===============================================================
From: yqdx@vax5.cit.cornell.edu
Newsgroups: sci.electronics
Subject: Home EEG- HELP me read brainwaves!
Date: 11 Apr 92 18:01:50 EST
Distribution: sci
Organization: Cornell University


  For about 15 years I have fantasized about building an EEG interface
to my home computer, to use for home sleep research.  My early efforts were
unsuccessful.  All I need is advice on how to make a simple amplifier circuit
to the following specifications:
  The input signal (from elecrodes on my scalp) is in the range of 1-50 
microvolts, at 1-100 Hz, presumably with very low current.  For safety reasons, 
the circuit should be powered by a low voltage, say 5, 9 or 12 volts.  The
voltage signal must be amplified into something that can be measured
conveniently.  Because of the low input voltage, my impression is that the most
popular op-amps would be inapproriate.
  OK, it would also be good to turn this into a digital signal that can be
sampled by the computer at roughly 100 Hz.  Can this be simply done?      
Please point me to any relevant references and introductory material.  Thanks.
-Chris B.
YQDX@VAX5.CIT.CORNELL.EDU
Cornell Biochem Dept

Xref: sparky sci.electronics:8090 comp.robotics:940
From: fc0v+@andrew.cmu.edu (Franklin Chang)
Newsgroups: sci.electronics,cmu.cs.robotics,comp.robotics
Subject: Commodore help
Date: 6 Apr 92 21:12:04 GMT
Article-I.D.: andrew.Yds=uYG00VolEnD0oe
Organization: Freshman, Math/Computer Science, Carnegie Mellon, Pittsburgh, PA

Hi,
  I was wondering if anyone knows of a simple hack that will allow the
commodore 64 to work off dc battery supply.  I've heard that the
computer uses the waveform off the ac powersupply as a timer.  Recently
someone posted a solution to this problem, but it required a 60 hz (not
Mhz) oscillator and I'm at a lost to find a 60hz oscillator.  If any can
help, it is fairly urgent.  Our robot is going to a competition on the
Wed 8th.
Thanks
Frank
***************************
   fc0v@andrew.cmu.edu
     Franklin Chang
 Carnegie Mellon University
***************************
Newsgroups: sci.electronics
From: richtt@aix.rpi.edu (Timothy G. Richter)
Subject: Engine Knock Sensor
Organization: Rensselaer Polytechnic Institute, Troy NY
Distribution: na
Date: Mon, 13 Apr 1992 05:32:22 GMT

I need to determine the output of an engine knock sensor.  As far as I
know, the knock sensor is a piezo-electric "microphone" which "listens"
for knock.  Knock occurs at 6.5kHz, and the knock sensor is (I'm guessing)
a narrow-band pass filter at 6.5khz.  Using this assumption, I'd expect
to get a 6.5kHz sine wave at the output when the sensor is exposed to knock.
I can't get engine under load to create knock, so I'm going to try using
a speaker.  Does anyone know how these sensors operate and what the output
is?  This is going to be connected to a microcontroller (68HC16) to help
with fuel injection and spark timing.

Thanks in advance for any help!

-Tim Richter
richtt@rpi.edu


Newsgroups: sci.electronics
From: pdh@netcom.com (Phil Howard )
Subject: Re: VCR+ Algorithm?
Date: Fri, 17 Apr 92 04:38:03 GMT
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Distribution: na

ferguson@bgsu.edu (Douglas Ferguson) writes:

>Boy, talk about misplaced anger.  TV Guide doesn't make money from the codes.
>VCR+ makes the money by selling the devices!  VCR+ is therefore protective
>of the algorithm.
>
>TV Guide (and all the newspapers who carry the codes) actually PAY FOR
>THE PRIVILEGE.  And VCR+ gets the money.  

They would not do this unless it was to their financial advantage.


>So why do the listing services pony up big bucks for the codes?  Because
>VCR+ has them convinced that if they don't, their competitors will.
>And as long as any one listing service does use the codes, the rest are 
>forced to fork over money for the codes.
>
>What a racket.

True.

Maybe I should go with my own code anyway.
-- 
/***********************************************************************\
| Phil Howard  ---  KA9WGN  ---  pdh@netcom.com   |   "The problem with |
| depending on government is that you cannot depend on it" - Tony Brown |
\***********************************************************************/
Newsgroups: sci.electronics
From: jeffj@seeker.mystic.com (Jeff Jones)
Subject: Where to find Sand prices of Strain Gauges?
Organization: Mystic Software Pittsburg, Ca
Distribution: usa
Date: Wed, 8 Apr 1992 21:09:42 GMT

I need to know where to find and what the prices are of strain
gauges for a project that I am doing. I need one to glue to a 
metal plate to measure the flex of. I checked out some transducers
but their prices where way out of sight. I don't need a lot of
accuracy so tolerences can be fairly loose. Thanks for any help
here!

Jeff

-- 
 Jeff Jones KC6SKV/AE      | Prediction is very difficult, especially
 UUCP   uunet!seeker!jeffj | about the future.
 Infolinc BBS 510-778-5929 |          Storm Petersen
From: lordSnooty@cup.portal.com (Andrew - Palfreyman)
Newsgroups: sci.electronics
Subject: Info on iron-on PCBs??
Date: Sun, 12 Apr 92 16:37:46 PDT
Organization: The Portal System (TM)
Distribution: world

I missed saving the fairly recent thread on iron-on PCBs, and now I
need the data. Could someone email me on this please?
				- Andrew Palfreyman
From: mark-r@ee.man.ac.uk (Mark Robinson (JO PhD))
Newsgroups: sci.electronics
Subject: Re: Whatever happened to IEC 617:12 ?
Date: 7 Apr 92 08:49:45 GMT
Reply-To: mark-r@sneezy.ee.man.ac.uk (Mark Robinson)
Organization: Dept Electrical and Electronic Eng, Manchester University, UK

In article <2139@exua.exeter.ac.uk> CDHWilli@exua.exeter.ac.uk (C.D.H.Williams) writes:
>
>A few years ago lots of digital people were getting excited about IEC
>617-12: Binary Logic Elements "revolution in symbology" they said.
>Well, it's half a decade later now and most people I know still draw
>logic circuit diagrams just like way granny used to.  What happened?
>Was it ever adopted?  If so does anybody find them genuinely helpful?
>If so, for what? Does anybody with significant commercial clout (eg
>DoD) actually insist that subcontractors/employees use them?

[ascii deleted]

Pop down to your local Maplins and have a look in the Texas Instruments
High Speed CMOS databook. This (and I believe all other TI literature)
uses the new-fangled symbols.

Fortunately, they also include an appendix explaining what they all mean
to those of us who are used to drawing circuits in old money.

I think companies which have installed CAD drawing systems probably use
these symbols extensively, the rest of us can't afford a new logic stencil
yet.

>Charles.          C.D.H.Williams@exeter.ac.uk

Mark
mark-r@snow_white.ee.man.ac.uk
From: shihtsun@ec.ecn.purdue.edu (Shih-tsun Alex Chou)
Newsgroups: sci.electronics
Subject: "smart" terminals list
Date: 6 Apr 92 18:40:50 GMT
Article-I.D.: noose.1992Apr6.184050.17901
Distribution: usa
Organization: Purdue University Engineering Computer Network

I'm planning to buy a used "smart" terminal, like WYSE50 or VT220.
Could anyone suggest more models? 
And, is that possible to buy a new "smart" terminal for under $200?
(I know it's quite impossible :-) ).
Thanks!!

Alex
Newsgroups: sci.electronics
From: dcovell@pcocd2.intel.com (David Covell)
Subject: Detecting muscle voltages
Organization: Development Tools Operation, Intel Corp., Hillsboro, OR
Date: Thu, 16 Apr 92 17:46:41 GMT


I'm interested in experimenting with the detection and digitizing of the
voltages involved with human muscle activity. I intend to use the electrodes
they use for EEG testing, placing them over certain facial muscles.
I don't know what sort of voltages I'll see, but I assume they'll be quite
low and I'll need to use a low-noise op amp before I do my A/D conversion.
Anyone out there have a good estimate of the levels I'll see?
------------------------------------------------------------------------------
DAVID COVELL (dcovell@pcocd2.intel.com)|Wrangler of acoustic, electric, and
INTEL FOLSOM (California)              |Midi guitars, basses, synths, CAD tools
DESIGN ENGINEERING, EPG GROUP          |and assorted other techno-beasties
From: smckinty@sunicnc.France.Sun.COM (Steve McKinty - Sun ICNC)
Newsgroups: sci.electronics
Subject: Re: Ohm's law for AC?
Date: 13 Apr 92 16:09:43 GMT
Organization: Sun Technologies Enterprise Inc.
NNTP-Posting-Host: hardy.france.sun.com

In article <oduNdSC00UhB81Orc1@andrew.cmu.edu>, rc4n+@andrew.cmu.edu (Raymond C. Chick) writes:
   > I record classical music and have recently begun to investigate the
   > affects of cable resistance on mic. level audio signals.  I used two
   > cables, one about 20' and the other about 350'.  I passed identical
   > signals through each cable and measured the  outputs levels for various
   > frequencies.  I found no difference in output level between the two
   > cables for frequencies from 100Hz. to 16Khz. Yet, the restistance of the
   > short cable was .5 ohms and the long cable was 5.5 ohms.
   > 
   > Shouldn't the long cable attenuate the signal or even roll of the high
   > frequencies?

Most hifi equipment has impedances much more than 5 ohms, and will probably
swamp such a small difference.

The inductance/capacitance of the cable will have a much greater effect. Try
applying an accurate 16Khz squarewave at one end of the cable, and look at
it on a 'scope at the other. Chances are it will have become slighly
rounded at the corners, since the different frequencies will have been
delayed (phase-shifted) by different amounts.

Steve
Newsgroups: sci.electronics,misc.consumers
From: scotty@verdix.com (Scott R. Chilcote)
Subject: Re: goodbye Heathkits
Organization: Verdix Corp.
Date: Tue, 7 Apr 1992 02:57:30 GMT

lstowell@pyrnova.pyramid.com (Lon Stowell) writes:

>   The Heath devotees were usually electronics techs or wannabees
>   that enjoyed wrapping cap leads around resistors before soldering
>   these onto a blank board.   At no time could you really save
>   money by buying Heath.


I can argue against this point.  When I was in high school making $2.65 an
hour for thirty hours a week, Heath made test equipment that was affordable
to me, when the prices of the "pro" stuff were way out of reach.  In particular
Heath had a line of modular items including a RLC Bridge, Audio Oscillator, and
RF Oscillator that sold for about $40 each.

Granted, this stuff was not price competitive with the real gear, and it ran on
9V batteries -- but it *was* useful and educational, and let me tackle some 
fixup work that kept me in stereo components and TV sets cheaply...

I knew I should have bought that matching power supply while I still could!


-------------------------------------------------------------
Disclaimer: I do not represent Verdix Corporation, and my
postings do not represent their opinions.  
-------------------------------------------------------------
                                            Scott R. Chilcote
                                            scotty@verdix.com  - or -
                                            scotty%verdix.com@uunet.uu.net
Xref: sparky sci.electronics:8254 rec.bicycles:9039 rec.motorcycles:12695
From: jrsargeant@lescsse.jsc.nasa.gov (JACK SARGEANT)
Newsgroups: sci.electronics,rec.bicycles,rec.motorcycles
Subject: Re: Sticky Demand Traffic Light problem solution
Date: 9 Apr 1992 16:31:16 GMT
Organization: Lockheed Engineering and Sciences

In <1992Apr8.151153.20720@ohrd.uucp> ohrd!jlevine@cs.toronto.edu (Jody Levine) writes:

>In article <-slj0+=.jps@netcom.com> jps@netcom.com (John Serafin) writes:
>>sagerian@delphinium.UUCP (Steve M. Sagerian) writes:
>>
>>>I fact I was supprised no one mention that aluminum (sp?) wheels have no effect on the sensor at all.
>>
>>Then how does an aluminum frame with aluminum wheels trip sensors?
>>(It happens frequently.)

>The question is, how do these things really work? Do they detect a change in
>reluctance (magnetic flux resistance, higher in air than iron) over the pad
>by measuring magnetic field due to the current loop elsewhere than in
>the loop, or do they detect voltage drop in the loop due to eddy currents in
>the passing object? My guess is the latter, as it's easier to detect energy
>losses than magnetic field patterns. If this is the case, then any conducting 
>object would work, as long as it's big enough.

They (at least the ones which have seen) detect the change in frequency of the
devices oscillator when something in the loop's field causes its inductance to
change.  

Proximity to the loop seems to have more efect than does total mass of the 
object in the loop field.  A low-slung car is easier to detect than a tall
18 wheeler truck!

I am not familiar with all of the detaila nor with the theory, but did see
a demonstration and discuss performance a little when a group experimenting
with these things was trying to find a loop antenna to use in mapping the
sensor loop's field.

>It could also be the steel in the engine, if they work the other way.

>I've        bike                      like       | Jody Levine    DoD #275
>     got a       you can        if you      -PF  | ohrd!jlevine@cs.toronto.edu
>                         ride it                 | Ontario Hydro Research
--
Jack R. Sargeant, Sr. W0RIJ             These opinions are mine and only mine 
Computer Systems Specialist             (unless you want to claim them).
Lockheed Engineering & Sciences Co.
Someday (maybe) we'll get E-Mail and FTP access.  In the meantime, we post.
From: dclaar@hpcuhe.cup.hp.com (Doug Claar)
Date: Wed, 8 Apr 1992 17:14:49 GMT
Subject: Re: Casio Databank Touch Screen Watches
Organization: Hewlett Packard, Cupertino
Newsgroups: sci.electronics

>A friend of mine in college a few years back claimed to have seen (had?)
>a version of the DB in which the calculator included scientific and trigo-
>nometry functions!  That would be GREAT!  Has anybody seen any such animal?
>Can anyone tell me/us where to get it?

I had one of these. It also did hex, octal, binary and decimal math,
but it didn't have any phone or appointment storage capability. 
Unfortunately, it died. Finding no satisfaction at the local stores,
I called Casio directly. No joy--they stopped making that model 
several years ago. I guess not enough nerds#####people bought them.
I now have the DBC-62, which has a really lame calculator (at least
compared to my old one, R.I.P.), world time, and room for 50 phone
numbers or appointments. 

What I'd really like to see is one that can be downloaded with
appointments...and a decent calculator again. Sigh. I miss my
old watch.

--Doug Claar
dclaar@cup.hp.com
From: dougm@pnet51.orb.mn.org (Doug Mcintyre)
Newsgroups: sci.electronics
Subject: Re: Sony remote controll
Date: 14 Apr 92 19:05:01 GMT
Organization: People-Net [pnet51], Minneapolis, MN.

>In sci.electronics, ldstern@rodan.acs.syr.edu (Larry Stern) writes:
>
>>To all: a neighbor of mine has a 6-7 year old Sony Trinitron, which works
>>well except for the remote control. The remote had an intermittent problem
>>where it would work fine for a few weeks, not work at all for a few days,
>>start working ok again, etc. It seems it is now, finally, dead. There is
>>one IC, a crystal, a few resistors and caps, and an LED inside. My question
>>is, what usually goes? Is this worth fixing? And finally, can this LED be
>>tested with an ohmeter like a "regular" diode?

In my experience, it is generally a cracked solder joint  from the remote
being ``dropped'' accidently or so. Since the circuit is so simple (yes an IR
LED is the same as a visable light LED), its fairly simple to trace the signal
around the circuit. Ie. check at the base of the transistor, and at the
collector, check at the LED, etc. etc. Wiggle things around alot.

UUCP: {tcnet, crash}!orbit!pnet51!dougm
ARPA: crash!orbit!pnet51!dougm@nosc.mil
INET: dougm@pnet51.orb.mn.org                                GENIE: D.MCINTYRE1
Newsgroups: sci.electronics
From: robin@uhunix.uhcc.Hawaii.Edu (Robin Amano)
Subject: 7 segment
Organization: University of Hawaii at Manoa
Date: Wed, 8 Apr 1992 20:26:53 GMT


Anyone know where I could get large 7 segment displays?
I'd like to make a timer, and a scoreboard.  I made some
5" X 7" with LED's but I was hoping I wouldn't have to
make anymore because they are kind of a pain.
Thanks!!  Oh, it doesn't have to be a certain size, just
pretty large would be good.

--
--------------

rob
uhcc
From: fdeck@sleepy.helios.nd.edu (francis deck)
Newsgroups: sci.electronics
Subject: Advice on high-speed ADC
Date: 15 Apr 92 15:59:15 GMT
Article-I.D.: news.1992Apr15.155915.1515
Organization: University of Notre Dame, Notre Dame


I am gearing up to build a "digital sampling oscilliscope"
which connects to the parallel printer port of an IBM PC.
My idea is to clock a high-speed flash ADC into a static
RAM chip.  After a "frame" worth of data are thus collected,
they are transferred to the PC at lower rate for subsequent
display, etc.  

I am looking at the CA3306D converter which can hum along
at 15 MHz.  So, this will be my target clock rate, with
lower rates available by dividing the clock down.

I would love to hear advice from anybody who has tried such
a project, or who has good ideas....

f. deck
From: froncio@caip.rutgers.edu (Andy Froncioni)
Newsgroups: sci.electronics
Subject: Timing, A/D, and LCD Displays
Keywords: circuits a/d timing
Date: 7 Apr 92 18:33:55 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

I am planning on building a very very small circuit board that
will fit on the steering wheel of a race kart.  I would like to
implement several functions:

    i) display of lap timing (driver clocks himself), with lap memory
   ii) display of engine rpms with MIN and MAX memory

and, in the far far future:

  iii) display of various MUX-ed channels (temp, oxy sensor, knock activity...)
       and storage of MAX. and MIN. values.

I am looking for IC's that will perform as many of these functions
as possible with as few external components as possible.  

Function i) could, for example, be handled by a chrono chip, but
can you get these off-the-shelf?  Who makes them?

Function ii) is considerably harder, I imagine.  Does anyone care
to suggest a nice tight design.  I am looking to make a very tiny 
box, remember...

Finally, what LCD displays/drivers will I need?  

Please send me your favorite implementations of these.  If there are
enough replies and enough interest, I will summarise the responses.

Thanx,

Andy
-- 
Andy Froncioni			CAIP Center Parallel Computing Lab
froncio@caip.rutgers.edu	Rutgers University, Piscataway, NJ

  " Until the lions have their own historians, 
    tales of hunting always glorify the hunter..."   Zulu proverb
From: saevans@l_cae14.icaen.uiowa.edu (Scott A Evans,,,)
Newsgroups: sci.electronics
Subject: Re: Intel Ad shows static-proof CPU! :-)
Date: 8 Apr 92 00:53:27 GMT
Reply-To: saevans@icaen.uiowa.edu

From article <9bqjdqq@lynx.unm.edu>, by dmckeon@hydra.unm.edu (Denis McKeon):
> There is an Intel ad on pages 10 and 11 of the April 13 Newsweek (USA
> news-stand edition) that shows two Van de Graaf generators on either
> side of an i486 (tm) with dual "lightning" paths jumping between them. 
> Caption reads: "The affordable power source for today's software."
> 
stuff deleted for brevity........

> You would really have to see the ad to get the full visual impact - 
> I was reading Newsweek in a restaurant, turned the page, and broke up.
> A couple of people asked if I was okay.  Luckily I was able to stop
> laughing before they tried to administer the Hiemlich maneuver.
>
It has also been on Television recently.  Maybe that's where they dig up the
random function generator... At least they stopped the Vacancy add campaign.
I was beginning to worry about all of the electronic noise from that flashing
neon!

--
                                              / /  *\  
          Scott A Evans                      /0/ __O/  
     (saevans@icaen.uiowa.edu)      |TTTTTTTTTTTTTT\\T| 
       Grad Student For Life        |IIIIIIIIIIIIIII\\|  
                                    |      / \      / \  
                 o                  |     /  /      \ |\
              _ /-_                 |                 |  
             (_)>(_)             --------------------------
From: stever@mrcnext.cso.uiuc.edu (Steve E. Robinette)
Newsgroups: sci.electronics
Subject: Electrostatic Field Promotes Hair Growth ???
Date: 8 Apr 92 07:08:56 GMT
Article-I.D.: ux1.1992Apr8.070856.10703
Organization: University of Illinois at Urbana

Has anyone heard of this??? It seems a company in Canada has designed a device that looks like a beauty salon hair dryer. The hood has four pairs of
positively and negatively charged electrodes, which are powered by a 12-volt
battery. While the patient sits under the hood for twelve minutes, his/her
head is surrounded by an electrostatic field of positive and negative charges
which stimulate hair growth. No one knows eactly why the treatment works, but when a patient takes the treatment once a week for a period of one to two years, hair comes back. This is a treatment not a cure. It must be continued for life

Can anyone "shed" any light on how this might work. Seems as though you
could build you own quite easily instead of the $4500 a month they'll be 
charging to use it. Be interested to hear some ideas...

stever@mrcnext.cso.uiuc.edu