HDTenEightyP/NetNews huggingface dataset:
From: brad_lange@chdqm1.sps.mot.com (Brad Lange)
Subject: Re: Thunderstorms
Followup-To: sci.electronics
Organization: Motorola inc.
Date: Wed, 7 Oct 1992 18:20:49 GMT

In article <1687984FF.FC138001@ysub.ysu.edu>, FC138001@ysub.ysu.edu (Phil
Munro) wrote:
> 
>   We've seen lots of theory, but only a few experiences, of lightning
> doing damage to computer equipment.  Would anyone have some details
> about damage done to equipment?  This might give us a better idea of
> how much of a problem lightning actually is, direct hits, EMP, etc.
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>   FC138001@ysub.ysu.edu  Phil Munro       Youngstown State University
>   Electrical Engineering Department           Youngstown  Ohio  44555

     My father had his IBMxt fried by a lightning hit a few years back. He
had installed a surge suppressor for both the power and phone lines. The
lightning actually blew most the chips off the mother board and destroyed
the modem board. It didn't damage any other boards plugged into the mother
board or the hard disk, floppy disk, or the monitor. The lightning also
blew out a heater floor mat under his desk. Apparently, the lightning had
hit the metal pole outside the building that the power lines came in
through. There was a melted portion visible on the top of the pole. This
occured in Indiana.

Brad
From: an938@cleveland.Freenet.Edu (George II Lenzer)
Newsgroups: sci.electronics
Subject: need MIDI merger help
Date: 9 Oct 1992 04:01:43 GMT
Organization: Case Western Reserve University, Cleveland, Ohio (USA)
NNTP-Posting-Host: slc4.ins.cwru.edu


	I am interested in building a MIDI merger box.  I was
going to try this a while ago and was told that it would require
a Microprocessor and some code.  I would like anybody's help with
this undertaking.  Right now I need to know which Micro to work 
with.  Does anyone possibly have a schematic of such a project?
Thanckz in advance!

						George II Lenzer

-- 
"I'll let you in on a little secret.
	The whole universe is totally INSANE!!!!"
						Mr. Natural
From: rkh@hongkong.WPI.EDU (R Kurt Heinzmann)
Newsgroups: sci.electronics
Subject: Re: Heat-battery - info needed
Date: 16 Oct 1992 22:59:49 GMT
Organization: Worcester Polytechnic Institute
NNTP-Posting-Host: hongkong.wpi.edu

In article <jms.1.719244147@cs.ufh.ac.za> jms@cs.ufh.ac.za 
(Inus Scheepers) writes:
>I'm looking  for information on what could be termed a Thermovoltaic cell:
>A battery that generates power from a heat differential. Does such a thing
>exist? All help, clues and info will be deeply appreciated... 
>--
>Inus Scheepers, Dept Comp Science, Univ of Ft Hare, Alice 5700, South Africa

Such a thing exists.  Thermoelectric couples can be used either to cool or
heat by the Seebeck effect (semiconductor heat pump), or to generate 
electricity by the Peltier effect (Seebeck effect in reverse).  Most 
commercially available thermoelectric devices consist of Bismuth Telluride
or Lead Telluride, and can withstand from 100C to 250C.  With the cold side
a few degrees above ambient, the efficiency is typically 5 per cent or less,
but they are nevertheless viable alternatives to other technologies in
some cases.  I suspect concentrated solar heat would be difficult to 
control; catalytic combustion of gas fuels is reliable.

After adding the required fins to transfer heat, power density is probably
in the neighborhood of 15-30 W/kg.  Cost is high; a single 2.1W unit costs
US$50 (unless you can get some kind soul to donate some :-)

-Kurt Heinzmann
From: dvsg0223@uxa.cso.uiuc.edu (David Salamon)
Newsgroups: sci.electronics
Subject: Universal Chip Programmer FOR SALE
Summary: Universal Chip Programmer For Sale
Keywords: programmer, for sale
Date: 14 Oct 92 02:55:09 GMT
Article-I.D.: news.Bw3C3z.G3H
Organization: University of Illinois at Urbana

FOR SALE:

Xeltek UNIPRO Universal Chip Programmer

This is a 40 pin universal programmer which communicates through a high-
speed bus interface to an IBM-PC/XT/AT or compatible.  Interface card and
the latest version of all the software are included.

Device Support:

	- All E(E)PROMs and Flash EPROMs of 24/28/32 pins up to 4 Mbits

	- Bipolar PROMs: Signetics (82S..), TI (18S..,24S..), 
	  National (74S..,87S..), AMD/MMI (27S.., 63S..)

	- PLDs: PALs, EPLDs, EEPLDs, GALs and more

	- Micro Controllers: Intel 87.., Signetics 87C, etc.
	  adapters available from Xeltek

	- IC Tester: TTL (74 series), CMOS (40/45 series) logic,
	  DRAM (4163, 41464...), SRAM (2114, 6116...)
          User can add other new devices to test library


This is exactly the same programmer advertised by JDR in their catalog as 
the Modular Circuit Technology "MOD-MUP" programmer.

This programmer is only 9 months old and is STILL UNDER WARRANTY!  Comes
with original box, software disks, etc.  Works very well.

Price:  US$350 and you pay shipping.

Please reply via email.

David

--------------------------------------------------------------
David Salamon                Physics Graduate Student (Slave)
d-salamon@uiuc.edu           University of Illinois
--------------------------------------------------------------
Newsgroups: sci.electronics
From: rg9538@ehsn8.cen.uiuc.edu (Ronald E Garnett)
Subject: 68HC11EVBU fanout data
Organization: University of Illinois at Urbana
Date: Mon, 12 Oct 1992 19:15:18 GMT

Does anyone out there in net land know how many SLAVE units that the 68HC11
EVBU board can drive from a master.  I'm referring to both synchronous and
asynchronous serial communications as well as their handshaking lines.  

I can't seem to find this data anywhere.


Ron Garnett

rg9538@ewshp.cen.uiuc.edu
.
From: chev@bigwpi.WPI.EDU (Kevin William Waid)
Newsgroups: sci.electronics
Subject: Timing circuit
Date: 13 Oct 1992 14:32:46 GMT
Organization: Worcester Polytechnic Institute
NNTP-Posting-Host: bigwpi.wpi.edu


Hello,
   I was wondering if someone could give me some advice on a project we
are working on at school.  We want to be able to measure in milleseconds
the time it takes a rod to fall 24".  This rod is in an aluminum housing,
which is partially open to light and has a diameter of about 10".  We
would like to use a photo-sensor of some sort.  We will be using a commercial
timer which can be started electronically.  All we have to do is have the
rod break the beam of light and stop the timer.  The only problem is that
I have no knowledge of photo diodes or detectors.  Any help you could
provide such as catalogs, or data on these devices would be greatly 
appreciated.  Thanks in advance for your help.
					chev@wpi.wpi.edu
Organization: Penn State University
Date: Tue, 13 Oct 1992 15:51:35 EDT
From: <GNR100@psuvm.psu.edu>
Newsgroups: sci.electronics
Subject: PSPICE Schematics Program

           Hi.  I have the Pspice schamatics program that runs under Windows,
but I am having difficulty figuring out how to run it.  Is there documentation
available for this package?  Thanks,
                Gordon Rogers
            gnr100@psuvm.psu.edu
Newsgroups: sci.electronics
From: FC138001@ysub.ysu.edu (Phil Munro)
Subject: Re: Thunderstorms
Organization: Youngstown State University
Date: Wed, 7 Oct 1992 13:27:26 GMT

  We've seen lots of theory, but only a few experiences, of lightning
doing damage to computer equipment.  Would anyone have some details
about damage done to equipment?  This might give us a better idea of
how much of a problem lightning actually is, direct hits, EMP, etc.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  FC138001@ysub.ysu.edu  Phil Munro       Youngstown State University
  Electrical Engineering Department           Youngstown  Ohio  44555
From: myers@hpfcso.FC.HP.COM (Bob Myers)
Date: Wed, 7 Oct 1992 19:11:59 GMT
Subject: Re: Any reason for GND around perimeter of PC Board?
Organization: Hewlett-Packard, Fort Collins, CO, USA
Newsgroups: sci.electronics

> I have looked at a some examples PC boards and have noticed that some
> have a thick ground trace around the perimeter of the board.  Any
> reason for this?
> 

Usually, this would be for protection from electrostatic discharge (ESD).



Bob Myers  KC0EW   Hewlett-Packard Co.      |Opinions expressed here are not
                   User Interface Tech. Div.|those of my employer or any other
myers@fc.hp.com    Fort Collins, Colorado   |sentient life-form on this planet.
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Newsgroups: sci.electronics
Subject: Re: Serial line booster
Date: 12 Oct 92 03:55:24 GMT
Organization: AI Programs, University of Georgia, Athens

Interesting.  I have a similar problem where one of the machines is a
Sparcstation whose outputs are +-5 volts rather than the usual +-12.
The first thing I'd check is whether you're getting true RS-232 voltage
out of both machines.  If not, add a booster at the source, not in the
middle of a 50-foot cable.  Are you sure the problem isn't something
else, such as crosstalk between wires?

-- 
:- Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
:- Artificial Intelligence Programs       phone 706 542-0359
:- The University of Georgia                fax 706 542-0349
:- Athens, Georgia 30602 U.S.A.          amateur radio N4TMI
From: hleaves@gems.vcu.edu
Newsgroups: sci.electronics
Subject: Halogen light dimmers
Date: 16 Oct 92 00:05:45 -0400
Organization: Medical College of Virginia

I've seen a lot of household halogen lamps with built in dimmer circuits. This
must lower the operating temperature of the bulb. Does this kill the life of
the bulb by preventing the halogen cycle? It seems like it would.
-- 
*******************************************************************************
** Hugh L. Eaves                      ** Internet: hleaves@ruby.vcu.edu      **
** Medical College of Virginia        ** Bitnet: hleaves@vcuruby             **
** Department of Human Genetics       ** Voice: (804) 371-8754               **
***************** All non-incendiary communication welcome! *******************
Newsgroups: sci.electronics
From: hbg6@phx.mcd.mot.com (John Schuch)
Subject: Re: How do those motion detectors work?
Organization: Motorola Computer Group, Tempe, Az.
Date: Mon, 12 Oct 1992 02:21:35 GMT

In article <1b30clINN7u1@usenet.INS.CWRU.Edu> an938@cleveland.Freenet.Edu (George II Lenzer) writes:
>
>	I would like to know how those motion sensing yard lights
>work.  Are they based on IR sensing?  Does anyone have a schematic?
>I would like to build one for use indoors.
>
>Would you like a few to play with? I just bought SEVERAL HUNDRED passive
IR motion detectors at an auction. If your interested, maybe we can make 
a deal.

John Schuch
From: dt@yenta.alb.nm.us (David B. Thomas)
Newsgroups: sci.electronics
Subject: Re: Phone Circuit Help Needed
Date: 14 Oct 92 07:54:08 GMT
Organization: yenta unix pc, rio rancho, nm

DI3QC@CUNYVM.BITNET writes:

>     I would like some help with a project I am working on. I am trying to buil
>d a circuit using a 68hc11e2 which will sense a phone ringing, pick up on n rin
>gs and then wait for a n digit code. Once correctly entered the user will get a
>new dial tone via the switching to another line. Are there any circuits all rea
>dy available to do such? Any ideas to this project I could use some help.

To detect rings, I'd put the phone line through a bridge rectifier, so the
polarity will not matter, then a voltage divider, to make it a reasonable level,
and then to the input of a 555 timer set up as a one shot with a delay longer
than the ring.  That way each ring puts the 555 through exactly one cycle.
Remember to protect the input of the 555 with reverse-biased diodes to the
power supply rails.

Then of course you feed the ring one-shot signal to any counter you like.
Many counters will give you an output for 1,2,4 or 8 rings, or else
you can detect any state of any counter and count any number of rings.

To make your circuit pick up the phone, have it switch a 600 ohm (or so)
resistor across the line with a relay.  To suck audio off the line once
it has been answered you could put a transformer in series with the
resistor, and feed its secondary to an audio amp.

There's a nifty chip to detect touch tones.  If you need a number I can
look it up for you.  This would detect any touch tone and strobe its value
out on 4 data lines.  You can feed these to shift registers, flip-flops,
or what-have-you to detect special combinations.

To finally connect in the other line, I've actually gotten away with
connecting them directly in parallel, observing polarity of course!
This is not recommended but it can work.  The real way to do it is to
use some sort of inductive network.  I'm not your source on that one.

					good luck -- cool project!
					little david
-- 
I'm a poet and I'm unaware of it.
From: sonix@schunix.uucp (Duane Morin)
Newsgroups: sci.electronics
Subject: FFT analysis for DSP?
Date: 13 Oct 92 12:45:25 GMT
Distribution: usa
Organization: SCHUNIX Public Access Unix for Worcester County, Massachusetts, USA

I apologize if this is posted in the wrong group, but I figured it was a good
place to start.  If someone can direct me to a more appropriate group (without
singing my eyebrows) it would be greatly appreciated and I'll happily move.

What we're looking for is research in the best ways to do FFT analysis for
digital signal processing.  We've found the traditional FFT approach to be 
slow, and are looking for new ways.  We've heard a little about something 
called wavelets, and would like to look further into this.

If anyone could provide a direction where we might be better off looking, 
thank you.  Responses via email will keep traffic off the net and I'll sneak
away quietly when I've got my information.

Thank you,
 Duane Morin
 Software Development Manager
 Walker Sonix, Inc
 Worcester, MA 01604
From: whit@milton.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: 25 ohm coax cable
Keywords: coax cable
Date: 9 Oct 92 01:30:13 GMT
Article-I.D.: u.1992Oct9.013013.2641
Organization: University of Washington, Seattle

In article <1992Oct8.120225.6247@fys.ruu.nl> vreeburg@fys.ruu.nl (Jurriaan Vreeburg) writes:
>In <bvr5pd.14o@wang.com> garyf@wang.com (Gary Field) writes:
>
>>dhina@dxcern.cern.ch (Mourad Dhina) writes:
>
>>>i am trying to realize a ... coax cable of 25 ohms impedance.

>>Put two pieces of 50 Ohm cable in parallel. It should be exactly the same.

>After reading Gary's answer I had some doubt of its correctness. It implies
>that by putting two 50 Ohm coax cables in series, one is able to create a 100 Ohm
>coax cable, which is certainly not true.

	No, that is NOT implied, unless you are making an analogy
to simple resistors (which is not exactly what Gary was doing).

>I think that putting two cables in parallel doesn't change the impedance, since
>the impedance is defined as:
>
>                   L
>Z = square_root ( --- )
>                   C
>L: inductance per unit length
>C: capacitance per unit length
>
>What happens if we put two cables in parallel: both the inductance and the capacitance
>increase by a factor of two -> Z doesn't change!!!

	Huh?  The capacitance goes UP by a factor of two, and the
inductance goes DOWN by a factor of two, so Z is halved.

	And, in the case of two cables in series, the inductance is
doubled, BUT the length is as well (so inductance per unit length
is not changed).  Same argument for capacitance per unit length.

	The original argument, two 50 ohm cables in parallel, is correct.
It isn't a good idea, though, unless you're SURE you can get the 
signals of interest through the 50 ohm cables with comparable losses
and shielding efficiency to the semirigid cable.  Around here,
we use semirigid only for exotic, high-performance applications,
and there is no good substitute.

	John Whitmore
From: keithl@klic.rain.com (Keith Lofstrom)
Newsgroups: sci.electronics
Subject: FREE PCB layout program for DOS
Date: 15 Oct 92 05:27:26 GMT
Article-I.D.: klic.1992Oct15.052726.20258
Organization: KLIC

Protel Technology is GIVING AWAY free copies of Protel Easytrax 2.  This 
appears to be complete, if simple;  you can save files, plot Gerber and 
laserprinter output (even Postcript Lino).  It doesn't appear to autoroute
( that's the $400 option ), it doesn't have an "undo", area fill is done 
by pasting down boxes, and it may have other limits compared to what you
are used to.  On the other hand, the price/performance ratio is hard to
beat.  It is certainly good enough to replace any PD/Shareware ECB layout
programs I've seen.  

The software was written in Australia - there are a few Austra-cisms in it,
like default paper size.  The options can be reconfigured for us provincial
Americans, though.

What's the catch?  I don't know yet. I guess they want you to buy their
superduper version, though this version is NOT crippleware, just a little
old.  The boards I do are pretty simple; I will probably never need anything
better.   A friend of mine bought a copy years ago when it was Protel's main
for-sale product, and it is still his favorite.

You can get a copy by calling 1-800-544-4186 (California).  All they will
ask for is your address;  even shipping is free (it took three weeks).  Hell,
it would be worth it even if you had to pay for the call :-)

Keith
-- 
Keith Lofstrom         keithl@klic.rain.com       Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Power ICs
Newsgroups: sci.electronics
From: govindg@ucunix.san.uc.edu (Girish Govind)
Subject: How can I repair this Wyse 99GT Terminal?
Organization: University of Cincinnati
Date: Wed, 7 Oct 1992 11:02:38 GMT

Hello netters!
I have a Wyse 99GT graphics terminal. A couple of days back the horizontal
drive for the display disappeared suddenly. When you turn this thing
on all that you see is a vertical line going thru the middle of the screen
(I can make out that the rest of the terminal is working ok for the line is
darker where there should have been text etc...)

Can anybody suggest a cheap way to solve this problem (safely)? Change the
flyback transformer?

Please let me know at govindg@ucunix.san.uc.edu because I don't think it would
be of general interest to post to everybody in this group

-- Girish Govind
   govindg@ucunix.san.uc.edu
Newsgroups: sci.electronics
From: anbo@wuee1.wustl.edu (Albrecht Jander)
Subject: Re: Max699 ( what is this for? )
Organization: Washington University, St. Louis Mo.
Date: Tue, 13 Oct 1992 15:33:55 GMT

In article <288200016@trsvax> pauls@trsvax.tandy.com writes:
>
>max699 - low power power-on reset and watchdog controller.
>call 800-998-8800 for samples/data sheet.
>
>
This device is used in microprocessor/microcontroller based systems.
Basically, it holds the reset line low when you turn on the device, until
the power has stabilized.  This prevents the processor from doing crazy
things while the power is coming up.  Also, if the power drops below some
critical value, the max669 holds the processor in reset for the same 
purpose.

The watchdog controller is usefull in critical situations, where failure
of the microprocessor to do its job would be detrimental.  Basically, the
MAX669 expects the processor to send it a "I'm still on track" signal
every so often.  If the MAX669 doesn't receive such a signal within a given
This is similar to a system they have in trains to keep the operator awake
during the long times when he really dosn't have to do anything.  They have
a button on each side of the cabin, and once every X minutes, the operator
has to push each button or the train stops.

Albrecht

time, it resets the processor in an attempt to get it started again.


---------------------------------------------------------------------------
                        Peltier was a cool dude!!
From: dale@ldgo.columbia.edu (dale chayes)
Newsgroups: sci.electronics
Subject: Re: Max699 ( what is this for? )
Summary: Its a watchdog reset
Date: 9 Oct 92 20:08:59 GMT
Organization: Lamont-Doherty Geological Observatory

In article <geb1.718651549@Isis.MsState.Edu>, geb1@ra.msstate.edu (Granville Barker) writes:
> I was just wondering what a MAX 699 IC is used for?
> 
> Thanks.
> geb1@isis.msstate.edu


From the Maxim 1992 "New Releases data book":

	"...monitors the +5VDC supply in processor and digital systems...
supplys a !RESET pulse of ate least 140ms duration on power up, power-down, 
and during low voltage "brown out" conditions....also provides a "watchdog" 
input to monitor microsprocessor activity. The !RESET output goes low if 
the watchdog input (WDI) is not toggled within 1 second. The watchdoe feature 
can be disabled by leaving WDI open." 


One might use this in an embedded and/or real-time system to reduce the 
probability of having a system "wedged" by power problems. The WD feature 
provides a way to recover from a program that runs amuck.

-Dale

-- 
Dale Chayes Lamont-Doherty Geological Observatory of Columbia University
Route 9W, Palisades, N.Y.  10964	dale@lamont.ldgo.columbia.edu
voice:	(914) 359-2900 extension 434	fax: (914) 359-6940
Newsgroups: sci.electronics
From: X1FT@VM1.CC.UAKRON.EDU
Subject: Re: Triggering multiple flashes to "paint with light"
Organization: The University of Akron
Date: Thu, 8 Oct 1992 01:19:35 GMT

Mark,
 
I guess I'm not sure why you need the delay.  Using one strobe, the delay
is unavoidable, but with multiple strobes, why is the delay needed?
I don't believe that by looking at a picture, it can be determined whether
the exposure was made all at once, or during a long interval (assuming
no ambient light, and ignoring reciprocity (sp) effects).
 
I've done some single strobe multiple exposures with interesting results.
Make sure you cover the "ready" light with black tape, or you will see a
red streak going between the various exposure sites.
                                          - Frank
*************************************************************************
Frank Tompkins              Internet: X1FT@VM1.CC.UAKRON.EDU
University of Akron      
Akron, Ohio   44325-3501 
  "I have not failed, I've just found 10,000 ways that won't work"
                                                     - Thomas Edison
Newsgroups: sci.electronics
From: sp@u36.kwnet.on.ca (Sean P Goggin)
Subject: Printed Circuit Boards, Maker Wanted
Organization: U36 Research
Date: Fri, 9 Oct 1992 14:53:53 GMT
Distribution: ont

I'm looking for someone to make a small quantity of 
printed circuit boards of professional quality.( < 10 )

Size is 7.5 x 13 cm G10 1.5 mm thick, double sided.

Any leads would be welcomed.

Thanks,

	Sean.

Sean P. Goggin
251, Bridge Street West, Waterloo, Ontario, Canada N2K 1L1
Voice +1 519 746 7535 Fax +1 519 747 2933 
email sp@bbi.kwnet.on.ca;sp@u36.uucp        N 43 29' 30" W 80 30' 15"
From: dbc@tc.fluke.COM (Dan Carson)
Newsgroups: sci.electronics
Subject: Re: NiCd fast charging.
Keywords: NiCd fast charge
Date: 9 Oct 92 17:37:38 GMT
Article-I.D.: tc.1992Oct9.173738.11691
Organization: John Fluke Mfg. Co., Inc., Everett, WA

In article <1992Oct06.105629.31330@bas-a.bcc.ac.uk> uclyjjd@ucl.ac.uk (Julian Daley) writes:
>A few months ago I read in a UK trade magazine about
>a chip that does all the sensing neccessary for
>negative delta V endpoint detection, when fast charging
>NiCd batteries.  It also had temperature sensing etc.
>
>I've lost the reference; anyone know who makes it ?
>
>Thanks,
>Julian.
>
>
>--
>        _________________________________________________________
>       | Julian Daley,                                           |
>       | Department Clinical Physics,                            |
>       | Guys Hospital, London.                j.daley@ucl.ac.uk |


Maxim. The MAX712 does zero dv/dt, the 713 does -dv.
Also Benchmarq Microelectronics' bq2003 does -dv.

Maxim Integrated Products (U.K.) Ltd. (0734)845255
Benchmarq Microelectronics, Inc. (Texas) (214)407-0011


Dan Carson
John Fluke Mfg.
Everett, WA
Newsgroups: sci.electronics