HDTenEightyP/NetNews huggingface dataset:
From: mcovingt@athena.cs.uga.edu (Michael A. Covington)
Newsgroups: sci.electronics
Subject: Re: wwv radios
Date: 28 Aug 92 18:11:23 GMT
Organization: University of Georgia, Athens

In article <87311@netnews.upenn.edu> george@mech.seas.upenn.edu writes:
>
>alas, radio shack has discontinued their 'timecube' wwv recievers.
>does anybody else carry these things? ( in the <$50 neighborhood.. )

Any cheap shortwave receiver should do.

>can i replace the crystals in a 'weatheradio'?

No.  Weather is on 162 MHz; WWV is on 5, 10, 15, and 20 MHz.
Quite a big jump.  Also, weather is FM and WWV is AM.

-- 
+ Michael Covington - Artificial Intelligence Programs - U of Georgia - USA 
+ Unless otherwise noted, these are private opinions, not official statements.
+ VOTE NO GEORGIA LOTTERY - we need not imitate mistakes of other states.
Xref: sparky sci.electronics:14755 misc.wanted:7911 misc.forsale.computers:30776
From: youngqd@atlantis.CS.ORST.EDU (Dean Youngquist)
Newsgroups: sci.electronics,misc.wanted,misc.forsale.computers
Subject: WANTED: keyboard chip, 8042 or 8742 for older AT motherboard.
Date: 23 Aug 92 19:44:56 GMT
Article-I.D.: leela.1992Aug23.194456.21936
Distribution: na
Organization: Computer Science Outreach Services - Oregon State University

I need 2 keyboard chips for 2 older DTK 286 motherboards I would like to
fix.  They originally had the 8042 which is the one time programable
version, or is it the one that is programmed during the manufacturing
process.  Anyway, I think I could use most any keyboard chip from a non-
working AT motherboard if you have one.  Alternatively, if someone has
a programmer for the 8742 or 8042 maybe I could send you my good chip
and you could program the code into a couple more.

All replies / info appreciated.

youngqd@atlantis.cs.orst.edu	Dean Youngquist		(503) 753-7646
Newsgroups: sci.electronics
From: massoud@chemteca.sdsu.edu (Massoud Ajami)
Subject: Re: Weird Science?
Organization: San Diego State University
Date: Wed, 2 Sep 1992 18:03:42 GMT

In article <17u3gbINNfuv@darkstar.UCSC.EDU> haynes@cats.ucsc.edu (Jim Haynes) writes:
>From: haynes@cats.ucsc.edu (Jim Haynes)
>Subject: Weird Science?
>Date: 31 Aug 92 21:38:19 GMT
>
>I've got this circuit which consists of
>   8:1000 ohm input transformer feeding
>   DIP bridge rectifier feeding
>   base-emitter junction of a transistor.
>The idea is to connect the 8-ohm input to the output of a radio or
>tape recorder and turn on the transistor when there is some signal.
>
>It works fine, at first.  After it sits for a while, turned off, it
>won't work.  Then I disconnect one of the secondary leads from the
>transformer, observe with an AC voltmeter that there is voltage there,
>and reconnect it.  At that point it starts working again.  I've been
>through several cycles of this - probably I'll connect the transformer
>with a clip lead to make it easy to get it going until I get to the
>bottom of it all - but does anybody have a clue what is going on here?
>Intermittent connection somewhere down inside the transformer?  Is there
>some latchup phenomenon with DIP bridge rectifiers?
>-- 
>haynes@cats.ucsc.edu
>haynes@cats.bitnet
>
>"Any clod can have the facts, but having opinions is an Art."
>        Charles McCabe, San Francisco Chronicle

Most likly the problem lies in the bridge rectifier, you need to use fast 
recovery diodes, normal bridges are design for power line, and can not 
perform at sound frequencies. They behave kind of short cicuit, then 
junction temperature increases, and that may be the cause of the Weird 
Science.




Peace and Prosperity!
  ---==< 110 >==---
From: v064mb9k@ubvmsb.cc.buffalo.edu (NEIL GANDLER)
Newsgroups: sci.electronics
Subject: TROUBLE TRYING TO FIND A WAY TO DRIVE ALPHA NUMERIC DISPLAYS
Date: 30 Aug 92 19:23:00 GMT
Organization: University at Buffalo
News-Software: VAX/VMS VNEWS 1.41

I am trying to design a stereo receiver and would like to indicate
functions and status using alpha numeric displays. For example for
my surround sound processor. When someonechooses matrix. The word
matrix appears on the display in alpha numeric characters. Is there
a chip that will convert a 4 or 8-bit signal and output an alpha
numeric display to the appropriate letter you choose. Then I could multiplex
this and have a 6-segment alpha numeric driver. I would appreciate any
help.
Newsgroups: sci.electronics
From: sgw@boy.com (Steven Warner)
Subject: Re: Needham Electronics PROM burner good/bad ?
Organization: Beach Systems / RTFM UN*X Solutions, Sunnyvale, CA, USA
Date: Mon, 31 Aug 1992 17:25:13 GMT
Keywords: PROM microprocessor

I also like the needham burner.

For those with older software, they have a new version of the
programming software available that is supposed to be very good.

It is FREE, and can be had by calling their BBS at 916-972-8042.
The file is called  EMP_DIST.exe.

----
 Steven Warner
 sgw@boy.com   (34W 36L)   " happiness = (reality - expectations) "

Newsgroups: sci.electronics
From: jastorqu@dcc.uchile.cl (ASTORQUIZA LUMSDEN JAIME RODRIGO)
Subject: Loking for information.
Originator: jastorqu@dcc.uchile.cl
Date: Tue, 25 Aug 1992 19:21:25 GMT
Organization: Universidad de Chile, Depto. de Ciencias de la Computacion

Hi.
I'm looking for information about Digital transmition of tv signal. 
I need information about equipment and theory.
Thanks in advance.
                         Jaime R. Astorquiza
                        jastorqu@dcc.uchile.cl
                     jastorqu@cecux1.cec.uchile.cl
From: rkarlqu@hpscit.sc.hp.com (Rick Karlquist)
Date: Wed, 26 Aug 1992 19:21:23 GMT
Subject: Re: contacting N.O. Sokal, Design Automation Inc.
Organization: Hewlett-Packard, Santa Clara, CA
Newsgroups: sci.electronics

In sci.electronics, mathiega@elec.canterbury.ac.nz (Grant A. Mathieson) writes:

> Since reading a paper...

> "Class-E Resonant Regulated DC/DC Power Converters: 
> Analysis of Operation, and Experimental Results at 1.5 MHz"
> Redl, R., Molnar, B., and Sokal, N.O., IEEE Power Electronics 
> Specialists Conference 1983

> ...I have developed an interest in Class-E techniques for 
> Power Conversion, which mimic those used in Class-E RF 
> Power Amplifiers. 

This is something I have wondered about for a long time, since
first reading about "Class E" some 20 years ago.  It seems to
be a solution looking for a problem to solve.  Now that Mr.
Sokol's patent on it is about to expire, I imagine he has
gone on to other things.  As near as I can tell, "Class E" is
basically just a resonant switching technique, of which there
must be a half dozen basic types in use today.  The difference 
is that Class E runs at a constant frequency, whereas the
resonant techniques now popular with power supply vendors such 
as Vicor use variable frequencies.  The variable frequency allows
the supply to do line and load regulation.  Most of the class 
E circuits I have seen are unregulated.  I don't know what 
Sokol does in the above paper to get regulation.

Kind of reminds me of Mr. Cuk and his "Cuk converter" whose
patent will also expire soon.

Then there is "integrated magnetics".

What they all have in common is a lot more papers written about
them than actual designs utilizing them.  

Rick Karlquist
rkarlqu@scd.hp.com
From: hardylh@wkuvx1.bitnet
Newsgroups: sci.electronics
Subject: Educational videos?
Date: 2 Sep 92 17:27:06 CDT
Organization: Western Kentucky University, Bowling Green, KY

I am interested in obtaining quality educational video tapes re:
transformer and motor design and applications
send information to:
HARDYLH@WKUVX1.BITNET

Thanks
From: dbell@cup.portal.com (David J Bell)
Newsgroups: sci.electronics
Subject: Re: Aligning a floppy drive?
Date: Tue, 25 Aug 92 22:14:01 PDT
Organization: The Portal System (TM)
Distribution: na

John R. Levine asks:

>I have a 3.5" 1.44MB floppy drive on my EISA 486 PC which is getting read
>errors on disks I have reason to believe are good, so I expect that the heads
>are out of alignment.

>What's involved in realigning them?  It is my vague recollection that I've
>occasionally seen do-it-yourself alignment kits advertised containing a
>reference disk and some kind of software.  Are they for real?

Yes, John, these "digital" alignment disks and software exist, and
they do work. Alignment of drives usually consists only of setting
the base (radial) head position - the head azimuth angle is not,
in my experience, adjustable. The alignment disk is created specially
with varying degrees of MISalignment built-in to the tracks and
sectors. Along with the disk is a usually a table specifying the
amount (+ or -) of radial misalignment in each of a number of tracks,
usually with the first few sectors written "correctly", and further
sectors written with progressively "worse" errors. 

The trick is to attempt to read the disk in raw track/sector addressed 
mode, and report exactly which sectors fail to read without error. 
If the head is properly aligned, the first two sectors to fail will have
the same absolute error, one + and the other - from nominal. If
the head (positioner, actually) is a bit off, one failure will be
at a greater or lesser error value than the other: +10 & -15, for
example. You then back out the screw(s) holding the positioner
motor down and rotate it SLIGHTLY to extend (in this example) or
retract the head a tiny bit - resulting in the failures being
at, say +12 & -12. This is then repeated for several tracks,
usually one near the edge, one near the innermost tracks, and one
in the middle. The error is kind of "spread around" to give
the best average alignment... Another track or set of tracks
allows you to check for head azimuth error in a similar fashion,
but as I said, you probably cannot adjust it.

All that having been said, have you tried a *really good*
cleaning? I had one 3.5" drive that seemed to have been contaminated
(Coke, I believe!) and it took 5 or 6 successive cleanings before
it started working right...

Dave
dbell@cup.portal.com
Newsgroups: sci.electronics
From: rmintz@ecst.csuchico.edu (Rich Mintz)
Subject: Filtering TV Commercials
Organization: California State University, Chico
Date: Thu, 03 Sep 1992 04:20:45 GMT

I'm interested in building a device (or making my 386sx 
act like one) that will be able to distinguish television 
commercials from television programs. I've talked to a 
few people and have heard of a couple of ways it is said 
that this can be done.
 
First, I was told that the audio during commercial 
announcements on tv is boosted higher than that used for 
normal programs (for obvious reasons). However, I've 
tried all kinds of analysis with volume levels, averages 
over specific periods of time, etc, using my computer's 
sound card (with stereo capability), with no luck at 
finding any dependable pattern to distinguish    ads from 
shows.
 
Someone else told me they had heard that what I'm wanting 
can be acomplished by analyzing the video transmission 
for the presence of computer-encoded information that 
accompanies programs, but not commercials. I assume he 
was referring to Closed-Captioned (CC) text sent along 
with many shows for the benefit of the deaf who have 
special receivers for these signals.
 
Any suggestions? Thanks.
 
   Rich -> rmintz@cscihp.ecst.csuchico.edu

Newsgroups: sci.electronics
From: landall_v@kosmos.wcc.govt.nz
Subject: Plastic Card HELP
Organization: Welligton City Council, Public Access.
Date: Sun, 30 Aug 1992 03:06:42 GMT

Hi

Could someone plase tell me how the NZ Phone cards are coded and/or the other
Plastic Cards with magnetic strips on them.

I would like to make a Plastic Card Reader (NOT A WRITER (Well not yet ;-) )).

Does anyone know how the data is writen on then (ie binary) and how to get the
data from the card to the serial port?

THANKS in advance...
-Landall_V@Kosmos.wcc.govt.nz
From: pjh@mccc.edu (Pete Holsberg)
Newsgroups: sci.electronics
Subject: Re: PADS software
Keywords: PADS schematics
Date: 30 Aug 92 02:32:29 GMT
Article-I.D.: mccc.1992Aug30.023229.11751
Organization: The College On The Other Side Of Route One

In article <1992Aug28.205445.16138@news.dfrf.nasa.gov> disbrow@skipper.dfrf.nasa.gov writes:
=I just got the PADS-PCB and PADS-Logic and associated libs off
=some FTP site.  Problem is it won't install.  Seems it needs to
=be installed from a floppy, but I get an error message something
=like "Can't find file, maybe not in your path".  Has anyone had
=any similar problems?  It doesn't tell me which file it can't find.

Just build the directories needed manually and then copy the files to
the proper places. Info is in one of the doc files.
Newsgroups: sci.electronics
From: heke@stekt.oulu.fi (Heikki Paananen)
Subject: Re: Sync seperator
Organization: University of Oulu, Dept. of EE, Finland
Date: Wed, 2 Sep 1992 14:20:37 GMT


In article <5977@m1.cs.man.ac.uk> mark-r@spec0.ee.man.ac.uk (Mark Robinson (JO PhD)) writes:

   Hi

   could someone email me a circuit to produce seperate sync signals from
   a 1V composite video signal. Also, I'd like it to change the black level
   of the video signal, so that black is 0V and white is 0.7V.


Hi,
 
Try LM1881 sync separator IC. 

   Mark
   mark-r@spec0.ee.man.ac.uk

Heke

-----------------------------------------------------------------
Heikki Paananen                           heke@stekt.oulu.fi
The University of Oulu                    
Department of electrical engineering    
Finland
-----------------------------------------------------------------
Two hudred Francs for sanctuary and she led me by the hand
to a room of dancing shadows, where all the heartache disappears
and from glowing tongues of candles I heard her whisper in my ear
"J `ntend ton coeur"                                      (Fish)
From: jimc@tau-ceti.isc-br.com (Jim Cathey)
Newsgroups: sci.electronics
Subject: Re: Minimum speed on processors
Date: 28 Aug 92 00:48:27 GMT
Organization: ISC - Bunker Ramo, Spokane, WA

In article <1992Aug27.201844.16764@ohm.york.ac.uk> u9dmlb@ohm.york.ac.uk (Duncan McL Barclay) writes:
>Incidently the Z80 was static so nice and easy to debug, just have a manual
>clock.

I think the Z-80 was semi-static.  You could hold the clock high
indefinitely, but you couldn't hold it low for too long.  Fully-static
processors (like the 1802) would run off of any ratty irregular clock
you could come up with, provided no edge was too close to another edge. 
(The 1802 would run off of ratty battery power as well, being fully
CMOS as well).

-- 
+----------------+
! II      CCCCCC !  Jim Cathey
! II  SSSSCC     !  ISC-Bunker Ramo
! II      CC     !  TAF-C8;  Spokane, WA  99220
! IISSSS  CC     !  UUCP: uunet!isc-br!jimc (jimc@isc-br.isc-br.com)
! II      CCCCCC !  (509) 927-5757
+----------------+
			"PC's --- the junk bonds of the computer industry"
Newsgroups: sci.electronics
From: billq@ms.uky.edu (Billy Quinn)
Subject: Complete B&W NTSC timing ???
Keywords: NTSC,TV,Video,timing
Date: Mon, 31 Aug 1992 17:24:11 GMT
Organization: University Of Kentucky, Dept. of Math Sciences

What does one have to do to a composite video signal to make the TV
do a verticle retrace?  This is for BLACK & WHITE video and it does
not need to be broadcast quality!  My only referrences to diagrams of   
this sort are for color video.  It seems that with out color one could
just keep the horizontal sync low for a while after the last line of 
video.  Is this true?  If so, how long does it take?  Any suggestions,
references etc?

Thanks a million!

Bill

-- 
*-----------------------------------------------------------------------*
*	Bill Quinn			billq@ms.uky.edu		*
*-----------------------------------------------------------------------*
Newsgroups: sci.electronics
From: geb1@ra.msstate.edu (Granville Barker)
Subject: RS-232 Line Monitor???
Organization: Mississippi State University
Date: Wed, 2 Sep 1992 23:39:56 GMT

I am trying to build a RS-232 line monitor.  

I want to connect it between two RS-232 devices, and have a wire comming 
off that I can connect to another computer and monitor both sides of the
conversation between the other two devices.  Ie.. a Plotter and a Computer.

I need to see what is being transmited and received, I tried hooking 
 pins 2 and 3 to diodes, then connecting rx on the monitor computer to
 the other end of the diodes.  THe other 2 devices still communicate ok, but
 I never see anything on my monitor computer.  I am connecting ground.

 Any ideas??


Thanks,

Granville Barker
geb1@isis.msstate.edu
From: paulh@minster.york.ac.uk
Newsgroups: sci.electronics
Subject: Re: Amperage meaning?
Date: 26 Aug 92 09:14:09 GMT
Organization: Department of Computer Science, University of York, England
X-Newsreader: Tin 1.1 PL5

Michael A. Covington (mcovingt@athena.cs.uga.edu) wrote:
: Voltage is the pressure that drives a current (amperage) through a load.
: 
: The way a power supply works is this:
: 
: the rated _voltage_ is the actual value you'll get;
: the rated _amperage_ is the maximum permissible.
: 
: The load determines how many amps will actually flow.  
: So the relevant question here is whether your load consumes more
: than 2.5 amps.  If not, you'll have no problem.
: -- 
: + Michael Covington - Artificial Intelligence Programs - U of Georgia - USA 
: + Unless otherwise noted, these are private opinions, not official statements.
: + VOTE NO GEORGIA LOTTERY - don't tie education to an unpredictable income.

    The assumption here is that the power supply provides a constant voltage.
There are power supplies that provide a constant current. In constant
current supplies the output current remains constant but the pd varies upto
some maximum.

    The limiting constant for both types of supplies is power, W = I.V

    Check the labels and be careful out there kids !!!

    H

Paul Hatcher			PHONE    +44 904 432771
Department of Computer Science	JANET    paulh@uk.ac.york.minster
University of York		INTERNET paulh@minster.york.ac.uk
Heslington, York, Y01 5DD	UUCP	 {mcsun,uknet}!minster!paulh
Newsgroups: sci.electronics
From: tmkk@uiuc.edu (Khan)
Subject: Re: Need encoding scheme for TV remote infrared controller
Organization: University of Illinois at Urbana
Date: Wed, 2 Sep 1992 21:09:37 GMT


In article <1992Sep2.181547.28000@aio.jsc.nasa.gov> mancus@zaphod.jsc.nasa.gov (Keith Mancus) writes:
>In article <BtyE2K.3ts@news.cso.uiuc.edu>, tmkk@uiuc.edu (Khan) writes:
>
>>>  (2) Is the encoding scheme standardized?
>> Not by a long shot.
> 
>  Odd.  I've seen "generic" controllers that can be programmed to
>drive a wide variety of remote-controlled devices.  It seems pretty
>difficult to do this w/out any standards!

Not so odd. A $20 cassette tape recorder can record and playback
spoken English, Spanish, French, Portuguese, Dutch, Afrikaans, etc. etc.
without their being any "standards" among the languages. Programmable IR
remotes work in precisely the same way: they memorize the signals your
remotes send, and duplicate those signals.

>> Borrow/obtain an oscilloscope....after playing around a bit,
>>you should be able to determine the encoding scheme used, or at the very
>>least which patterns go with which....
> 
>  <groan>  That's just what I was hoping to avoid.  Sigh.

Hey, it's not THAT bad. You'll definitely learn a lot! ;-)
From: dino@inqmind.bison.mb.ca (Tony stewart)
Newsgroups: sci.electronics
Subject: Re: How hot can the 486-50 cpu run ?
Date: Mon, 31 Aug 92 22:52:35 CDT
Organization: The Inquiring Mind BBS  1 204 488-1607

riepe@ifwm11.ifw.uni-hannover.de (Michael Riepe) writes:

> I'm sorry but you're talking nonsense.
> Silicon semiconductors have max. chip temperatures of about 75 to 125 deg C.
> I may be wrong, but I think the maximum for the 486-33 is 85 deg C. The case
> temperature depends on the case type (ceramics or plastics) but will always
> be lower, approximately 40 to 60 deg C.
> 
> Anyway, in PC-486's sold today, the max. temperature will be exceeded in most
> cases unless you are using an additional cooling fan *near* the CPU and/or
> an ICECAP or s/t like that.
> 
> -- 
>  Michael Riepe                         <riepe@ifwm11.ifw.uni-hannover.de>
> 
>      IIII  FFFFFFFF  WWWW           WWWW             Univerit"at Hannover
>     IIII  FFFF       WWWW   WWW   WWWW    Institut f"ur Fertigungstechnik
>    IIII  FFFFFFF     WWWW WWWWW WWWW       und spanende Werkzeugmaschinen
>   IIII  FFFF         WWWWWW WWWWWW                   Schlosswender Str. 5
>  IIII  FFFF          WWWW   WWWW              W-3000 Hannover 1 (Germany)
> --

Also reliability of silicon drops by 2 for every 10 degree C increase...
So  keep your silicon no more than 20'C above ambient(25C) if you want
a reliable device.

dino@inqmind.bison.mb.ca
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607
Newsgroups: sci.electronics
Subject: Re: Can 220V 50 Hz Stuff be run on US 220V 60 HZ power ?
From: Rick Jansen <SSCPRICK@HASARA11.BITNET>
Date: Tuesday, 1 Sep 1992 09:31:43 CET
Distribution: sci
Organization: SARA - Stichting Academisch Rekencentrum Amsterdam

As far as I know the only possible problem with higher
frequency power supply (60 instead of 50Hz) is that the
internal losses inside the transformer are a bit higher
at higher frequencies. So the transformer could get a
little warmer.
 
-Rick.
--------------- cut here ----- here ------- or here -----------
Rick Jansen                  | e-mail: Rick@SARA.NL
SARA System Support Dept.    |         SSCPRICK@HASARA11.Bitnet
 
Space is a) something containing nothing
         b) nothing containing everything
from A Scientific Encyclopaedia For The Enquiring Young Nome
by Angalo de Haberdasheri
Newsgroups: sci.electronics
From: hbg6@phx.mcd.mot.com (John Schuch)
Subject: Re: 68HC705KICS - Worth of try?
Organization: Motorola Computer Group, Tempe, Az.
Distribution: sci
Date: Fri, 28 Aug 1992 13:08:40 GMT

In article <HEKE.92Aug25115735@stekt.oulu.fi> heke@stekt.oulu.fi (Heikki Paananen) writes:
>Now I am just wondering are these K-series MCUs useful. From the ad 
>I got the idea that the K1 MCU holds only 0.5K EPROM and 32b of RAM. 
>In what kind of projects it is applicable for? I would like to hear
>of applications you out there have done with that creature.

I'm working on two applications for mine. The first is the controller
for a 'smart' ventilation controller, and the other is part of a
DTMF decoder circuit. 

John


Newsgroups: sci.electronics
From: jeffn@nuchat.sccsi.com (Jeff Noxon)
Subject: Computer on a car battery
Organization: /etc/organization
Date: Sun, 30 Aug 1992 03:55:42 GMT

I would like to run a small computer on a car battery.  Low power drain is
a must, since it will be running constantly.  Here is approximately what
I will be wanting to power:

   80c286 1/3rd size board, running at about 4 MHz
   Some Alpha A-BUS cards for D/A, A/D, and digital in/outputs.
   A solid state SRAM disk drive, about 256k-384k, with its own battery.

The system will be able to monitor its battery life and shut itself
completely off to prevent excessive battery drain, but my goal is for
at least 2 days of operation without charging.

Question 1: How can I power the motherboard?  I am interested mostly in
efficency.  Would 5V regulator ICs do the job as well as anything?  I
assume most motherboards don't use -5 or -12 volts...  The A-Bus cards
themselves simply require any unregulated 12V source.

Question 2: How much battery life could I expect?  I have never seen
car batteries with amphour capacities stated; just their maximum
cranking amps.  I assume more cranking amps means a greater Ah capacity,
but this does not necessarily indicate a predictable relationship
between the two.  A dual battery isolator will be used to provide a
battery just for this job, however...  Probably the best die-hard I can
afford.

Thanks a million for any responses...

-- 
Jeff Noxon
jeffn@nuchat.sccsi.com
713/721-6820 CDT Houston TX