HDTenEightyP/NetNews huggingface dataset:
From: schaerer@isi.ethz.ch (Thomas Schaerer)
Subject: Re: 12 V -> 3V, 0.6 A
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
X-Newsreader: TIN [version 1.1 PL6]
Date: Mon, 9 Nov 1992 11:48:33 GMT

Babak Sehari (sehari@iastate.edu) wrote:
: 
: There are many ways to do this the cheapest way is to put:
: 
:   12-3
: --------- = 13 diodes in series with the input voltage of your CD player,
:     0.7
: 
: Like this:
: 
: +12V -|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|- +3V
: GRD  --------------------------------------------------
: 
: The problem might be generated if the input voltage swings.  To avoid
: this problem try putting a 2N3055 transistor as follows:
: 
: +12V |>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-    ---+3V
:                                         | \_/ Emitter
:                                         R  |
:                                         |--|
:                                         |
:                                         ||>|-|>|-|>|-|>|-|>|-|
:                                                              |
: GRD ---------------------------------------------------------+-----
:                                     
: 
: R=1000 ohm
: Trans=2n3055
: Diodes= 1N4001 or 1N4005
: 
:                          With highest regards,
:                               Babak   Sehari.
: -- 

Sorry but all this is nonsense bcause of the high current. If you realise
a linear regulator you will generate very high lostpower. In this example
will be 0.6A * 9V = 5.4W. The better way is to build a switched regulator.
The advandage is the high efficiency ang therefore less powerdissipation.
There are many ic which can do this with a few additional components. 
Take the Switching-Regulator L296 from SGS-THOMSON. There is a kit with
pcb-board and the needed components. Ask a SGS-THOMSON-Distributor.

So I hope I can help you.	Greeting from Thomas
From: aslt@acad2.alaska.edu
Newsgroups: sci.electronics
Subject: top
Date: 5 Nov 92 23:48:49 GMT
Article-I.D.: acad2.1992Nov5.194849.1
Organization: University of Alaska

Hi all,

I'm thinking of building the AC inverter that is in the Oct 92 issue of Radio
Electronics.  Before I start, I'd be interested in hearing comments 
or thoughts on it?  Has anyone out there actually built it?  If 
so, any gotchas or improvements orwisheyedduns?

Thanks.  E-mail replies welcome.

Lee
Newsgroups: sci.electronics,misc.forsale.computers.pc-clone,misc.forsale.computers.d
From: u9147063@cs.uow.edu.au (Richard Barry Ling)
Subject: Re: 486 CPU KOOLERS FOR SALE
Organization: Dept of Computer Science, Wollongong University, Australia
Date: Thu, 12 Nov 1992 06:48:17 GMT

   
  I wish to apologise sincerely for a rather unrelated article which appeared
earlier in this thread.  This article was crossposted to some inappropriate
newsgroups, and offended some readers of USENET.

  As a result, disciplinary action has been taken at my institution and
steps have been taken to ensure this kind of posting is not repeated.
Please allow this matter to die peacefully.  Again, I express regret for any
offence caused.

________________________________
Richard Ling
u9147063@cs.uow.edu.au
#include <standard_disclaimer.h>
From: smckinty@sunicnc.France.Sun.COM (Steve McKinty - Sun ICNC)
Newsgroups: sci.electronics
Subject: Re: HELP : HD SCSI or IDE and the A1200
Date: 9 Nov 1992 13:28:55 GMT
Organization: SunConnect
Distribution: world
NNTP-Posting-Host: hardy.france.sun.com

In article <mckillnm.721308930@unix2.tcd.ie>, mckillnm@unix2.tcd.ie (Marky Mark) writes:
>
> 
> 	1) A Microscience Int Crop (model HH-1050)
> 	or
> 	2) An old Seagate ST-238R
> 
> 		  My first question has to be ... which, if any, have an
> IDE interface ? 
I don't know, but try asking in comp.amiga.hardware. If they are IDE
then a simple cable is all you need.

> 
> 		  Provided the hardware connections go ok ... what has to
> be done to the software to make it "see" the harddisk ?  How do I format
> the disk (just like a black floppy) ?

There should be a program called HDToolBox which will look after
all the configuration for you.

Steve

-- 
Steve McKinty
SUN Microsystems ICNC
38240 Meylan, France
email: smckinty@france.sun.com	   BIX: smckinty
Newsgroups: sci.electronics
From: lus@ucs.orst.edu (Shih-Lien Lu)
Subject: help: question about multi-screen TV
Followup-To:  sci.electronics
Summary:  large display; multiple TVs displaying a single image
Keywords: multiple TV display, question
Organization: University Computing Services - OSU
Distribution: us
Date: Sat, 7 Nov 1992 16:13:18 GMT

I am interested in finding references about displaying a single
image on multiple displays (n^2 number of displays where
n is a positive integer). I believe most the modern sport's Colosseums
have large displays composed of multiple screens. And these large
screens display real-time real-life images? Could some kind
soul point me to references and explain to me the basic idea behind
it? Thanks in advance. 

Shih-Lien Lu
sllu@ece.orst.edu
Newsgroups: sci.electronics
Subject: Re: 12 V -> 3V, 0.6 A
From: MATGBB@LURE.LATROBE.EDU.AU (BYRNES,Graham)
Date: Tue, 10 Nov 1992 05:35:22 GMT
Organization: La Trobe University
X-News-Reader: VMS NEWS 1.24

In <sehari.721280522@class1.iastate.edu> sehari@iastate.edu writes:

> In <1992Nov7.141550.538@ludd.luth.se> d89-ahg@ludd.luth.se (Anders Hedberg) writes:
> 
> >A friend wants to listen to his CD player powered from the car.
> 
> >The CD-player wanna have 3Volts at max 600 mA, and the car has a battery
> >of 12 volts.
> 
> >I thought of a LM317 or something similar, but I've never designed something
> >alike, and I need to know how to calculate the resistor values.
> 
> >/Anders Hedberg
> 
> There are many ways to do this the cheapest way is to put:
> 
>   12-3
> --------- = 13 diodes in series with the input voltage of your CD player,
>     0.7
> 
[stuff cut]
> -- 
DONT DO THIS!!!!
Car batteries can swing between 11.5 and 16 volts. The above will give a
voltage ranging from 2.4 to 7 to your CD player. Worse, switching spikes
of > 50 volts are common in car electricals, applying 41 volts (=death)
to your CD player. (This assuming .7 volt drop across each diode,
which is not really correct, IMHO). MUCH better to use an LM317 (simpler, too).
Someone else has quoted the R values needed. (toss in a 220uF cap each side
as well).

You may still have problems if you want to connect the CD direct to your
car stereo due to the way the battery negative is connected to the signal
ground, but it will work fine for headphones (until you hit a pot-hole).
Cheers,
Graham Byrnes
Newsgroups: sci.electronics,comp.robotics
From: schaerer@isi.ethz.ch (Thomas Schaerer)
Subject: Re: on 74ls139
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
X-Newsreader: TIN [version 1.1 PL6]
Date: Fri, 6 Nov 1992 12:46:21 GMT

Kenneth Mtz. (YONIX) (martinez@rodan.acs.syr.edu) wrote:
: 
:  Could anyone tell me more about what this device does (?)
:  What is the pinout layout?

This is a common digital ttl-device. You can find it in every ttl-
databook of many companies like TEXAS INSTRUMENTS, MOTOROLA or
NATIONAL SEMICONDUCTORS.

Bye Thomas

Newsgroups: sci.electronics
From: sakaria@vipunen.hut.fi (Sakari Aaltonen)
Subject: 68000 and Cache?
Keywords: 68000
Reply-To: sakaria@vipunen.hut.fi (Sakari Aaltonen)
Organization: Helsinki University of Technology
Date: Fri, 6 Nov 1992 22:55:06 GMT

Several accelerator boards with cache RAM are available for Atari ST
computers that use the 68000 processor. As the 68000 doesn't seem to
have any provision for a cache, I've been idly wondering how the cache
is implemented.

Does anyone have an idea?




-- 
-----------------------------------------------------------------------------
Sakari Aaltonen                             Helsinki University of Technology
Email: sakaria@vipunen.hut.fi               ---- Finns Do It in the Snow ----
Newsgroups: sci.electronics
From: MHUSSAI@cms.cc.wayne.edu
Subject: Serial To paralle Communication?
Organization: Wayne State University, C&IT
Date: Fri, 6 Nov 1992 21:11:12 GMT

Hello:
I am trying to build a seriall to parallel converter. Can anyone suggest
some information on it such as books, articles or personal experience.
Thanks.
Mohammed
From: bezenek@plains.NoDak.edu (Todd M. Bezenek KO0N)
Newsgroups: sci.electronics
Subject: 455MHz dangerous to pacemaker wearers?
Date: 11 Nov 92 19:59:29 GMT
Article-I.D.: ns1.BxKI76.DqB
Distribution: usa
Organization: North Dakota State University, Fargo, ND


Does anyone know whether or not 455 MHz radio frequency radiation is
dangerous to pacemaker wearers?  If so, at what effective radiated power
or voltage (uV/m) density is it dangerous?

Please email a response, and include a published reference (hints are
OK) if possible.

Thank you in advance,
Todd
--
Todd Michael Bezenek, KO0N
bezenek@plains.nodak.edu
From: dino@inqmind.bison.mb.ca (Tony stewart)
Newsgroups: sci.electronics
Subject: Re: IC to isolate device from telephone line?
Date: 6 Nov 92 08:40:47 GMT
Organization: The Inquiring Mind BBS  1 204 488-1607

kehoe@netcom.com (Thomas David Kehoe) writes:

> I heard that someone, maybe Motorola, makes a chip
> that isolates devices from telephone lines, allowing
> a device that has not been certified under FCC Part 68
> to connect to the network.
> 
> I know that Tellabs makes such a 2-wire to 4-wire
> hybred, but it's a big thing.
> 
> I called Motorola and Greybar, but couldn't find
> someone who'd heard of this chip.
> 
> If you know more about such a chip, please let me know!
> -- 
> "Why my thoughts are my own, when they are in, but when they are out
> they are another's." - Susannah Martin, hanged for witchcraft, 1692.
> Thomas David Kehoe          kehoe@netcom.com         (408) 354-5926

I believe Moto calls it the SLIC chip Std Line interface Cjip for 
telephony 2 wire interfacing.

dino@inqmind.bison.mb.ca
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607
From: Ted_Eugene_Viens@cup.portal.com
Newsgroups: sci.electronics
Subject: Re: RF leakage from TV cable system
Date: Tue, 10 Nov 92 21:38:40 PST
Organization: The Portal System (TM)
  <1992Nov9.034219.29018@athena.cs.uga.edu>
  <1992Nov9.143426.28306@erenj.com>

>|>
>
>I live next to a Hospital, and am frequently getting interference (I think
>from the hospital- ambulances, etc) on Cable channel 21. The best part
>is, Channel 21 is the weather channel, and the interference only comes at
>the time when my local forecast is telling me something useful. As soon
>as the transmission stops, I can see which cold front from Manitoba is
>going through North Dakota.
>
>Could leakage in my own house be letting that interference in? If not, I
>guess I oughta call the cable company and demand they fix it somewhere, but
>then I'd cause a lot of people with splitters, descramblers, etc to get caught
,
>huh?
>--
>----------------------------------------------------------------------
>Scott Ferguson                        Exxon Research & Engineering Co.
>Project Engineer                      New Jersey
>----------------------------------------------------------------------
>"Always bark at a dog."
>
Cable channels 19, 20, and 21 are co-frequencies with narrow-band commercial
land use two way radios and a few other commercial radio users.  Any fault
in a cable system that allows leakage or 'signal egress' also allows 'signal
ingress' or the entry of interfering signals.  If you live near a major
airport, you might be able to intimidate your system into improving the
interference problems by mentioning the possibility of leaks in the neighbor-
hood.  However if your TV set RF section is poorly sheilded, the ingress
could be happening right at the back of your set...
Good luck...  Ted..
From: clarke@acme.ucf.edu (Thomas Clarke)
Newsgroups: sci.electronics
Subject: Information and Sources for Teeny Camcorder CRTs
Keywords: camcorder CRT viewfinder
Date: 10 Nov 92 16:38:30 GMT
Article-I.D.: cs.1992Nov10.163830.667
Organization: University of Central Florida

Oh gurus of the network, I have noted that camcorders contain
little teeny CRTs in their viewfinders.  These CRTs may be of
use in a virtual reality display device I am developing.

Does anyone know of where I can get information on the the
interfaces to the viewfinder modules?  Many camcorders seem to mount 
the viewfinder CRT seperately in a module connected with a
short cable; what are the pin-outs?  No doubt brand specific.

Are the viewfinder modules available separately as replacement parts?

Etc. Etc.  Many questions.

Will summarize e-mail responses.

--
Thomas Clarke
Institute for Simulation and Training, University of Central FL
12424 Research Parkway, Suite 300, Orlando, FL 32826
(407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu
From: legrady@ug.cs.dal.ca (Tom Legrady)
Subject: Re: 486 CPU KOOLERS FOR SALE
Organization: Math, Stats & CS, Dalhousie University, Halifax, NS, Canada
Date: Thu, 5 Nov 1992 16:18:40 GMT

	csmith@plains.NoDak.edu (Carl Smith) writes:

>I guess a more meaningful calculation would be to use the price
>of the CPU.  Grabbing the first (and probably overpriced) catalog
>on my desk, I see they want $500 for a 486/33 (that seems a high, but
>I'll use that number as an example).  So $30 for a cooler is 6% of the
>price of the CPU, so if it extends the CPU's life by more than 6%, it
>has paid for itself in economical terms.  (And I am sure that it will
>extend the life by at least 6%).   But again, this only matters if
>you plan on keeping your PC long enough that long term heat induced
>problems might occur.  I do...

I don't know about the exact relationship of heat and lifetime for
electronics comnponents, but there is an inverse exponential effect on
the life of high-intensity lamps, such as the ones used for stage
lighting. I have to fudge the exact numbers, since I've been out of
theatre for a number of years, but dropping a lamp to 90% full
intensity generally doubles the expected life of a lamp. Dropping to
80% results in an unlimited expected life. Since our reaction to light
is non-linear, dropping to 90% has little effect on preceived
brightness. Since the lamps used cost $30 - $50  or more apiece and
have an expected life ranging from 300 - 2000 hours, doubling the life
is a desirable things to do. Of course, if you drop it, it still dies. 

I would suspect ( but without any evidence ) that similar effects hold
with electronics, that a relatively minor reduction in heat would have
a great effect on life and operation.


Tom Legrady
Newsgroups: sci.electronics
From: tmkk@uiuc.edu (Khan)
Subject: Re: Big Brother Radio Shack
Organization: University of Illinois at Urbana
Date: Fri, 6 Nov 1992 13:26:54 GMT


In article <HARKCOM.92Nov6091919@spinach.pa.yokogawa.co.jp> harkcom@spinach.pa.yokogawa.co.jp (Alton Harkcom) writes:
>In article <1992Oct30.150034.15841@bony1.bony.com> billg@bony1.bony.com
>   (Bill Gripp) writes:
>
> =}If you feel as I do that your phone number is something private, that
> =}it's none of RS's business (or other similarly nosey companies), just
> =}tell 'em you don't have one.
>
>   Lying to protect ones belief in one's rights.  Do we have a politician
>in our midsts? :)

Bad analogy. Bill is lying to someone who has no right to know the
answers to the questions being asked. Politicians lie to people who DO
have the right to know. :-/

Xref: sparky sci.electronics:18375 misc.forsale.computers.pc-clone:610 misc.forsale.computers.d:277
From: bketcham@stein.u.washington.edu (Benjamin Ketcham)
Newsgroups: sci.electronics,misc.forsale.computers.pc-clone,misc.forsale.computers.d
Subject: Re: 486 CPU KOOLERS FOR SALE
Date: 5 Nov 92 16:56:59 GMT
Article-I.D.: u.1992Nov5.165659.15518
Organization: University of Washington, Seattle

In article <1992Nov5.145945.22170@cam-orl.co.uk> tdb@cam-orl.co.uk (Thomas D Blackie) writes:
>In article <1992Nov5.083110.7351@u.washington.edu> bketcham@stein.u.washington.edu (Benjamin Ketcham) writes:
>

>
>Well I quess your sample really has been small, or you've been very
>lucky.  In the past 10 or 12 years I have seen numerous examples of
>systems failing due to overheating; of course it's difficult to say if
>it's actually the CPU, but keeping the silicon cool certainly cured
>many of the situations.  
>
>More recently and specificaly here at Olivetti we have several DX2 and
>50Mhz 486's which run perfectly when cooled but stiff when not.  
>
>So Ben, in short we have first hand experience of CPUs stiffing due to
>overheating, and directed cooling solves the problem.
>

Well, I guess I stand corrected then, both by this post and a former one.
I have not had any such experience with CPUs failing or becoming flaky
due to temperature under "normal" (ie, someone sold it that way)
operating conditions.

So now the question is, if indeed the 486 tends to run so close to the
85 C limit in typical (albeit not ideal) conditions, then why doesn't
Intel design the package with a built-in heatsink?  Even if the CPU
really does run OK without a heatsink or fan in a correctly-designed
box, it is so predictable that many boxes will not be thusly designed
that you would think it would be in Intel's interest to do this, to
avoid the stigma of a flaky or under-designed chip.

Comments, Intel?
From: fhl@milton.u.washington.edu (Dean Pentcheff)
Newsgroups: sci.electronics
Subject: Re: CCD camera questions
Date: 13 Nov 92 05:29:50 GMT
Article-I.D.: u.1992Nov13.052950.4121
Reply-To: dean2@tbone.biol.scarolina.edu (Dean Pentcheff)
Followup-To: sci.electronics
Organization: Department of Biology, University of South Carolina, Columbia

jack@robotics (replying to an earlier question) writes:
>>The second CCD camera question deals with the CCD's response to IR.
>>What is the response curve of a CCD camera?  How quickly does the CCD's
>>sensitivity taper off as the frequency of the light drops below visible
>>and into IR?   And how come I can see the IR on my monitor/view-finder?
>>(try pointing your TV remote at the cam-corder).  My potential application
>>is a pseudo-night-vision device.
>
>It depends on the CCD used, and the optical filters in front of it that
>make specific CCD elements sensitive to red, green, or blue. But as you've
>observed, they do see some IR. Your monitor displays this signal as
>visible image (TV remote IR LED's are actually pretty bright).
>...

Although this won't help you with your camcorder... It turns out that
most CCD chips have pretty good IR sensitivity.  A very good and very
cheap way to get an IR video camera is to buy a cheap B&W video camera,
open it up, and (carefully) remove the IR filter that was placed over
the CCD by the camera manufacturer.  We do this to record animal (blue
crab to be specific) behavior under IR illumination.  Like us, a lot of
animals are insensitive to IR.

-Dean
--
Dean Pentcheff  (Internet: dean2@tbone.biol.scarolina.edu) (803) 777-8998
Department of Biology, University of South Carolina, Columbia SC 29205
From: ryoung@pollux.svale.hp.com (Roderick Young)
Date: Mon, 9 Nov 1992 21:56:25 GMT
Subject: Re: 12 V -> 3V, 0.6 A
Organization: Hewlett Packard CPCD, Sunnyvale CA
Newsgroups: sci.electronics

Warning on using LM317 to drop 12V to 3V at 600mA...

You car battery could put out as much as 14-15V sometimes.  Let's say 13V.
That means a (13-3 = 10V) drop across this linear regulator.  At 600 mA,
that's 6 WATTS.  It might work, if you use the TO-3 version, and a very
good heat sink.  You might consider putting a 8-ohm, 10-watt resistor
in series with the LM317 input to disspate some of the power.

I actually used a (surface mount) LM317 to drop 12V to 5V, as less current
than you specify.  The chip got so hot, it melted its own solder!
Newsgroups: sci.electronics
From: kolstad@cae.wisc.edu (Joel Kolstad)
Subject: Re: Cable TV Rules
Organization: U of Wisconsin-Madison College of Engineering
Date: 5 Nov 92 18:10:37 CST

In article <1992Nov5.122636.5499@hemlock.cray.com> andyw@aspen32.cray.com (Andy Warner) writes:
>
>In article <720883631snx@nlbbs.UUCP>, paula@nlbbs.UUCP (Paula Stockholm) writes:
>> 
>> [...]
>>         I'm the last one who would be considered and advocate for the
>>         Cable Companies but . . . suppose you wanted to hook-up another
>>         water heater - you would expect to pay for the extra juice.
>> 
>>           The cable signal is not as easily "meter-able" but you would
>>           be using more cable signal.
>
>Good analogy. The power company at least has the honesty to put
>a meter on your feed, and charge you accordingly.

Oh, give me a break!  Sending cable to more than one TV does not use up
any more natural resources than sending it to one!

If you REALLY want to keep on going with this STRAINED analogy, though,
fine: As someone else suggested earlier, you can just go buy a distribution
amp so that the cable company always "sees" a 75 ohm impedence going into
your house, and the "power" you draw from their line is the same.

>Every other utility has expended a non-trivial
>amount of effort to bill you according to usage, it seems that the
>cable & sat carriers would rather expend effort legislating than
>developing a metering method (a gross generalisation, which I will
>probably be mercilessly flamed for)..

This is truely warped.  You're telling me that if I use 4 22W flourescent
bulbs, getting the equivalent of about 400W of incandescent light, the
power company should charge me for 400W!?  It would seem so, according
to what I can figure out for your use of the word "usage"!  (Since after all,
with those 4 22W lights, I can light up a lot more space and enjoy my
house a lot more!)

I'm sorry if I sound a little hyperactive here, but I think you analogy
is just FULL of holes.

					---Joel Kolstad
From: markz@ssc.com (Mark Zenier)
Newsgroups: sci.electronics
Subject: Re: Restrictions on 46/49MHz band?
Date: 5 Nov 92 23:34:10 GMT
Distribution: usa
Organization: SSC, Inc.,  Seattle, WA
X-Newsreader: TIN [version 1.1 PL6]

Joel Kolstad (kolstad@cae.wisc.edu) wrote:
: Hi,
: 
: I'm just curious... does anyone out there know the bandwidth limitations
: on the baby monitor/cordless phone/RC car/etc. non-lincensed 46 and 49MHz
: radio bands?

There are two paragraphs (as of 1989, gotta get a new copy)  15.233 and
15.235.

15.233 is restricted to cordless phones, with the 10 channels, each
a maximum of 20 kHz, and 10,000 uV/m at 3 meters.  (In both the 46 and
49 MHz channels.)

15.235 is for other things.  Specifically excluding cordless phones.
The band is 49.82 to 49.9 MHz, field strength is 10,000 uV/M at 3 m.

There are some specific authorizations for home built equipment in 15.235.
Like total project power consumption of 100 mW (at the power terminals)
and an antenna of 1 meter or less.  Sounds good, but you can only
build up to 5 units and not market them. (per 15.23)

Mark Zenier  markz@ssc.wa.com  
Newsgroups: sci.electronics
From: schaerer@isi.ethz.ch (Thomas Schaerer)
Subject: Re: Idea for LED sequencer
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
X-Newsreader: TIN [version 1.1 PL6]
Date: Thu, 5 Nov 1992 13:38:24 GMT

Michael Ardai (ardai@zax.eda.teradyne.com) wrote:
: In article <1992Nov3.094923.44351@kuhub.cc.ukans.edu> heacock@kuhub.cc.ukans.edu (Doug Heacock) writes:

: One resistor for the current limiting will work fine.  Good luck.

That's wrong! Think about maximum reverse-voltage of LEDs. About this 
problem you can read in this current subject more from myself.

Greeting Thomas