HDTenEightyP/NetNews huggingface dataset:
From: levy@levy.fnal.gov
Subject: Re: 555timer/flasher
Organization: Fermilab Computing Division
Date: Mon, 16 Nov 1992 17:12:14 GMT

 In article <ahs1h2a@rpi.edu> wilusd@rpi.edu writes:
>
>	Well, I'm a beginner in the field of electronics, so please excuse this perhaps "trivial" question:
>	I'm trying to wire a 555 timer chip to simply flash an LED.  If anyone could possibly give me description of where the 8 pins go, it would be greatly appreciated...thanks for any help.
>  
>	Dave

Take a look at the LM3909.  Rat shack has it, and it even comes with notes on
how to hook it up.

================================================================================
[ Mark E. Levy, Fermilab          |                                            ]
[ BitNet:   LEVY@FNAL             | Unix is to computing                       ]
[ Internet: LEVY@FNALD.FNAL.GOV   |       as an Etch-a-Sketch is to art.       ]
[ HEPnet/SPAN: FNALD::LEVY (VMS!) |                                            ]
================================================================================


Newsgroups: sci.electronics
From: ajackson@ernie.Princeton.EDU (Andrew William Jackson)
Subject: Re: 'DreamLight' wanted!
Originator: news@nimaster
Organization: Princeton University
Date: Mon, 16 Nov 1992 21:08:53 GMT

In article <1992Nov16.111944.4390@kth.se> e92_anh@vaxkab.lne.kth.se () writes:
>On Sunday 15 November 1992, I was watching 'Beyond 2000' on Discovery
>channel. One of the wonders they were showing this time was an apparatus
>. . . The problem is that 'Beyond 2000' is an American program (I
>think) and I live in Sweden. 
>
>                                                         Andre'
>Heinonen, Royal Institute of Technology, Sweden


Beyond 2000 is an australian show.


Newsgroups: sci.electronics
From: miked@syscon.rn.com (Mike DeMetz)
Subject: Re: Death of remote controls
Organization: Syscon Corporate Headquarters - South Bend, IN USA
Date: Thu, 19 Nov 1992 19:44:42 GMT
X-Newsreader: TIN [version 1.1 PL6]

I also broke a remote by dropping it which broke the resonator.
They are available from Digi-Key.

Newsgroups: sci.electronics
From: andyw@aspen32.cray.com (Andy Warner)
Subject: Re: Surface mount device prototyping
Originator: andyw@aspen32
Organization: Cray Research, Inc.
Date: 20 Nov 92 13:45:47 CST


In article <By0L3D.LD8.2@cs.cmu.edu>, rwc@g3.ius.cs.cmu.edu (Randy Casciola) writes:
> In article <rda735z.722158097@nella16.cc.monash.edu.au>, rda735z@nella16.cc.monash.edu.au (Simon Cocking) writes:
> > I just got some specs for the MC68HC16Z1, and it looks like there is only a
> > PQFP / PQFP in a molded carrier ring package available.  My question is,
> > how would one go about prototyping (read wirewrapping) with one of these?
> > Are there sockets available which take these devices?  Or am I going to have
> > to construct a small daughter board to mount it on?
> [...]
> Antona Corp. in Los Angeles makes sockets mounted on PCBs with wire wrap wire coming
> through the bottom.  We bought the 100 pin PQFP version.  It was very expensive.
> $84.00.  Their number is 310-473-8995.
> [...] 

Syntax also make an adapter PCB, you have to solder the
chip to the board, and then you can use wire-wrap headers
to interface with the rest of your circuit. They're more
work, but the price was right : $12 or so. Part number PC-162

They can be got from

Electronics 123 (aka MING Engineering), (800) 473-6606, or (818) 912-9469

The boards are made in Taiwan by Syntax, I don't know if they have a
distributer in Oz.
-- 
andyw.	N0REN/G1XRL

andyw@aspen.cray.com	Andy Warner, Cray Research, Inc.	(612) 683-5835
From: jeh@cmkrnl.com
Newsgroups: sci.electronics
Subject: Re: How can a radar detector bedetected?
Date: 20 Nov 92 18:38:56 PST
Organization: Kernel Mode Consulting, San Diego, CA

In article <1992Nov20.100124.26519@rvgs.vak12ed.edu>, abond@rvgs.vak12ed.edu (Andrew H. Bond) writes:
> I am by no means an expert, but I read somewhere that these
> [radar detector] detectors pick up the high frequency leakage from the
> [radar] detectors... If this is the case a properly shielded [radar] detector
> might be undetectable. Any RF experts out there to back me up?
> -- 
> Andrew H. Bond, Roanoke Valley Graduate Center

I'm far from an RF expert (and keep in mind that theory and practice of RF,
especially the "practice" part, can get a little bit strange up in the GHz
ranges used by police radar).... however I do know that there is at least one
company, Bel, selling a radar detector that is claimed to be invisible to the
radar detector detectors. 

I imagine that "properly shielding" the unit is kinda tough when it has to have
an open feedhorn to receive the signals it's trying to detect! 

	--- Jamie Hanrahan, Kernel Mode Consulting, San Diego CA
Internet:  jeh@cmkrnl.com, hanrahan@eisner.decus.org, or jeh@crash.cts.com
Uucp:  ...{crash,eisner,uunet}!cmkrnl!jeh
From: woodson@dewey.soe.berkeley.edu (Charles Woodson)
Newsgroups: sci.electronics
Subject: Magnetic recording on cards
Date: 23 Nov 1992 16:56:20 GMT
Organization: University of California
NNTP-Posting-Host: dewey.soe.berkeley.edu

What information is recorded on the magnetic trip on copy cards
and mass transit tickets?  How is it encoded?
From: myers@hpfcso.FC.HP.COM (Bob Myers)
Date: Thu, 19 Nov 1992 19:25:13 GMT
Subject: Re: Laptop Tops
Organization: Hewlett-Packard, Fort Collins, CO, USA
Newsgroups: sci.electronics

> From "The Flash" A Blacklighting Publications 800-252-2599, page 18, Fall 1992
> 
> "Careful of closing laptop computers with the LCD displays when
> the computer is running or hot. The scree is made of liquid crystals
> and overheating can change their electrical propoerties and even their
> chemical structure. Once changed, the crystals may moose the ability
> to display information. Major bummer."

Yeah, moosing your crystals is a major no-no.  Sounds like what happens
when New Age religion meets Bullwinkle.


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: george@beta.ee.ufl.edu (George L)
Newsgroups: sci.electronics
Subject: Valves (was Re: Tube primer?)
Date: 22 Nov 92 07:52:13 GMT
Organization: EE Dept at UF

In article <1emj5lINNmlr@usenet.INS.CWRU.Edu> wb8foz@skybridge.scl.cwru.edu (David Lesher) writes:
>Others said
># So, a tube works more like an FET from a practical
># standpoint.
>
>Sigh....
>Am I the only one on the Net old enough to recall FETs being
>explained as working just like tubes......

I remember reading some years back about giant pnuematic speakers that were 
driven with water pressure. I can't recall anything about what was driving 
them, but there were some pictures of some boats that had these huge horns 
on top of them. I think these experiments were done on the Great Lakes.

So how does this relate? Maybe it doesn't, but I imagine these speakers were 
driven by something like the pnuematic equivalent of a tube. Maybe the valve 
term is related to this?

Anyone out there old enough to remember anything about this?
>
>--
>A host is a host from coast to coast..wb8foz@skybridge.scl.cwru.edu
>& no one will talk to a host that's close..........................
>Unless the host (that isn't close).........................pob 1433
>is busy, hung or dead....................................20915-1433

Thanks,
george@alpha.ee.ufl.edu
Organization: Penn State University
Date: Thu, 19 Nov 1992 02:12:38 EST
From: <TJR122@psuvm.psu.edu>
Newsgroups: sci.electronics
Subject:    4SALE: Power Glove - NEW! - $45

I have a few Power Gloves from the Nintendo System, in NEW condition,
size LARGE, still in the box!  This is a great 'toy' for either VR
on a PC or even for some stand-alone project (some simple circuitry
should suffice to run it without a PC or Nintendo, i.e. Clock Generator,
CLR, etc.)   You'll have to pay shipping (a couple of bucks)
...Let me know if you're interested...

Tom Rusnock  TJR122@PSUVM.PSU.EDU
Newsgroups: sci.electronics
From: vinlai@cbnewsb.cb.att.com (vincent.lai)
Subject: Possible to upgrade PC from FCC Class B to A?
Organization: AT&T
Date: Mon, 16 Nov 1992 19:27:30 GMT

I posted an article on EMI/RFI a while back and got really good
feedback, especially from someone who gave me info from ARRL (Thanks,
btw).  After doing a little research, I found out that my PC was FCC
Class B, meaning it's supposed to be used in the office.  Guess where
it is at this moment?  

With this new information, I'm wondering if the methods used to filter
out EMI/RFI will still work.  That brings up the idea of digging into
the PC hardware to upgrade its FCC Class from B to A.  First, is it
possible?  Second, and if so, how to go about it?  Or am I SOL (S--t
Out of Luck)?  Thank ya ...

--------------------------------------------------------------------
"Mom, we're hungry!" - Bud Bundy          "Why tell me?" - Peg Bundy

Vincent Lai
vlai@attmail.com
vinlai@cbnewsb.att.com
wcmnja!lai@somerset.att.com
--------------------------------------------------------------------
From: whit@carson.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: Whatever happened to tunnel diodes ?
Date: 18 Nov 92 22:35:49 GMT
Article-I.D.: u.1992Nov18.223549.3341
Organization: University of Washington, Seattle

In article <3sL6TB1w165w@inqmind.bison.mb.ca> bills@inqmind.bison.mb.ca (Bill Shymanski) writes:
>I have an old General Electric "Transistor Manual - 7th Edition", which
>looks like it was published in 1964 or so.   They have quite a few
>illustrations of the use of tunnel diodes.   Whatever happened to the
>tunnel (Esaki) diode ?

	Tunnel diodes can amplify, mix, and oscillate.  They operate
at sub-1V power supply levels, and at moderate (1 mA) currents.
Unfortunately, they are two-terminal devices (so they don't separate
the output signal from the input), and operate at such high frequencies
(2 GHz is typical) that UHF design rules should be used to ensure
acceptable results.

	Until relatively recently, every UHF TV tuner had a tunnel
diode local oscillator.   Silicon and GaAs FETs have taken over
from Ge (germanium, not General Electric) tunnel diodes.

	EEM lists several sources for tunnel diodes/back diodes.

American Microsemiconductor       (201) 377-9566
Diotec Electronics Corp.          (310) 767-1052
FEI Microwave                     (408) 732-0880
Germanium Power Devices           (508) 475-5982
Microphase                        (203) 866-8000
Relay Specialties                 (201) 337-1000
Solid State Devices               (714) 670-7734

	Of these, I think American Microsemiconductor is a
stockpiler of old parts, and Germanium Power Devices actually
manufacturers obsolete designs to order.

	John Whitmore
From: row0@ns1.cc.lehigh.edu (RICHARD O. WHITE)
Newsgroups: sci.electronics
Subject: Re: 0-38mV ==> 4-20mA Conversion
Date: 19 Nov 92 18:18:55 GMT
Organization: Lehigh University

In article <jtaylor.5.722100058@dseg.ti.com>, jtaylor@dseg.ti.com (Jeff Taylor)
writes:
>Can anyone suggest the best method (or design) to convert a 0 to 38 mV
>pressure transducer signal to a 4 to 20 mA signal that I can send down
>1000' of cable? I'm aware of the Burr Brown current transmitter devices,
>but am seeking a simple op-amp solution. The BB chips need a much larger
>voltage span as input.
>
>Thanks,
>
>Jeff :  JTAYLOR@DSEG.TI.COM
>
Try 1-800-872-9436  OMEGA technical assistance.... nice outfit
they carry exactly what you want at reasonable prices..
also ask for their books or call 800-222-2665 hotline
pressure-strain book has applications sections and product line data
I'm not assocated or a rep.... just a satisfied customer....
there are analog ckts avaible by Ti or Motorla ect if you wish to
design your own.. but why reinvent the wheel... they went through the
stability-noise-freq problems already..

second thought voltage -> freg converter might be a little better....
analog devices, intersil, might be a source .. I believe they have
datat aqua. chips with front end gain to give 1000 to 1 v-f & f-v
conversion...

1000' is a long antenna .....

hope this helps.....
-- 
Newsgroups: sci.electronics
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Help with refresh/record scheme needed!
Date: Sat, 21 Nov 1992 21:39:15 GMT
Organization: U of Toronto Zoology

In article <2b0a0a91.de77@grace.cri.nz> srgxnbs@grace.cri.nz writes:
>Its a long time since I played with DRAMS, but I would think that with 
>a bit of judicious programming you may be able to avoid a refresh 
>circuit. As long as you access all rows (columns?) within 4 ms the ram 
>gets refreshed, so while you're recording you'll be refreshing anyway, 
>ditto for playback. The rest of the time you could possibly arrange an 
>interrupt routine every 4 mS to just read the necessary number of 
>addresses if you can't build it into your program. If this is all B.S. 
>then someone please say so :)

No, it's a legitimate although tricky approach.  The very first Sun systems
used software refresh.  If you were really clever, you could hand-craft an
interrupt routine that did the refresh while also accomplishing something
useful (a friend of mine wrote a mouse-tracking refresh routine).

The trouble is, if that interrupt routine gets lost or has a bug, your
memory contents can evaporate.  Debugging such systems gets exciting.
Later-model Suns had hardware refresh.
-- 
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  henry@zoo.toronto.edu  utzoo!henry
Newsgroups: sci.electronics
From: gw214790@LANCE.ColoState.Edu (Galen Watts)
Subject: Re: police laser radar
Date: Mon, 16 Nov 1992 22:50:43 GMT
Distribution: usa
Organization: Environmental Science and Technology Center

When talking about IR, generally you speak of wavelength, not frequency.
Looking at a handy catalog, the only one I can find uses a wavelength of
788nm.

If the police LIDAR systems use commonly available IR LaserLEDS, you could
fit a few around the front of your car so a cop in any position in front of you
sees at least ond diode.  Modulate the power supply with a little noise (like
ignition noise) and the officer won't be able to get a reading that makes any 
sense to his machine.

If your source is brighter than the reflection of the officer's source.

If they find the system on your car, say it is your garage door opener.

Better yet, if you're a ham, it's an experimental radio device, since hams can
use any freq above 300 GHz.

Newsgroups: sci.electronics
From: dpalmer@mcnc.org (W. Dev Palmer)
Subject: Re: Is lead solder bad for me?
Summary: Not necessarily, but be careful
Organization: MCNC Center for Microelectronics, RTP, NC
Date: Tue, 17 Nov 1992 21:27:09 GMT

I wondered the same thing when I was making tens of thousands of solder
joints (literally) as part of a prototype production project at a local
university.  I won't tell you which, but they do have a terrific men's
basketball team.  The occupational health office finally agreed to give
me a blood lead test, and found the level to be lower than the national
average.

This was somewhat surprizing, until the doc pointed out that it is
probably the flux that creates the bulk of the vapors which we all
inhale some of.  The solder itself doesn't vaporize until you get it
REALLY hot, which is why the guy at the radiator repair shop seems so
unusual.  The main source of blood lead in the average American is from
car exhaust.  You probably get a higher chronic level of lead exposure
from driving around and filling the tank of your car than you do from
all the soldering you will ever do (as a hobbyist, anyway).  When you
read "unleaded" gas, think "decaffienated" coffee.

What I would recommend is to use the lead-free solder from Radio Shack
that you mentioned (they are good for SOMETHING, if your not too
paranoid to reveal your name), don't hold the solder in your mouth
while you have both hands on your work (I have seen people do this),
put a small fan blowing across the workbench to disperse the smoke, and
make sure you wash your hands between soldering and eating, drinking,
or smoking.  Should be normal for the rest of your life!

Good Luck,

Dev Palmer
dpalmer@mcnc.org
MCNC Room 212
P.O. Box 12889
RTP, NC  27709-2889
(919) 248-1837
(919) 248-1455 FAX
From: Ted_Eugene_Viens@cup.portal.com
Newsgroups: sci.electronics
Subject: Re: Directions for building strobe circuits
Date: Wed, 18 Nov 92 21:43:48 PST
Organization: The Portal System (TM)
  <1992Nov17.005004.21980@mintaka.lcs.mit.edu>

>
>I'm considering trying to build a setup making use of a rapidly
>flashing strobe bulb.  I've had some luck finding the bulbs (thanks to
>people on this list!), but haven't been able to find any references to
>books or kits detailing the construction of circuits for driving the
>bulbs.  I've found a few kits that operate in the range of 1 to 2
>flashes per second, but I'm looking for a much greater flash rate
>(probably from about 10-100 Hz).
>
>
>Would anyone on this list happen be able to refer me to a source for
>either a kit or literature that would discuss the construction of such
>a circuit?
>
>Any help will be enormously appreciated!
>
>Nate
>--
>------------------------------------------------------------------------------
-
>Nate Osgood                     | ARPA: hacrat@catfish.lcs.mit.edu
>CS Graduate Student             |
>MIT LCS Room NE43-636           | UUCP: ...!uunet!catfish.lcs.mit.edu!hacrat
>
Hello, Nate....
I don't mean to embarass you...  At least not too much.... 
Dr Harold Edgerton was the formost American inventor of Strobe Lights and
related equipment.  I am not sure, but I think he died in the past year.
He had been a professor at MIT since the mid twenties I think.  His laboratory
was right below the great dome of the main building.  As a freshman, I was luck
y
enough to take a course in strobe technology from him in the late sixties.  If
his lab is still open and if other professors are still engaged in stroboscopic
research and teaching, you probably daily walk below the greatest resources in
the United States for your Strobe Light questions...  I really hope this is
still possible...
Good luck...  Ted...
From: cstadbg@csv.warwick.ac.uk (Mr M J Brown)
Newsgroups: sci.electronics
Subject: Anti Shoplifting Devices/Mag media
Date: 17 Nov 1992 10:06:52 -0000
Organization: Computing Services, University of Warwick, UK
Distribution: world
NNTP-Posting-Host: lily.csv.warwick.ac.uk

Recentley,  bdenckla@husc10.harvard.edu (Benjamin Denckla) wrote

>This morning I walked in and out of a number of shops with
>anti-shoplifting detectors similar to the security devices they have in
>libraries, i.e. two vertical inverted U-shaped bars on either side of the
>exit.  Then I found that the disk I had been carrying had some errors on
>it which were not there beforehand.  I assume that this is some kind of a
>detector for non-demagnetized, i.e. not bought merchandise.  I have heard
>that the demagnetizing pads on the check out-counter will erase credit
>cards so I try to stay away from them.  But can anyone tell me if my disk
>could have been damaged by the detectors?  Also, how far away should I
>keep magnetic media like disks, credit cards, and DAT's from the
>demagnetizing check out counter pad?  is a foot enough?  If anyone could
>help I would really appreciate this as this is a very scary situation,
>especially without information as to exactly how scared I should be.

Legally, if it can be proved you have suffered a loss of data due to these 
devices, who can you hold responsible? The shop? .... Interesting....

BTW most of these systems work on radio frequencies, and are not magnetic.
Otherwise it would screw up credit cards etc. that people would have taken
into the shop with them. Maybe 'tis coincidence, but then again there could be
exceptions....

The demagger at the desk I should keep away from, they *will* damage disks if
you get near enough....

=============================================================================  
     _/      _/   _/   _/  _/   _/_/_/_/   |
    _/_/  _/_/   _/   _/_/     _/          |         Michael Brown
   _/  _/  _/   _/   _/       _/_/         |
  _/      _/   _/   _/_/     _/            |   cstadbg@csv.warwick.ac.uk
 _/      _/   _/   _/  _/   _/_/_/_/  _/   |
=============================================================================
From: erik@peewee.nwc.navy.mil (Erik van Bronkhorst       Code 3814                               Phone 939-1421)
Newsgroups: sci.electronics
Subject: Re: police laser radar
Date: 19 Nov 92 21:56:35 GMT
Distribution: usa
Organization: NAVAIRWARCENWPNDIV, China Lake

In article <keating.722030848@galena13> keating@rtsg.mot.com (Edward Keating) writes:
>dag@col.hp.com (David Geiser) writes:
>
>>> sees at least ond diode.  Modulate the power supply with a little noise (like
>>> ignition noise) and the officer won't be able to get a reading that makes any 
>>> sense to his machine.
>
>>On second thought, it's fairly easy to descriminate the
>>reflections.  In fact, it's probably really necessary given all
>>the regular IR stuff out there like your fan blade chopping the
>>engine heat, vibrations of the car body due to resonance or 500W
>>woofers, etc.
>
>Perhaps it may be easier than you think. All we'll need is the expected 
>modulating frequency of the laser and then send back a much more intense
>bandswept signal to drown out the reflection. Sorta like trying to 
>stargaze during the noonday sun. Does anyone really have the hard spec's on
>the wavelength involved and what IR leds would come close to that spec?

I have read that the laser is not actually "modulated", it is simply 
pulsed and that the speed measurement is made by comparing succesive
distance readings to a timebase rather than using the Doppler effect
like RF radars.  Given this, a continuous emission would prevent it
from "seeing" its own pulses rendering it useless.  All you need is
lights of about the right "color" and to turn them on and leave them on.
I doubt it if the detector is as narrow as the output of the laser so
I assume you wouldn't need to use laser sources.  You would have to
make sure your light beamed directly into the unit however, this could
be tough.

-- 
Erik van Bronkhorst KC6UUT DoD#4342585443 AMA#[classified]
"Truth is false and logic lost, now the fourth dimension is crossed..."
Newsgroups: sci.electronics
From: kehoe@netcom.com (Thomas David Kehoe)
Subject: Is lead solder bad for me?
Organization: Netcom - Online Communication Services (408 241-9760 guest)
Date: Tue, 17 Nov 1992 17:55:50 GMT

Will I get lead poisoning from breathing the smoke
from solder?  I work next to an open window, and leave
the soldering iron on the window sill, but when I'm
doing close soldering work, I can't avoid breathing
the smoke form the solder.

My father got lead poisoning last year when burning
paint off his house, so I know that lead can vaporize
in smoke.  I think his symptoms were headaches and
dizziness.

I've switched to lead-free solder, which is 97% tin and
3% silver (available at Radio Shack).  The label still
says to avoid breathing the smoke.  Why doesn't everyone
use th
-- 
"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
From: echeeve1@cc.swarthmore.edu (Erik Cheever)
Newsgroups: sci.electronics
Subject: 68HC11 c compiler
Date: 20 Nov 92 17:08:29 GMT
Organization: Swarthmore College, Engineering Dept

Can anybody out there recommend a good (cheap, free?) C compiler for the 6811. 
The ability to easily produce ROM-able code is a necessity.  

Thanks much,
Erik Cheever
echeeve1@cc.swarthmore.edu 
Newsgroups: sci.electronics,rec.video