HDTenEightyP/NetNews huggingface dataset:
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Subject: Re: Sources for UV lightbulbs
Organization: AI Programs, University of Georgia, Athens
Date: Sat, 14 Nov 1992 04:26:28 GMT

In article <BxKrnB.JnM@acsu.buffalo.edu> v064mcqs@ubvmsb.cc.buffalo.edu (NEIL GANDLER) writes:
>
>  I have been working with small scale pc board making and hate the direct etch
>and photocopy toner iron on methods. They just are a waste of time and money.
>I have been trying photo etching. For a while I have been using a plan light 
>to expose the board. It does not do a good enough job and exposure
>time takes almost 40 minutes. I am looking for a UV lightbulb that would
>screw into a standard socket.                    ^^^^^^^^^^^^^^^^^^^^^^^
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

You could try a photoflood bulb from a camera store.  They are very bright
(and even fairly bright in the UV) because they run at a very high temper-
ature.  They're cheap.
-- 
:-  Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
:-  Artificial Intelligence Programs       phone 706 542-0358
:-  The University of Georgia                fax 706 542-0349
:-  Athens, Georgia 30602-7415 U.S.A.     amateur radio N4TMI
From: ps10@jet.uk (Paul Simmonds)
Newsgroups: sci.electronics
Subject: Re: Headlight Reminder Circuit Wanted
Keywords: Idiot Reminder
Date: 5 Nov 92 08:43:52 GMT
Organization: Joint European Torus

In <1992Nov3.220234.23476@u.washington.edu> whit@carson.u.washington.edu (John Whitmore) writes:

>In article <davej.40.0@gmuvax2.gmu.edu> davej@gmuvax2.gmu.edu (David F. Juraschek) writes:
>>This is probably a very beat up old horse, but does anyone have a 
>>simple circuit they could post for an automobile headlight reminder
>>circuit? 

>	The standard trick is to connect from the switched +12V
>on the instrument panel to the (+) lead of the headlamps; if
>the headlamp terminal is more positive than the switched +12,
>a buzzer (low-current type, connected in series with a diode)
>goes off.  The buzzer has to be a low-current type because the
>current it draws is set by the quiescent draw of the instrument
>panel, which is the current sink for the circuit.

>	Auto shops often sell a small kit for this purpose,
>complete with fuse-block connectors and instructions.

>	John Whitmore

A better solution is to go from the +12 Switched sidelight feed, via a
buzzer to the drivers door light switch, you then need to put a diode in the
door circuit to stop the other doors operating the buzzer.

         +12v  (sidelights)
          |
        +----+
        |    | Buzzer (12v)
        +----+
          |
          +-------|<|-------- To existing drivers interior light switch
          |       Diode
          |
          O
         ----|  Drivers door switch
          O
          |
         Car Chassis

Thus when you leave your lights on *AND* open the drivers door, the buzzer
sounds.  If you mean to leave your lights on, just shut the door and the
buzzer stops!

Paul Simmonds  (ps@jet.uk)


- Disclaimer: Please note that the above is a personal view and should not 
  be construed as an official comment from the JET project.
From: giri@umail.umd.edu
Newsgroups: sci.electronics
Subject: Radio Transmitter
Date: 5 Nov 92 15:13:15 GMT
Organization: Univ of maryland

I need to make a simple radio frequency transmitter with the following
characteristics: range of a few miles, transmit on a single frequency, 
energy derived from a button cell, CHEAP.

Any ideas on how I can build something like that?  Would a simple crystal
oscillator do?  

Thanks for your help.  Please email me at gn1@umail.umd.edu
Newsgroups: sci.electronics
From: ggpcy@cc.newcastle.edu.au
Subject: Help : Humidity measurements
Organization: University of Newcastle, AUSTRALIA
Date: Fri, 6 Nov 1992 01:27:32 GMT


Hi there I need some advise needed for my University research project.

What I am intending to do is to measure the humidity levels 
in a crop canopy over a 8-24 hour period. The simplest way to 
do this (I thought) would be simply to connect up some type of
device (variable resistor ??) that is sensitive to changes in 
humidity to an analogue data logger which the university 
already have (maybe in working order). The restrictions that 
apply are that there is no AC power supply available in the 
field and that my electronics knowledge is very limited.

I have spoken to several local electronics firms about trying
to find such a 'device' but without any great success (Hopefully
this is due to their lack of interest in the small quantities 
concerned). Does anybody know of the existence of a device that 
would suit these purposes ???


Thanks in advance

Peter.

----------------------------------------------------------------
Peter Young		|  Email : young@winkle.bhpese.oz.au (preferred)
Honours Student		|     or   ggpcy@cc.newcastle.edu.au
University of Newcastle |       
N.S.W. Australia.	|
From: mollers.pad@sni.de (Josef Moellers)
Newsgroups: sci.electronics
Subject: Re: chaser lights
Keywords: chaser lights
Date: 4 Nov 92 11:10:46 GMT
Organization: Siemens Nixdorf Informationssysteme AG, Paderborn, Germany

In <1992Oct30.194327.841@phx.mcd.mot.com> schuch@phx.mcd.mot.com (John Schuch) writes:

>In article <1992Oct22.143703.6299@sactoh0.sac.ca.us> jhp@sactoh0.sac.ca.us (Jim H. Puga) writes:
>>I understand I missed an article about how to build chaser lights
>>and was hoping that if someone still has that article if they could
>>e-mail it to me?
>>
>>If anyone has any suggestions on how to do it, I will gladly
>>accept those also.
>>

>Build an oscillator with an LM555, connect to output to a 7493
>TTL binary counter, connect the BCD output to a 74154 TTL BCD to
>1 of 16 decoder, connect the outputs of the 74154 to solid state
>relays starting with output 1, connect the first unused output
>from the 74154 to the reset input of the 7493.

Jim was probably referring to these "KITT"-like lights that go back and
forth.
You'd have to use an up/down counter (don't have the number) and combine
both the first and last output of the decoder to generate a trigger
input to a flip-flop supplying the input for the up/down signal.

-- 
| Josef Moellers		| c/o Siemens Nixdorf Informationssysteme AG  |
|  USA: mollers.pad@sni-usa.com	| Abt. STO-XS 113	   | Riemekestrasse   |
| !USA: mollers.pad@sni.de	| Phone: (+49) 5251 835124 | D-4790 Paderborn |
From: seaney@engr.wisc.edu
Newsgroups: sci.electronics
Subject: 0to24V to -12to+12V Converter
Date: 5 Nov 92 20:19:13 GMT
Organization: Univ of Wisconsin Madison


Hello!

I'm in a bind.  The gradstudents before me goofed an purchased a 0 to 24 Volt
Power Supply (15Amps) to drive a Power OpAmp.  After close inspection it became
apparent the the OpAMp needs -12to+12V.  Since the OpAmp drives a motor we need
as much current as possible.

Is there a cheap way to convert 0 to 24 Volts (Floating) to -/+ 24 Volts.  The
hard part seems to be the 15 Amp current requirement.

Thanks a lot for the help.  

(Yes, I'm an ME)

Steve
From: carmijo@hpnmdla.sr.hp.com (Chris Armijo)
Newsgroups: sci.electronics
Subject: Re: Help: What is an Independent Current Source!?
Date: 9 Nov 92 17:30:01 GMT
Organization: Hewlett-Packard, Santa Rosa, CA

In sci.electronics, steuer@clam.rutgers.edu (robert Steuer) writes:

    I understand an Independent Voltage source is like a battery and I
    understand that an Independent Current source can supply a current,
    but what is a REAL-LIFE example of an Independent Current Source?
    I have asked fellow students, my teachers, even a teacher with a
    Doctorate Degree and still I get hmmm, thats a good question!

I can think of two examples of current sources:
  1)  A bench power supply which has a constant-current output.  It's
      true that the vast majority of power supplies are set for constant
      voltage (like a battery), but you *can* purchase supplies which
      will output a constant current (over some given voltage range).
      You may have seen adds for the new  HP-E3610 supplies.  These
      have constant voltage or constant current outputs.

  2)  The most common example of a circuit-level current source is
      the collector output of a bipolar transistor.  Bipolar transistors
      typically have output resistances on the order of 10-20k ohm.
      While this doesn't seem like a lot, it's enough for them to
      be considered "current sources" to a first approximation.
      If you look at a schematic for an op-amp, you will see many examples
      of this -- where the collector of a transistor is feeding another
      circuit with a relatively constant current.

The second example brings up a good point.  In reality, there isn't any
such thing as an ideal current source, just like there are no ideal
voltage sources.  All sources will have some finite impedance.  Whether
you call a source a "voltage source" or a "current source" really
depends on how you are using it.  In general, if the source impedance 
is much lower than the circuit you are driving, then you call it a
voltage source.  If the source impedance is much higher (like the
second example above), then you call it a current source.

Chris
Newsgroups: sci.electronics
From: rg9538@ehsn2.cen.uiuc.edu (Ronald E Garnett)
Subject: 68HC11 Floating Point Routines
Organization: University of Illinois at Urbana
Date: Sun, 8 Nov 1992 03:50:17 GMT



Help!  I'm looking for a library of assembly routines for floating point.
I don't have time to write them myself.  I have access to a C compiler
which has a floating point library, but the code size is (relatively)
enormous.  Also, if anyone has any great ways to convert a floating
point to a string, please tell me.  I devised a way using floating
point log10() and pow10().  pow10(x) simply raise 10 to a power of X.
This works, but is probably not optimal.

	if (preference == E-Mail) {
	
		Address = rg9538@ewshp.cen.uiuc.edu;

		send( mail, address);

	} else {

		post( message, group );

	}


Regards,

Ron Garnett

University of Illinois at Urbana-Champaign
(Every time i write that, I get thirsty for some reason)




P.S.  Is there a 68HC11 group out there? Methinks there should be!

Newsgroups: sci.electronics
From: hunter@oakhill.sps.mot.com (Hunter Scales)
Subject: Looking for audio reverb chip
Organization: Motorola Inc., Austin, Texas
Date: Tue, 10 Nov 1992 23:00:32 GMT

Hi:

I'm looking for an audio echo or reverb chip (CCD bucket brigade) to
add to my thermin circuit.  Also would like a single-chip audio amp
that runs off 9V.  Anybody have a favorite they can recommend?

Thanks.

-- 
Motorola Semiconductor Inc.             Hunter Scales
Austin, Texas                           hunter@prometheus.sps.mot.com
#include <disclaimer.h>
From: terry.walter@outlan.ersys.edmonton.ab.ca (Terry Walter) 
Newsgroups: sci.electronics
Subject: WHERE CAN I GET
Date: 12 Nov 92 00:20:00 GMT
Reply-To: terry.walter@outlan.ersys.edmonton.ab.ca (Terry Walter) 
Distribution: world
Organization: Outland BBS  UUPCB  403-475-9588

Where Can I get a MOSTEK CHIP???
                                                                                               
Newsgroups: sci.electronics
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Subject: Re: RF leakage from TV cable system
Organization: AI Programs, University of Georgia, Athens
Date: Mon, 9 Nov 1992 03:42:19 GMT

In article <1992Nov7.213033.163@gems.vcu.edu> hleaves@gems.vcu.edu writes:
>I have some questions about RF leakage from a cable TV source:
>
>1. Why does the cable company check for RF leakage? Is it merely to see who
>is tapping their signal and not paying for it? Is it a health hazard? Or does
>it cause interference to other TV's? 

It causes interference to other radio services.  Remember that "cable
channels," unlike real TV channels, are not allocated for TV usage outside
the cable.  For example, 155 MHz is in the middle of a cable TV channel,
but is allocated to police radios.  So if the cable signal escapes from
the cable, the police can't hear each other.  Similar things happen to
aviation radios, hams, etc., depending on the frequency.

Also, any cable leak that lets a signal leak _out_ will also let signals
leak _in_, so that someone viewing TV suddenly hears the police or the
fire department on top of his TV program...

>2. How do they detect leakage? I'm suprised there is enough leakage from
>a leaky system to be detectable. How much stray RF actually comes out of
>the leaks?]

Easily detectable with a radio receiver tuned to the frequency of the
leak.  I've seen cable technicians walking around with "TV sound" radios
(cheap, the kind they sell at K-mart) scanning for leaks.

Some cable leaks are audible for miles on a good receiver.

>3. What is the best way to reduce RF leaks in a home cable system.

Be very vigilant about not breaking the shielding -- use proper connectors
and replace any cable that gets broken.
-- 
:-  Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
:-  Artificial Intelligence Programs       phone 706 542-0358
:-  The University of Georgia                fax 706 542-0349
:-  Athens, Georgia 30602-7415 U.S.A.     amateur radio N4TMI
Newsgroups: sci.electronics,misc.forsale.computers.pc-clone,misc.forsale.computers.d
From: gk@kksys.com (Greg Kemnitz)
Subject: Re: 486 CPU KOOLERS FOR SALE
Organization: K and K Systems
Date: Fri, 06 Nov 1992 22:10:20 GMT

In article <1992Nov4.182328.19037@news.clarkson.edu> faruque@sun.soe.clarkson.edu (Abdullah Faruque,334CH,3752,2654247) writes:
>>>>Two -- We have NEVER seen a system fail in service due to a processor chip
>>>>failure.  This is despite having sold many many hundreds of systems.  Our
>>>>customers are in general long term customers, and most of our business is
>>>>repeat business, so we have the opportunity to track the history of the
>>>>systems we have sold.  We also service a large number of systems sold by
>>>>others, many with substandard cooling, and have never seen a failed cpu chip
>>>>in them either.
>> 
>The above statement reminds me the following quotation:
>
>"The difference between a computer salesman and a used car salesman is
>that, the used card salesman knows how to drive a car and when he is
>lying"
>-Faruque
>Email: faruque@sun.soe.clarkson.edu

Interesting... what evidence do you have that anything in the quoted
statement constitutes a lie?  
-- 
Greg Kemnitz / K and K Systems / PO Box 47804 / Plymouth, MN 55447-0804
Internet: gk@kksys.com  / Voice: +1 612 475 1527 / Fax: +1 612 449 0488
Alternate Internet: gk@kksys.mn.org   /   ICBM:  44 59 20 N, 93 28 22 W
Newsgroups: sci.electronics
From: johnh@macadam.mpce.mq.edu.au (John Haddy)
Subject: Re: Idea for LED sequencer
Organization: Macquarie University, Sydney
Date: Thu, 5 Nov 1992 07:47:55 GMT

In article <1992Nov3.094923.44351@kuhub.cc.ukans.edu>, heacock@kuhub.cc.ukans.edu (Doug Heacock) writes:
|> I'm putting together a quick-and-dirty circuit that will light 10
|> LED's in sequence, one after the other.  Here's my idea so far:  I
|> intend to use half of a 4011 (quad 2-input NAND gate) as a clock
|> oscillator to drive half of a 4518 (dual synchronous up counter),
|> which will in turn drive a 4028 (BCD-to-decimal decoder), which will
|> actually drive the LED's.  I was thinking I could connect all of the
|> LED cathodes to ground through a single 330-ohm resistor, since only
|> one would be lit at a time.
|> 
|> Does this sound workable?  I welcome more elegant solutions--these
|> chips just happen to be the ones I have on hand at the moment.
|> +-----------------------------------------------------------------+
|> | Doug Heacock, Academic Computing   | heacock@kuhub.cc.ukans.edu |
|> | Services, The University of Kansas | heacock@ukanvax.bitnet     |
|> | Lawrence, KS 66045                 | Amateur radio: N0NZQ       |
|> +-----------------------------------------------------------------+

Use a 4017 decade counter. One chip solution (plus maybe a couple of
inverters/NAND gates for the oscillator).

Note that you should use Schmitt input gates for making RC oscillators - current
is minimised and the output will be cleaner, with a faster risetime.

Actually, a 74HC4017 is capable of driving a high-efficiency LED directly (keep
the current under 5mA or so). Yes, you can common-cathode the LEDs in this
application.

JohnH

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

      |  _  |_   _   |_|  _   _|  _|              Electronics Department
    |_| (_) | | | |  | | (_| (_| (_| \/           School of MPCE
    ---------------------------------/-           Macquarie University
                                                  Sydney, AUSTRALIA 2109

    Email: johnh@mpce.mq.edu.au, Ph: +61 2 805 8959, Fax: +61 2 805 8983

----------------------------------------------------------------------------
Newsgroups: sci.electronics
From: miguel@ldgo.columbia.edu (miguel maccio)
Subject: Seeing cane
Keywords: Ultrasound Range Module, Seeing Aids
Organization: Lamont-Doherty Geological Observatory
Date: Mon, 9 Nov 1992 15:24:33 GMT

Hi there!

	Is there any device that can help blind people locate objects by 
proximity?

	Years ago, a classmate of mine, worked on a project designing a 
kind of 'electronic cane' that, using ultrasound, would convert echo 
ranging signals into an audible sound whose pitch indicated the 
distance to objects. Pointing it in different directions it would give 
the user an estimate of distance to objects and help move without 
using his/her vision.

	The son of a friend of mine has recently lost his vision due to 
an unfortunate car accident (mother and sister died in the accident). 
The boy is only four and it seems not eligible to own or be helped by 
a seeing dog until is 18 years old.
	I think that a device like the one mentioned above may be 
helpful for this young and bright kid.

	I would appreciate any information as to whether devices like 
this are available commercially, or leads into research regarding the 
matter that can help me construct it. I am an electronic engineer 
with several years of experience in underwater acoustics 
instrumentation and am sure somebody must have worked out the 
details already for a design like this. Some people have suggested that
Polaroid has a kit, ultrasonic range module that could be used. Any ideas
where I could get it?

Please forward your responses to my e-mail address:
'miguel@lamont.ldgo.columbia.edu'
I would post a summary of the inquire.

Thank you.

Miguel Maccio
Lamont-Doherty Geological Observatory
of Columbia University
Palisades, N.Y. 10964
(914) 359-2900
FAX (914) 359-2931

Newsgroups: sci.electronics
From: pierson@cimcad.enet.dec.com (Dave Pierson)
Subject: Re: PC-MCIA Info
Organization: Digital Equipment Corporation
Date: Sat, 7 Nov 1992 00:22:48 GMT

In article <1cs8f7INNrgt@gap.caltech.edu>, jkubicky@cco.caltech.edu (Joseph J.
Kubicky) writes...

>Could someone please tell me the best place to find out info on the PC-MCIA
>spec?  

	A nit, perhaps, but its PCMCIA.

	Personal Computer Memory Card International Association.
	1030B East Duane Ave
	Sunnyvale, CA.

	Not a company, but a consortium.  (and not just for memory, any more.)

thanks
dave pierson			|the facts, as accurately as i can manage,
Digital Equipment Corporation	|the opinions, my own.
146 Main St			|I am the NRA.
Maynard, Mass		01754	pierson@msd27.enet.dec.com
"He has read everything, and, to his credit, written nothing."  A J Raffles
Newsgroups: sci.electronics
From: teemu@krkmoon.krk.fi (Teemu Hakala)
Subject: Re: chaser lights
Organization: Radio Club of Kauniainen (OH2NRG)
	<1992Oct30.194327.841@phx.mcd.mot.com>
	<1d8b3mINNgqe@uranium.sto.pdb.sni.de>
Date: Sat, 7 Nov 1992 16:08:47 GMT

   >In article <1992Oct22.143703.6299@sactoh0.sac.ca.us> jhp@sactoh0.sac.ca.us (Jim H. Puga) writes:
   >>I understand I missed an article about how to build chaser lights
   >>and was hoping that if someone still has that article if they could
   >>e-mail it to me?
   >>
   >>If anyone has any suggestions on how to do it, I will gladly
   >>accept those also.
   >>

   >Build an oscillator with an LM555, connect to output to a 7493
   >TTL binary counter, connect the BCD output to a 74154 TTL BCD to
   >1 of 16 decoder, connect the outputs of the 74154 to solid state
   >relays starting with output 1, connect the first unused output
   >from the 74154 to the reset input of the 7493.

   Jim was probably referring to these "KITT"-like lights that go back and
   forth.
   You'd have to use an up/down counter (don't have the number) and combine
   both the first and last output of the decoder to generate a trigger
   input to a flip-flop supplying the input for the up/down signal.

   -- 
   | Josef Moellers		| c/o Siemens Nixdorf Informationssysteme AG  |
   |  USA: mollers.pad@sni-usa.com	| Abt. STO-XS 113	   | Riemekestrasse   |
   | !USA: mollers.pad@sni.de	| Phone: (+49) 5251 835124 | D-4790 Paderborn |

 You guessed it, I'm lazy, and I use GNUS.
 I'd like to bring my fruit to this conversation about the most useful electornics
application -- the running light. You could use some circuit designed to read analog
signal (voltage) and drive some leds (in row or matrix). The input of the IC is very
easy to use, just drive voltage into it, and the led for that voltage shines. Circuit
UAA170 is one of those, it's designed to drive a 4 by 4 matrix of leds, operariong 
voltage 12 volts. It's real easy to get different effects out of it, just try different
oscillators (sine wave being great for KITT-light) in the input head.

--
Teemu Hakala     |     E-Mail to :     | These opinions are mine, and so are
Kasavuorentie 9B | teemu@krksun.krk.fi | all those *ing mistakes. Do NOT think
02700 Kauniainen | Teemu.Hakala@krk.fi | abt. Radio Club when I make a mistake
Newsgroups: sci.electronics
Subject: Re: PSPICE 5.1 for Windows
From: sciamanda@edinboro.edu
Date: 4 Nov 92 21:45:33 GMT
Organization: Edinboro University of Pennsylvania

In article <1992Oct29.151559.9496@umr.edu>, spoulsen@mcs213k.cs.umr.edu (Steven P Poulsen) writes:
> Where can one get PSPICE 5.1 for Windows [FTP].  I can't seem to find it?
> -- 
> ===========================================      ,--,
>   Steven P. Poulsen <spoulsen@cs.umr.edu>      ,'  '--,
>   Student of Electrical Engineering            ---, ,'
>   University of Missouri - Rolla                ,','

MicroSim Corp 1-800-245-3022
Get it - it's GREAT!

-Bob Sciamanda
Edinboro Univ of PA
Newsgroups: sci.electronics
From: meric@ptolemy.arc.nasa.gov
Subject: Where to find 68HC11 evaluation boards?
Organization: NASA-Ames Research Center, Moffett Field, CA
Distribution: usa
Date: Mon, 9 Nov 1992 18:07:26 GMT

Does Motorola still produce these? I remember seeing the
advertesiments in the IEEE Spectrum last year. I appreciate it very 
much if someone can tell me where to find one.
Thanks.

Meric
meric@kronos.arc.nasa.gov
From: Damian_Wallace@panam.wimsey.bc.ca (Damian Wallace)
Newsgroups: sci.electronics
Subject: Home Automation
Distribution: world
Date: 7 Nov 92 17:29:29 PST
Organization: Commodore Computer Club / PaNorAmA


Does any one know of Mail Order Houses that offer home automation
equipment.  If so, please let me know.  


P.S. I'm from Canada, so no 800 numbers please as they don't always work
from Canada.


-- Via DLG Pro v0.995

Newsgroups: sci.electronics
From: kharstin@MtHolyoke.edu (Ken Harstine)
Subject: Re: Phone line monitor
Organization: Mount Holyoke College
X-Newsreader: Tin 1.1 PL5
Date: Mon, 9 Nov 1992 16:49:47 GMT


Just a not on on phone line impedances.  The FCC requires that off hook
impedance should be greater than 5 Meg.  You should be able to achieve
this bye scaling the impedances of the divider.

Also the FCC requires that there should be greater than 2 Kvolt isolation
between the phone lines and the user (you) parts, and or earth ground. 
Placing the unit in a plastic box, and using your battery instead of an AC
mains transformer is also a good way to achieve this. 

Of course since this is strictly home brew, you probably don't have to
worry about regulations.  I would not recommend that you tie any portion of
this circuit to ground, as this would unbalance the phone line, and might
cause distortion of the sound.

---Ken Harstine