HDTenEightyP/NetNews huggingface dataset:
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Tone frequencies on telephone
Date: Sun, 22 Nov 1992 01:29:34 GMT
Organization: U of Toronto Zoology

In article <1992Nov19.174629.2336@netcom.com> kehoe@netcom.com (Thomas David Kehoe) writes:
>build a keypad with 0-9, #, *, and A-D.  What you'd do
>with the A-D keys I don't know...

If memory serves, in some military phone systems they are used to indicate
the priority of a call (so that two stock clerks arguing about who was
responsible for losing a pair of boots get thrown off the line when NORAD
calls to announce incoming missiles).
-- 
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: pagorm@iastate.edu (Paul A Gormley)
Subject: Re: Sources for UV lightbulbs
Organization: Iowa State University, Ames, IA
 
	I have been making p.c. boards for my personal projects for
	As far as the technologies are concerned I would recommend
	As for the light bulbs, I have found that the Blacklight (regular)
	I'm sure there are other places out there like Kepro, I just
Date: Wed, 18 Nov 1992 20:18:57 GMT


				See ya around,
				Paul Gormley    [@:{)


	
Newsgroups: sci.electronics
From: schuch@phx.mcd.mot.com (John Schuch)
Subject: Re: police laser radar
Organization: Motorola Computer Group, Tempe, Az.
Distribution: usa
Date: Wed, 18 Nov 1992 19:55:25 GMT

In article <1992Nov16.205142.28519@julian.uwo.ca> wlsmith@valve.heart.rri.uwo.ca (Wayne Smith) writes:
>In article <1992Nov16.164531.2036@phx.mcd.mot.com> schuch@phx.mcd.mot.com (John Schuch) writes:
>>>Does anyone know what fequencies the police are using for their speed  
>>>detecting lasers?
>>
>>My guess would be about 1.5E+11 Hz
>>
>But seriously, if Lidar detection is as difficult as it seems to be
>(thanks to the way its used; quick and close), could an incoherent
>but strong IR source (heat lamps?) interfere with the readings, or
>would you need a laser IR source of your own, pointing back?

And would it be against the law?

John

-- 
| ONE LINE NOVEL: She backed away from the corpse slowly, not so much out  |
| of fear, but simply unsure of what the crowd expected her to do with it. |
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
Newsgroups: sci.electronics
From: gt8741b@prism.gatech.edu (Chris Adams)
Subject: Tone frequencies on telephone
Organization: Georgia Institute of Technology
Date: Tue, 17 Nov 92 07:57:19 GMT

Can someone tell me what the frequencies of the buttons on a telephone generate
and what the dial tone frequency is?  I am trying to build something, and I
need to recognize a dial tone, and generate button presses.
--
Chris Adams                       | "If tin whistles are made of tin,
Georgia Tech                      |  what do they make foghorns from?"
Internet: gt8741b@prism.gatech.edu|       --  Lonnie Donegan
----------------------------------+ 
Newsgroups: sci.electronics
From: dcovell@hfglobe.intel.com (David Covell)
Subject: Re: 4x12 -> 2x12
Organization: Intel Corporation
Distribution: usa
Date: Wed, 18 Nov 1992 00:59:46 GMT

brunetm@JSP.UMontreal.CA (Brunet Martin) writes:

>Hi there,

>      I have a little problem. I got a speakers cabinet (4x12" speakers) and I want
>to change it for a 2x12". I know there are 2 pair of speakers in series and the 2 pair 
>are in parallel to make a total of 8 ohms. Each speakers is 8 ohms. Can I put 2 speakers
>in serie with a 16 ohms resistance in parallel ? Thanks to all answer!


You won't damage the amp this way, but you will experience some change in
frequency response. An amplifier sees a speaker as a reactive load with an
impedance value that changes according to the frequency of the output.      
Thus the nominal 16 ohms of the branch comprised of two 8 ohm speakers in
series will vary with frequency, while the pure resistance (very nearly) of
the 16 ohm resistor will not change. Therefore the current flow through
the two branches will only be equal at one frequency, causing non-linearity
of the frequency response of the speakers. 
You might be better off just running the two speakers in series as a 16 ohm
load. Assuming your amp has an 8 ohm output jack, you'll have an impedance
mismatch and will lose some power, but you'll preserve the frequency
response curve of the speakers. It's generally safe to run a mismatch when
the load is > the amp output.
From: whit@carson.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: Is lead solder bad for me?
Date: 18 Nov 92 23:01:53 GMT
Article-I.D.: u.1992Nov18.230153.5536
Organization: University of Washington, Seattle

In article <Bxvx51.MLv@cmptrc.lonestar.org> neal@cmptrc.lonestar.org (Neal Howard) writes:
>In article <1992Nov17.175550.14583@netcom.com> kehoe@netcom.com (Thomas David Kehoe) writes:
>>Will I get lead poisoning from breathing the smoke
>>from solder?  

>>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

>Long term exposure to lead fumes from doing close soldering work is
>most definitely bad for you. My father's health is showing the effects

	Exposure to lead from soldering is NOT due to 'fumes'.  The
vapor that comes from soldering is the flux, NOT the lead or tin
(both of which have low vapor pressure at soldering temperatures).
Wash your hands after soldering or handling soldered objects,
because ingestion is the important danger here.

>that seems so innocent like soldering. BTW tin is also a toxic heavy metal
>and will poison you just as much as lead. 

	Tin is not toxic.  Tin cans for food, tin salts in toothpaste,
and tin in approved solder for potable water (and food handling
machinery) have been accepted for years, and there is NO indication
that this has been an error.


	John Whitmore
Newsgroups: sci.electronics
From: scotto@ipars.cts.com (Scott O'Connell)
Subject: Trans ID Help
Organization: Spectrum Data Services - Carlsbad, CA
Date: Wed, 18 Nov 1992 07:23:43 GMT
X-Newsreader: TIN [version 1.1 PL6]
Keywords: mitsubishi transistor 

I need help identifying a transistor I pulled out of an UPS.  I have four
of them and am wondering if they're worth keeping.

They look similar to the following ascii drawing:

   / --------- \
  / |         | \  (Hmm, I just held it up to the screen and this is almost
 /o |         | o\  actual size -- not bad huh?)
 \  |         |  /
  \ | E  C  B | /
   \ --------- / 

The entire back is metal the package is plastic.  The manufacturer is
Mitsubishi.  There is a label above the pins that says TYPE QM50HG-H and
NO. 90AC1.

What is it?  What's the rating?  What is it good for?

Many thanks in advance.
-- 

Scott O'Connell - N6ZEK                UUCP: {nosc, ucsd}!crash!ipars!scotto
Spectrum Data Services                 ARPA: crash!ipars!scotto@nosc.mil
Carlsbad, CA                           INET: scotto@ipars.cts.com
From: iqbal@yazoo.eel.ufl.edu (M.Iqbal)
Newsgroups: sci.electronics
Subject: Test
Date: 18 Nov 92 08:28:43 GMT
Article-I.D.: eng.1992Nov18.082843.26065
Organization: University of Florida

test............

-- 

-----------------------------------------------------------------------
Don't go around saying the world owes you a living.  The world owes you
nothing.  It was here first.
                -- Mark Twain
                                            
      						 >><<<     >>><<<<
Iqbal@sioux.eel.ufl.edu		 		 (o o)     (o) (o)
University of Florida				 [ | ]        | 
                                  		   -         ---
Newsgroups: sci.electronics
From: jtaylor@dseg.ti.com (Jeff Taylor)
Subject: 0-38mV ==> 4-20mA Conversion
Organization: Texas Instruments, Incorporated
Date: Wed, 18 Nov 1992 15:20:58 GMT

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
From: woodson@dewey.soe.berkeley.edu (Charles Woodson)
Newsgroups: sci.electronics
Subject: Magnetic recording on cards
Date: 23 Nov 1992 16:34:29 GMT
Organization: University of California
NNTP-Posting-Host: dewey.soe.berkeley.edu

What information is records on copy cards and mass transit tickets
in the magnetic strip?  How is it encoded?

Newsgroups: sci.electronics
From: rda735z@nella16.cc.monash.edu.au (Simon Cocking)
Subject: Surface mount device prototyping
Organization: Monash University, Melb., Australia.
Date: Thu, 19 Nov 1992 07:28:17 GMT

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?

Thanks,
Simon.
-- 
+---------------  Simon Cocking, sgc@yoyo.cc.monash.edu.au  -------- /// -+
|               Robotics & Digital Technology / GAUnix Group        ///   |
|                             Monash University                 \\\///    |
+-------------------------  Melbourne, Australia.  ------------- \XX/ ----+
From: sakaria@vipunen.hut.fi (Sakari Aaltonen)
Newsgroups: sci.electronics
Subject: Re: 68HC11 Floating Point Routines
Date: 9 Nov 92 21:42:42 GMT
Reply-To: sakaria@vipunen.hut.fi (Sakari Aaltonen)
Organization: Helsinki University of Technology

In article <BxDpBv.JyH@news.cso.uiuc.edu> rg9538@ehsn2.cen.uiuc.edu (Ronald E Garnett) writes:
>
>
>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
>.................................................

Motorola's application note AN974 has a listing for such a library.

The source code is available for ftp, too. Somewhere there's an .edu
site that has rather a lot of HC11 stuff. You guessed it: I can't remember
the name of the site...

-- 
-----------------------------------------------------------------------------
Sakari Aaltonen                             Helsinki University of Technology
Email: sakaria@vipunen.hut.fi               ---- Finns Do It in the Snow ----
Newsgroups: sci.electronics
From: barr@tramp.Colorado.EDU (BARR DOUG)
Subject: Re: Inductors
Organization: University of Colorado, Boulder
Date: Mon, 16 Nov 1992 17:43:59 GMT

In article <Vc99TB2w165w@digsol.jpunix.com> newton@digsol.jpunix.com (Michael Nichols) writes:
>I'm getting started in electronics and have been reading about inductors. 
>Although it says that inductors resist change in voltage, it doesn't give 
>any distinct mathematical method for determining how much an inductor of 
>given inductance-rating will affect the waveform of the circuit.  Could 
>somebody explain this to me?
>
>Mike Nichols
>newton@digsol.jpunix.com
Inductor rules:
1. An inductor is a short circuit to a DC voltage or current source.
2. v = L d (i)  (voltage across an inductor equals L times the first
         dt       derivative with respect to time of the current i)

Doing this requires understanding calculus and simple differential equations.
If you have the following simple circuit:

      -------------------------
      |                       | 
     /\  i                  N \ v = L d  i 
      |                       /       dt
      |_______________________| 
 

d is the first deviative with respect to time.
dt
t is the variable time, v is the voltage across the inductor, 
where N is an inductor, i is current, L is the inductance of the inductor
in henrys,  the funny \/ combination is an inductor. Now if i is sine(2*pi*f*t)
(where f is some frequency), then v (the voltage across the inductor) is
the first derivative of sine(2*pi*f*t). The first derivative of sine(2*pi*f*t)
is 2*pi*f*cos(2*pi*f*t). Evaluate this for all time t from 0 to 2*pi, and
plot i and v and notice the relation.

Newsgroups: sci.electronics
From: fraser@praha.jpl.nasa.gov (Scott Fraser)
Subject: Re: Tone frequencies on telephone
Organization: Jet Propulsion Laboratory
Date: Tue, 17 Nov 1992 20:27:43 GMT

In article <1992Nov17.075719.23612@riacs.edu> gt8741b@prism.gatech.edu (Chris Adams) writes:
>Can someone tell me what the frequencies of the buttons on a telephone generate
>and what the dial tone frequency is?  I am trying to build something, and I
>need to recognize a dial tone, and generate button presses.
>--

For TOUCH-TONE or TOUCH CALLING, the following is true,

Low     |
 Group  |
 (hertz)|
        |
--------|-------|-------|-------|
697     |   1   |   2   |   3   |
--------|-------|-------|-------|
770     |   4   |   5   |   6   |
--------|-------|-------|-------|
852     |   7   |   8   |   9   |
--------|-------|-------|-------|
941     |   *   |   0   |   #   |
--------|-------|-------|-------|---------------------
        | 1209  | 1336  | 1477  | High group (hertz) 

Each digit is composed of one frequency from the low group and one frequency
from the high group.  The frequencies have been chsen to minimize voice
simulation.


If you are using another system, the above chart will not hold true, but this
is what is found in 'most' phones here in the US.


Scott



Standard disclaimers apply!

Newsgroups: sci.electronics
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Subject: Re: Possible to upgrade PC from FCC Class B to A?
Summary: FCC rules are for real
Organization: AI Programs, University of Georgia, Athens
Date: Tue, 17 Nov 1992 04:48:07 GMT

In article <1992Nov16.213442.3829@julian.uwo.ca> wlsmith@valve.heart.rri.uwo.ca (Wayne Smith) writes:

>The FCC may have some teeth as far as dealing with your local TV or
>radio station, and it may even shut down a pirate, or someone running
>a 1000 watt CB rig, but what can they do as far as consumer electronics
>(computers) goes?  If someone wants to market a pc, or a limited production
>device for lab or research work, do they really (I mean, *really*) have to
>worry about FCC hassles?  (UL and CSA stuff is a different thing).

The reason you haven't heard from our FCC is that you live in Canada :)

Seriously, the FCC has been known to raid exhibits at COMDEX.  The FCC
has been involved in regulating incidental emissions ever since the 1950s,
when there was a rash of TV sets interfering with each other via their
local oscillators.  Uncertified computers are rather uncommon on the market
in this country.

The rules as I understand them specify what you can _sell_ rather than what
you can _use_.  Obviously the FCC doesn't go looking for homebuilt devices
(although if an actual case of interference were to arise, they could
restrict you from using an office-grade computer in a residential area,
probably).


-- 
:-  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
From: chris@luchs (Christian Forst)
Subject: Darkroom timer
Keywords: Darkroom, Enlarger, Timer
Organization: Inst.of Theor.Chemistry,Univ.of Vienna,Austria
X-Newsreader: Tin 1.1 PL3
Date: Fri, 13 Nov 1992 16:45:25 GMT

Hi

Has s/o instructions or a wiring diagram for a timer of an enlarger handy?
It should display the desired time (LED) display and count down in
1second-steps (or 1/10 sec-steps optional - switchable). Also it should have
buttons to switch on and off the enlager manually.

	Christian
--
+-----------------------------------+-----------------------------------------+
| Christian Forst		    | Phone: +43-1-40-480-670                 |
|				    | Fax:   +43-1-40-28-525                  |
| gargl, wonz, bazong, zawapp, gurp,| Email: Christian.Forst@itc.univie.ac.at |
| schwuppdi, bla, bingo, murx,boink,|                                         |
| zappadong, hau wech, knurps, ...  | No more comments on Disclaimers ...     |
+-----------------------------------+-----------------------------------------+
Newsgroups: sci.electronics,rec.photo
From: pngai@adobe.com (Phil Ngai)
Subject: Re: Lamp intensity vs. lifetime (was Re: 486 CPU KOOLERS FOR SALE)
Organization: Adobe Systems Incorporated
Date: Tue, 17 Nov 1992 21:07:40 GMT

In article <1992Nov16.164101.20150@bnr.ca> mwandel@bnr.ca (Markus Wandel) writes:
>What about photographic floodlights?  These things have expected lifetimes
>of just 2-8 hours.  I thought if I ever use the lamps and bulbs that I have

Why would you want to use those when you can now get 1.5 kilowatt
halogen floodlights?

-- 
My opinions are my own.
From: markey@flash.ATC.Olivetti.Com (Tim Markey)
Newsgroups: sci.electronics
Subject: Has anyone used surface mount components in home-made boards?
Date: 23 Nov 92 19:36:10 GMT


     The subject says it all.  I might need to use a 28 pin surface mount
     IC in a project.  I would like to know whether anyone has used surface
     mount components in home made projects and how difficult is it?  What
     layout software did you use?  I have PADS shareware, can I use this
     to design the layout?  Also what methods are used to attach the surface
     mount IC to the board.  I have heard of some electrically conductive 
     glue which can be used instead of solder or maybe a heat gun?  As you
     can see I don't know much about this and would like to know more.

     Tim Markey



Newsgroups: sci.electronics
From: schuch@phx.mcd.mot.com (John Schuch)
Subject: Re: police laser radar
Organization: Motorola Computer Group, Tempe, Az.
Distribution: usa
Date: Mon, 16 Nov 1992 16:45:31 GMT

In article <1992Nov12.225737.21262@rtsg.mot.com> schulkow@tophat2 (Diane Schulkowski) writes:
>
>Does anyone know what fequencies the police are using for their speed  
>detecting lasers?
>

My guess would be about 1.5E+11 Hz

:-)
John


-- 
| ONE LINE NOVEL: She backed away from the corpse slowly, not so much out  |
| of fear, but simply unsure of what the crowd expected her to do with it. |
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
Newsgroups: sci.electronics
From: rda735z@nella12.cc.monash.edu.au (Simon Cocking)
Subject: Re: Servo Controller Chips? (NE554, XR2264, etc)
Keywords: Servo, PWM, motor control
Organization: Monash University, Melb., Australia.
Date: Sun, 22 Nov 1992 05:45:39 GMT

tod@cco.caltech.edu (Tod Edward Kurt) writes:


>Hi all,

>	Does any one know of a source for Servo Control ICs?  Signetics used
>to make one --the NE554-- and Exar used to make three -- the XR2264, 65, 66.
>These parts have been outdated and discontinued, but if anyone knows of 
>replacements or other chips, please let me know.  I've called both Signetics
>and Exar.  Neither produces a modern replacement.

By servo control IC's, I assume you mean motor (DC / stepper) controllers?
If so, then Hewlett Packard also produce one, and it's fairly good, the
HCTL-1100.  I've played with these for the past 6 months, and they work
well.  If you hear of any others, I'd be interested to hear about them (I'm
looking for controllers besides the HP chip.)

>						-Tod

Simon.
-- 
+---------------  Simon Cocking, sgc@yoyo.cc.monash.edu.au  -------- /// -+
|               Robotics & Digital Technology / GAUnix Group        ///   |
|                             Monash University                 \\\///    |
+-------------------------  Melbourne, Australia.  ------------- \XX/ ----+
Newsgroups: sci.electronics
From: rky57514@uxa.cso.uiuc.edu (Tall Cool One )
Subject: CD4514 4-16 decoder
Organization: University of Illinois at Urbana
Date: Fri, 20 Nov 1992 01:06:35 GMT


Does anyone know about the CD4515 4-bit latched/4-16 line decoder?  I have one
connected to a 4-bit binary counter.  The idea is a sequencer or chaser light.
Problem is that the LEDs light correctly sometimes, and other times, not at
all.  I have the data sheets, and it doesn't tell me anything useful.  I just
want to use th 4514 as a decoder.  I really don't need the latch part of it..
Any suggestions would be greatly appreciated!  Thanks!


 _I_______________________________________________________________________I_
(_@_)                                                                   (_@_)
|   |   Raymond Yeung               Internet: Nimbus@uiuc.edu           |   |
|   |                                         rky57514@uxa.cso.uiuc.edu |   |
|   |   EE student at the                                               |   |
|   |   University of Illinois    CompuServe: 70700,1011                |   |
|   |   at Urbana-Champaign                                             |   |
(___)-------------------------------------------------------------------(___)
  I                                                                       I
Newsgroups: sci.electronics
From: whit@carson.u.washington.edu (John Whitmore)
Subject: Re: Heat sink
Keywords: Modelling
Organization: University of Washington, Seattle
Date: Wed, 18 Nov 1992 22:44:31 GMT

In article <1e8p9mINNa4o@iskut.ucs.ubc.ca> ivar@unixg.ubc.ca (ivar jonsson) writes:
>I am looking for S/W packages that are capable to model and simulate
>a HEAT SINK .  My objective is to optimize the haet removal from a high
>powered circuit.  Any suggestions will be helpfull.

	How about SPICE?  You just make a subcircuit for
the heat (heat capacity = capacitor, heat source= current source,
temperature= voltage on capacitor, heat dissipation = voltage-dependent
current source) and let SPICE solve it.

	This will require extensive information on air flow,
temperature, and the characteristics of the heat sinks.  Usually
these are specified only as limits, not as accurate values,
so some experimentation will be required in any case.

	John Whitmore
From: frank2@odie.ee.wits.ac.za
Newsgroups: sci.electronics
Subject: Solder fumes
Date: 18 Nov 92 14:46:42 GMT
Article-I.D.: odie.frank2.6
Organization: Wits Electrical Engineering (Novell Users).

I have regularly wondered, as I've been leaning over a circuit board and 
inhaling the fumes coming off the molten solder, what the effect of these 
fumes are.

Any information on their toxicity?


--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
David Frank                       {} "Time is unforgiving. That's why
<frank2@underdog.ee.wits.ac.za>   {} in Greenwich they call it mean."
University of the Witwatersrand   {} - Unknown	
Johannesburg                      {} 
-----------------------------------------------------------------------------
ps:	If you send me a picture postcard to the following address, I'll 
	send one right back to you.

			David Frank
			91 Mowbray Road
			Johannesburg
			2193
			South Africa
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Newsgroups: sci.electronics
From: klebl@iis.ethz.ch (Marcel Klebl)
Subject: Voltage controlled current source ???
Summary: voltage controlled current source
Keywords: voltage controlled current source
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
Distribution: sci
Date: Thu, 19 Nov 1992 14:03:30 GMT


Dear reader,

I'm looking for a cheme of an circuit of an voltage controlled current source.
I'd like to "drive" the circuit with an D/A converter. So the input voltage
will be between 0 and 5 V.
The output current should be at least 1 A. I think the circuit will contain two
Op Amp's and an FET.    


Please if you now such a circuit which should be very common then e-mail me.

		thanks in advance

				marcel


klebl@iis.ethz.ch