HDTenEightyP/NetNews huggingface dataset:
From: pmw2c@csissun10.ee.Virginia.EDU (Paul Michael Wayner)
Subject: Re: Detecting Sine Wave freq
Reply-To: pmw2c@csissun10.ee.Virginia.EDU (Paul Michael Wayner)
Organization: University of Virginia
Date: Sun, 10 Jan 1993 02:43:15 GMT

 I'm interested in designing a circuit that will determine
 if a sine wave frequency is in a certain range of values,
 specifically, 45-51 MHz.  It is very important that the
 detector be as reliable a possible, so I would like to use
 only a few active components and try to stick to RC's as
 much a possible.
 
 Any suggestions would be welcome.
  					Paul Wayner
Xref: sparky sci.electronics:22144 sci.energy:6691 rec.autos:31125
From: ems@michael.apple.com (E. Michael Smith)
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: 28 Dec 92 20:52:57 GMT
Organization: Circle 'C' Shellfish Ranch, Shores-of-the-Pacific, California

In article <1992Dec25.134459.7728@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>In article <1992Dec22.214616.27043@fcom.cc.utah.edu> bbarkey@lark.utah.edu (Brian Barkey) writes:
>>	And gasoline isn't explosive? 
>>	I may be mistaken but any power source capable of propelling
>>	a ton or more at speeds greater than 50 mph for hundreds of 
>>	miles must have a significant amount of energy in it. 
>>
>>	Brian Barkey	
>
>You don't understand. The gasoline *does* contain the same amount of
>energy as the flywheel, that's the whole point of the exercise. 

Harvesting a minor nit:  It is the combined masses of gasoline AND 
oxigen that contain the same energy.  The gasoline alone is rather
lacking in available energy ...  (This just makes your point more
strongly, so you may have been indulging in a bit of understatement...)

>But liquid gasoline can't explode. Only gasoline vapor properly mixed
>with oxygen, 14:1 air/fuel ratio, can explode. When it's arranged
>thusly it's called a FAE bomb. When the US dropped one during Desert
>Storm, British troops radioed their headquarters and reported that
>the "bloody yanks" were using nukes on the Iraqis. 

The research effort that resulted in the FAE bomb was aimed at 
duplicating some of the heat/blast effects of a nuke, but on a 
small scale, so this isn't too surprising (unless you are on the
recieving end of one !! ;-)

>Now with the flywheel failure, all the energy is released at once.
>The only difference between a fire and an explosion is the *rate*
>at which it occurs. This time the timescale is microseconds. You
>wind up with an explosion that is about equivalent to 200 pounds
>of dynamite. 

This is, IMHO, the most telling example.  Energy released equivalent
to 200 lbs of dynamite on a similar time scale could have a very 
large quantity absorbed in {phase change, chemical bonds breaking, etc.}
and still have enough left to be disasterous!  Heck, take 99% of it
away and you still have 2 lbs of dynamite.  The car is history at
this point ...  (I'd love to see someone postulate what chemical/physical
processes are going to happen in a flywheel failure that are going
to be MORE THAN 99% efficient at converting kinetic energy to non-thermal
forms ...)

-- 

E. Michael Smith  ems@apple.COM

'Whatever you can do, or dream you can, begin it.  Boldness has
 genius, power and magic in it.'  -  Goethe

I am not responsible nor is anyone else.  Everything is disclaimed.
Date: Thu, 7 Jan 1993 21:32:29 EST
From: H Campbell <HCAMPBEL@vma.cc.nd.edu>
Newsgroups: sci.electronics
Subject: Re: nicads for Gameboy?
Distribution: usa

In article <1993Jan5.042534.5631@cbnewsk.cb.att.com>, tbc@cbnewsk.cb.att.com
(thomas.b.cook) says:
>
>The manual for Gameboy says not to use nicad batteries. I
>called their hot line where I was told that this is because
>the nicads can explode and damage the game. What are the
>conditions where this is a concern? I have some ideas but
>I'd appreciate the net.wisdom interpretation of this warning.
>
I had the same question and when I pushed for an answer they
finally conceded that (1) the display would be slightly dimmer and
(2) they were concerned that people would mix standard batteries
with nicads.  They said that my game would not be harmed
by using nicads and so far (6 months) they seem to be correct.

H Gregory Campbell               |   hcampbel@vma.cc.nd.edu
Systems Programmer               |   hcampbel@irishvma
Univ. of Notre Dame              |
Notre Dame, Indiana, USA         |   (219) 631-5600
From: garyg@warren.mentorg.com (Gary Gendel)
Newsgroups: sci.electronics
Subject: IR Boost
Date: 4 Jan 1993 19:22:24 GMT
Organization: Mentor Graphics Corp. -- IC Group
Distribution: world
Reply-To: garyg@warren.mentorg.com
NNTP-Posting-Host: garyg.warren.mentorg.com

	My Mother-in-law suffered a stroke and has restricted movement.  She
cannot raise the remote control high enough to trigger the receptor on the TV.
Anyone know whether these strap on IR boosters would solve her problem, and where
they are sold?  Thanks.


Gary



Newsgroups: sci.electronics
From: dave@dlb.com (Dave Buck)
Subject: Re: X10 Control Interface
Keywords: X10
Reply-To: dave@dlb.com (Dave Buck)
Organization: D.L.Buck & Associates, Inc.; San Jose, Calif.
Date: Tue, 12 Jan 1993 21:19:25 GMT

In article <1993Jan7.144400.2501@progress.com> fossey@progress.COM (Paul Fossey) writes:
>I recently purchased an 'X10' home control interface for my PC. This box is
>connected to an RS-232 port, and is able to control light and appliances
>throughout the house. The control modules are sold by 'X10', Stanley, and
>Radio Shack. 
>
>I want to build some custom control modules. Has anyone ever seen specs on the
>signals sent over the house wiring for these modules ?

Nah, you really want to buy them, not build them. But I'll let you be the judge
of that.

Send mail to archive-server@dlb.com, and say "send tw523". You might also want
to say "send index".
-- 
Dave Buck   dave@dlb.com   {amdahl,ames,daver,netcomsv,sun,zygot}!dlb!dave
D. L. Buck and Associates, Inc.;   San Jose, California;    (408) 972-2825
Newsgroups: sci.electronics
From: Gary  Truemner <truemner@rd.hydro.on.ca>
Subject: HELP...find sealant/insulation for Ultrasonic crystal
X-UserAgent: Nuntius v1.1.1d12
X-XXMessage-ID: <A7704F621D03C8B9@pc-truemner.rd.hydro.on.ca>
Organization: ONTARIO HYDRO Research Lab
Date: Wed, 6 Jan 93 14:01:19 GMT
X-XXDate: Wed, 6 Jan 93 08:57:06 GMT

We would appreciate ANY info RE: a material and/or process to seal (from
water
absorption) and also electrically insulate a piezo-electric ceramic
crystal,
to be used for Ultrasonic flaw detection in hostile environment:
-Lithiated heavy water (Ph-10) at 300@ C, 1500psi. (10MPa)
-High radiation fields (>1 Mrads gamma + neutrons)

We have tried Cotronics Inc. ceramic adhesive & sealants but the curing
process 
does not lend itself well to this assembly. 

---------      |         |
|          |      ---------     Gary Truemner.ONTARIO HYDRO.Automated
NDT&Welding
|          |         |         |      R&D Lab.800 Kipling.m/s
KR172.Toronto.(416) 207 6380          
---------                       _from a Never Ending Story believer.avoid
the NOTHING
From: jeh@cmkrnl.com
Newsgroups: sci.electronics
Subject: Re: Laser gunsights (was: Info on CO2lasers wanted
Date: 12 Jan 93 10:22:16 GMT
Organization: Kernel Mode Consulting, San Diego, CA

In article <1993Jan11.103744.23729@actcnews.res.utc.com>,
 Bob.Clarke%bbs@actcnews.res.utc.com (Bob Clarke) writes:
> In message <1993Jan10.001114.1112@cmkrnl.com>
> dated 10 Jan 93 08:11:14 GMT
> jeh@cmkrnl.com writes:
> > [...]
> Your comments are not justified!  Actually you are quite rude.

Yes, I certainly was.

> 1) NVGs are not keyed to the LSS for the M16.

They certainly are in other systems; why not for this one?  It's much easier to
pick a weak signal out of background noise if you know exactly what the signal
looks like. 

> 2) I don't read Guns and Ammo.
> 3) I do read Defense Electronics. I have a MS in Physics (optics)
> 4) I designed and built a Helmet Mounted Infantry Display for the ARMY
>    , Fort Belvoir.  I am somewhat familar in this area.
> 5) The right minds in the military do bother with a LSS that is good for 
>    50 yards, and actually they love it!

Can you explain anything about the intended application?  What situation or
tactics would lead to the need for such a device?  

The one use I can see is in the (unlikely) event that your enemy doesn't know
you're there.  e.g., an ambush.  But if they have IR sensing gear, won't they
know you're there as soon as you switch on the laser? 

> 6) "I'll Just empty a clip in his general direction" shows your level of
> thinking.  Such as Soldier of Fortune.

*My* level of thinking?  Not at all.  It's the level of thinking of the folks
who are only 50 yards away.  They're going to be emptying clips in *your*
direction, throwing grenades, etc., while you're busy trying to get that little
aiming dot on a target...

...which reminds me of another question:  Why bother putting a precision
targetting system (*any* precision targetting system) on an M16?  I suppose
because "that's the rifle the Army uses", and I'm not being facetious here,
that's a perfectly valid reason -- it just seems a little mismatched, like
using a laboratory balance to weigh mail.  

> Christ, grow up.  For the rest of you, please forgive my reply, I will not
> response further.

I hope you will respond; if I'm to take your comments at face value, there is
clearly something about this that I'm not understanding.  Or else it's another
instance of the military's enthusiasm for high-tech gear -- not all of which
proves practical in battle.  (But, often they don't know which ones until they
test them) 

	--- 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: apn@Apple.COM (Alex Novickis)
Newsgroups: sci.electronics
Subject: Re: Why etch? Is copper deposition possible?
Date: 11 Jan 93 02:58:14 GMT
Organization: Apple Computer Inc, Cupertino, CA

In article <C0nqAB.55B@gantz.bowlgreen.oh.us> gantzm@gantz.bowlgreen.oh.us (Michael L. Gantz) writes:
>I have been reading all the articles concerning the etching of circuit
>boards, something I have a great need to do.  And they all assume that
>one would be etching the copper off of the board.  Is it possible for
>the home hobbyist to devise a system to deposit copper onto blank
>boards?
>
>I would picture a system where the hobbyist would pre-drill a blank
>board, then treat it with a photo-sensitive material.  After the
>photo-sensitive material has been applied both sides of the board
>would be exposed.  The exposed images would then be developed most
>likely in a chemical process.
>
>After the circuit images have been developed the board would then be
>treated either chemically or electrically to bond copper to the traces
>developed on the board.  The might solve the problem of plated through
>holes as they might get coated also.
>


Here would be a possible process, and the problems I see -

A) predrill blank panel ( no copper)
B) resist, expose, develop, bake, touchup - negative image
C) electroless plate entire surface
   
   electroless plating requires a surface that allows some of the
catalylst (typically rubidium chlorides) to soak in - this is easy
in holes, smooth surfaces are hard to do this on... but say you got this
to work somehow.

D) remove resist

  Electroless copper is very delicate, and you'd have to be able to
not damage it on removal... this is another real good place for problems.

E) Ok, now elecltroplate the entire board.

   this would be difficult also since you need to be able to tie all the
copper segments together to plate them - kinda tough. Ok, so, for some
boards lAyouts it would work.  I dunno if the electrical characteristics of
plated copper would be OK. And, Economically, - 1) Copper cost from
electroplating lots of copper on a board is high and, 2) Possible high
energy cost of electroplating lots of copper



Ok, so, you say, take out step E & D and just do electroless deposition.
You could, I suppose, but .... I've found *that* to be a very tricky
*and* time consuming thing in itself for a very thin layer. it's very
unlikley you will be able to get away with ONLY electroless. Also the grain
tends to be large which would not conduct uniformly.





-- 
Alex P. Novickis, Real Time systems demi-guru.  (W)   408-862-4541
ALINK:alex.n                                    (H)   415-691-0657
UUCP:{amdahl,claris,pyramid,sun,decwrl,well,ubvax,ames}!apn@apple.com,apn@nonvon
"I think... I think it's in my basement. Let me go upstairs and check"-Escher.
Newsgroups: sci.electronics
From: awpaeth@watpix.uwaterloo.ca (Alan Wm Paeth)
Subject: Power Inverter Problems (12VDC to 117VAC switcher)
Organization: University of Waterloo
Date: Mon, 11 Jan 1993 19:27:24 GMT

My brother received a "PowerStat" 12VDC - > 117VAC inverter over the holidays.
It has been a real disappointment. The ad claimed it was good for 140W normal
and 200W peak power. It barely manages 100W into a resistive load (lamp), and
it simply cannot drive even the smallest drill (its intended use). My EE degree
and scope can't help (I live half a continent away) hence this net posting.

To anyone with experience or familiarity with this/such beasts:

  (1) How can he test it a/o improve its output?
  (2) How can he better cope with power factor/inductive loads?

It strikes me that a series cap would be prohibitively large. Or maybe the
"modified sinewave" harmonic content is hell on a motor. Or perhaps I can send
him a matched pair of industrial strength VFETS (??). A circuit diagram would
help, or at least confirm/deny my suspicions that "100VA max, non-reactive
loads only" is about all one can expect. E-mail most welcome. Many thanks.

   /Alan Paeth VE3AWP
   Computer Graphics Laboratory, University of Waterloo
From: povlphp@uts.uni-c.dk (Povl H. Pedersen)
Newsgroups: sci.electronics
Subject: RS 232 & RS-422 voltage specs wanted
Date: 5 Jan 93 02:24:47 GMT
Organization: UNI-C, Danish Computing Centre for Research and Education

My Mac's serial port has partly died. It will receive data from RS-232
units, and both send and receive  to my DeskWriter which is RS-422.
So I would like to know what voltages does the standards use ?
What voltage is on the TxD when the port is not in use ?

thanks,
Povl
-- 
Povl H. Pedersen   -   Macintosh specialist. Knows some DOS and UNIX too.
pope@imv.aau.dk    -   povlphp@uts.uni-c.dk
From: geek+@CMU.EDU (Brian E. Gallew)
Newsgroups: sci.electronics
Subject: Re: CATV Block Converter Wanted
Date: 6 Jan 93 03:52:55 GMT
Article-I.D.: andrew.ofGiErO00WC0Q2pWNR
	<726207401snx@nlbbs.UUCP>
Distribution: world
Organization: Administrative Computing & Info Services, Carnegie Mellon, Pittsburgh, PA

Maybe I'm being excessively stupid, but is there anything a Radio
Shack converter can do that a "cable ready" VCR can't?  (I realize
that the original poster had a screwy TV setup, but I want to know for
my own purposes!)

                                  -Brian

-------------------------------------------------------------------------
| "Are they dead?"                                                      |
| "Does it matter?"                                                     |
|   - Pugsley and Wednesday in "The Addams Family."                     |
-------------------------------------------------------------------------
Newsgroups: sci.electronics
From: gopstein@helix.bms.com (Rich Gopstein)
Subject: PC board etching questions
Organization: Bristol-Myers Squibb PRI
Date: Mon, 4 Jan 1993 13:12:54 GMT


I would like to try making a small quantity of photo-etched PC boards
for experimentation purposes.  I entered a small schematic using the
PADS-LOGIC software, and did a layout using PADS-PCB.  I have two
questions:

1) Can I realistically make double sided PC boards?  My first board will be
   single-sided, but I would like to try more complicated boards later.

2) What are the best photo-resist methods and chemicals?  I have seen ads for
   both positive and negative photo resist.  Is there any difference other than
   the need for negative vs. positive artwork?

Any recommendations on etching suppliers would be appreciated, also.

I'll summarize responses to the net.  Maybe this would make a good start
for an FAQ...

Thanks!

-- 
Rich Gopstein

gopstein@bms.com
rutgers!bms.com!gopstein
From: whit@carson.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: HDTV Question
Date: 13 Jan 93 01:30:43 GMT
Article-I.D.: shelley.1ivrc3INNnmg
Organization: University of Washington, Seattle
NNTP-Posting-Host: carson.u.washington.edu

In article <1is3e2INNrvq@rave.larc.nasa.gov> kludge@grissom.larc.nasa.gov (Scott Dorsey) writes:
>In article <1iqoofINNmek@gvgspd.gvg.tek.com> mrk@gvgspd.gvg.tek.com (Michael R. Kesti) writes:

>>	If CDs are digital, what are the number of available pitches
>>	for playback.

>>Of course, being digital in no way limits the number of available pitches.
>
>Bzzt, try again.  Being digital does indeed limit the number of available
>pitches.  There is quite a variety of them, and certainly more than the ear
>can pick out, but it's not continuous, since time is being quantized when
>the sampling is taking place.

	The limit on the number of pitches is related to the duration
of the CD's long list of samples... it is NOT a limit that need concern
any musician, just a figment of using a finite number of samples
(not finite SAMPLING RATE, finite NUMBER OF SAMPLES) to represent
the sound.  For a one-hour CD, the frequency granularity is 
in the few-microHertz range.

	That's approximately 0 semitones, in musical jargon...

	John Whitmore
From: alex@anat3d1.anatomy.upenn.edu (Alex Shrom)
Newsgroups: sci.electronics
Subject: RF amplification from video equipment output
Date: 10 Jan 93 01:39:36 GMT
Organization: University of Pennsylvania


	I was just looking at my old C64 and I noticed that the video
out is labled "RF", which I assume means "radio frequency" or
whatever, and there is, of course, a switch next to it that allows you
to select the TV channel you want it to "broadcast" on to.
	My question is: is there any way of amplifying this output so
that I can broadcast short distances with it? I wasn't necessarily
thinking of taking over my neighbor's TV with video games (everyone
has cable now, anyway), but it would be a neat trick, if nothing else.

tanks!
Newsgroups: sci.electronics
From: cmwolf@mtu.edu (christopher m. wolf)
Subject: Re: telephone ringer voltage
Organization: Michigan Technological University
Date: Wed, 6 Jan 1993 18:39:24 GMT

jecome01@vulcan.spd.louisville.edu (Eric Comer) writes:
>I was wondering if anyone knew the voltage that is sent on the ringer
>line of a telephone cable when a call is incoming.  any help would be
>greatly appreciated.
>
(extracted from a lengthier document)
...
You should conform to the following:

TYPE				MIN (Ohm)	NOM. (Ohm)	MAX. (Ohm)
====================   		=========	=========	=========
*******************************Impedance**********************************
--------------------------------RINGING-----------------------------------
AC (at 40Hz, T=R)		1,000
AC (680 Hz to 1660 Hz)		2,000
...
The Phone Company will provide you:

TYPE				MIN		NOM.		MAX.
====================   		=========	=========	=========
Voltage DC (T=R)		47 V		48 V		105 V
Ring AC voltage (T=R)		40 Vrms		90 Vrms		130 Vrms
Ring frequency			15.8 Hz		20 Hz		68 Hz
Ring ON/OFF time				1s/1s
DC current			20mA		30mA		120mA
Noise								15dBrnC
...
T=R means tip to ring
Newsgroups: sci.electronics
From: koch@eis.cs.tu-bs.de (Andreas Koch)
Subject: 64x64 Digital Crossbar Switch ICs?
Organization: TU Braunschweig,Informatik,EIS,West Germany
Date: Thu, 7 Jan 1993 12:02:55 GMT

Does anyone know of a 64x64 digital crossbar switch circuit
(bus frequency at least 25 MHz). I know only of the Sierra
Semiconductor SC11320 32x32 XBar switch, which can be used
in groups of 4 chips to provide a 64x64 switching matrix.
However, due to space constraints, I would prefer a more 
integrated solution. Any hints are appreciated!

Andreas Koch
-- 
Andreas Koch                                Email  : koch@eis.cs.tu-bs.de
Institut f"ur theoretische Informatik       Phone  : x49-531-391-2384
Abteilung Entwurf Integrierter Schaltungen  Phax   : x49-531-391-5840
Gaussstr. 11                                Telex  : 95 25 26
Newsgroups: sci.electronics
From: michthom@bnr.ca (Michael Thomson)
Subject: Re: Ancient Scope Info Required
Organization: BNR Europe Ltd, Maidenhead, UK
X-Newsreader: TIN [version 1.1 PL8]
Date: Thu, 7 Jan 1993 17:00:40 GMT

Wes, I'm OVERJOYED! If you own a Mac, I may be able to return the favour in
kind... if not, please accept my thanks for your help.

Cheers,
	Mike Thomson, and a VERY happy 'scope.
--
*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*
+    Michael Thomson   + The opinions expressed here, while definitely NOT  +
+    BNR Europe Ltd.   + those of my employer, may OR MAY NOT be mine!      +
+ Phone +44 628 794416 + --------------------------==========-------------- +
+   Fax +44 628 776017 +        This space intentionally left blank         +
*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*
Newsgroups: sci.electronics
From: tidedu@ariel.lerc.nasa.gov (William T. Dedula)
Subject: How to prevent feedback in a intercom ckt ???
News-Software: VAX/VMS VNEWS 1.41    
Organization: NASA Lewis Research Center
Distribution: usa
Date:  4 Jan 1993 11:03 EST  

Hello All;
I'm designing a multi-station, multi-channel intercom 
system which will utilize a headset-microphone combination 
at each station. Since one of my requirements is to allow 
BOTh the Headset, and the Microphone to be enabled at each 
station, I am told that I could have a problem with feedback. 
I intend to use Low-Cost Power Amplifier IC's as well as 
741 Op Amps. I'd like to get some ideas from the net of ways
that this feedback problem can be greatly minimized, or 
eliminated. Is there any special way the circuit can be 
designed, or is there any special type of headset or microphone
which could be used, etc ... 

Thank You very much !!!

Tim

W. Tim Dedula                        Internet: 
N.A.S.A. Lewis Research Center       tdedula@nasamail.nasa.gov
Mail Stop 77-3                       tidedu@mars.lerc.nasa.gov
21000 BrookPark Road                 aa252@cleveland.freenet.edu
Cleveland, Ohio 44135
Phone (216) 433-3668

The National Aeronautics and Space Administration: Science and
Technology ... for the Benefit of ALL Mankind !!!

Newsgroups: sci.electronics
From: cthomas@athena.mit.edu (Michael T Ford)
Subject: Re: Voice modification...how?
Organization: Massachusetts Institute of Technology
Date: Sat, 9 Jan 1993 22:11:59 GMT

In article <C0LqHA.JCp@usenet.ucs.indiana.edu> graham@venus.iucf.indiana.edu writes:
>For some time, I've wanted to build a small "box" that, when spoken into,
>reproduces my voice as that of a Cylon Raider from the old Battlestar
>Galactica series.
>My problem is a simple one.
>Is the voice actual voice simply "modulated", or is tone mixed with the
>original voice and then modulated?

One really easy way to do that is take your mic into a 741 op-amp.  Then
have a 555 clocking away at your favorite frequency for a voice.  Better yet,
put a potientiometer in to control the frequency.  Now grab an NPN x-sistor.
Connect the output of the op-amp to the base, the output of the 555 to the
collector, and then run the emitter to another op-amp.  What you end up
doing is AM'ing the signal from the 555.

Mike WZ0C
Newsgroups: sci.electronics