HDTenEightyP/NetNews huggingface dataset:
From: nagle@netcom.com (John Nagle)
Subject: Re: Hot Tub Controller
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Date: Fri, 18 Dec 1992 08:15:30 GMT

more_da@pts4.pts.mot.com (Dan Morera) writes:
>Greetings and Happy Holidays Netters,
>I am developing a system to remotely control a hot tub, and I have not
>previously worked with the large AC voltages needed to do so.

     Given your discussion, I suggest you get a licensed electrician to
do the job.  You've missed a few key safety issues.

     This is NOT to be taken as a complete list, but first, where you
have water near power, you're usually required to use a GFCI breaker,
and for a hot tub, you definitely should.  Second, you need low-water
and overtemp detectors for the heater to prevent fire should the water
stop flowing or be absent.  Most hot-tub heaters have these built in,
but check.  Redundant overtemp switches are common, and may be required.

     Switches where a wet person can reach them require special handling.
The usual hot tub switch is an air button, a squeeze bulb connected by
a tube to a pressure switch.  Just putting the controls on the +5 supply isn't
good enough, because something might short to the low-voltage portion of
the system.  UL-approved switches for very wet locations exist, but
are expensive.

     And remember, plumbing isn't ground in the era of plastic pipe.

     Have you figured out how much it will cost to heat a hot tub
electrically?  Most people use gas or solar.

     Go with an electrician.

					John Nagle

Newsgroups: sci.electronics
From: digennar@fcs280s.ncifcrf.gov (Frank S. DiGennaro)
Subject: Question...
Keywords: Digital Electronics
Organization: Frederick Cancer Research and Development Center
Date: Fri, 18 Dec 1992 19:16:01 GMT


Question of the day...

	I came across the expression " smearing a sign bit across a word."
Can anyone explain to me what this means?

Thanks.

Frank DiGennaro
National Cancer Institute
Frederick, Md.
digennar@fcs280s.ncifcrf.gov  


Newsgroups: sci.electronics
From: LJ09735@LMSC5.IS.LMSC.LOCKHEED.COM (Jeff Schaefer)
Subject: Re: Hot Tub Controller
Organization: O/19-61
Date: Fri, 18 Dec 92 20:51:28 GMT

In article <1992Dec18.081530.13580@netcom.com>, nagle@netcom.com (John Nagle) writes:
> 
> more_da@pts4.pts.mot.com (Dan Morera) writes:
> >Greetings and Happy Holidays Netters,
> >I am developing a system to remotely control a hot tub, and I have not
> >previously worked with the large AC voltages needed to do so.
> 
>      Given your discussion, I suggest you get a licensed electrician to
> do the job.  You've missed a few key safety issues.
> 
>      This is NOT to be taken as a complete list, but first, where you
> have water near power, you're usually required to use a GFCI breaker,
> and for a hot tub, you definitely should.  Second, you need low-water
> and overtemp detectors for the heater to prevent fire should the water
> stop flowing or be absent.  Most hot-tub heaters have these built in,
> but check.  Redundant overtemp switches are common, and may be required.
> 
>      Switches where a wet person can reach them require special handling.
> The usual hot tub switch is an air button, a squeeze bulb connected by
> a tube to a pressure switch.  Just putting the controls on the +5 supply isn't
> good enough, because something might short to the low-voltage portion of
> the system.  UL-approved switches for very wet locations exist, but
> are expensive.
> 
>      And remember, plumbing isn't ground in the era of plastic pipe.
> 
>      Have you figured out how much it will cost to heat a hot tub
> electrically?  Most people use gas or solar.
> 
>      Go with an electrician.
> 
> 					John Nagle
> 
> 
>
Just one thing to add to John's recs....  It's wise to separate the low-voltage
from high-voltage circuitry with opto-isolators as an added precaustion! 

Otherwise, I'd follow all of his recs!  

-Jeff
From: stlucas@gdwest.gd.com (Joseph St. Lucas)
Newsgroups: sci.electronics
Subject: SEGA info anywhere?
Date: 18 Dec 92 21:10:32 GMT
Distribution: usa
Organization: General Dynamics Corp.

We just decided to get my son a Sega Genesis thing for Christmas, among
of things, because I like the stuff I've seen on this group describing
pinouts and the like.  However, since our site deletes old messages
(after about 3 days), and I didn't think then to save the info, I'd like
to know if that information had been saved anywhere I can ftp to.  If
anyone has saved all the Sega messages, please email me and let me know,
please don't send it all to my inbox.  Thanks.

-- 
Joe St.Lucas    stlucas@gdwest.gd.com        Standard Disclaimers Apply
General Dynamics Space Systems, San Diego
My blood runs Husker red.
Xref: sparky sci.electronics:20851 alt.cyberpunk:6673
From: curt@oasys.dt.navy.mil (Curt Welch)
Newsgroups: sci.electronics,alt.cyberpunk
Subject: Re: Caller ID block?
Date: 16 Dec 92 15:14:53 GMT
Reply-To: curt@oasys.dt.navy.mil (Curt Welch)
Followup-To: sci.electronics
Organization: Carderock Division, NSWC, Bethesda, MD

>mdk@col.hp.com (Mark Keisling) writes:
>Can't you instead of blocking have the number be reported as something other
>than the number you are calling from, like the old blue/black box ttrick

In alt.cyberpunk, lruppert@rodan.acs.syr.edu (Dahr--The Beastmaster) writes:
>I was thinking of something just along those lines the other day.  All you'd
>have to do is send a short signal to block/jam the legit one sent by the phone
>company, and then send yours afterwards,

I seriously doubt that any phone switch that can send Caller-ID will allow
that.  I know mine doesn't.  I just testted it last night.  Your call
isn't connected to the other line until after they pick up.

Curt
From: sef@drutx.ATT.COM (Scott E. Farleigh)
Newsgroups: sci.electronics
Subject: Sovtek Tubes
Date: 14 Dec 92 15:46:36 GMT
Distribution: sci
Organization: AT&T, Denver, CO

Pardon me for not following this discussion, but could someone send
me an address of where I can find Sovtek Tubes. I have an OLD
Fisher Brand Stereo that uses an ELL80 (a.k.a. 6HU8). If they can
be found in the U.S. they are VERY expensive.

Thanks
Scott Farleigh
Newsgroups: sci.electronics
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: How full is a nicad
Date: Sun, 20 Dec 1992 03:17:03 GMT
Organization: U of Toronto Zoology

In article <1992Dec19.230112.8340@klic.rain.com> keithl@klic.rain.com (Keith Lofstrom) writes:
>>The output-voltage curve of a NiCd is essentially flat from pretty nearly
>>full charge to pretty nearly empty.
>
>There are many applications where knowing the charge on the battery is 
>crucial.  Given my rudimentary knowledge of electrochemistry, it would
>seem that one could provide a third electrode on a battery, of some other
>materials than the main electrodes, designed to indicate the balance of
>electrolytes in the cell...

If you're willing to tinker with the battery design, then you can get a
binary version of this easily enough:  both the temperature and the
internal pressure of a NiCd rise sharply when overcharging begins.
Premium-market NiCd systems often use cells with temperature or pressure
sensors built in.
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry
Newsgroups: sci.electronics
From: mellob@cary115.its.rpi.edu (Wyle E. Coyote)
Subject: magazines
Reply-To: mellob@rpi.edu
Organization: Rensselaer Polytechnic Institute, Troy, NY.
Date: Tue, 15 Dec 1992 23:38:54 GMT

 to: Mr. Fox, my mail server isn't finding your address 

  Well, Mr. Fox, The only time I buy a magazine from a newsstand
        is when I've never read one before. If I like the magazine, I
        subscribe. That way, I don't have to go get it. And because they
        (magazine) have it delivered to my door for me, I get a discount
        off the "annual newsstand price." I'm sure you've heard that before.

            But anyways, I live in Saugus, MA, right next to Lynn. Maybe
        you've heard of it? Reading and Greeting carries the whole nine
        yards. i.e.: Pop Comm, Pop Elec, Radio Elec, CQ, and that other
        one that CQ Communications publishes (slipped my mind.) B. Dalton
        Bookstores carry electronics magazines and in addition to that they
        actually stock technical books. I bought "Understanding Electronics"
        and my "Passport to World Band Radio" at B. Daltons.

            You may also want to try You-Do-It Electronics in Needham. Las
        time I was there they had a modest selection.


        Radio Electronics
        Subscription Service
        P.O. Box 51866
        Boulder, CO. 80321-1866
        1-800-999-7139 for subscription

        Popular Electronics
        Subscription Dept.
        P.O. Box 338
        Mt. Morris, IL. 61054-9935

        Popular Communications
        76 North Broadway
        Hicksville, N.Y. 11801-9962

        Monitoring Times
        P.O. Box 98
        Brasstown, N.C. 28902
        1-800-438-8155

        Oh yeah Pop Elec# 1-800-435-0715, and Pop Comm# 516-681-2922

       Brett A. Mellor
	Rensselaer Polytechnic Institute
Newsgroups: sci.electronics
From: ren@rap.ucar.edu (Ren Tescher)
Subject: Re: Best nicads??
Keywords: nicad
Organization: NCAR, Research Applications Program
Distribution: usa
Date: Sat, 12 Dec 1992 17:02:13 GMT

In article <1992Dec12.131021.19612@panix.com> schuster@panix.com (Michael Schuster) writes:
>In article <rich.724149537@pencil> rich@pencil.cs.missouri.edu (Rich Winkel) writes:
>>In <1992Dec10.083347.10926@hemlock.cray.com> n3022@cray.com (Jim Knoll) writes:
>>>Can someone tell me if there is a possible FAQ that rates the
>>>different manufacturers of nicad batteries according to quality,
>>>power output, etc.?
>>Consumer Reports ran an article on batteries about a year ago, I think
>>it was nov 91.  They tested standard, alkaline and nicad batteries.
>>I seem to recall radio shack (gasp) had among the best nicads, especially
>>in the D size, which were something like twice the capacity of all other
>>D sized nicads.  The reason is that other brands' D nicads were actually
>>C sized nicads camouflaged in D cases.
>Are you sure the Radio Shack endorsement didn't just apply to their alkaline
>cells? The Radio Shack D nicads are =AA= cells in D cases!
I don't have the article in front of me either, but I recall that it was
their 'HiCapacity' NiCad D cell which had the full size cell inside.
The article mentioned that _one_ other manufacturer had a full size D cell
nicad (I don't recall who).
I just checked the CR Dec'91 5-year index, no mention of rechargeable battery
tests.  Maybe it was in the past year?
ren n0pvi
dona nobis pacem
From: tquinn@heartland.bradley.edu (Terry Quinn)
Newsgroups: sci.electronics
Subject: Re: Sony control L
Date: 17 Dec 1992 17:36:55 -0600
Organization: UTexas Mail-to-News Gateway
Reply-To: tquinn@heartland.bradley.edu
NNTP-Posting-Host: cs.utexas.edu



> : Does anyone know where I can find details of Sony control L?
> 
> The only information I have got is here: A couple of years ago Sony
> used round 5-pin connector for the same purpose as now popular 2.5 mm 
> minijack, which is nowadays in Sony camcorders. That info I got from
> Sony Finland who promised to send me a adapter cable to convert from 5-pin
> to 2.5 mm minijack! (I have not received one yet - but hope soon!) 
 
 
I don't have any information on the technical specs, but I can 
give you the polarity on the 5 pin to 2.5 mm connection, as was 
provided to me by a friend.  It is a two conductor connection.
 
 
 
5 pin connector, pins facing you
             -----
           /     o \
          /         \
          | o  0  o |
          |         | 
          \C o   o A/
           ----^----
 
 
                                            ----------------\
Stereo Mini-Mini (greatly blown up)        |                 \
                                           |                  \
                                           |                   |
             / ----------------------------|                   |
           /    A  |  B   |     C          |                   |
           \       |      |                |                   |
             \ ----------------------------|                   |
                                           |                   |
                                           |                   |
                                           |                   |
                                            \----------------  |
                                                            |__|
 
 
Connect A to A and C to C.  B is unused and there is NO other 
connection, including the shield on the 5 pin.
 

--
                                    Terry Quinn
                                     Germantown Hills, IL
                                      tquinn@heartland.bradley.edu
from Compuserve . . .                  >INTERNET: tquinn@heartland.bradley.edu
Xref: sparky sci.electronics:21229 sci.energy:6286 rec.autos.tech:16965
From: carl@SOL1.GPS.CALTECH.EDU (Carl J Lydick)
Newsgroups: sci.electronics,sci.energy,rec.autos.tech
Subject: Re: Flywheel batteries as EV power source
Date: 20 Dec 1992 23:01:12 GMT
Organization: HST Wide Field/Planetary Camera
Distribution: world
Reply-To: carl@SOL1.GPS.CALTECH.EDU
NNTP-Posting-Host: sol1.gps.caltech.edu

In article <1992Dec17.192329.25210@news.cs.brandeis.edu>, andyh@chaos.cs.brandeis.edu (Andrew J. Huang) writes:
=Take a 50's Caddy going 100mph.  Put it into many barrels of sand.
=Did it go BOOM?

You seem to be missing something here:  The amount of energy you'd have to
store in a flywheel to make it work as a "battery" for an EV is MANY times more
than the energy required to accelerate a 50's Caddy to 100 mph.  Further, the
flywheel's presumably going to be in something intended to contain it in the
event of a catastrophic failure.  If that container fails, it will nearly
instantaneously release much of the energy that had been stored in the
flywheel.  In other words:  Release a lot of energy inside a pressure vessel,
and allow that vessel to fail.  BOOM!  Really?

=Take a loaded tractor-trailer with bad brakes.  Put it down a mountain
=road.  Send it up the "Failed Brakes" escape road.  Did it go BOOM?

Try picking a vaguely valid analogy next time, will you?
--------------------------------------------------------------------------------
Carl J Lydick | INTERnet: CARL@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL

Disclaimer:  Hey, I understand VAXen and VMS.  That's what I get paid for.  My
understanding of astronomy is purely at the amateur level (or below).  So
unless what I'm saying is directly related to VAX/VMS, don't hold me or my
organization responsible for it.  If it IS related to VAX/VMS, you can try to
hold me responsible for it, but my organization had nothing to do with it.
Newsgroups: sci.electronics
From: careyj@spot.Colorado.EDU (CAREY JOSEPH M)
Subject: Re: Request for information about TEMPEST
Organization: University of Colorado, Boulder
Date: Wed, 16 Dec 1992 20:01:47 GMT

zhang@rwthi3.informatik.rwth-aachen.de (Xiaoming Zhang) writes:

>Can anybody tell me how I can get as much information as possible about
>TEMPEST (Transient-Electro-Magnetic Pulse Emanation Standard)? I have no
>idea about it. Can anybody recommend some books, papers, and the names of
>conferences? Any information is appreciated.

I agree with the other responders, last time I worked on a TEMPEST
project the standard was classified.  I didn't have clearance either,
even though we were designing the circuit.  One of the guys from the
lab went out when the thing was tested and he said they really could
tell what was going on - Our project was a monochrome display for
gov`ment PCs - they got the images off the screen just from radiation.
We finally decided the spec was 3 dB below invisible :).  BTW, if I'm not
mistaken the TEMPEST spec changes with technology, so as new snooping
technology becomes available the spec becomes more and more rigorous.

Joe
joe@lobos.colorado.edu
Newsgroups: sci.electronics
From: philip@mentorg.com (Philip Peake)
Subject: Re: Wow, really BIG resistors....
Date: Mon, 14 Dec 1992 19:00:45 GMT
Distribution: global
Organization: Mentor Graphics
Keywords: 
Followup-To: 

In article <1gag1gINNcvf@crcnis1.unl.edu>, mpaul@unlinfo.unl.edu (marxhausen paul) writes:
|> I finally got in touch with the right folks at Dale and got their full
|> line catalog so I can find the 1 gigaohm resistor I need.  But hey, turns
|> out that's nuthin'...they have resistors in values up to _100 teraohms_,
|> that's, uh, 100,000,000,000,000 ohms. There are a few models where the
|> _smallest_ value you can get is 10 Gohm.  
|> 
|> Yikes.  What do these get used for?  Especially the 40 watt and larger
|> models?????

Insulation ?

Philip
Newsgroups: sci.electronics,sci.edu,comp.multimedia,comp.edu,comp.ai.edu,comp.dcom.isdn
From: johnh@macadam.mpce.mq.edu.au (John Haddy)
Subject: European Labs Visits Request
Organization: Macquarie University
Date: Thu, 17 Dec 1992 23:15:58 GMT

(Apologies for this appearing in groups other than rec.travel - I just want
to reach people in the appropriate fields of study)

I will be in Europe next (northern) summer and in the US for a short period
after, for the purpose of researching methods of remote delivery of educational
material. I am interested both in existing systems (both educational and
commercial) as well as current research in the area. I am principally
interested in delivery of university level (undergraduate and postgraduate)
technology-based course material.

My reason for posting is to reach as many people as possible in my field of
study, and to ask whether you would mind having an Aussie stop by for a chat
sometime.

Topics of interest include:

	Interactive video distribution and control e.g. delivery of lectures
		to multiple sites (both on and off campus).
		
	Multi-media in its application to tertiary technology education.
	
	Integrated information systems.
	
	Commercial service provision by universities e.g. provision of lecture
		material to corporate sites (I'm interested in costing
		structures, growth patterns, student participation etc).
		
	Local / Wide area network service provisions for multimedia and
		interactive video distribution (e.g. dedicated lines vs
		packet switched networks etc).
		
	Management of interactive teaching networks.
	
	Methods of delivery of service e.g. satellite, fibre, etc.
	
	Commercial equipment related to service distribution.
	
	Any other related topics! My brief is extremely broad, with a goal of
	identifying an implementation strategy for my university which allows
	for campus-wide, city-wide and [intra/inter]national delivery of
	educational material, with the ability to target whichever sectors of
	the education market (undergrad, postgrad, corporate, community
	education) are required.
	
I am an engineer with a background in computer communications and
digital systems design, so I am more interested in the technical and
management aspects of service provision, rather than the pedagogy of remote
teaching. However, I would like to hold discussions, in broad terms, with
people experienced in the use of such systems from an educator's viewpoint.

Please mail me - this is not really a topic of world wide interest to be
kept on the net!

Thanks,

	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

----------------------------------------------------------------------------
From: bb099@cleveland.Freenet.Edu (Adam Trent Phillips)
Newsgroups: sci.electronics
Subject: Re: Simple question about line-in voltages, please help
Date: 15 Dec 1992 20:54:51 GMT
Organization: Case Western Reserve University, Cleveland, Ohio (USA)
NNTP-Posting-Host: slc10.ins.cwru.edu


cs348c00@ibmb8.cs.uiuc.edu (Frank D.) on  Mon Dec 14 22:35 1992 posted:
|
|Hi,     I have a simple (probably dumb) question regarding the line-in/
|line-out voltages of my stereo.  I'd like to digitize it, but don't
|know what voltage range it is in.  Since the stereo is at home, I
|don't have any scopes handy or any other fancy equiptment.  My volt
|meter won't work (i.e. won't tell me any voltages, maybe it's changing
|too fast/too small?).   Anyway, if anyone can help me out by telling
|my the voltage range, I'd greatly appreciate it!  Also, since this is
|my first time playing around w/ the line-in/-out any hints/advice is also
|greatly welcomed!
|
|                T H A N K S !!!
 
 
	The line in/out voltages should be about 100mv, even though
I have seen a few oddballs with about 500mv. But most are 100mv.
Many volt meters are designed to work with AC at 60Hz and have 
very poor accuracy above and below that. There are a few CKTs that
you can hook your meter to to make it work better in the Audio range.
 
	If I am correct Z should be 1000 OR 5000 ohms, I cannot remember
which. I also know a few tricks about Line jacks that are handy.
 
	I would suggest designing the ADC/DAC ckt. to handle the
0-150mV range, but make it so you can raise or lower it if need be.
 
 
	Drop me some Email if you areinterested in a few other
tricks I know.
 
 
-- 
A. TRENT PHILLIPS |" A mirror is a negative space with a frame and a place for
  also known as   | your face, it reveals what the rest of us see. It conceals
   WHITE  ROOK    | what you'd like you to be."--Blue Oyster Cult
-------bb099@cleveland.freenet.edu-----aa1439@freenet.lorain.oberlin.edu-------
From: tbeatty@sedona.intel.com (Tim Beatty~)
Newsgroups: sci.electronics
Subject: Re: Transmission line question
Date: 16 Dec 1992 20:40:21 GMT
Organization: Intel Corporation
Distribution: world
NNTP-Posting-Host: thunder.intel.com
Originator: tbeatty@sedona


In article <1992Dec15.202004.15878@ucsu.Colorado.EDU>, barr@tramp.Colorado.EDU (BARR DOUG) writes:
> Some specs I have call for ethernet coax to be grounded in one location
> and one location only! I am wondering why this is. Antenna effects,
> current loops or something else. Does anyone know why this is the case?
> 
Ground loops.  Senturia and Wedlock have a good entry level discussion on ground
loops and single point grounding in their "Electronic Cicuits" or something like
that.

Tim
-- 
--------------------------------------------------------------------------------
 Tim Beatty              |  tbeatty@az.intel.com
 Intel Corp., CH3-91     |  The opinions expressed are my own.
 5000 W. Chandler Blvd.  |
 Chandler, AZ  85226     |  "It is so hot in some parts of the world
                         |   that the people there have to live other places."
 (602)554-8156           |   - Unknown Fifth Grader on Science test
--------------------------------------------------------------------------------
From: dag@col.hp.com (David Geiser)
Newsgroups: sci.electronics
Subject: Re: Flywheel batteries as EV power source
Date: 16 Dec 1992 19:22:03 GMT
Organization: HP Colorado Springs Division
NNTP-Posting-Host: hplsdor.col.hp.com

I can just see myself in the next energy crunch, skulking along
at night with my portable flywheel/generator/motor and magnetic
contacts (called leeches in the future vernacular), looking for
some unprotected flywheel to bleed down.

or

How about some kind of emergency windup on the flywheel, a gear
and ratchet rope/pulley similar to lawn mowers.  A folding arm to
throw the rope over, and a loop in the end for one's foot.

Let's see, step-lift 200lbs, 2ft high, how many times to get the
car to a spinup station?  Yo! Mama!  Forget that diet!  This is
one time pounds are positive!