HDTenEightyP/NetNews huggingface dataset:
From: mwilson@ncratl.AtlantaGA.NCR.COM (Mark Wilson)
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: 23 Dec 92 18:33:35 GMT
Organization: NCR Engineering and Manufacturing Atlanta -- Atlanta, GA

In <1992Dec23.154010.13703@fcom.cc.utah.edu> bbarkey@lark.utah.edu (Brian Barkey) writes:

|>The flywheel will try to dissipate it's energy over a span of milliseconds.
|>
|I guess I missed the part about dissipating energy over ms. What's the 
|basis for this?

Because of the speeds at which it rotates, the instant the flywheel becomes
unbalanced it will shake itself apart.  The first failure sets up a shock wave
that travels at the speed of sound.  The shock wave has so much energy that it
literally vaporizes the material it is passing through.

|Also, sometimes in accidents the gasoline does mix sufficently well
|with the air to be a hazard (remember the Pinto?).

I've got news for you, no Pinto ever exploded, despite the sensationalist
headlines.  What happened was that the gas tank ruptured and the victims
burned.  For gas to explode the gas has to be vaporized, the gas has to
be mixed with air in the proper ratio.  It takes time to vaporize several
gallons of gas, during this time if there is any breeze, the previously
evaporated gas will be blown away before it can ignite.

At best any explosion will only ignite several ounces of gas.  This is
a tiny, tiny fraction of the energy that the flywheel contains.

|I'm certain that
|in a flywheel powered car there wil be accidents that will be explosive
|and many that are not. Isn't this a factor of the design?

If the flywheel fails it will explode.  The question is, was the accident
severe enough to cause the flywheel to explode.  Another problem with
flywheels is that they can fail spontaneously, just because the rotor
got too old.

|Maybe the flywheel isn't safe. Could it be used in a smaller capacity 
|to augment accelerations from braking energy? All of this discussion is
|conjecture, but aren't ideas wonderful to ponder?

There was some conjecture about putting such beasties in buses and vans
a few years ago.  (Popular Science again, if I am not mistaken.)
They choose buses and vans because they were the only vehicles big enough
to put the flywheels that were technologically doable at the time, in.

I have no idea if any such systems were ever built.

-- 
Mob rule doesn't become any prettier, just because the mob start to call itself
a government.
It ain't charity if you are using someone else's money.
Mark.Wilson@AtlantaGA.NCR.com
Newsgroups: sci.electronics
From: medha@cbnewsg.cb.att.com (keshav.havnurkar)
Subject: Cordless phone batteries
Organization: AT&T
Date: Mon, 21 Dec 1992 19:15:18 GMT

Hi
Recently I purchased a Southwestern Bell Cordless phone FF1755.
I have a question regarding the cordless phone handset . It looks like
the handset needs to be kept on the base for atleast 10 hrs per day
to keep them charged. This unfortunately does not serve my purpose.
So , what type of baterries do these phones have ? Can I replace
them with other kind of batteries ( Say AA type ). I do not mind
if I have to keep them in an outside container and connet the wires
Has anybody tried some thing like this ?

Thanks
keshav@gouda.att.com
Newsgroups: sci.electronics
From: kgdykes@thinkage.on.ca (Ken Dykes)
Subject: Re: help needed building water level sensor
Organization: Thinkage Ltd. (Rube Goldberg Division)
Date: Wed, 30 Dec 1992 00:24:01 GMT

In article <1992Dec29.222452.16068@ntg.com> dplatt@ntg.com (Dave Platt) writes:
>>serial link.  Some more work will have to be done to determine the optimal
>>protocol for the link and so on.  Most probably have to develop an entirely
>>new one.
>>
>>There is obviously still quite a bit of design to do here, but this is just
>>a start.  Any other ideas would be appreciated. ;)
>
>Kids these days got _no_ sense of proportion.
>
>Why, in the old days, we didn't fiddle around with any of this
>microcontroller nonsense.  We just glued a couple of 1" copper pipes in
>the corners of the aquarium, clamped wires to them, and put them in
>series with the motor power wire.  When the water level dropped below
>the ends of the pipes, the current was cut off and the pump stopped.
>A handful or two of salt in the water make it plenty conductive, and the
>free chlorine electrolyzing off of the electrodes got rid of all that
>algae.  Simple, crude, brute-force... and we liked it!

urinal/toilet water level detector anyone?

of course the physics student approach would probably involve a laser
(a few jillion megawatts worth of ruby or something :-)
shone through the water to a detector on the other end of the tank.
water disperses beam => no detection, no water => detection!

and pretty sparkly effects on the gravel too!

   -ken, the fish is not dead, it's pining for the fjords...

ps: i dont suppose floating the pump itself with a short power cord
    and then when the level drops the cord unplugs... :-)
-- 
   - Ken Dykes, Thinkage Ltd., Kitchener, Ontario, Canada    [43.47N 80.52W]
         kgdykes@thinkage.on.ca   postmaster@thinkage.com   thinkage!kgdykes
         harley-request@thinkage.on.ca             kgdykes@math.uwaterloo.ca
Xref: sparky sci.electronics:21478 sci.energy:6413 rec.autos:30410
From: stead@skadi.CSS.GOV (Richard Stead)
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: 23 Dec 92 18:11:39 GMT
Followup-To: sci.energy

In article <1992Dec23.154010.13703@fcom.cc.utah.edu>, bbarkey@lark.utah.edu (Brian Barkey) writes:
> I guess I missed the part about dissipating energy over ms. What's the 
> basis for this?

This has all been hashed out a couple of times, but I'll summarize.
The energy dissipates over microseconds to milliseconds because of how
fast the material fails, and how fast it will fully interact with the
container.  These follow from the stress on the material and the velocity
at which it moves.

> Also, sometimes in accidents the gasoline does mix sufficently well
> with the air to be a hazard (remember the Pinto?) I'm certain that

The Pinto as well has been mentioned - Pintos did not explode except in
movies, but they did burn rather spectacularly.  It takes time to create
a cloud of mist or vaporized gas at the proper ratio of gas to air.  It
has to stay in place (no wind) and then be ignited by something.  This
is why burning gas is nowhere near as dangerous as a fuel-air bomb,
even though there is usually less gas in the bomb than in a gas tank.

> in a flywheel powered car there wil be accidents that will be explosive
> and many that are not. Isn't this a factor of the design? If the 

Yes, it is a factor of design and basics physics.  Fundementally, any
large amount of energy stored mechanically in a small volume is subject
to explosion.  The reason is that failure of the mechanical storage
releases all the energy at once.  With gasoline, you need to vaporize the
stuff and then mix it with air.  This takes time and is hard to do
completely with a large amount of gasoline (and even when you do, the
volume of air is so large that the explosion takes place in a big volume
dissipating energy and force).  The mechanical failure occurs far more
quickly, and all the energy is released when it does.

> flywheel power source is a viable and marketable option I'm certain
> that manufacturers in lawsuit happy countries like this would 
> make a couple of prototypes and run 'em into walls to see what happens.

The question really is - Are these "manufacturers" for real, or just
cheap hucksters out to con "investors" and naive government officials
out of money.  Think about the free-energy con men.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov
From: jeh@cmkrnl.com
Newsgroups: sci.electronics
Subject: Re: Basic bench equipment query
Date: 27 Dec 92 11:05:36 GMT
Organization: Kernel Mode Consulting, San Diego, CA

In article <BzwHA7.6y@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer)
 writes:
> In article <2B3582F9.18867@news.service.uci.edu> gkwan@balboa.eng.uci.edu (Greg Kwan) writes:
>>1. Get the best DMM you can--it's the most important test instrument.
>>I have a Fluke 77 and have been very happy with it, but would probably
>>go for an 87 or 79 now. You'll probably use the freq. counter since
>>it's a pain to fire up the scope just to measure a frequency...
> 
> Note, though, that any frequency measurement using something other than
> a scope relies heavily on assumptions about waveform.  When I first got
> my current scope, I hoked up a little audio-frequency square-wave generator
> with a 555 as an independent test signal.  I was a bit surprised to find
> that my frequency counter read twice what the scope showed me.  
> [...] There is no substitute for seeing exactly what's happening.

I'll second this, and LOUDLY, too.  

It appalls me to see frequency counters (and instruments like DMMs that include
counters) that have no trigger level control, no input coupling selector (AC or
DC), no edge selector (rising or falling).  You wouldn't buy a triggered-sweep
scope without such controls; of what possible use is a counter without them? 

I've seen many of these idiot-box counters (Star-Tek, Optronics, etc.) misread
a pure sinewave at audio line level.... they may be good for "transmitter
sniffing", where the input is at very low level, but I doubt they're good for
much else. 

Anyone who trusts one of these counters without checking the waveform on a
scope, if only to get in the right ballpark, is being as foolish as the person
who thinks that a digital watch must be accurate simply because it isn't
analog.  

> -- 
> "God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
>        -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry

"God" was willing -- none of the relevant physical laws or principles of
chemistry have changed that I know of, so the the hardware designed in the
sixties ought to work just fine today. It was Senator Proxmire who wasn't
willing. 

	--- 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
Newsgroups: sci.electronics
From: billg@bony1.bony.com (Bill Gripp)
Subject: Re: Railroad crossing gates -the ups and downs???
Organization: LA&W RR
Date: Tue, 22 Dec 92 14:23:28 GMT

In article <1h4r8rINNjsu@hp-col.col.hp.com> cab@col.hp.com (Chris Best) writes:
>> The old style worked by detecting a short circuit between the rails 
>> (a locomotive is pretty conductive). If you walk the track near a
>> crossing and pay attention to where the rail ends meet, you will see
>> that some are electrically connected and some are isolated. You will
>> also find cables connected to the rails running under-ground toward
>> a nearby electrical box which controls the whole thing.

>Indeed, the old style worked by shorting the rails.  Used to be, you
>could connect the rails together with jumper cables, and the gates
>would activate, or a nearby block signal would turn green (trust me).
>
>That was in my childhood - but not long ago, I tried the same thing 
>near a protected crossing, and nothing happened.  At the time, I just
>figured that the equipment was smarter, and knew better than to
>respond to a "train" that just appeared on a block without being on
>an adjacent block first.

>So I had that part right, but I don't see why they'd change the
>sensing scheme - just the interpreting curcuitry.  But if the
>guy who "drives the big trains" sez so, I guess it's so...


'Cause if the train is going fast, the gates go down, in 30 seconds the
train comes, it clears the crossing and the gates open.  If the train
goes slow, the gates go down, the train doesn't show up for 2 minutes
and the impatient drivers go around the gates.  Eventually, one of them
gets hit.  The new sensing scheme allows the gates to close x seconds
before the train gets to the crossing rather than when the train is y
feet away.  Reduces the risk of hitting a motorist.

Newsgroups: sci.electronics
From: jhwhit01@ulkyvx.louisville.edu
Subject: Re: Looking For...74S14
Date: Thu, 24 Dec 1992 13:14:10 GMT
Organization: University of Louisville

In article <BzqJqG.8nH@ncifcrf.gov>, digennar@fcs280s.ncifcrf.gov (Frank S. DiGennaro) writes:
> 
> Thanks to everyone who answered my question concerning pulse shaping.
> 
> I need to run an 80 Mhz Sine wave into a Schmitt trigger to square
> it up. The 74LS14 Schmitt trigger can't even almost handle this
> speed. The 74S series chips are supposed to handle up to 125 Mhz.
> The thing is, I don't even see a 74S series Schmitt trigger listed
> in any of my catalogs. Does this chip exist? 
  
I haven't found a 74S14 listed in any of my catalogs.  However, I have found
a 74F14 listed in my 1988 Arrow Catalog (1-800-93-ARROW) as well as a recent
(1991 or 1992) American Design Components Catalog (1-800-776-3700).  The 74F
series is less power and usually faster than the 74S.  I hope this helps.
If you order from Arrow, try Motorola part MC74F14N (stock #1439CSL) or the
Signetic part N74F14N (stock #9778BPT).  If you order from ADC, you take what
they have stocked under part number 74F14.
  
 
Jeff White    jhwhit01@ulkyvx.bitnet
From: kurdzo@gdc.com (Jim Kurdzo)
Newsgroups: sci.electronics
Subject: Re: Good way to prototype analog circuits?
Date: 4 Jan 93 02:27:53 GMT
Organization: General DataComm Ind. Inc., Middlebury, CT 06762
X-Newsreader: TIN [version 1.1 PL6]

John Paul Morrison (jmorriso@ee.ubc.ca) wrote:
> 
> Does anyone want to share their tips on prototyping analog circuits?
> Specifically: sensitive, high gain circuits; RF circuits etc.
> 
> These kind of circuits work well with PC boards with ground planes,
> but are there any simple, easy to make changes, techniques for this?
> Are there any pre-made boards with a ground plane, and holes with solder
> contacts on them?
> 

I always use the pre-punched vector board with copper clad on one side.
Vector p/n  169P84WEC1 is  8.5" x 17" and available from Digi-Key for around
$20.  Just cut it up into smaller pieces with tin snips.  Wherever you
DON'T want a ground connection, ream out the ground plane with a 1/4" drill
bit.

Good Luck!

--

Jim Kurdzo   N1KKA
General DataComm
Middlebury, CT  06762-1299
(203) 758-1811 x7550
kurdzo@gdc.com
From: paley@netcom.com (Dan Paley)
Newsgroups: sci.electronics
Subject: Nuts & Volts 3/94, 4/92
Date: 22 Dec 92 18:49:33 GMT
Organization: Netcom - Online Communication Services (408 241-9760 guest)


Does anyone have a copy of the march and april 92 issues of
Nuts & Volts Magazine?  There is something about building a 2 meter
transmitter/receiver and I was just wondering if someone could 
send me a copy. (fax/e-mail/usps). Yea, I'm too cheap to shell out $5 
each for reprints for something I'll never build.

  thanks
  --dan

paley@netcom.com
From: schuch@phx.mcd.mot.com (John Schuch)
Newsgroups: sci.electronics
Subject: Re: Soundblaster for low rent data acquisition?
Date: 27 Dec 92 18:35:58 GMT
Organization: Motorola Computer Group, Tempe, Az.

In article <PHR.92Dec22195830@napa.telebit.com> phr@telebit.com (Paul Rubin) writes:
>I am interested in a cheap way to monitor some slowly changing
>voltages (read: DC) in a piece of test equipment.  8-bit resolution
>is fine.  I can scale the voltages to the 0-1 VDC range (or similar)
>using resistor networks if I need to.
>Does anyone know if a Soundblaster is a reasonable way to do this?

Couldn't you use a game(joystick) port? I haven't tried it but the
boards are cheap and I imagine they would make a reasonable 4 channel
analog input system, albeit low resolution.

John

-- 
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
| N7XVS - schuch@phx.mcd.mot.com - (602) 438-3008 - CompuServe: 70733.3330 |
+--------------------------------------------------------------------------+
Newsgroups: sci.electronics
From: butts#@shocker.ee.twsu.edu (Ronald W. Butts -SUPER ACCT)
Subject: Searching for Spread Spectrum building blocks
Keywords: spread spectrum,RF
Organization: Electrical Engr. Dept, Wichita State Univ.
Date: Wed, 30 Dec 1992 08:06:44 GMT
X-Posted-From: gegan1.ee.twsu.edu
NNTP-Posting-Host: sol.ctr.columbia.edu

Hello,

I am searching for off-the-shelf IC's or modules to implement a two-way,
full-duplex 900MHZ spread spectrum voice link--in essence a proprietary 
cordless phone.

Do any of you know of a source for spread-spectrum building block components?

My dream would be to find, for example, a module that I supply with VCC, 
outgoing audio, n-bits of digital code to select spreading sequence for TX 
and RX, and a final RF stage for transmitting and Rx isolation. However, 
nothing RF is ever that easy.

If possible, email me direct, and I will summarize and post any and all 
replies. Thanks.


Bill Butts
butts @ shocker.ee.twsu.edu


Newsgroups: sci.electronics
From: schuch@phx.mcd.mot.com (John Schuch)
Subject: Re: Microwave Oven Diode Help
Organization: Motorola Computer Group, Tempe, Az.
Date: Tue, 22 Dec 1992 18:59:28 GMT

In article <123760001@hpindda.cup.hp.com> liang@hpindda.cup.hp.com (Alf Liang) writes:
>I am trying to find a replacement for a diode that is used in a "Tarpan (sp?)"
>Microwave oven.  This diode has the part number HVPR15-4 (manufacturer's
>part number is 198T016P01 8018).  Any pointers to where to order the exact
>replacement or suitable substitutions are greatly appreciated.

I most large communities, there is at least one large appliance parts
center. In Phoenix, it's 'Arizona Parts.' They carry parts for most 
makes and types of home appliances. That's where I got the doide for
mine. Ask a local service guy where he gets his parts from, or check
"Appliances- Parts" in the yellow pages. By the way, that's probably
a TAPPAN microwave.

John


-- 
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
| N7XVS - schuch@phx.mcd.mot.com - (602) 438-3008 - CompuServe: 70733.3330 |
+--------------------------------------------------------------------------+
Newsgroups: sci.electronics
From: schaerer@isi.ethz.ch (Thomas Schaerer)
Subject: Re: Need circuit for switched 14 Mhz oscillator
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
X-Newsreader: TIN [version 1.1 PL8]
Date: Wed, 23 Dec 1992 20:31:16 GMT

Wayne (wayne@r-node.gts.org) wrote:
: I'm working on a project that requires a switched 14 Mhz oscillator.
: I am currently using a 14 Mhz crystal, a 1M feedback resistor and a
: couple of capacitors on a 74HC00. My problem is that the oscillator
: will occasionally either not start or oscillate at a higher harmonic.
: When it does work the output is also pretty feeble so I know I'm doing
: something wrong.

Hello Wayne,

You wrote too less about your crystal-oscillator. But I believe I see
your problem: The oscillator can not allways start or it starts with
a higher harmonic frequency. The gain is to less with basic crystal-
frequency. Perhaps you have a highpass between the first and second gate
of the 74HC00. In this case, it's possible the cornerfrequency of this
highpass is too high. Another ting, can it bee the 1 M-Ohm resistor
makes with a parasit-capacity a lowpass which also can reduce the needed
gain with basic crystal-frequency?

So I hope I can help you. If have more problems write to my mailbox.
Nice X-Mas 	Thomas


Newsgroups: sci.electronics
From: bbs.haymore@tsoft.net (Ed Haymore)
Subject: Looking for Motorola Pulsar II mobile radiotelephones
Organization: The TSoft BBS and Public Access Unix, +1 415 969 8238
Date: Thu, 24 Dec 1992 08:07:42 GMT

A friend of mine is looking for some old Motorola Pulsar II mobile
radiotelephones.  If you have any to sell him or know of any for sale, 
please email me (bbs.haymore@tsoft.net) and I'll pass the word along.

Thanks --
Ed
bbs.haymore@tsoft.net

--
Ed Haymore (bbs.haymore@tsoft.net)
Newsgroups: sci.electronics
From: jmorriso@ee.ubc.ca (John Paul Morrison)
Subject: Re: RFI free dimmer switches...
Organization: University of BC, Electrical Engineering
Distribution: na
Date: Sat, 26 Dec 1992 22:45:00 GMT

In article <1hhum3INNfau@usenet.INS.CWRU.Edu> wb8foz@skybridge.scl.cwru.edu (David Lesher) writes:
>I'm a little confused by the present discussion.
>
>If you only turn ON at the zero-crossing, you will, I suspect, avoid
>RFI problems. But, first off, does this not give you problems in
>modulating the output? You could only have setting that are multiples
>of the number of {half} cycles. [I suppose that is not TOO limiting,
>though, is it?]

You would have to vary the duty cyle more discretely (only at zero crossings)
but that still lets you turn the the triac on or off up 120 times per second
(sin2pift = 0, t = n/120). You would get 0% to 100% duty in 0.83% steps
>
>Secondly, won't such a dimmer make the lamp singing problem far worse?
>The filament gets heated, and cools, over a much longer period than
>with chopper-type dimmers.

Since the dimmers make the bulb ring even at 100%, (the triac should be 
on constantly), the harmonics must be coming from non-linearities in
the triac (or diodes etc.). The bulb rings more at lower duty cycles.
and it doesn't ring at ALL if the dimmer circuit is removed.


>
>I suppose the solution is to use line power of a frequency far above
>the audio range. Back when I was taking a course on electronic power
>control, I recall reading of scheme to provide large office buildings
>with ~100khz to run the gas discharge lighting. The idea was to reduce
>the losses in the ballasts. Not only does that increase the "light/kw$"
>but it would also reduce the "waste heat/lumen" that has to be cooled
>by the HVAC.  Wonder what ever came of that idea....

not gonna rewire my dining room!
>--
>A host is a host from coast to coast..wb8foz@skybridge.scl.cwru.edu
>& no one will talk to a host that's close..........................
>Unless the host (that isn't close).........................pob 1433
>is busy, hung or dead....................................20915-1433


-- 
__________________________________________________________________________
 John Paul Morrison                     |  
 University of British Columbia, Canada |  
 Electrical Engineering                 |   .sig file without a cause
 jmorriso@ee.ubc.ca              VE7JPM |  
________________________________________|_________________________________