HDTenEightyP/NetNews huggingface dataset:
From: king@reasoning.com (Dick King)
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: 28 Dec 92 19:57:30 GMT
Organization: Reasoning Systems, Inc., Palo Alto, CA

In article <Bzu6DJ.I6v@ns1.nodak.edu> csmith@plains.NoDak.edu (Carl Smith) writes:
>In article <1992Dec25.134459.7728@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>
>>You don't understand. The gasoline *does* contain the same amount of
>>energy as the flywheel, that's the whole point of the exercise. But
>>liquid gasoline can't explode. Only gasoline vapor properly mixed
>>with oxygen, 14:1 air/fuel ratio, can explode. 
>
>Normally I wouldn't find fault with such an insignificant detail, but
>I have seen this so many times during this tread that I thought I would
>make a comment.  14:1 is the IDEAL mixture, but there is a rather wide
>range over which the mixture will ignite.  Eventually it will be so rich
>that it will be hard to ignite due to "lack of oxygen," and in the other
>direction there can be so little gas fumes that you couldn't cause an
>explosion.  You don't need perfect 14:1 to cause an explosion.


The ambient temperature also matters.

The key point is that a certain volume of the proposed explosive has to give
off enough heat to raise a like volume to the ignition point.  This is an
easier constraint to meet for higher temperatures.

The reason why Diesel engines can run unthrottled but Otto engines can't, is
that the cylinder misture is raised above the ignition point by compression.
Therefore, any mixture, however lean, is already explosive.

-dk
From: garland@ohstpy.mps.ohio-state.edu
Newsgroups: sci.electronics
Subject: Wanted: Wavetek 111 Manual
Date: 1 Jan 93 08:59:59 EST
Organization: The Ohio State University, Department of Physics

WANTED: Manual for a Wavetek 111 function generator.  I'll be glad to xerox and
send it back. 
Jim Garland
(614) 548-7277
From: tomb@hplsla.hp.com (Tom Bruhns)
Date: Tue, 22 Dec 1992 21:57:59 GMT
Subject: Re: How full is a nicad
Organization: HP Lake Stevens, WA
Newsgroups: sci.electronics

henigan@quando.quantum.de (Kevin Henigan) writes:

>I believe you can tell how full a nicad is from it's Voltage, so does
>anybody have a table with voltage & capacity in % full?

As Henry already posted, nope.  The voltage is more dependent on other
factors, so it's not a reliable charge indicator in itself.  However,
batteries as they reach full charge heat significantly and as a result
change their terminal voltage rather quickly.  Detecting that rather
sudden (relatively) change is how many chargers turn off (or turn to
"trickle").  If you could monitor pressure in the cell, I believe that
an increase in pressure would also be a good indicator of full charge...
Xref: sparky sci.electronics:21709 sci.energy:6494 rec.autos:30700
From: lordSnooty@cup.portal.com (Andrew - Palfreyman)
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: Tue, 29 Dec 92 18:20:47 PST
Organization: The Portal System (TM)
Distribution: world
  <51718@seismo.CSS.GOV>

Richard Stead hypothesises that the specific energy (J/Kg) of
a practical flywheel will not be able to exceed the specific
energy of gasoline, when both the shielding mass and realistic
materials' stress characteristics are taken into account.
This is a key parameter in this whole discussion, independent
of the safety debate which has been raging here; i.e. if this
assertion is true, then flywheels look really unattractive in
any case, modulo political and environmental arguments of course.
Let's look at that.

Let the flywheel be of mass mf, density df, radius r, thickness f
and rotational speed (rad/sec) of w.
Its energy E = 0.5*mf*(r*w)^2 and mf = pi*df*f*r^2.

Model the shield as a sphere of radius r (more or less), density ds,
mass ms and thickness s, where ms = (4*pi/3)*ds*[ (r+s)^3 - r^3 ].  

We need a relationship between s and E.
Generally we could write s = k*E^n, but let's intuit (probably gravely
wrong!) that, like viscous drag (m*d2x/dt2 = -a*dx/dt), s will need to
vary as k*sqrt(E), where k is determined by the fragments' maximum
expected mass (mx), the viscosity (a) of the shield material, and the
proportion (x) of the total energy (E) carried by a worst-case fragment.
Classically k= sqrt(2*mx*x)/a. So assume that s = k*sqrt(E).

The specific energy of the system comprising flywheel plus shielding is
A = E / (mf + ms). Since s is a function of E, there will be an optimal
A, which we find by partially differentiating A wrt E.
I find this to be at the critical flywheel mass

mfc = (2*pi*ds*k/3)*(k^2*E*sqrt(E) - 3*r^2/sqrt(E)) 

Hopefully, for the large E-values we're playing with, this is a positive
number. Assuming further that it's realisable, the substitution into A
gives
Amax = 1/( 4*pi*ds*k *(k^2*sqrt(E) + 2*k*r + 2*r^2/sqrt(E) - r^2/(E*sqrt(E)) )

Note that Amax depends inversely on k, which makes sense when you realise
that a small k-value translates into a thinner shield for a given E.
However, note also that Amax depends inversely on ds, which is naively
obvious, but disregards the relationship between k and ds for real
materials; one would expect ds to be inversely related to k. This implies
that there is a further optimisation on the shield material to be made.

If you've tagged along so far, I expect that you're expecting a conclusion.
Well, there ain't one :-). Although the specific energy for gasoline 
burned in an IC engine is known, and one could estimate ds = 10^4 Kg/m^3,
I still don't know k, the shielding parameter with units metres/sqrt(Joule).
So let me know what you come up with yourselves!
 --------------------------------------------------------------------------
| lord snooty @the giant |  Would You Like Space Potatoes With That?       |
| poisoned electric head |              andrew_-_palfreyman@cup.portal.com |
 --------------------------------------------------------------------------
From: rick.franks@hal9k.ann-arbor.mi.us (Rick Franks) 
Newsgroups: sci.electronics
Subject: NEW MEMBER
Date: 24 Dec 92 13:15:00 GMT
Distribution: world
Organization: HAL 9000 BBS, (313)663-4173, Ann Arbor, MI, USA
Reply-To: rick.franks@hal9k.ann-arbor.mi.us (Rick Franks) 

The folks down here in Myrtle Beach SC, would like to say hello
to you up in W-NET. And would like to inform you'all we are now
cross-linking this confernece with our own BUM_NET network.
Have a Merry Christmas and a Happy New Year...
---
 . Cam-Mail . The Chess Board BBS 803-236-7711 : Myrtle Beach, SC
From: kludge@grissom.larc.nasa.gov (Scott Dorsey)
Newsgroups: sci.electronics
Subject: Re: Strange microcontroller
Date: 2 Jan 1993 01:03:58 GMT
Organization: NASA Langley Research Center and Reptile Farm
NNTP-Posting-Host: grissom.larc.nasa.gov

In article <N2sPwB1w165w@tfsquad.mn.org> mike_d@tfsquad.mn.org (mike diack) writes:
>Anyone ever heard of a microcontroller&/microprocessor called a
>D77P20D ?. I met a few of these the other day, and a quick glance in
>someone elses IC Master (mine is about 8000 miles away at present) told
>me that it was a DSP optimised chip with a bloody fast multiply - well
>compared to a '51 or 6805/11 anyway. My interest was aroused that these
>could be useful in grotty little audio applications where the more fancy
>(and expensive) DSP units were not needed. They are made by NEC and are
>in a ceramic windowed package.

These are fairly nifty chips, with a rather slick 8-bit DSP design.  They
aren't TMS320's by any means, but they look like they'd be easy to work
with and fine for a lot of simple work.

The bad news is that NEC doesn't want to sell you any.  I managed to get
data out of them only after several hours talking to various people at
the US offices.  They basically told me that none of their distributors
will handle it, and since I only needed a couple hundred, I was small
potatoes and not worth talking to.

NEC is really ghastly to deal with.  But Sanyo is even worse.
--scott
Xref: sparky sci.electronics:21651 sci.energy:6468 rec.autos:30602
From: carl@SOL1.GPS.CALTECH.EDU (Carl J Lydick)
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: 28 Dec 1992 20:25:17 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 <1992Dec22.204130.18133@enterprise.rdd.lmsc.lockheed.com>, () writes:
=In article <51694@seismo.CSS.GOV>, stead@skadi.CSS.GOV (Richard Stead) writes:
=> 
=> Flame on.
=> 
=> The rampant idiocy on flywheels just continues.  How many ways do people have
=> to be told about conservation of energy?
=
=Conservation of energy exactly, where do you think you get the energy to 
=turn a carbon carbon fly wheel into cotton candy from?  Before you start
=flaming at others for not doing the math, do it yourself.

Before you start your own flame, perhaps you ought to read a bit more of the
thread.

=Wrong again, a hyper speed carbon carbon flywheel is not designed to fail at
=once it is designed to fail a bit at a time, as cotton candy, using up a 
=significant fraction of the energy stored in the disk over a period of time 
=(although that time may be microseconds).  
= 
=> You think fluff is harmless?  Let's tie you down and hit you with "fluff"
=> traveling at several km/s and at a temperature of a few thousand degrees.
=> Let's see if we can find any teeny parts of you after the impact.
=
=Obviously this fluff created by a failed flywheel is not exactly safe.  But
=you contain this fluff inside another carbon carbon shell such that the
=expanding hot fluff makes more fluff until the energy is such that it can
=be contained by a container.  The object is not to stop the flywheel failure
=at any given point, but to slow it down and cause it to loose energy.  

Yup.  Now, since someone has calculated that the flywheel is storing enough
energy to VAPORIZE 40 kilograms of iron, just how big is your containment
system going to be?  Will there be room for people in the car?
--------------------------------------------------------------------------------
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.
Xref: sparky sci.electronics:21875 sci.energy:6596 rec.autos.tech:17347
From: stead@skadi.CSS.GOV (Richard Stead)
Newsgroups: sci.electronics,sci.energy,rec.autos.tech
Subject: Re: Flywheel batteries as EV power source
Date: 3 Jan 93 20:08:05 GMT
Followup-To: sci.energy

In article <1993Jan2.053258.5064@adobe.com>, pngai@adobe.com (Phil Ngai) writes:
> In article <30DEC199200153934@pierre.mit.edu> chuck@pierre.mit.edu (Chuck Parsons) writes:
> >  Second mechanical strength of materials is _not_ greater than the
> >strength of the chemical bonds forming the material. 
> 
> In a flywheel, there is a relationship between material strength and
> stored kinetic energy, but it is hardly 1 to 1. This would be almost

Correct - it is worse.  Check my post on direct comparison of energy stored
to bond strength in the material based on C-C bonds at graphite density.
Even if the flywheel could be spun to the limit of the theoretical material
strength, it could only store half the energy represented by the bond
strength before the atoms flew apart.  Comparing this energy density
to that of gasoline proved very unfavorable.  When a maximum material
strength of 1 Mpsi for carbon composite was used in the calculation, a
minimum rotor mass of 510 kg was obtained.

> like arguing that the kinetic energy of a bullet or meteor is limited
> to its material strength.

No.  All kinetic energy is not created equal.  Storing kinetic energy
in a flywheel necessarily stresses the material since it is under
continuous acceleration.  However, I can establish an inertial reference frame
on any bullet or meteor (in a vacuum) in which that object has zero kinetic
energy.  There are no forces acting on the object, so it is not under stress.
No inertial frame can be established on the rotor to change its stored
kinetic energy due to rotation - this energy is the same in all inertial
frames.

Therefore it is indeed true that energy storage in a flywheel is limited
by material strength.  But in a collision, a meteor or bullet is only
limited by relativity considerations in the energy it can contribute to
the collision.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov
From: bk233@cleveland.Freenet.Edu (Jack W. Weinmann)
Newsgroups: sci.electronics
Subject: 150 - 200 W. Amplifier
Date: 29 Dec 1992 10:12:32 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: bk233@cleveland.Freenet.Edu (Jack W. Weinmann)
NNTP-Posting-Host: slc10.ins.cwru.edu


A friend of mine plays the organ and wants to expand his system with
external speaker cabinets and higher power amplifiers.  His main problem is
to come up with 4 channels of 150 - 200 Watts each without suffering a
financial breakdown.

My question is whether there are any plans or kits that he could use to
build his own amps.  Are there any power amp modules that can be employed
to make his life easier?

I have replaced a power amp module in a stereo amplifier, but I believe it
was only around 40 Watts or so.  Are there any that will handle 150 - 200
Watts?  If there are, how difficult is the surrounding circuitry to
complete the driving stages?

Help will be appreciated.

Jack Weinmann  bk233@cleveland.freenet.edu
Newsgroups: sci.electronics
From: kepley@cs.unca.edu (Brad Kepley)
Subject: Re: need some basic help with DIODES
Organization: University of North Carolina at Asheville
Date: Thu, 31 Dec 1992 00:09:35 GMT


>Which way does the band on a diode go (+/-)?

It depends on what it's used for.  If it helps any, the band is the
cathode end and to forward bias the diode you would apply a negative
(in respect to the other end) voltage to the band end.
From: baden@sys6626.bison.mb.ca (baden de bari)
Newsgroups: sci.electronics
Subject: Re: [* NINTENDO PG PINNOUT... *]
Date: Mon, 21 Dec 92 20:03:58 CST
Organization: System 6626 BBS, Winnipeg Manitoba Canada

 
       There is also a little black box that comes with the pg... are the 
pinouts any different??
 
        >>Baden<<
Newsgroups: sci.electronics
Subject: Plans for the Akai GXC-36D
From: zoltar@amigans.gen.nz (Grant Thoms)
Date: Wed, 23 Dec 92 17:02:12 GMT+1
Organization: Wanganui Amigans, Wanganui, New Zealand

Hello,
I have an Akai GXC-36D Tape deck, and it is recording quite Bassy, also 
it's either recording lower on one channel or the level meters are 
incorrect on playback.  
 
I would like to get the plans for this machine, any help would also be 
greatly appreciated.
 
Grant

-- 
---------------------------------------------------------------
Zoltar@glasgow.amigans.gen.nz - Radio/Television Broadcasting  
    //         Grant Thoms, Wanganui, New Zealand    o o       
  \X/AMIGA              -*-*-*-*-*-*-*-*-            `-'`Smile'
Quote: `If I was any nicer, I'd be moving in with your grandma'
---------------------------------------------------------------
From: omori@ee.fit.edu (Ricardo Omori)
Newsgroups: sci.electronics
Subject: Peltier Plate/Devices
Date: 21 Dec 92 23:19:38 GMT
Organization: Florida Tech, CP/EE Dept.

Hello!

Peltier Devices are used for temperature control. I've had
problems finding and contacting manufactures of such device.
Could anyone e-mail me any info on which company produces the
Peltier Plate?

I would greatly appreciate any info mailed to
omori@ee.fit.edu

Thank you very much,

R. Omori
Xref: sparky sci.electronics:21454 sci.energy:6399 rec.autos:30388
From: jimf@centerline.com (Jim Frost)
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: 23 Dec 1992 14:20:59 GMT
Organization: CenterLine Software, Inc.
NNTP-Posting-Host: 140.239.3.202

bbarkey@lark.utah.edu (Brian Barkey) writes:
>>It doesn't matter what form the flywheel takes after disintegration.
>>It could even turn into a gas or sub-atomic particles.  What causes the
>>BOOM is all of that kinetic energy being turned into heat.
>>
>	And gasoline isn't explosive? 

Not inherently.  It needs oxygen.

jim frost
jimf@centerline.com
From: st1r1@rosie.uh.edu (Montoya, Jose T.)
Newsgroups: sci.electronics
Subject: Help with ftp file transfer...please!
Date: 21 Dec 1992 23:14 CST
Organization: University of Houston
Distribution: world
NNTP-Posting-Host: rosie.uh.edu
News-Software: VAX/VMS VNEWS 1.41    

Hello,

Im new to the computer scene and i'm having problems understanding some things.

Here are a few questions that I have. Any help would be gr}ieatly appreciated.


1) How do you download files using ftp?

2) Don't you need an account on the host system to even be allowed
   to look through their files, even if they are freeware/shareware?

3) I assume that even if you are still able to download to your account on
   the VAX, then how do}i you transfer that file to your PC?



Thanks for your time and patience.

Send replies to ST1r1@jetson.uh.edu.







Newsgroups: sci.electronics
From: schriste@uceng.uc.edu (Steven Christensen)
Subject: Re: How would you detect lack of a square wave?
Organization: University of Cincinnati
Date: Sat, 2 Jan 1993 18:28:16 GMT

In article <1993Jan2.172332.21070@socrates.umd.edu> jimbo@socrates.umd.edu (Jim Bogard) writes:
>What's the best way to detect the presence/lack of a square wave?


You can use a classic "missing pulse" detector. Basically it is a
retriggerable monostable multivibrator (one-shot) whose timeout is
slightly longer than the longest period expected in the square wave.
Basically, the square wave keeps the timer constantly triggered, so the
output is stable. When the pulse isn't there, the output changes and
you can detect that.

I've seen these made with the good ol' NE555.

>-- 
>Jim Bogard  (jimbo@socrates.umd.edu)
>                                            "Implement now, tweak later."
>Tech at large / gigging daemon
>

		Steven Christensen
		(I didn't spend 5 years at an engineering college
		for nuttin'! )
-- 
Steven V. Christensen
schriste@uceng.uc.edu
From: aceman@cup.portal.com (Stanley - Heitmueller)
Newsgroups: sci.electronics
Subject: Re: Soundblaster for low rent data acquisition?
Date: Tue, 29 Dec 92 20:10:35 PST
Organization: The Portal System (TM)

Well the perfect device you can use is your joystick port on your PC.
port to measure analog signals and it works quite well.
Newsgroups: sci.electronics
From: snydert@dmapub.dma.org (Tony Snyder)
Subject: Yamaha Chip STK3042 III
Organization: Dayton Microcomputer Association: Dayton, Ohio
X-Newsreader: TIN [version 1.1 PL8]
Distribution: na
Date: Fri, 25 Dec 1992 02:46:43 GMT

I believe I have at least one of those amplifier modules around.  Put a 
message up here, to me, on this subject, if you don't have good luck elsewhere.
If you do find some elsewhere, I'd be curious as to the price.
	I have no access to mail.
Newsgroups: sci.electronics
From: andy@laguna.santafe.edu (Andy Mell)
Subject: Re: lasers/collimated light i
Date: Thu, 31 Dec 92 21:12:39 GMT
Organization: Santa Fe Institute
Distribution: sci

In article <1992Dec31.4265.27373@dosgate> "glen mead" <glen.mead@canrem.com> writes:
>
>Hmmm, I'd never heard of this before.  I can't get close enough to the
>unit to check it out but I haven't seen any hint of white light.  It's
>quite an impressive system...they project animations and phrases as well
>as all kinds of graphics and lissajous figures with the unit.  Is this all
>possible with a Xenon lamp?  Do you have any more info on this subject?

I just went to have a look on the side of my emulator, it is made by
Lightwave research, Austin, TX, USA. I dont have  a full address, but you 
could probably do some research in that direction. Be warned, they cost
big bucks, 15000 odd dollars. And yes, they use Phillips MSR1200 bulbs.
Goddamn f*cking bright, a MSR bulb is something like 4 times the output of
a standard xenon bulb (4.6k of light - sheesh)

A

-- 
-------------------------------------------------------------------------------
Andy Mell, Applied Physics Department,  |   andy@santafe.edu
University of Hull, Hull, HU7 6RX       |   amell@nyx.cs.du.edu
England.                                |   torq@gnu.ai.mit.edu
From: behnke@FNALF.FNAL.GOV
Newsgroups: sci.electronics
Subject: Re: help needed building water level sensor
Date: 29 Dec 92 18:28:25 GMT
Reply-To: behnke@FNALF.FNAL.GOV
Distribution: usa
Organization: Fermi National Accelerator Lab
NNTP-Posting-Host: fnalf.fnal.gov

In article <1992Dec29.175243.10083@cbnews.cb.att.com>, wrb@cbnews.cb.att.com (wallace.r.blackburn) writes:
>
> *MASSIVE* amount of master and slave controller info deleted
>

 Heck, we just may have a supercomputer or two to run the whole shebang(?).

 Just have to figure a way to get it out of the building in my lunchbox ;-)

mb

My opinions are my own, and MOST of them don't mean a thing !

mb
From: dino@inqmind.bison.mb.ca (Tony stewart)
Newsgroups: sci.electronics
Subject: Re: Clocks
Date: Mon, 28 Dec 92 13:20:34 CST
Organization: The Inquiring Mind BBS  1 204 488-1607

flux@sys6626.bison.mb.ca (John Kamchen) writes:

> I'm having a problem with a circuit I'm trying to build.
> What I need is a 14Mhz clock that doesn't jitter the length of a video 
> line.  
> An LM1881 provides the syncs, and the clock should be stable as possible.
> Looks like this
> --____----------------------------------------------
> _-____-_-_-_-_-_-_-_-_-_-_-_-  and so on  this is the 14Mhz clock
>  
> I suppose what I'm trying to do is simulate a color-burst sync circuit
> (but using a 14Mhz clock).  The goal is to enable me to address
> a pixel every 70ns (for video sampling, image manipulation & such).
>  
> Anyone know what I can do ?  I've tried Xtals & inverters, all I could 
> think of.  I did get this working using a 74HC4046 PLL chip, but
> the cost was high ($2.50 for the chip), and at the end of the video line, 
> the clock wasn't too stable.
> 
> So, that's what I need.  Need help!
> -John
> SSE BBS (204)589-1078 v32bis AmiTronics- MEGS of 'em

THIS IS A JOB FOR AN XTAL PLL, although I have made it work using XTAL 
INJECTION LOCKED OSCILATORS.
Since you want to ADDRESS each pixel, why not use a standard DIVIDE-BY-N
PLL, so the the COUNTERS become your PIXEL ADDRESSES...

Use any design for the Divide by N counter, single chip or cascaded 
binary counters and gates.
If the Xtal OSC and pixel clock are both stable, you may be able to sync 
using a simple Voltage control using VARACTOR or any DIODE to control 
Capacitance, hence frequency and use a digital mixer and filter to 
control the voltage.

Or .. have U tried the ILL approach? (Injection Locked Loop)
Use the Trailing edge of Sync to trigger a stable 1 SHOT of approx <30 nS 
and inject it using a small cap into a 14MHz feedback OSCILLATOR.  This 
works by triggering on the Fourier harmonics of the Sync pulse, however 
your Q must be large to be stable (almost any XTAL). Hand tuning is a 
must sine the CAPTURE RANGE will also be small (200 ppm)

I worked on this 11 years ago doing Scrambling research and VBI data 
reception methods for a Wpg ENg consulting Co. for MTS.

Call if U need help.
Tony Stewart/ Unisys Canada  (204)257-9233 All opinions are my own!
                        home   "  253-6959

dino@inqmind.bison.mb.ca
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607
Newsgroups: sci.electronics