HDTenEightyP/NetNews huggingface dataset:
Newsgroups: sci.electronics,rec.video.satellite
Subject: VIDEOCRYPT encryption system by Fergusson
From: geoffrey@cosc.canterbury.ac.nz (Geoff Thomas)
Date: Mon, 4 Jan 1993 02:47:57 GMT
Organization: Computer Science,University of Canterbury,New Zealand


Anybody know how the VIDEOCRYPT encryption system works?
It is manufacted by in the UK by Fergusson Ltd. The
decoder has a smart card which needs to be inserted into
it for it to decode the video signals (audio is unscrambled).

How does it do the encryption? Is it based on wiggling sync
pulses? Or maybe on jumbling up video scan lines? Or maybe
something else?

Anybody know?

Cheers,
Geoff.

Newsgroups: sci.electronics
From: gerg@netcom.com (Greg Andrews)
Subject: Re: 486DX2 Crystals
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
Date: Wed, 30 Dec 1992 06:42:22 GMT

walvdrk_r@research.ptt.nl (Kees van der Wal) writes:
>iqbal@omaha.eel.ufl.edu (M.Iqbal) writes: 
>>walvdrk_r@research.ptt.nl (Kees van der Wal) writes: 
>>|>
>>|> [about clock frequency to be fed to 486DX2]
>>|>
>>|>Though I still wonder where my DX2 get's its 66MHz
>>|>clock from if the crystal runs at 33MHz only. Does it contain some
>>|>internal clock doubler circuitry? 
>>
>>Square wave have infinte number of frequencies: a fact explained in 
>>any introductory communication book. If you do not believe me than 
>>try finding Fourier Transform of a pulse train or see a specturm
>>of a pulse train on a spectrum analyzer. 
>
>I believe the book. The book say that symmetric waveforms have no even
>harmonics, so the probably symmetric 25 or 33MHz clock has to be converted into
>something asymmetric to be useful. 
>

What does your book say about a Sawtooth (Ramp) wave?


      /|    /|    /|    /|    /
     / |   / |   / |   / |   /
    /  |  /  |  /  |  /  |  /
   /   | /   | /   | /   | /
  /    |/    |/    |/    |/

According to my reference, a Sawtooth wave has both odd and even harmonics,
whose amplitude is inversely proportional to the harmonic number itself.
I.e.  the 2nd harmonic is 1/2 as loud, 3rd harmonic is 1/3 as loud, 4th is
1/4 as loud, etc.

>
>It would require some kind of filtering to select the second harmonic. As 
>having some LC-filtering on-chip doesn't seem very likely, I'm still wondering 
>how the 486-designers made it work.
>

I've seen probably a dozen frequency doubling techniques in various magazines
and those huge books in the library that reprint circuits from everybody's
data sheets.  Most of them are analog, but there are enough purely digital
ones that it shouldn't be too hard for Intel's engineers to find one for
their cpu.


-- 
:::::::::::::::::::  Greg Andrews  gerg@netcom.com  :::::::::::::::::::
It has just been discovered that research causes cancer in rats.
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
From: whit@carson.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: RFI free dimmer switches...
Date: 29 Dec 1992 23:47:33 GMT
Organization: University of Washington, Seattle
Distribution: na
NNTP-Posting-Host: carson.u.washington.edu

In article <1992Dec27.051620.22808@ee.ubc.ca> jmorriso@ee.ubc.ca (John Paul Morrison) writes:
>In article <1992Dec26.063254.23524@murdoch.acc.Virginia.EDU> alexander@kronos.pharm.Virginia.EDU (Robert Alexander) writes:
>>In article <72415@cup.portal.com> dbell@cup.portal.com (David J Bell) writes:
>>>
>>>>But a light dimmer I have installed makes the lightbulb RING alot, and
>>>>it's very annoying. The ringing gets worse when you dim the light. I'm
>>>>wondering if a "RFI free" dimmer will reduce this ringing.


>At 120 V 60 Hz, the bulb doesn't make any noise. But with the dimmer
>(triac + stuff), it does ring, and not at 60Hz (which wouldn't be bad)
>but it rings around 2-3 kHz, which is ANNOYING (since hearing is very acute
>around there).

	Either you have to have enough filter components (inductors
or capacitors) to filter higher frequencies than 60 Hz, or you
have to have a light bulb thatoesn't acoustically respond to
the various frequencies generated by the dimmer.

	One can presumably operate 12V halogen lamps on regulated
12V switching power supplies (most of which are adjustable, and
therefore allow dimming).  Going the build-it-yourself route is
expensive and not recommended for power circuitry, unless it
can't be bought.

	Or, one can use a dimmer circuit that doesn't generate
any harmonics; I refer, of course, to a variable autotransformer
(VARIAC or similar brand).

	It is possible to make regulated high-frequency AC with a
switching resonant converter, but (aside from some microwave ovens)
this kind of circuit is not commercially available in suitable
form for running incandescent bulbs.  I have run lamps with
a microwave oven (works best on neon and low-pressure gas lamps),
but this sems not entirely practical...

	Almost all dimming circuits use the simple SCR or TRIAC
switching scheme that generates significant acoustic-frequency
'buzz', and any coiled-filament bulb will convert some of this
energy to audible sound.  Perhaps trying different kinds
of bulb and selecting for least whine is the easiest route to take.

	John Whitmore


Xref: sparky sci.electronics:21282 sci.energy:6315 rec.autos.tech:17000
From: mwilson@ncratl.AtlantaGA.NCR.COM (Mark Wilson)
Newsgroups: sci.electronics,sci.energy,rec.autos.tech
Subject: Re: Flywheel batteries as EV power source
Date: 21 Dec 92 14:23:10 GMT
Organization: NCR Engineering and Manufacturing Atlanta -- Atlanta, GA

In <1992Dec21.004947.11290@cis.ohio-state.edu> rubin@grape.cis.ohio-state.edu (Daniel Rubin) writes:

|OK I agree that cars do not expode like seen on the big screen.  A car
|can expolde though.  Take the above example and add a high amperage electrical
|system and loads of wires to the top of the gallon of gas.  Now if the
|conditions are good the gas will spatter the vapor will come in to contact
|with a spark from two shorting wires and you will get a nice explosion.  
|Fuel-Air explosions are quite nasty.  Buring gas will not do that much, but
|produce heat, whereas buring gas vapor mixed with oxygen in the air will
|produce a powerfull explosion...

|Try it.  Drip a few drops of gas in a fire pit or some other similiar type of
|open ended enclosure ( no more than 5 or 10 drops of gas ).  Wait for it to
|vaporize and then throw a match in.  Whooomppp you will feel the shock wave
|and it most likely with scare the sh-eck out of you...

|>You can also try shooting it with a rifle or whatever. I have.
|>It's pretty boring.

|This can cause a rather large gas vapor cloud with the first shot assuming it
|is a high enough power rifle to rupture the container somewhat.  If the 
|container is steel and the bullet is steel a second shot should knock your
|socks off...

|>>>Unless you wrap the flywheel in a massive enough container that it can absorb
|>>>all that energy without vaporizing, you're going to have an explosion.
|>>
|>>Why bother, we don't wrap our gas tanks in a container that would contain
|>>their explosion?
|>
|>Because gas tanks don't explode. Movies are not reality.

|Car crashes violently, gas tank is ruptured and gas is forced out of the 
|rupture by the crash.  Gas vapor cloud forms rapidly and comes in contact 
|with the shorting positive battery post agains the frame of the car.  That
|will cause a rather large explosion and quite a lot of fire.  This would
|be a rare case and the individual would most likely not survive the crash
|itself...

True, fuel-air explosions are nasty things.  And it is possible for some
of the vaporized gasoline to ignite.  The question I believe would be,
What percentage of the gasoline that used to be in the tank takes part in
such an explosion?  I would think that it would be just 1% to 2%, if that
much.  Also how much time does it take for the vapor cloud to form?
Unless the occupants were incapacitated by the crash, they could use that
time to escape.  A flywheel on the other hand would most likely fail on
the moment of impact.

-- 
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,sci.energy,rec.autos
From: bbarkey@lark.utah.edu (Brian Barkey)
Subject: Re: Flywheel batteries as EV power source
Organization: University of Utah
Date: Tue, 22 Dec 92 21:46:16 GMT

In article <78564@ncratl.AtlantaGA.NCR.COM> mwilson@ncratl.AtlantaGA.NCR.COM (Mark Wilson) writes:
>In <1992Dec21.193621.12001@microware.com> troyf@microware.com (Troy Frericks) writes:
>
>|>If I were a terrorist, I would drool at the thought of being able to
>|>get such wonderful bombs so easily... All you'd have to do is arrange
>|>for the vacuum valve to be opened on command or the magnetic bearing
>|>to be turned off, etc.
>|>
>|>BOOM!
>
>|Modern composit materials, when used in a flywheel, will disintegrate
>|with such a failuar.  This bomb would be about as wonderful as some
>|fiber-glass insulation falling out of your attic.
>
>You haven't been listening have you?
>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? 
	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
From: kludge@grissom.larc.nasa.gov (Scott Dorsey)
Newsgroups: sci.electronics
Subject: Re: stand alone UART ??
Date: 22 Dec 1992 14:00:07 GMT
Organization: NASA Langley Research Center and Reptile Farm
NNTP-Posting-Host: grissom.larc.nasa.gov

> Does anyone know of a current part like the old Western Digital
> TR1863/1865. It is a stand alone UART, i.e. pin programmable
> with separate physical recieve and transmit sections.
> The 1863 appears in the 1984 Data book but WD now only make all
> singing/all dancing ones that require a microprocessor to talk
> to them (load registers etc).
> Michael Katzmann  

How about the General Instruments AY-3-1015?
--scott
Xref: sparky sci.electronics:21650 sci.energy:6467 rec.autos:30601
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 20:22:50 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 <1992Dec22.214616.27043@fcom.cc.utah.edu>, bbarkey@lark.utah.edu (Brian Barkey) writes:
>>You haven't been listening have you?
>>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? 
No, pure gasoline is *NOT* explosive.  Hell, pure gasoline isn't even
flammable.  You see, you've got to mix it with air.  I don't recall the
proportions for actual gasoline, but if we were talking about iso-octane
(C8H18), we'd want to burn that to produce 4CO2 + 9H2O, which means we'd need
8.5 times as much oxygen, (42.5 times as much air) as gasoline vapor, by
volume, or 2.38 times as much oxygen (10.7 times as much) air as gasoline, by
weight.  Now, getting this particular mixture by chance, and having the air and
gasoline thoroughly mixed, is no simple task (that's why fuel/air bombs aren't
all that common as weapons:  they're REAL finicky).

>	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. 

Though the gasoline contains lots of energy, it's damned near impossible to
extract all that energy in under a second out-of-doors.  So we're comparing the
failure of a flywheel (which would, for flywheels spinning at the speeds in
question, take less than a second) with burning the gasoline over a period of
many minutes.
--------------------------------------------------------------------------------
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: jmorriso@ee.ubc.ca (John Paul Morrison)
Subject: RFI free dimmer switches...
Organization: University of BC, Electrical Engineering
Date: Fri, 25 Dec 1992 23:52:06 GMT


Since I don't spend most of my life browsing the home electrical sections,
I just noticed that some light dimmers claim to be RFI free. I assume
they are using a zero voltage switch, to suppress transients.
(zero voltage = zero crossing detector, to fire the triac when the line
voltage is off (0 VAC), instead of firing the triac mid cycle (that's why
normal switches arc))

Now, people on the net are going to wonder why I'm obsessed with dimmers!
But a light dimmer I have installed makes the lightbulb RING alot, and
it's very annoying. The ringing gets worse when you dim the light. I'm
wondering if a "RFI free" dimmer will reduce this ringing. Anyone know?
(I took mine apart, and it's just a triac and some passive things, and 
a couple diodes; no hint of anything fancier).

(I tried suppressing the high frequencies with a 20 uF, 440V cap in parallel,
but the triac didn't exactly like firing with a leading pf...sort of dim
with buzzing going all the way back to the breaker. BTW kids, don't try
this at home, unless you have an oil filled Sprague 440V 60Hz capacitor
to play with on the AC line. This reminds me, I've been meaning to
"reduce" my electricty bill ..... :-)



-- 
__________________________________________________________________________
 John Paul Morrison                     |  
 University of British Columbia, Canada |  
 Electrical Engineering                 |   .sig file without a cause
 jmorriso@ee.ubc.ca              VE7JPM |  
________________________________________|_________________________________
Newsgroups: sci.electronics
From: whit@carson.u.washington.edu (John Whitmore)
Subject: Re: Vector wire pencils
Organization: University of Washington, Seattle
Date: Mon, 21 Dec 1992 23:31:35 GMT

In article <1992Dec21.152708.11873@kong.gsfc.nasa.gov> stephens@kong.gsfc.nasa.gov (mark stephens) writes:
>Are these useful?  They are the "pencils" which wrap a wire around a post
>and you then solder it.  I'm trying to determine what system to use for
>creating circuits for this new (to me)  hobby.  Etching seems to be a tad
>much for (probably) one shot boards and wire wrapping might be overkill. 
>With the pencil, do you need special posts for inserting into a perf
>board?

	Yes, the solder-wrap things are VERY useful.  I've used them
for years (actually, I made my own tools, after the Vector one broke
or was lost).  The wire requires a HOT soldering iron (800 degree
tip on a WTCP-type regulated iron), to burn through the insulation,
but otherwise it's as simple as any other soldering.

	No special tools needed; the leads of a resistor can be staked
with a pair of needlenose pliers into a wrappable state.  What
IS useful is the little 'wiring loom' plastic strips, to keep the
wiring neat (though with practice, one can route around
corners so that the wire stays put).  Always get the heavier of
the two gauges of wire offered (it is easier to see, and holds
a bend better).  Bulk wire for this purpose is Beldsol magnet
wire (you don't have to buy it from Vector), available from
Belden distributors. (Belden type 8056)

	Direct wrapping to IC pins works well, as does wrapping to 
soldertail socket pins; wirewrap sockets are OK, but the extra pin
length is not needed.

	An end-cutting scalpel and narrow-nose forceps are useful
for wire routing and snipping.  Since the wire needn't be cut to
length and stripped, one can daisy-chain a large number of connections,
solder them, and cut out the extra bits afterward (which is where
the end-cutting scalpel is handy: use it like a chisel).

	John Whitmore




Newsgroups: sci.electronics
From: ua123@freenet.victoria.bc.ca (Matthew A. Skala)
Subject: IR remote controls info?
Reply-To: ua123@freenet.victoria.bc.ca (Matthew A. Skala)
Organization: The Victoria Freenet Association (VIFA), Victoria, B.C. Canada
Date: Wed, 30 Dec 1992 17:56:45 GMT



I'm an independent student working on a project where I need to have a computer
send IR remote control commands to a VCR to start and stop a tape.  I'd like
it to be able to work with many different VCRs and so I need a way for it to
"learn" the command sequence to send and then send it.  I know this is possible
because those "universal" remotes exist which can record a command sequence and
then play it back well enough to fool the VCR.  The simplest approach would be
to just hook an IR phototransistor and an IR LED to the 'pooter, have it sample
the command at a suitable rate, and then play it back out of the LED.  Trouble
is, I believe some remote controls send their data by modulating a carrier, and
so my sampling rate would have to be high enough to capture the carrier
frequency.  This might be impractical.

Does anybody have any suggestions?  Please reply by EMail and I will post a
summary of the responses I get.
-- 
CENSORSHIP SUCKS!  UP WITH THE PEOPLE!

Matthew Skala - VE7MSK - ua123@freenet.victoria.bc.ca
Newsgroups: sci.electronics
From: iqbal@creek.eel.ufl.edu (M.Iqbal)
Subject: Re: Caller ID block?
Organization: University of Florida
Date: Thu, 24 Dec 92 20:00:10 GMT

In article <28815@oasys.dt.navy.mil>, curt@oasys.dt.navy.mil (Curt Welch) writes:
|> In sci.electronics, vporguen@unlinfo.unl.edu (victor porguen) writes:
|> >If you call an airline to get a flight schedule, they now may call
|> >you back.  At any time. In the middle of the night. For any purpose.
|> >Sales, solicitation, you name it. Or give your number to anyone they
|> >please.  For any purpose.
|> 
|> >Caller ID is a weapon, and it's aimed at YOU!
|> 
|> Why are you so scared of such a feeble weapon like the phone?  Did
|> your parents beat you with a phone when you were a child?  Or is it just
|> the thought of having a stranger call you that scares you so much?  You
|> really should work on overcoming your fears.
|> 
|> Guess what.  The airlines can call you anytime they want, whether
|> they have caller ID or not.  If you use their 800 number, they
|> get your phone number - and they always have.
|> 
|> Guess what.  I have your name and e-mail address.  It's a weapon too. 
|> And I've got it aimed right at YOU!
|> 
|> Are you going to start complaining about how e-mail and news messages have
|> a return address on them next.  And start crying about how unfair it is
|> that any crazy USENET reader (like me) can start harassing you?
|> 
|> And by posting in sci.electronics, there are now thousands of people that
|> have your name and e-mail address.  Why are you so worred about one
|> company getting your phone number but you don't seem to mind giving your
|> e-mail address to thousands of people all around the world?
|> 
|> If you send e-mail to my account I think it's only fair that I know who
|> it came from.  And if someone calls me on the phone, I think it's only fair
|> that I know who called me.
|> 
|> I agree that the phone company is forcing you to do something you don't
|> want to do (i.e. give out you phone number), and that's not nice.  No one
|> likes to be forced to do anything they don't want to do.  And many people
|> don't like Caller ID just for this reason - not because they don't like
|> it - but because they were never given a choice.
|> 
|> But thinking that Caller ID has no use but to make the phone companies
|> more money is a bit off base.  Get a grip guy.  You don't have to like
|> it, but you do have to live with it.
|> 
|> Curt Welch


After reading you response, I read your email address just for curosity and
I understood your reply right away.


---------------------------------------------------------------------------
"If your annual income today is $50,000, you have the same buying power as
the average coal miner did in 1949, adjusted for taxes and inflation," John
Sestina, nationally recognized Certified Financial Planner;  quoted in 1987.
                                            
      						 >><<<     >>><<<<
Iqbal@sioux.eel.ufl.edu		 		 (o o)     (o) (o)
University of Florida				 [ | ]        | 
                                  		   -         ---

Xref: sparky sci.electronics:21665 sci.energy:6485 rec.autos:30635
From: stead@skadi.CSS.GOV (Richard Stead)
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: 29 Dec 92 01:44:29 GMT
Followup-To: sci.energy

In article <1hcmi5INN7fd@armory.centerline.com>, jimf@centerline.com (Jim Frost) writes:
> I thought it was assumed that the flywheel operated in vacuum?  The
> "shock wave" will be expanding particles thrown off from the wheel
> itself, and the speed will depend on how fast the particle was moving
> when the wheel disintegrated.  I suspect that'll be a whole hell of a
> lot faster than the speed of sound.

Hyper velocity rotor failure will likely include a shockwave in the rotor
itself as a result of the hypervelocity fracture of the material.

> This discussion is great, but as I mentioned before it's also moot
> unless someone's figured out a way to eliminate gyroscopic effects
> from the flywheel.  These would be considerable, you know.

The torque would be less than 250,000 N-m.  (The 250000 comes from a
flywheel 1 meter in radius storing 92000 kCal and spinning 2775 radians/s.
Since angular momentum is energy divided by angular velocity, a more
reaonably sized flywheel (which would necessarily spin faster) would
store the same energy, but result in less torque.  The turn was 90
degrees in 1 second).  This is a lot, but probably could be managed for
awhile.  We can assume that 2 flywheels are mounted with opposing spin,
so net torque is zero, but the frame would be strongly and repeatedly
flexed with 10,000 to 100,000 N-m of torque.  The mounts or frame
would eventually distort or fail.  I don't have any figures for this
sort of failure, so I can't compute when a typical mount might fail.
I would guess it would be a long time, on the order of years, by just
gross comparison to normal engine torque and the failure of engine
mounts.  I assume the flywheel mounts would be designed so as to minimze
torque on the frame itself.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov
From: red@esse5.dei.unipd.it (Piergiorgio Sartor 274199/IL)
Subject: components identification
Organization: D.E.I. Universita' di Padova -- Italia
Date: Tue, 29 Dec 1992 09:16:30 GMT

Does anyone know what are the following components:

MC3487 (this is an IC)
PE-5762 (this has 6 pins, seems a rele')

please reply possibly via e-mail.
thanks a lot in advance,
-- 
					red@paola.dei.unipd.it
					red@sabrina.dei.unipd.it
From: Chris_F_Chiesa@cup.portal.com
Newsgroups: sci.electronics
Subject: New (to me) laser-beam pickup application
Date: Sun,  3 Jan 93 10:59:34 PST
Organization: The Portal System (TM)

By now we all (hopefully) know that lasers are used to read signals from
CDs and videodiscs, but last weekend while visiting friends over Christmas
I heard of a new application for the same (or similar) technology: reading
good ol' vinyl records by contactless laser pickup.  Has anyone here heard
of this, and can anyone provide any details on HOW it is being done?  This
is one of those ideas that, to me, seems obvious in retrospect, and "it's
a wonder nobody thought of it sooner."

Chris Chiesa
  Chris_F_Chiesa@cup.portal.com
Newsgroups: sci.electronics