waashk/20ng huggingface dataset:
In article <C5v13M.C37@bcstec.ca.boeing.com> rgc3679@bcstec.ca.boeing.com (Robert G. Carpenter) writes: >I'm wondering if it's possible to use radio waves to measure the >distance between a transmitter(s) and receiver? > >Seems to me that you should be able to measure the signal strength >and determine distance. This would be for short distances (2000 ft), >and I would need to have accuracy of 6 inches, or so. > This would be susceptible to fading, multi-path etc. We used to use a system at the shop made by Tellurometer in South Africa. It used a 10 GHz signal between 2 units across the distance to be measured. The 10 GHz was just the carrier: the real signals were several switched ones around 7.5 MHz or so, whose relative phases at the receiver would read out the digits of the distance down to 10 cm if needed. The units came with psychrometers (sp?) to measure the relative humidity and instructions for correction of the measurements due to RH and temp. They were rather heavy and required an operator at each end. Current technology uses polarized reflectors, dual polaization TX/RX and psuedo-random coding of a radar pulse. about the same resolution at X band, much better at 47GHz. (Only one end is heavy :-)  ).   Regards, Stu Beal, VE3MWM, U009@CSX.CCIW.CA, National Water Research Institute, Burlington, Ontario, Canada.
Hi,  	Being a Electronic Engineering Student with only Electronic II under my belt, I find myself *needing* to build a moderate wattage Audio Amp. So,  I'll throw out a couple of question for the vast knowledge of the 'net'!  	Please Explain how Watts are calculated in Audio Amp circuits. No, Not P=I*E, Just how it relates to one of the following:  	Ai [Current Gain] 	Av [Voltage Gain] 	Ap [Power Gain] 	or whatever.  I already have a ?wonderful? cheap I.E <$20 schematic for a 20W amp, but I would like to Cross/improve the circuit. The problem is that the parts list has IC1 and IC2 as NEC70001AB amplifiers. They look like ?11 pin?  SIP packages with a heatsink. This schematic was published in a 1991 mag so it may be non-existant now. Anyway, I tried looking up a replacement in the latest Digi-key Cat and found it  not listed 8(. The closes I could figure was a 9 pin SIP as TDA1520BU. Anyone got any Ideas?   	I thought, hey I can rin a PSPICE simulation using 741 opamp  models. Yea, great! It worked. But, I guess the 741 wasn't made for High power amps. As a result, I got a Voltage gain of ~15mV/V. Worse than I started with 8(... Does anyone have a PSPICE CKT file with cheap yet good gain? How about some models for some of the chips listed in this  E-mail? Any ASCII Chip info you guys can send me?   I'm open to Suggestions/Ideas/Comments/Help! Please E-mail since I have little time to search the News...  And I'll post if there's and interest! John
> 	If my life depended on it, I'd say that it's a scope that > 	uses long-persistance phosphor to keep the successive > 	taces on the screen for some unit of time - "store" them. > 	Do I get to live?  We'll let you live, but just this once....  There's more to a real "storage" scope than just a long-persistence phosphor.  Actually, the phosphor ISN'T usually anything special at all; what makes a storage tube work is a screen placed just *behind* the phosphor, which becomes charged as the electron beam intially "writes" the trace. With the trace now written to the screen, a separate low-level "flood" electron gun keeps the image lit by exciting those areas of phosphor which are next to the "written" areas on the storage screen.  There are some problems with this - the resolution is limited compared to a non-storage tube, and the stored trace tends to "bloom" with time.   Of course, this is pretty much obsolete technology, done in by the current digital scopes which use raster-scan displays and keep everything in a frame-buffer memory anyways.  > / Filip "I'll buy a vowel" Gieszczykiewicz. | Best e-mail "fmgst+@pitt.edu"  \           ^^^^^^^^^^^^^^^^^^  Ah, yes - from the same people who brought you that amazing new reading program that's sweeping Eastern Europe: "Hooked on Consonants!" :-)
Hello,  Has anyone used the Requirements Analsys methodology Hatley & Pirbhai ? I am a British final year real-time degree student, and as a project I am covering this methodology. I would be very grateful to anyone who could give me their views on this method. Please mail me if you feel you can help, and I will send you my questions.  Thanks in advance,
I just installed a Motorola XC68882RC50 FPU in an Amiga A2630 board (25 MHz 68030 + 68882 with capability to clock the FPU separately).  Previously a MC68882RC25 was installed and everything was working perfectly.  Now the systems displays a yellow screen (indicating a exception) when it check for the presence/type of FPU.  When I reinstall an MC68882RC25 the system works fine, but with the XC68882 even at 25 MHz it does not work.  The designer of the board mentioned that putting a pullup resistor on data_strobe (470 Ohm) might help, but that didn't change anything.  Does anybody have some suggestions what I could do?  Does this look like a CPU-FPU communications problem or is the particular chip dead (it is a pull, not new)? Moreover, the place I bought it from is sending me an XC68882RC33.  I thought that the 68882RC33 were labeled MC not XC (for not finalized mask design).  Are there any MC68882RC33?
Fiberglass boards are available in several colors.  Sitting right here, I have unetched board stock that is white, blue, green and yellow respectively.  I've also seen black boards.  Solder mask is available in a variety of colors too.  Depending on the supplier, the color helps indentify the material.  Don't forget conformal coating.  I don't think I've seen phenolic impregnated paper boards in anything other than the familar brown, but it would not be difficult to add a dye to change the color.
schaefer@imag.imag.fr (Arno Schaefer) writes:  >In article <1993Apr21.085848.12704W@lumina.edb.tih.no>, ketil@edb.tih.no (Ketil Albertsen,TIH) writes: >|> In article <1993Apr20.230749.12821@reed.edu>, mblock@reed.edu (Matt Block) writes: >|>  >|> >	I guess what I am saying is that your question is difficult, if not >|> >impossible, to answer.  What exactly do you want to know?  Do you need a good >|> >one for a project you are working on?  How secure must it be?  Are you trying >|> >to crack one that someone else has used?  I can probably make suggestions, >|> >assuming the activity is strictly legal.  (In general, it is a BAD idea, >|> >legally, to tamper with copy protection.  It can also lead to corruption of >|> >files which you necessarily do not have back ups of (being as they are copy >|> >protected,) which can be devestating.)  Do you have absolutely no ideas for >|> >practical applications, and are merely curious? >|> >	Please clear up those questions, and I'll try to help as much as I >|> >can. >|>  >|> May we interpret this as an offer to volunteer as editor for a >|> "Copy protection FAQ" ? I am quite sure that I am not alone welcoming such >|> an initiative! *I* will volunteer to ask some of the questions, if you will >|> provide the answers :-) >|>  >|> Ketil Albertsen  >Hey, now will you stop encouraging him? Copy protection only serves one pur- >pose: to keep the honest buyer from making (legal) backup copies. It will >definitely not stop any pirates. If you want to protect you soft, supply a >good documentation and support. This is IMHO the *only* way of effectively pro- >tecting software.  >Best Regards,  >Arno  >--  >-------------------------------------------------------------------------------- >Arno Schaefer				ENSIMAG, 2e Annee >Email: schaefer@silene.imag.fr >Tel.: (33) 76 51 79 95			:-) >------- No, you're not paranoid - the world is really out to get you -----------  Your wrong.  Never give up.  Update your program as much as possible, with a very low price of upgrade to registered users (and *PLEASE* make sure you keep a list of registered numbers!)...  -- ------------------------------------------------------------------------------- George Gruschow                                Death do you gronk. ag625@yfn.ysu.edu                              ggruscho@nyx.cs.du.edu
In article <1993Apr19.231050.2196@Rapnet.Sanders.Lockheed.Com> babb@rapnet.sanders.lockheed.com (Scott Babb) writes: > >The Federal Communications Act of 1934 made it *legal* for you to >operate a radio receiver of any kind, on any frequency (including >X, K, and Ka bands) in the United States.  The Electronic >Communications Privacy Act of 1989(?) restricted the FCA of 1934 >by making it illegal to receive the land-mobile telephone service, >including (I believe) cellular phones.  Illegal to receive land-mobile telephone service?  Don't you have to have a mobile reciever to even have land-mobile telephone service?  What about ship-to-shore telephone service?  >No restriction was placed >on receiving RADAR (or, curiously, cordless phones.)  Enforcement >of the Virginia law is in violation of the FCA of 1934.
<lots of pretty good stuff about how the huge towers near most nuclear power plants are there to cool the used steam back into near ambient temperature water deleted>  >>water.  As I recall the water isn't as hot (thermodynamically) in many >>fossil fuel plants, and of course there is less danger of radioactive >>contamination.  >       Actually, fossil fuel plants run hotter than the usual  >boiling-water reactor nuclear plants.  (There's a gripe in the industry >that nuclear power uses 1900 vintage steam technology).  So it's >more important in nuclear plants to get the cold end of the system >as cold as possible.  Hence big cooling towers.        as a point of info, some of the early nuclear power plants in this country used the fission pile as a first stage to get the water hot, and then had a second stage -fossil fuel- step to get the water (actually steam) VERY HOT.     I remember seeing this at Con Edison's Indian Point #1 power plant, which is about 30 miles north of NYC, and built more or less 1958.   dannyb@panix.com
Anyone know a reasonable circuit for programming PALs?  I am interested in programming a wide range of EPLDs but would be happy with something  that could handle a 22V10 or thereabouts.  Thanks in advance, --Tim
I am interfacing some simple circuits that run on 9V to my cpu board which runs at 5-6V.  The optoisolator is a 4N35. On the led side, I put the signal I want through a 10k resistor to the base of a 2N2222.  On the transistor side, I tie my cpu input line to the collector which has a pull-up resistor of 47k.  It functions OK, but seems VERY slow.  I can detect pulses that occur at about 2kHz, but not much faster.  Isn't the rise/fall time of this device, something like 5uS?  I should be able to detect my target of 40kHz, but I can't get 16kHz. This is done using wire-wrap and the wires going to the cpu and to the test pin are about 8 inches long, but I'm not doing anything high-speed.  In the Art of Electronics, it mentions tying the base of the phototransistor to ground through a resistor to improve the speed.  Is that what I need to do?  How do I calculate the resistor value?   --
In article <hcbC5un9L.DD0@netcom.com> hcb@netcom.com (H. C. Bowman) writes: > >Hello-- > >I just bought a new portable CD player for the office, and I notice that >it proudly proclaims "8 TIMES OVERSAMPLING" on the box.  Now while I think >I understand what oversampling is (the rate of discrete "samples" >exceeds the highest frequency component of interest by some factor), >I don't understand this "8 TIMES" business...  It seems to me that when >I bought my first CD player (was it REALLY 10 years ago?!), the specs >said "4 TIMES" ...  Could someone please tell me whether I'm getting >senile?  If I'm not, then what good does it do for the player to take >samples at a higher rate?  If I really wanted better fidelity, wouldn't >I have to have the same higher rate of sampling during the recording >process?  Furthermore, am I wrong in interpreting the sampling rate >(from the player's point of view) as being the same thing as the data >rate for the bit stream coming off the optical medium?  Does this mean >that the data rate (related to the rotational speed of the disk) has  >changed since 1983?  [Note: I just tried to figure this stuff out about a month ago myself, from various people on the net, so I could be wrong.]  The data is only ever read once (barring mistracks and such, of course), and eventually gets turned into 44.1 KHz, 16 bit, two channel data. Oversampling takes two discrete data points, and interpolates n-1 points between them for n times oversampling.  When I asked, people said that the interpolation was not simply linear interpolation, but significantly more complicated.  Anyway, then, the purpose of oversampling is to move the "effective" sampling rate up to n times 44.1 KHz, in order to use higher frequency antialiasing filters.  For the same quality filter, higher oversampling lets you build cheaper filters, whereas for the same price filter, higher oversamplings lets you build better filters.  So, assuming the quality of all other components in a CD player remained the same, oversampling should allow a manufacturer to produce _slightly_ better sound due to anti-alias filtering.
Hi there,  I have a friend who'd like to get a hold of a bunch of those simple voice recognition chips that Radio Shack used to sell (and no longer does).  If anybody knows of a source for these, please e-mail me.  I'll forward the responses to him.  Thanks!
In article <1993Apr2.204617.14179@mprgate.mpr.ca>, vanderby@mprgate.mpr.ca (David Vanderbyl) writes: |> dtmedin@catbyte.b30.ingr.com (Dave Medin) writes: |> >The CRT, in fact, does have an intentional built-in capacitor for |> >its function just as IC's have built-in transistors, etc. |>  |> Gee, Mr. Myers, are we going to let this go without a CORRECTION?  Two things:  	1. Read your own posts. I was agreeing with Bob. No correction 	   needed.  	2. Don't quote stuff out of context.  --  --------------------------------------------------------------------        Dave Medin			Phone:	(205) 730-3169 (w)     SSD--Networking				(205) 837-1174 (h)     Intergraph Corp.        M/S GD3004 		Internet: dtmedin@catbyte.b30.ingr.com   Huntsville, AL 35894		UUCP:  ...uunet!ingr!b30!catbyte!dtmedin     ******* Everywhere You Look (at least around my office) *******
In article <WD.93Apr26122020@sam.cs.tu-berlin.de> wd@cs.tu-berlin.de (Wolfgang Diestelkamp) writes:    In article <1rg36hINNsr6@darkstar.UCSC.EDU> hugo@cats.ucsc.edu (Hugo Calendar) writes:     > I'm wondering if I can tote my American touch tone phone around with me    > to Sweden and Germany.  It's DC powered, and I can buy a special adapter    > for that in Europe.  The question is if the general electronics work    > the same.  I can buy a different wall plug and refit it (I'm sure I'd    > have to), but would that do the trick?     Two things to watch for:    In Germany (and I think the same holds for Sweden) only some    of the connections can handle tone dialing, so make sure the    phone can be set to pulse dialing.  Most (if not virtually all) swedish exchanges can handle tone dialling. Many older electromechanical exchanges have been modified accept tone dialling.
I want to connect a very small "home-made" speaker up to the headphone jack on my macintosh LC for an experiment. The dc resistance of the speaker is 1 ohm.  Any ideas how I can do this safely?  I think I need some kind of an impedance transformer or something.? -tony  wayne@uva386.school.virginia.edu
In article <1qk4hj$qos@vtserf.cc.vt.edu> prasad@vtaix.cc.vt.edu (Prasad Ramakrishna) writes: >I had a GE Emerson 13" color TV for about 3 years and one fine day, >while we were watching something (I doubt if the program was the cause), >we heard a mild explosion.   Our screen went blank but there was sound, >so we thought, 'oh we have special effects on the program'.  But soon >the sound stopped and smoke started to appear at the back of the TV. >The brilliant EEs we are, we unplugged the TV and called customer service >only to be thrown around by please hold, I will transfer u to blah blah.. >  Finally we abandoned the idea of trying to fix the TV and got a new one >(we wanted a bigger one too!). > After all the story, what I wanted to know is: Is my problem an isolated >incident or a common one? (I recall reading about Russian TVs exploding, but >not here, in the US). Why would the picture tube explode or even smoke? > I still have the left over TV set, I might dig into it this summer. Any >idea where I can get parts for these things? (probably will cost more than TV). >  Heh, heh, heh, heh....I laugh because I have the same damn TV, and it did the same thing!  Actually it is a Goldstar, but it's essentially the same TV and electronics--just a different face plate and name.  #1.  Fortunately, TV tubes don't explode.  I'd think the TV mfrs want to make this possibility remote as possible.  If at all, they'll  *implode* and the glass that blows out would be the result of the glass boucing off the back of the tube due to the implosion. In any case, don't kick it around! :-)   #2  I fixed the TV after getting a hold of some schematics.  It turned out to be a blown 2W resistor feeding the flyback transformer.  I guess the original resistor was a bit too small to dissipate the heat it created, burning itself out.  I checked to make sure the flyback wasn't shorted or anything first!  Oh, luckily, I had a resistor handy lying around that had just the right value for what I needed.  I can't see it being more than 50 cents!.
In article <1993Apr14.172145.27458@ecsvax.uncecs.edu>, crisp@ecsvax.uncecs.edu (Russ Crisp) wrote: >  > Hello > I'm considering modernizing some old wiring in my home, and > I need a little advice on outlet wiring.  Several outlets > are the old 'two prong' type, without the ground.  Naturally, > the wire feeding these outlets is 12/2, WITHOUT the ground > wire.  I noticed at the fusebox that some circuits have the > 12/2 with ground, and that on these circuits, the ground > wire was tied to the same bus as the neutral (white) wire. >  > SO..  Here's my question.  It seems to me that I'd have the > same electrical circuit if I hooked the neutral[D[D[D[D[D[D[D[D[D[D[Da jumper from the neutral > over to the ground screw on new 'three prong' grounding outlets. > What's wrong with my reasoning here?    First, it will not pass a National Electrical code inspection. Secondly, The neutral wire is current carrying and the ground wire shouldn't be, or only during a fault condition.  The reason the neutral and ground are tied together in the panel is the tranformer on the power pole has a grounded center-tap secondary, with the grounded center-tap the neutral.  This gives 120v to neutral(ground) from each side of the transformer and 240v across the transformer.  So in effect the neutral and ground should be at the same potential.   ------------------------------------------------------------------ Mark E. Kilpela              email mkilpela@mtu.edu Michigan Technological University School of Technology
Does anyone know the pin-outs for the 27C512 EPROM??  I have bought several of them, none of which has come with the pin-outs!  Any info would be appreciated....
Dave Martindale (dave@imax.imax.com) wrote: : They require two separate grounds.  One ground goes to the ground pin : of the outlet, and the other ground wire is connected to the outlet's : mounting tabs (and thus grounds the box and faceplate screw and metal : faceplate, if any).  I thought the ground WAS connected to the metal frame on the socket.  --  ------------------------------------------------------------------------------ Christopher Wolf             Electrical Engineer                cmwolf@mtu.edu
Can anybody send me Pinouts of Real Time Clock IC of OKI Semiconductors, 58321. I wish to know if any RTC IC of OKI has an inbuilt crystal rather than an external 32.768KHz crystal. Thanks in advance. Nilesh Parikh nilesh@shakti.ncst.ernet.in
Hello netters:)  Does anyone out there know any FTP sites for projects, plans, etc of an electrical nature?    -Jason
Article: 41686 of sci.electronics Newsgroups: sci.electronics Path: news.nd.edu!spool.mu.edu!howland.reston.ans.net!bogus.sura.net!news-feed-1.peachnet.edu!gatech!asuvax!ennews!mcdphx!schuch From: schuch@phx.mcd.mot.com (John Schuch) Subject: Food Dehydrators Message-ID: <1993Apr19.154356.17880@phx.mcd.mot.com> Sender: news@phx.mcd.mot.com Nntp-Posting-Host: bopper2.phx.mcd.mot.com Organization: Motorola Computer Group, Tempe, Az. Distribution: usa Date: Mon, 19 Apr 93 10:43:56 EST Lines: 9  >  Does anybody out there have one of those food dehydrators I've been seeing >all over late-night TV recently? I was wondering if they use forced air, heat, >or both. If there's heat involved, anybody know what temperature they run at? >My wife would like one and I'm not inclined to pay >$100.00 for a box, a fan >and a heater. Seems to me you should be able to throw a dehydrator together >for just a few bucks. Heck, the technology is only what? 1,000 years old? > >John  Try Mother Earth News, Feb/March 1993, pg 54, "Build a Food Dryer"
In article <1qlg9o$d7q@sequoia.ccsd.uts.EDU.AU>, swalker@uts.EDU.AU (-s87271077-s.walker-man-50-) writes: >  >  > I really don't know where to post this question so I figured that > this board would be most appropriate. > I was wondering about those massive concrete cylinders that > are ever present at nuclear poer sites. They look like cylinders > that have been pinched in the middle. Does anybody know what the > actual purpose of those things are?. I hear that they're called > 'Cooling Towers' but what the heck do they cool?  Water. Nuclear stations don't generate electricity directly from the reactor, they use the reactor to generate heat. The heat is then used to heat water just as in a conventional oil or coal station, and the resultant steam drives the turbines.  The cooling towers are used to cool the steam and recondense it into water to continue the cycle  Steve
The title says it all.  Contact me via EMAIL if you would can help me out...  Mike Harpe University of Louisville  P.S.  I KNOW IT IS DISCONTINUED.  I want someone who would like to sell       an old copy.
Chris Best (cab@col.hp.com) wrote: : > This is not a new idea.  At least 10 years ago I got this little gadget with : > a keyboard on the back and 8 LED's in a vertical row on the front.  It has a : > long handle and when you wave it in the air it "writes" the message you typed : > on the keyboard in the air.  :  : This is not news.  In fact it's where I got the idea from, since it was : such a neat item.  Mattell made it, I believe, modeled after a "space  : saber" or "light sword" or something likewise theme-y.  My addition was  : using a motor for continuous display, and polar effects in addition to  : character graphics.  I should have protected it when I had the chance.   : No one to kick but myself... :  : Ten years ago is about right, since I built mine in '84 or '85.  It's even older than that.  I remember seeing a description of a garage operation selling them at some of the early Computer Faires  in San Francisco about 5 years before that.
In article <1993Apr19.185326.9830@Princeton.EDU> mg@cs.princeton.edu (Michael Golan) writes: >The board itself is also identical, with room for all three caps. The >US/Can versions is clearly indicated in both places. > >How does that make sense? 0.047/2 is 0.0235, essentially 0.022 for caps >(there are just standard caps, no special W/type/precision).   This may be a safety issue; the CSA is more paranoid in certain areas than UL and such.  Two caps in series means that you don't have a short if one of them shorts.