waashk/20ng huggingface dataset:
Dean Anneser (anneser@pwa-b.uucp) wrote: : My 9 yr old son has signed up to do a science report on batteries.  I was : wondering if anyone could provide me with some information as to how to : construct a home-built battery.  In my grade school days, I remember seeing : the 'ice cube tray' version, but I don't remember what to use as a good : electrolyte or what the easily obtainable metals were.   :  : Thank you in advance.   I remember watching a whole "Mr. Wizzard" program on this subject when I was a kid.  The battery constructed on the program which made the  biggest impression on me, and generated the most power, was made using a galvanized bucket (for the zinc) and a copper toilet tank float.  The electrolyte was sauerkraut!
Others said: # >... Why would the picture tube explode or even smoke?  Naw, it was the penguin on TOP of the set that exploded... ;-}
In article <rcstage1.132.735807672@urc.tue.nl> rcstage1@urc.tue.nl (Guido Klemans) writes:  [stuff about hardware keys]  >If you put another computer on the port instead of the key, you can hack  >them by reading what happens. So I've been told, I've never seen this done  >but I think it's possible. You'd need some hardware knowledge and some  >software to read the port!  True, which is why many of the newer keys ship out, oh, maybe 32 bits or so, have the key encrypt them, and return them to the PC.  Making a bunch of these 32 bits part of your program code is a good way to make sure things won't run without the key. :-)  Anyway, then, this scheme at least defeats your approach.  It's a little costly, though.  Personally, I don't believe in copy protection, and agree with the thought that the mass inconvenience that it causes all legal users far outweighs the gains from what few pirates won't be able to copy the program.
idh@nessie.mcc.ac.uk (Ian Hawkins) writes:  > When constructing active filters,  odd values of resistor are often required  > (i.e. something like a 3.14 K Ohm resistor).(It seems best to choose common  > capacitor values and cope with the strange resistances then demanded). >  > Is there a PD program out there that will work out how best to make up such > a resistance, given fixed resistors of the standard 12 values per decade?.(1, > 1.2,1.5,1.8,2.2,3.3 etc ).  It is a common enough problem,  yet I cant  > recall seing a program that tells that Rx+Ry//Rz gives Rq,  starting with  > q and finding prefered values x,y and z. >  >  > 			Cheers > 				Ian H   >   WHen trying to choose a resistor with a tolerance better than 1%, you  need a trimmer or to screen devices, it can't be made from adding 2  resitors of 1% value in parallel, since the smaller device will have the  error of 1% to cope with.  You have 3 choices; a) live with the error of 1% tolerance devices for low Q circuits or low  sensitivity designs b) buy resistors with better than 1% tolerance (Vishay/Dale) c) use trimmers or SOT's (Select-On-Test)
In article <C6728H.Luy@cbfsb.cb.att.com> rdell@cbnewsf.cb.att.com (richard.b.dell) writes: >In article <1993Apr27.211036.1@ulkyvx.louisville.edu> jhwhit01@ulkyvx.louisville.edu writes: >>In article <1993Apr26.221422.17208@mprgate.mpr.ca>, vanderby@mprgate.mpr.ca (David Vanderbyl) writes: >> ><lots of stuff deleted> > >>The lead-acid secondary cell discharge reaction is EXOTHERMIC.  I am glad >>you do not dispute this point.  If you don't want the lead storage battery >>to discharge, it should be stored such that its charged state is the >>equilibrium state.  During winter, the ground, be it covered with >>concrete, dirt, or wood, maintains a cooler temperature on average than >>the surrounding air or the battery.  The heat capacity of air is less than >>that of concrete, dirt, or wood, so it heats faster.  Conversely, air cools >>faster, too. >> >>The normal storage procedure for a battery is to leave it in an unheated >>garage or basement.  The storage surface is often cooler than the >>surrounding air, with the battery temperature somewhere in-between.  E.g., >>the basement air temperature may be 70 F, the floor temperature 65 F, and >>the battery temperature 66 F. >> >>The air temperature is HIGHER than the battery temperature.  The heat of >>reaction is not going to move up the gradient.  The floor temperature is >>LOWER than the battery temperature, and heat is going to move to it.  The >>floor is an incredible heat sink. >> > >Might depend on where you live .. I know locally, for most of the winter >the ground, and concrete floor, within sheds and garages (unheated) is >signifacantly warmer than the average air temperature.  The air does get >warmer during the day, but during the night, the ground and concrete >is definitely warmer, especially when protected by the walls from the >albedo effect.  And the nights are longer by several hours than the >days. > ><rest of quoted text deleted> >> >>Jeff White       jhwhit01@ulkyvx.louisville.edu > >Richard Dell  Sorry about following up my own article, but I wanted to continue that what might be being missed here is that the important thing might not be temperature differences per se, but the action of heat sinking the battery.  Perhap someone could conduct an experiment, taking two identical lead acid batteries, placing both on wooden shelves, but putting one of them in a water bath designed to act as a heat sink.  This would eliminate the 'concrete floor effect', and keep both batteries at the same ambient temperature.  I think the argument over temperatures is not pertinent, but the one over heat conductance and removing the exothermic heat may have some validity.
Just saw an article in New Scientist; AT&T videophones won't talk to (?)BTI  videophones. The AT&T ones use a 19.2kb modem, BTI uses 14.4kb. AT&T models  have to communicate using all AT&T exchanges, whereas the BTI can route  via most current exchanges. Suggestions include building standards converters  into telephone exchanges - the mind boggles :)= . The BTI design is a bit  more conservative and is better able to cope with current data compression  hardware on long-distance lines.  (not having the magazine to hand, I may have mis-remembered BTI. I think it is a British one made by GEC-Marconi, and currently selling to other countries).   Yet Another Standards Screw-up.
Well here in Australia you dial  11544 to get the number read back to you if you live in the country include the area code of the nearest capital city eg for wa 09 11544  Yours Mark
One week to the Robot Olympic games.  Fire up the mechanoids for combat and come on down.  Competitors please note that there has been a slight change; the registration desk will now be in the forward building of the Science Centre rather than in the main competing hall.  When you arrive, please go to this desk.  Those that have pre-registered by real-mail will find badges waiting.  Is all.  See you here.
I would like to experiment with the INTEL 8051 family.  Does anyone out   there know of any good FTP sites that might have compiliers, assemblers,   etc.?
LLBGB@utxdp.dp.utexas.edu wrote: : Distribution: usa : Reply-To: lihan@ccwf.cc.utexas.edu  : While I'm on the net bugging everyone, is there such a thing as a chip : or chipset to decode Code 39 barcode?  I ask for a couple of reasons -- : mainly I want a reasonably compact encoding scheme to write information : on magstripe cards and Code 39 appears to be about right.  (If the 'right' : way to do it is something else, and it's reasonably easy, can someone let : me know?)  : I might not get a chance to reply too quickly to this or my earlier post, : but I'll get to them within a couple days, I think ..  : thanx everyone!  <BGB>  lihan@ccwf.cc.utexas.edu  Hewlett Packard has a series of barcode decoder ICs HBCR-1800, HBCR-2000, and HBCR-2010 and they support 3of9  extended 3of9  interleaved 2of5   and UPC codes. The 2000 and 2010 pieces add codabar and code 128.  These chips support HP's barcode wands and slot readers.  An 1800 + a HEDS-3050 wand run about $150 CDN .
fsset@bach.lerc.nasa.gov (Scott Townsend) writes:  >I got a question from my dad which I really can't answer and I'd appreciate >some net.wisdom.  >His question is about some 18-24" diameter balls which are attached to >electric power lines in his area.  He's seen up to a half dozen between >two poles.  Neither of us have any experience with electric power distribution. >My only guess was that they may be a capacitive device to equalize the >inductance of the grid, but why so many between two poles?.  >Anyone know what they really are?  Is there a related FAQ for this? >Is there a better group to submit to?  >We'd both appreciate some enlightenment.  I think those are to make the lines more visible to airplanes and helicopters... cheaper than blinking red lights.  'course I could be wrong.
I have a question about accessing certain addresses on a chip, particulary a 27C512 EPROM.  Although I don't know that much about it, as I understand it, there's a pin on the chip that, when voltage is applied, kicks up the address.  The question is how do you determine how many bytes the address is incremented by??  For example, if I have code I want to be accessed at $2000 and also at say $4000 how do I move the address pointer to those positions??  Thanks for any info...
Greetings. I've been seeing the word "storage" mentioned 	around oscilliscopes but I'm curious, what does it mean?  	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?  	Also, I've been shopping for a decent, used, [old] scope 	since my Tek 514A (portable...NOT!) and my Heathkit O-1000 	are all single trace and I need more... like 2 or 3 and at 	least 50MHz (maybe 100...)  	During my shopping at hamfests etc. I've run into the  	problem of "old scope" terminology. I can imagine what 	a "mainframe" and "plug-in" are but some things like 	the above "storage", "coax input" (Hey, where do I get a  	probe that fits this? I had to fiddle with mine for a week  	before I got anything resembling "a good trace" - they all 	come with BNC connectors!), "unblanking" (huh?), and, oh, 	just like my 514 manuals, MANY changes were made along the 	way to the schematic - scopes, even with IDENTICAL model  	numbers, have different (better?) response/performance than 	others - how can I pick the better one? Does the rule of the 	higher SN the better apply?  	Take care.
In article <C5x75A.48H@ms.uky.edu>, msunde01@mik.uky.edu (Mark  Underwood) writes: > In article <1r76sbINNkap@flop.ENGR.ORST.EDU> noeler@xanth.CS.ORST.EDU   > (Eric Richard Noel) writes: >> I hate hard copy manuals, and would rather have all docs online - *not* >> because I want to copy the program, but because its usually faster and >> and convenient than sifting through an old book I can't find. >  > Just MHO, but I prefer hardcopy books because you can have three or four   > of them open spread across the bed (next to the desk in my dorm) and   > reference them while using the program full-screen.  The Windows Help   > things come closest to good on-line documentation I've seen, but they   > generally aren't detailed enough and would probably take a LARGE amount of   > space (even compressed) which is at a premium on my system . . ..  In   > fact, the manuals are the primary reason I bought Borland's C++ compiler   > instead of using the one the lab licensed (in the lab, of course).  I've   > got a SHELF full of books to help me out when I'm stuck.  :-)   To each   > his own . . . :-)   It is also much easier to scribble corrections on a hard-copy manual.
In article <1993Apr6.161107.2235@b30news.b30.ingr.com>, dtmedin@catbyte.b30.ingr.com (Dave Medin) writes: |> In article <1993Apr2.182402.28700@walter.bellcore.com>, deaddio@ski.bellcore.com (Michael DeAddio) writes: |>  |> |> |> The 'beam' is split in two, with one beam aimed at the target car (sort of) and |> |> |> the other at the ground.  The speeds of each are calulated for the final |> |> |> number |> |>  |> |> Actually, this is true on the more expensive ones, but the cheaper ones |> |> just read the speedometer. |>  |> I've never seen a speedometer-reading model. Are you sure? Who makes |> them? Consider the difficulty of reading the speedo on various makes |> of cars in use... I've seen single beam moving-mode and split beam |> moving-mode.  Obviously the police officer reads the speedometer. I cannot believe the nit-picking in this group. There's 2 beams, there is not, is too, etc....
camter28@astro.ocis.temple.edu (Carter Ames) writes:   >   I was just wondering one thing, actually two. ( I hope that this is the >proper place to post this subject)  >  Why does a lead acid battery discharge and become dead (totally unuseable) >when stored on a concrete floor?   >  I decided to bring the battery in from the lawn mower and the motorcycle >from the unheated garage this year, *to preserve them* and I just >went to use them and noticed that not only do they not work, but  >they act like the two terminals are shorted.  I asked a friend >and he said that you should never do that, 'cause it ruins them, >but he couldn't tell me why.  I don't see any way that the concrete floor could do anything to the battery.  However, you would have been better off leaving them outside. Keeping them cold would have been better for them than bringing them inside. A warm battery will self-discharge faster than a cold one.  When you are storing a battery it's a good idea to charge it once a month. Letting a battery go completely dead is bad for it (I suspect this is what caused your problems).  --
In article <segal.734995860@corolla7>, segal@rtsg.mot.com (Gary Segal) writes: |> I've recently picked up some TIL311 display chips, but I can't find |> any information on them.  It seems they are no longer made by TI, and |> I don't have an old enough data book.  :-( |>  |> It appears to have a dot-matrix led display capable of showing one hex |> digit.  It is in a 14 pin DIP package, but pins 6, 9, and 11 are not |> present. |>  |> If you have any information on this part (pinout, power requirments, |> functions, ...) please send me e-mail. |>  |> Thank You, |>  |> --  |> Gary Segal                             Motorola Inc.             |> segal@oscar.rtsg.mot.com               Cellular Infrastructure Division |> 	--- we are standing here only to gaze at the wind ---   pin      function  1      led supply voltage  2      latch data input b  3      latch data input a  4      left decimal point cathode  5      latch strobe input  6      omitted  7      common gnd  8      blanking input  9      omitted 10      right decimal point cathode 11      omitted 12      latch data input d 13      latch data input c 14      logic supply voltage (5v)  LATCH STROBE INPUT, pin 5, when low, the data in the latches follow the data on the latch data                              inputs.  When high, the data in the latches will not change.  If the                                display is blanked and then restored while the enable input is high,                                the previous character will again be displayed.  BLANKING INPUT, pin 8,    When high, the display is blanked regardless of the levels of the other                               inputs.  When low, a character is displayed as determined by the data                               in the latches.  The blanking input may be pulsed for intensity modulation.  LATCH DATA INPUTS, pins 2,3,12,13,   Data on these inputs are entered into the latches when the enable                                           input is low.  The binary weights of these inputs are A = 1,                                           B = 2, C = 4, D = 8  DECIMAL POINT CATHODES, pins 4, 10,   These LEDS are not connected to the logic chip.  If a decimal point                                           is used, an external resistor or other current limiting                                           mechanism must be connected in series with it.  LED SUPPLY, pin 1            This connection permits the user to save on regulated Vcc current by using                                  a separate LED supply, or it may be externally connected to the logic                                  supply (Vcc).  LOGIC SUPPLY (Vcc), pin 14      Separate Vcc connection for the logic chip  COMMON GROUND, pin 7,      This is the vegative termnal for all logic and LED currents except for the                               decimal points.
In <FRITZM.93Apr20225937@sun.panix.com> fritzm@panix.com (Fritz Mueller) writes: >I just moved to NYC and wondered if there are any electronics hackers >out there who could point me to places in NYC that sell individual >electronic components (switches, pots, transformers, caps, >...  Try Cables and Chips ... let me dig out a reciept ...  Here we are...  Cables & Chips at 121 Fulton Street, that's near South Street Seaport and  Wall Street.  Phone is 212-619-3132 and 800-843-4117.  However, when ordering there, be VERY exact or there's a good chance they'll  screw up.  Otherwise, they're pretty good, and they deliver too.  Cheers, Rob
In article <mdonahue.15x9@amiganet.chi.il.us> mdonahue@amiganet.chi.il.us (Mike Donahue) writes: > >As for Adcoms Mobil, They are going with amps that canb use Balanced Inputs, a >VERY nice toy, but I'm afraid its goig to push their amps beyound resonable >price ranges.  especialy because taking advantage of those balanced inputs >requires a $120+ RCA to Balanced adapter...  Umm, when I was doing sound reinforcement for a living, I used to get direct boxes (which convert unbalanced 1/4" jacks to balanced XLRs) for about $25 each, or a little more for higher quality. You'll need two for a stereo signal, of course, and a little adapter thingy from  Radio Sh#$&^t to convert from RCA to 1/4". Total cost should be around $50. You can also buy transformers for quite a bit less and wire them yourself. Total cost there should be under $30. You can get all this stuff from any pro music shop that sells sound reinforcement gear. The benefit? NO noise that you can hear will be generated in the cables going to the component with the balanced inputs, even when you run them in bad places, like next to power lines.
In article <1993Apr20.183416.18744@dres.dnd.ca>, sburton@dres.dnd.ca (Stan Burton) writes: >  > -- >  > I would like to be able to detect the angular position (low accuracy) of an > IR emitting source at a distance of about 100 meters (more is better) in > daylight.  The IR source could be emitting a signature; I'm leaning toward > 30 KHz square wave with 50% duty cycle. >  > I am considering the use of a quadrant detector from Centronic Inc. to give > information to a pan/tilt head to point the sensor and thus determine the > angles.  For the source I am considering wazing the heck out of an IR LED(s), > possibly an Optek OP290 or Motorola MLED81.  Wazing would mean at least 1 Amp > current pulses.  At this current the duty cycle of the LED drops to 10% and I > would need to cycle five of them in turn to get the 50% required. >  > Has anyone done something like this? > Why don't you just run one LED at 60 KHz and use a flip flop at the receiving end to divide by 2 and give you a good square 30KHz signal. Just a thought. LORI   > Stan Burton (DND/CRAD/DRES/DTD/MSS/AGCG)                 sburton@dres.dnd.ca > (403) 544-4737     DRE Suffield, Box 4000, Medicine Hat, AB, Canada, T1A 8K6
>>SO..  Here's my question.  It seems to me that I'd have the >>same electrical circuit if I hooked the neutral jumper from the >>neutral over to the ground screw on new 'three prong' grounding >>outlets. What's wrong with my reasoning here?  >First, go to the local hardware store and pick up a copy of "Wiring >Simplified" by H.L. Richter.  Now if your house is wired with metal >conduit, you don't need a seperate ground wire (assuming the house >is wired correctly and the pipes are connected to a cold water >pipe in your basement).  The outlets that have a neutral hooked to >the ground screw seem wrong.  Anyone else think so?  Back in the 70's I was a service technician for a cash register company. The cash registers used microprocessor circuits and back then they were VERY susceptible to electrostatic discharge and line noise.  The biggest problems came from outlets that were not properly grounded.  In almost every place we went to do an installation, we found outlets with the ground connected to the neutral.  For 99.9% of the things you can plug into one of these, they work fine.  For our cash registers they were a nightmare -- line noise tended to scramble the memory periodically.  With modern electronics using switching power supplies this should be less of a problem.  Even the company I used to work for is no longer recommending a dedicated line with a seperate ground for their equipment.  I imagine if you check MOST household wiring you will find that the ground and neutral are connected.  Although not ideal, it should be o.k. for most applications.  ---  . SLMR 2.1 . My reality check just bounced.
I repair a lot of monitors here, and I'd like to know where I can get a pattern generator (or a circuit for one) that will provide MDA, EGA and VGA signals. Using a whole PC to do this takes up too much space on my bench, and is somewhat less than portable. I guess I could sit down and design something, but I don't have the time right now - any (reasonable) suggestions would be appreciated.  TNX  TG
In article <1qvlmaINNhuu@shelley.u.washington.edu>, ptorre@hardy.u.washington.edu (Phil Torre) wrote: >  > Is CCI still published?  If so, does anyone have their address?   Circuit Cellar Inc. 4 Park St.  Suite 20 Vernon, CT  06066 (203)875-2751
In sci.electronics timd@fenian.dell.com writes:  >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.  I too would be interested in ANY information on the subject of programing PALS etc.....    Better to know what your on about before you start something, I always say. Often saves you a packet as well !!  Thanks in advance..  Chris ;-)    +====================================================================+   |Name : Mr Chris Smith       |     Twang on that 'ole guitar !       |   |Addrs: scst83@uk.ac.liv     |                                       |   |Uni  : Liverpool University |Quest: To build more and more hardware |   |Dgree: Computer Science     |                                       |   +====================================================================+   "What ever the Sun may be, it is certainly not a ball of flaming gas!"   -- D.H. Lawrence.
Can anybody recommend a good, application-oriented beginner's reference to RF circuits?    I am pretty good on theory & know what different types of modulation mean,  but don't have a lot of practical experience.  A book detailing working circuits of different types (modulation, power, frequency, what is legal, what is not, et cetera), would be very helpful.  Thanks.  ----------------------------------------------------------------------------- Steve Klinkner                AT&T Bell Labs               srk@boeing.att.com                                                            att!boeing!srk
Hi,  I have a few questions about laying out a PCB. I am using easytrax for dos which is a great program. But what my question is When laying out traces what thickness should they be? I am mainly designing low voltage low current boards for micro controller apps. What should pad sizes be for resistors? I will be turning to a commercial PCB maker to produce 1's of these boards and I was wondering what is the minimum distance traces should be from each other. Well any info would be great. Thanks.                                                  Anton