HDTenEightyP/NetNews huggingface dataset:
From: bb099@cleveland.Freenet.Edu (Adam Trent Phillips)
Newsgroups: sci.electronics
Subject: Re: Can LED segments be fixed?
Date: 4 Jan 1993 05:28:23 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: bb099@cleveland.Freenet.Edu (Adam Trent Phillips)
NNTP-Posting-Host: slc4.ins.cwru.edu


In a previous article, silver@fraser.sfu.ca (Craig Silver) says:

>I have an old tv converter.  It's a Jerold, the one with the remote 
>that takes a 9 volt.  Some of the red LED segments that make up the 
>channel display don't light up anymore.  I know the converter is 
>probably not worth fixing, but I'm just curious as to whether or 
>not these things can be done at a barable cost.
>-- 
>
>----------------------------------------------------------------------
>Craig Silver	           Computer Science at Simon Fraser University
>silver@sfu.ca (Internet)   Burnaby, B.C., Canada
>


	Heck, you can REPLACE it for under $1 ! The store I go to 
sells two $1.50 ( 75 cents apeice !). Just make sure you get the right
type (IE: common cathode vs. common anode)

-- 
A. TRENT PHILLIPS |" A mirror is a negative space with a frame and a place for
  also known as   | your face, it reveals what the rest of us see. It conceals
   WHITE  ROOK    | what you'd like you to be."--Blue Oyster Cult
-------bb099@cleveland.freenet.edu-----aa1439@freenet.lorain.oberlin.edu-------
From: dino@inqmind.bison.mb.ca (Tony stewart)
Newsgroups: sci.electronics
Subject: Re: White noise generator???
Date: Wed, 30 Dec 92 08:55:08 CST
Organization: The Inquiring Mind BBS  1 204 488-1607

jsawyer@crash.cts.com (John Sawyer) writes:

> 
> 	How do I get/generate White noise easily???  Any help would be
> greatly appreciated:  Please e-mail jsawyer@crash.cts.com
> Thanks!

diodes are ideal noise sources, but there is also a chip that produces 
Pseudo-random audio noise.

** Mental flossing prevents moral decay. **

Tony Stewart

dino@inqmind.bison.mb.ca
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607
From: d89-ahg@ludd.luth.se (Anders Hedberg)
Newsgroups: sci.electronics
Subject: Filter for DIMMER with TRIAC ???
Summary: How do I build a good one ?
Date: 30 Dec 92 19:48:49 GMT
Organization: Lule} Tekniska H|gskolas Datorf|rening - Ludd

The cicuit looks like this :


----------------------------+ Light bulb +
				 	 I
220 VAC, 50 Hz, 4 A			 I
----------------------------+ Triac +----+
				+
				Triac control circuit


Problem: It emits RFI and I don't wan't it to!

(Problem two: Money :)

-- 
/Anders Hedberg             d89-ahg@ludd.luth.se                  Lulea, Sweden
Newsgroups: sci.electronics
From: billn@hpcvaac.cv.hp.com (bill nelson)
Subject: Re: Fuses in Europe and USA
Organization: Hewlett-Packard Company, Corvallis, Oregon USA
Date: Sat, 26 Dec 1992 06:46:05 GMT

greg@cs.washington.edu (Greg Barnes) writes:
: [This is posted for a friend in Germany.  Please do not respond to me,
: but to shiva@mpi-sb.mpg.de.   ---Greg]
: -----------------------------------------------
: I'm in Germany and using my 110V stereo on the 220V supply with a step
: down transformer. A fuse rated 3.15A/125V has blown in my stereo. I
: can't find another with a 125V rating in the local shops. I can get a
: 3.15A/250V fuse, though.
: 
: I was told the following: The voltage drop across a working fuse is anyway
: negligible, and the 250V rating refers to the maximum voltage that the
: fuse will block once it has burned. So the important thing is the
: ampereage that the fuse permits. So it would be okay to replace the
: part with a 3.15A/250V fuse.
: 
: Can anyone tell me whether the above explanation is reasonable? Any
: other advice would be appreciated also.

It is fine. Use the 250V fuse. Many fuses will show something like
3A 125/250V.

Bill
Xref: sparky sci.electronics:21316 sci.energy:6328 rec.autos.tech:17027
From: king@reasoning.com (Dick King)
Newsgroups: sci.electronics,sci.energy,rec.autos.tech
Subject: Re: Flywheel batteries as EV power source
Date: 21 Dec 92 21:59:40 GMT
Organization: Reasoning Systems, Inc., Palo Alto, CA

In article <72055@cup.portal.com> lordSnooty@cup.portal.com (Andrew - Palfreyman) writes:
>Frank E Perdicaro writes:
>: As an interesting side light, the largest forging ever made is 
>: the largest flywheel ever that stores energy at MIT for the 
>: ALCATORC-MOD fusion reactor.  It takes like 500 hp all night to spin it up, 
>: and 3 seconds to stop when the switch is flipped.  
>: 
>: Yeah, megajoules, many of them.  If there was a quake when the thing
>: was spinning, it would remove a large section of Cambridge.  
>: 
>: Its surface speed is just below the speed of sound, and it weighs like
>: a very large steam locomotive ; and its right next to the FISSION
>: reactor..... they know there is no way to stop it if there is a quake,
>: so its just in a simple flimsy building.
>
>I have a problem with this; if v^2 ~= 1e5 (m/s)^2 and you've pumped in
>about 3MJ, the mass must be about 60Kg for a disc shape. Perhaps the speed
>is not nearly so high - this is hardly a locomotive weight!
>(Hint: use Disc Energy = 0.5m(r*w)^2 and 1hp = 764W).
>

Nobody said 3MJ.

500 HP = 300 KW

300 KW * 28800 seconds [all [the 8 hour] night] = 8640 megajoules.  

Mr. Perdicaro should perhaps have written "Yeah, GIGAjoules, several of them.".

-dk
Newsgroups: sci.electronics
From: paul@grafted.UUCP (james caldwell)
Subject: Re: Wanted (1) MC1405L (analog chip from early two chip DVM set)
Organization: GRAFTED, Central Indiana's Usenet BBS 317-881-4369
Date: Sun, 20 Dec 92 00:01:07 CST

bailey@fenris.com (Kirk Bailey) writes:

> I'm looking for a source of one of these to fix a broken piece of test
> equipment.  I've been told that they became obselete a couple of years ago an
 I checked and it is a motorola ic it's companion ic is an mc1505
 also it is made by AMD am1405A
                    Lambda las1505
                    Panasonic mn1405
                    Sanyo     LB1405

 It is an analog to digital converter 3 1/2 to 4 1/2 digit ramp type
 2 device set decimal output. 
 I could not find a supplier :( but try calling Motorola or asking 
 one of the Motorola Employees I see chatting here.
 The info came from the 1985 edition of IC master.
                        Hope this helps
                        Happy xmas
                        Paul

--
james caldwell
The Grafted Branch BBS
317-881-4369
internet: paul@grafted.UUCP
uucp: ..!uunet!grafted.UUCP!paul
 = = Grafted Branch BBS (317) 889-6997 2 Gig on-line = =
From: rbattle@hydra.unm.edu (Ron M Battle STUDENT)
Newsgroups: sci.electronics
Subject: NEED source for CHEAP 68HC705C8S
Date: 24 Dec 92 07:50:38 GMT
Distribution: usa
Organization: University of New Mexico, Albuquerque


I found a source for 68HC705C8P micros. These are the One-Time-Programmable
plastic versions. Only $11.25 ea in quantities of 25 from:
 PCG Component Sales (800) 435-1150.

NOW, does anyone have a source for the EPROM version of this chip, and
in SMALL quantities for a reasonable cost (cheap!) ?  (68HC705C8S)

Thanx!
From: kc@dcs.ed.ac.uk (Kenneth Cameron)
Newsgroups: sci.electronics
Subject: Re: Vector wire pencils
Date: 22 Dec 92 19:55:10 GMT
Reply-To: kc@dcs.ed.ac.uk (Kenneth Cameron)
Organization: Laboratory for the Foundations of Computer Science, Edinburgh U

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?

For a small circuit (about dozen trans, maybe a couple of ICs), I use a bit of
strip board. For anything bigger I do a PCB if it'll layout single sided.
Otherwise wire-wrap (but then I have access to a mains gun so
it's real quick). I tried using solder wrap once and only once, I found it a
real pain to make changes. I also have a hand wire wrap tool for use at
home, it's slower but I like the flexibility of wirewrap. I you find solder
wrap suits you great, but don't dismiss wire wrap. The startup costs for the
hand versions of each should n't be that different. Maybe you need to borrow
each if you can to decide.

-- 
Kenneth@Edinburgh.ac.uk                                         kc@dcs.ed.ac.uk
4th Year Honours Student, Dept of Computer Science, The University of Edinburgh
Project: Acceleration of Constructive Solid Geometry Using a Custom VLSI Device
Newsgroups: sci.electronics
From: kcarver@dante.nmsu.edu (Kenneth Carver)
Subject: Re: How full is a nicad
Keywords: nicad rapid charge
Organization: New Mexico State University, Las Cruces, NM
Date: Tue, 22 Dec 1992 17:01:46 GMT

>In article <BzD705.C94@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>>In article <1992Dec15.103954.6299@quando.quantum.de> henigan@quando.quantum.de (Kevin Henigan) writes:
>>>I believe you can tell how full a nicad is from it's Voltage...
>>
>>No, you can't.  This is one of the fun problems of building a NiCd charger.
>>The output-voltage curve of a NiCd is essentially flat from pretty nearly
>>full charge to pretty nearly empty.

Ah, but there *is* a way to determine when full charge is reached.
The November, 1983 issue of the UK magazine Wireless World (now called
Electronics World) had a construction article for a device that would
safely charge any nicad battery pack in just one hour.  Here is the
basis of that circuit:
 "If a moderately heavy charging current is applied to a NiCd cell for
a short period, the terminal voltage will quickly rise to a level
somewhat higher than the voltage marked on the cell.  Discharging the
cell a little will reduce the terminal voltage once more.  A repeating
cycle of rapid charge and light discharge will produce a succession of
slowly rising `peak' and `trough' voltages, as shown in diagram.
 If the cycle is repeated for long enough, there will come a stage at
which the peak voltage is increasing much more steeply than the trough
voltage.  At the point the cell is losing the ability to accept
further charge and the charger can be shut off.  By measuring the
trough voltage as a fraction of the peak voltage it is possible to
make an end-point detector which works independently of the number of
cells under charge, since the proportions will be constant whether
there is just one cell or a dozen.  If the charge and discharge
currents are selected to correspond with the rated capacity of the
battery, the same setting of the detector should be able to cope
effectively with all cell sizes."

                                               ..........peak
                                         ...~~~
v|                                 ...~~~
o|                         ....~~~~
l|            ........~~~~~
t|....~~~~~~~~                       ....................trough
a|            .............~~~~~~~~~~
g|....~~~~~~~~
e|___________________________________________|_______________
                           time            60 min

For 500 mah batteries, the device typically produces 650 ma charge
periods for 30 seconds, alternating with 50 ma discharge for 10
seconds. 

--Ken Carver
Xref: sparky sci.electronics:21510 sci.energy:6425 rec.autos:30456
From: Ted_Eugene_Viens@cup.portal.com
Newsgroups: sci.electronics,sci.energy,rec.autos
Subject: Re: Flywheel batteries as EV power source
Date: Wed, 23 Dec 92 16:22:59 PST
Organization: The Portal System (TM)

>In article <1992Dec21.193621.12001@microware.com>, troyf@microware.com (Troy F
r
>ericks) writes:
>> In article <1992Dec19.192819.1816@adobe.com> pngai@adobe.com (Phil Ngai) wri
t
>es:
>> >If I were a terrorist, I would drool at the thought of being able to
-----
>> >BOOM!
-----
>AARRGGGHHH!
>
>Flame on.
>
>The rampant idiocy on flywheels just continues.  How many ways do people have
>to be told about conservation of energy?
-----
>Get it through your thick head - energy is conserved.  A flywheel that can pow
e
-----
>realize how big an explosion a few gallons of gas can make, when properly mixe
d
-----
>> >My opinions are my own.
>Good thing - they're pretty damned stupid for anyone else.
>
>--
>Richard Stead
>Center for Seismic Studies
>Arlington, VA
>stead@seismo.css.gov
>
I am sure there is no need to tell you, Richard, that there is more to Physics
than the conservation of energy....  As you know, there are laws of thermo-
dynamics, laws of plasma physics, and one or two other 'laws' that explain our
physical surroundings.   If I took a megajoules worth of Gasoline vapor and the
perfect amount of air and compressed it into a mythical light alloy housing
and then applied an erg or two of electrical discharge, we both agree that it
would be terribly unhealthy to stand nearby.  And I doubt that we would argue
over the difficulty of finding all of the pieces of the housing...  These laws
of thermodynamics we are both familiar with.  Now let us take this same housing
and pass two large electrodes into it. One through each bearing sleeve.  I mean
two inch in diameter, fully intergrated into the housing, Humongous electrodes.
Then let us place about a kilogram of graphite directly between them.  Now let 
us discharge, as quickly as power source resistance will let us, a megajoule of
energy through the graphite.  This is where we will part in our agreement.  My
thoughts are that a person standing next to the housing would here a very (very
,
very) loud bang.  If they turned to look at the housing, they would see it
turning bright red.  And if the housing temperature exceeded the plasticity
limits of its material, they might even see the housing begin to collapse as 
the vapor pressures of carbon and the light alloys quickly fell to nothing...
Same energies vastly different results...  All within the bounds of some 'law'
of physics here or there...
Again, I am sure we might disagree somewhere....
Bye...  Ted..
From: paula@nlbbs.UUCP (Paula Stockholm)
Newsgroups: sci.electronics
Subject: Cordless phone batteries
Date: Tue, 22 Dec 92 12:27:48 GMT
Reply-To: paula@nlbbs.uucp
Distribution: world
Organization: The Electronics Workbench - Cumberland Maine

        Unless the batteries were on their last legs when you purchased
        the phone (it happens, rarely), there is no reason your phone
        shoud have to be on the charger that much.  A few hours
        overnight should handle all but the heaviest usage.

        The rechargable pack inside COULD be replaced with regular batts
        but that would indeed be a pain. It would most likely involve
        some pretty clever modification to adapt regular battey clips to
        fit in a space specifically designed for the battery packs which
        are made-up of several batteries with spot-welded
        interconnections.

Newsgroups: sci.electronics
From: adkins@singha.eng.ohio-state.edu (Kenneth C. Adkins)
Subject: Re: VCR Repair
Summary: Books
Organization: The Ohio State University Dept of Electrical Engineering
Distribution: usa
Date: Thu, 31 Dec 1992 12:34:39 GMT

To the person who requested books on VCR Repair.  I recently checked
out two books from the area library on VCR Repair:

	"Complete Guide to Videocassette Recorder Operation
	 and Servicing," John D. Lenk, Prentice-Hall, 1983.

	"Home VCR Repair Illustrated," Richard C. Wilkins and
	Cheryl A. Hubbard, TAB Books, 1991.

The first one (Lenk) can get as technical as you want, describing the
basics of TV signals, modulation methods used by the VCR, etc.  The
second one (Wilkins and Hubbard) seems to be more of a technicians
repair guide with many useful photos of the internal structures.

Hope this helps,
Ken
-- 
                                            ____________
Kenneth C. Adkins                          /           /  
               -------8888888888===========------------ 
adkins@ee.eng.ohio-state.edu               \___________\  
Newsgroups: sci.electronics
From: VBHARGAVA@Meena.CC.URegina.CA (Bhargava, Vipin k)
Subject: Help on LCD FE0204-D
Date: Mon, 21 Dec 1992 20:53:44 GMT
X-News-Reader: VMS NEWS 1.24
Organization: University of Regina, Regina, Sask., Canada

Hi,

Does anyone have any info on an LCD FE0204-D? Any data sheets, manufacturer,
pinouts, anything.....

Thanks, 
Vip
From: sysrick@orion.spd.louisville.edu (Rick McTeague)
Newsgroups: sci.electronics
Subject: Re: Telephone Headsets
Date: 23 Dec 92 17:59:51 GMT
Organization: University of Louisville


lenny@hobbs.hunt.inmet.com (Lenny Goodman) writes:

> I've been looking into telephone headsets (the things that telephone
> operators usually wear) and the prices are much higher than I expected:
> $160 - $200 and UP.  Basically, the thing consists of half a headphone,
> a microphone, and a small amplifier.  I would have thought that the price
> would be $60 to $80.  Does anyone know why they are so expensive; or,
> does anyone know a source where the price is more reasonable??  Thanks.
> 
>   -- Len

Radio Shack sells a couple of different headsets. The 43-590 is a self-
contained phone set, and costs $49.95 (I think). Don't get the other headset,
which is intended to hook up to an existing phone, as it's inconvenient to use.

If you're looking for just a headset, you can order a replacement headset from
RS National Parts for $15-20.

Rick

-- 

Rick McTeague
Electrical Engineering Department, Speed Scientific School
University of Louisville, Louisville, KY 40292
(502) 588-7020

Internet: sysrick@starbase.spd.louisville.edu

Disclaimer: I'm a stand-up comedian; if anyone takes me seriously, I'm
            doing something wrong!
Newsgroups: sci.electronics
From: nagle@netcom.com (John Nagle)
Subject: Re: help needed building water level sensor
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Date: Thu, 24 Dec 1992 04:30:28 GMT

schuch@phx.mcd.mot.com (John Schuch) writes:

>In article <00965764.D96DDB80@Msu.oscs.montana.edu> uchrgrh@Msu.oscs.montana.edu writes:
>>I would like to build a solid state device that would turn off a water
>>pump in my aquarium if the water level drops  below a certain level.
>>I am willing to look at prefabricated stuff but would prefer to build it
>>my self.

      OK, check out the National Semiconductor LM1830 Fluid Detector,
which is designed specifically for turning things on and off based on
water level.  This unit uses a pair of conductive probes in the liquid,
and drives them with an AC signal at, typically, 6KHz, to avoid
electroplating crud onto the sensing probe.   Specifically recommended
for aquaria in the data sheet.  Will drive a 20mA load.  

      Also useful is the LM1801 Battery Operated Power Comparator, which
is also suitable for water level detection.  This part has provision for
hysteresis feedback, so that the pump doesn't turn on and off rapidly when
the level is near the threshold.  Will drive a 500mA load.  Designed for
battery operatio from a 9V alkaline battery for one year of standby 
(no output) operation.  Often used for leak alarms, etc.  Drives the
probes with DC, though, so it doesn't protect the probes from corrosion.

      Typically, you would drive an optically-isolated solid-state power
relay from one of these.  Something like the Digi-Key GH7018-ND.

					John Nagle
Newsgroups: sci.electronics,sci.energy,rec.autos
From: jmorriso@ee.ubc.ca (John Paul Morrison)
Subject: sci.flywheels newsgroup?
Followup-To: sci.energy
Organization: University of BC, Electrical Engineering
Date: Tue, 29 Dec 1992 02:55:12 GMT


This annoying subject is still getting cross-posted all over the place.
For lack of a better alternative, maybe we can all followup to sci.energy.
Perhaps those who really like to show off their highschool physics can 
create a newsgroup sci.flywheels or something. Whatever, I'd be happy to
get this off of sci.electronics.

-- 
__________________________________________________________________________
 John Paul Morrison                     |  
 University of British Columbia, Canada |  
 Electrical Engineering                 |   .sig file without a cause
 jmorriso@ee.ubc.ca              VE7JPM |  
________________________________________|_________________________________
Newsgroups: sci.electronics
From: sakaria@vipunen.hut.fi (Sakari Aaltonen)
Subject: Scope Suggestions?
Reply-To: sakaria@vipunen.hut.fi (Sakari Aaltonen)
Organization: Helsinki University of Technology
Date: Mon, 28 Dec 1992 21:50:21 GMT

I'm thinking of buying an oscilloscope. I wonder if anyone would care
to offer suggestions as to what I should look at? Maker? Type?

Two channels should suffice, but I really don't know about bandwidth.
I'm mostly interested in digital signals, so the usual entry-level 20MHz
is probably too small. Let's say 25ns pulses should be at least visible -
would 40 MHz be enough? Or is it rise time that matters?

Thanks in advance,
-- 
--------------------------------------------------------------------------
Sakari Aaltonen                              Email: sakaria@vipunen.hut.fi
"... implementing hardware interrupts in a PC peripheral interface is like
falling off a log."              Horowitz and Hill, The Art of Electronics
Newsgroups: sci.electronics
From: jmorriso@ee.ubc.ca (John Paul Morrison)
Subject: mc68hc705k1 Ocsillator modes?
Organization: University of BC, Electrical Engineering
Date: Wed, 23 Dec 1992 22:02:44 GMT


The MC68hc705k1 has five methods for setting up oscillation,
but I can't find accuracies fro two of them.

Crystals, external clocks and ceramic resonators, I can find out the accuracy,
but for the 2 pin and 3 pin RC oscillator, I can't find any 
accuracy/stability specs. Obviously, an RC circuit won't be great, but
if it can gaurantee less than 5% error (approx) then it might be useable
for this project (with 25-50 copies, $$$ is important)



thanks

-- 
__________________________________________________________________________
 John Paul Morrison                     |  
 University of British Columbia, Canada |  
 Electrical Engineering                 |   .sig file without a cause
 jmorriso@ee.ubc.ca              VE7JPM |  
________________________________________|_________________________________
Xref: sparky sci.electronics:21479 sci.energy:6414 rec.autos:30419