HDTenEightyP/NetNews huggingface dataset:
From: smckinty@sunicnc.France.Sun.COM (Steve McKinty - Sun ICNC)
Newsgroups: sci.electronics
Subject: Re: Voltage drop across 1N4148 diode?
Date: 21 Jan 1993 13:19:47 GMT
Organization: SunConnect
Distribution: world
NNTP-Posting-Host: hardy.france.sun.com

In article <1993Jan21.101200.8651@mr.med.ge.com>, szopinsk@picard.med.ge.com (Jerry Szopinski Mfg 4-6983) writes:
> 
> 
> The voltage drop across the 1N4148 diode depends on what type of
> semiconductor material it is made of.  If the diode is made of
> germanium (no, not the flowers) the drop is around 0.7V; if it
> is made of silicon then the drop is around 0.5V.

I think the 1N4148 is a silcion diode, but isn't the voltage drop
the other way round? About 0.6 for Silicon and 0.3 or so for Germanium?

Steve

-- 
Steve McKinty
SUN Microsystems ICNC
38240 Meylan, France
email: smckinty@france.sun.com	   BIX: smckinty
From: choy@dvinci.USask.Ca (Henry Choy)
Newsgroups: sci.electronics
Subject: New Disk Standard Question
Date: 27 Jan 1993 16:39:50 GMT
Organization: University of Saskatchewan
NNTP-Posting-Host: dvinci.usask.ca
X-Newsreader: TIN [version 1.1 PL6]

What's the scoop on the new read/write optical disk and digital tape
standards that will soon come to a store near you? How can I get
technical data? Are schematics, manufacturing processes, etc. for
drives, players, and storage media available anywhere.

Would anyone be interested in building a 2-disk, 2-tape machine that
sells from $200? How about building CD upgrade kits? I imagine the
work on improving storage capacity would be fun.



--

Henry Choy
choy@cs.usask.ca

What rolls down stairs alone or in pairs            This has been brought to 
Rolls over your neighbor's dog?                     you by the numbers 4
What's great for a snack and fits on your back?     and 9 and the letter P.
It's Log, Log, Log!  -- "The Log Song", from            -- Big Bird
                         Ren & Stimpy

Math is tough!       -- Barbie
From: Brad.Welch@p978.f70.n109.z1.fidonet.org (Brad Welch)
Sender: Uucp@blkcat.UUCP
Newsgroups: sci.electronics
Subject: Laser Mania: Lasers for sell
Date: Tue, 26 Jan 1993 01:32:42 -0500

Howdy,
I too am a laser buff, but really just getting started. I'm in the middle of
building a power supply for a 5 mw Hene tube. Really hiped up about getting
started in Holography.!! Have you any experience in this field?? If so let me
Know, please. Oh, Bye-the-way ...........Where do those surplus ripoff places
get there stuff from? Or is that close guarded family secret?
Thanx
Brad

Newsgroups: sci.electronics
From: schuch@phx.mcd.mot.com (John Schuch)
Subject: Re: Etchant types
Organization: Motorola Computer Group, Tempe, Az.
Date: Thu, 21 Jan 1993 14:37:49 GMT

In article <1993Jan19.165044.24068@feline.uucp> gray@feline.uucp (Kelly Gray) writes:
>In article <C0vrzx.77p@acsu.buffalo.edu> v064mb9k@ubvmsb.cc.buffalo.edu (NEIL GANDLER) writes:
>>
>>   What are the advantages of Ferric Chloride vs. Ammonium Persulphate.

> You might want to re-think using the immersion heater on the
>persulphate etchant. If it's metal, there's a fair chance that the
>etchant will attack the heater element too!
> 

Use a glass aquarium style heater.

John

-- 
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
| N7XVS - schuch@phx.mcd.mot.com - (602) 438-3008 - CompuServe: 70733.3330 |
+--------------------------------------------------------------------------+
From: sergei@upenn5.hep.upenn.edu (Sergei Borodin)
Newsgroups: sci.electronics
Subject: Re: Wanted: Nicad Charger Plans
Date: 21 Jan 93 17:45:10 GMT
Organization: University of Pennsylvania

In article <1993Jan21.084525.25298@macc.wisc.edu> jvannes@vms.macc.wisc.edu writes:
>In article <1jhvkuINNb8d@flop.ENGR.ORST.EDU>, slezal@gyro.ECE.ORST.EDU (Lee Slezak) writes...

>>I am looking for some plans to build a charger for sub-C size nicad batteries.

>I have a serious Ni-Cad fetish.  I have them in everything I own, flashlights,
>music equipment, etc.  I have a number of simple chargers based on the LM317

  Maxim recently released Max712/Max713 NiCad/NiMH 
  "Battery Fast-Charge Controllers". The ICs provide
  fast charge at rates from C/4 to 4C and C/16 trickle
  charge rate as well. 

  These devices can charge 1 to 16 series cells.
  A voltage-slope detecting ADC, a timer, and a 
  temerature window comparator determine charge 
  completion.

  Nice point #1: ICs require few external components.
  Nice point #2: Available as free samples from
  Maxim (1-800-998-8800).

  Linear Technology also produces fast-charge controllers,
  but unlike generous Maxim, samples are not available for
  universites (I was designing a HV power supply and ran
  across one LT's PS controller, called LT for a sample 
  (actually we needed a hundred of HV PSs, but still I wanted
  to test the IC before starting a production) and got
  an answer that LT's policy is not to deal with universities :(.


  So - stick with Maxim.


 S.B.
From: ballen@convex.csd.uwm.edu (Bruce Allen)
Newsgroups: sci.electronics
Subject: Wanted to purchase: scope probes with 10x display actuator
Date: 25 Jan 1993 16:03:34 GMT
Organization: Computing Services Division, University of Wisconsin - Milwaukee
NNTP-Posting-Host: 129.89.7.30

I have an old (1971) Tektronix 432 dual-trace scope that I've been
fixing up for home use.  This scope has vertical gain controls
whose readings can be changed by the scope probe.  I'm looking for
a couple of good-condition probes, either Tek or another manufacturer,
which have a x1 and x10 switch and incorporate a display actuator
which switches the vertical gain displays appropriately.

The scope is modest bandwidth, about 50Mhz, and 1Mohm input impedance, 
so just about any decent probes should work.  If you've got a pair lying
around, please sell them to me!  You can reach me at 414-229-6439 (work)
or 414-962-0516 (home) - central time zone.  Or email me directly at
work: ballen@dirac.phys.uwm.edu .
	Thanks,
			Bruce Allen

Newsgroups: sci.electronics
From: sorgatz@avatar.tti.com (sorgatz)
Subject: Re: Why no FAQ
Organization: Transaction Technology Inc.
Date: Fri, 22 Jan 1993 23:31:21 GMT

In article <C16Csw.n27@waterloo.hp.com> siim@waterloo.hp.com (Brad Siim) writes:
>I keep seeing the same questions every month?
>
>PCB help
>book recomendations
>PAL help
>power supplies/regulators
>amplifiers
>PC layout package requests
>passive component questions
>equipment questions. What to buy
>protocal and IEEE standards questions
>How to prototype high speed digital/analog
>
>And these are just the ones that have caught my attention.  There are many
>beginner type queries as well. Anybody got the time to administer a FAQ or 10?
>(I'm not sure how its done but I'm sure someone has to volunteer.)
>Many of these FAQ's would be a great source of reference to a full time
>designer and to the hobbiest, but much of the information is lost because
>many of us do not have time/will to re-answer an old question. 
>
>Brad Siim

 Probably because no one is willing to spend the time or disk space to make
an FAQ a reality. Then there is the other very-real problem, that of the new
or non-english speakers that will ALWAYS waste bandwidth to ask the Internet
how to fix their broken TV/VCR/Radio/tape deck/etcetra ad nauseum..I suggest
the creation of a new newsgroup for such requests:

    alt.can-someone-please-help-me-fix-my-appliance


 Because the truth is, even though most of these requests come from people
who work in the "hi-tech" fields, there is no ammount of assistance that will
carry them through when it come to ACTUALLY repairing the device! They will 
fuss and futz with it and finally say "FUCK IT!", trash the bastard and buy`
another anyway. If there was a formal place for the techno-ignorant and the
techno-martyrs to meet we could reduce the volume here to something like 40%
...and I don't want a bunch of sniveling flames from you wannabe teachers, face
it: 99% of the world's populace is unable to draw a crystal set schematic, let
alone actually fix a vcr - even with help. They should RTFM first ANYWAY!


-Avatar-> (aka: Erik K. Sorgatz) KB6LUY           +-------------------------+
TTI(sorgatz@soldev.tti.com)                       *   Think Eco, not EGO!   *
3100 Ocean Park Blvd. Santa Monica, CA  90405     +-------------------------+
(OPINIONS EXPRESSED DO NOT REFLECT THE VIEWS OF CITICORP OR ITS MANAGEMENT!)
From: long@spk.hp.com (Jerry Long)
Newsgroups: sci.electronics
Subject: SAGAMI to RCA X-ref Needed
Date: 27 Jan 93 19:31:24 GMT
Organization: Hewlett-Packard
X-Newsreader: TIN [version 1.1.4 PL6]


 I have in hand a DC to DC converter made by SAGAMI. The
mfgr pt# is 5262081. Does anyone have a cross-ref to RCA or
information relative to this manufacturer??

Any help would be greatly appreciated.


Jerry Long  @spk.hp.com
From: garland@ohstpy.mps.ohio-state.edu
Newsgroups: sci.electronics
Subject: Re: need advice on computer fix
Date: 26 Jan 93 21:21:44 EST
Organization: The Ohio State University, Department of Physics

In article <728068245.14740.0@romulus.mercury.andrew.cmu.edu>, Ken Zuroski <kz08+@andrew.cmu.edu> writes:
> Greetin's:
> 
> I have a Tandy 1400 laptop computer, dual disk drive, backlit LCD screen.
> It's an obsolete beast, maybe 3 or 4 years old, but since I used it mostly
> for word processing it fit my needs perfectly (semi-portable, etc.) 
> Unfortunately the other night my wife spilled water on the LCD display
> and shorted something out; the screen lost several "rows" of LCD's, thus
> making reading your writing kinda difficult, if not impossible.
> 
> Now, I'd rather not buy a new computer right now, but the 1400 seems to
> be discontinued and I'm not sure if I can get it fixed; and, if I could
> get it fixed, I'm not sure I want to pay Radio Shack's fixit prices, since
> basically all they have to do is remove the LCD screen as a unit and plug
> another in (I've had the computer apart already and it's very easy to
> replace. I also made note of the contacts on which several IC's are mounted
> in the exact place where the water was dumped, so I have a good idea what
> shorted out).
> 
> Question: if you were me and wanted to fix this thing, how would you go
> about it cheaply? Should I find someone who knows how to troubleshoot
> the circuitry to find out which IC's are burnt? Should and can I find
> some mailorder place that sells LCD boards that would fit this computer?
> Your suggestions are most welcome.
> 
> Thanks--
> 
> Ken
> 
> ---
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Ken Zuroski
> Department of English
> Carnegie Mellon University
> Pittsburgh, PA 15213 USA
> kz08@cmu.edu

> ~~~~~~~~~~~~~~~~~~~~~~~~~~~
I'm not familiar with the Tandy 1400, but have had this same problem with other
laptops. Often there is a flat flexible cable connecting the LCD display to the
motherboard; the cable resembles a flat strip of mylar, with the parallel
conductors etched onto the strip.  Typically, this strip just pushes into a
mating connector on the motherboard, sometimes held only by the friction of the
contacts. You might try unplugging the flat strip and wiping the ends off with
a lint-free cloth and reinserting it into the connector.  I doubt that your
problems are caused by an electrical failure of a component; the problem is
more likely an intermittent or bad contact.
From: rubin@cis.ohio-state.edu (Daniel J Rubin)
Newsgroups: sci.electronics
Subject: Re: Pyrotechnics
Date: 23 Jan 1993 16:32:01 -0500
Organization: The Ohio State University Dept. of Computer and Info. Science
NNTP-Posting-Host: zion.cis.ohio-state.edu

>I am looking for some info on how to design a computerized firing  
>sequence.  Any sort of direction to find info would be just as helpful,  
>such as books, magazines or if anyone has designed one of their own.  

With an IBM-compatible it would be realitivly easy.  There are cards out there
that let you control electronic switches from software.  I remeber seeing one
from JDR Microdevices that had about 24 channels, if I can remember correctly.
The Macintosh is a different story.  I have yet to see some kind of a 
peripheral device for the Mac that lets you control external things. If anyone
know of something like this please fill me in.

If you want several rapid sequences of pyrotechnic devices, I would suggest
you use one channel for each sequence and a 555 timer/decade counter/power
transistor or relay array circuit close to the devices.  When the main
switch is thrown by the computer software the 555 cycles the decade counter
and the squibs, another term for ignitors.  Having this device close to the 
pyrotechincs will save you a lot of wire and you can use a smaller gauge
because the battery can be close also.  You would only need one set of wires
from the "control site" to the shooting area for each sequence. Small guage
would do fine here because all you are doing is letting the 555 know that it 
is time to start counting with this pair.  From the 555/decade device the 
power transistors will feed current to the squibs through larger gauge wire.
It would also be easy to control the speed of the sequence with the 555.

You may want to ask the guru's that read rec.pyrotechins about this.  A lot of
them shoot display's part time and know a lot about using squibs, electronic
ignition etc...

later                                                              - Dan

-- 

             Daniel Joseph Rubin     rubin@cis.ohio-state.edu 
     
                       GO BENGALS!      GO BUCKS!
Newsgroups: sci.electronics
From: schumach@convex.com (Richard A. Schumacher)
Subject: Re: DC to AC on large scale???
Organization: CONVEX Computer Corporation, Richardson, Tx., USA
Date: Tue, 26 Jan 1993 00:44:45 GMT
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <1k0rksINNc34@rave.larc.nasa.gov> kludge@grissom.larc.nasa.gov (Scott Dorsey) writes:


>Actually, motor generator sets were pretty common up until about ten years
>ago when efficient silicon stuff became available.  You even see AC-DC

Sure, but the original question was about regional power distribution.
Did anyone ever use MG sets to convert AC to DC to feed more than a
few city blocks?

Newsgroups: sci.electronics
From: ctdonath@mothra.syr.EDU (Carl T. Donath)
Subject: Re: Recording sound on chip
In-reply-to: sivaram@hplabsz.hpl.hp.com's message of Mon, 25 Jan 1993 21:40:46 GMT
Organization: Syracuse University
Date: Tue, 26 Jan 93 23:28:15 EST

In article <1993Jan25.214046.9622@hplabsz.hpl.hp.com> sivaram@hplabsz.hpl.hp.com (S. Sivaramakrishnan) writes:

   I am looking for a cheap method to record and playback about 15 seconds of
   sound on a chip.

See the ISD 1000A Family, available from Hamilton/Avnet (1-800-677-0769).

To summarize the ad:

The 1000A Family provides _single_chip_ solution for
	- record, store, play back up to 20 seconds of audio
	- "To build a complete record/playback system, you simply add
	   a microphone, a speaker, several passives and a battery."
	- Contains mic preamp, anti-aliasing, automatic gain control, 
	  smooting filter, power amp, control logic & storage.
	- NON-VOLATLE! uses CMOS EEPROM (no battery backup needed).

No price given. (Of course.)
--
    ___________________________________________
 __/ ctdonath@rodan.acs.syr.edu  Carl T Donath \____
/ The government is not your mother. Do it yourself. \
Newsgroups: sci.electronics
From: rusty@anasazi.com (Rusty Carruth)
Subject: Re: Heat gun pcb cannabalization
Organization: Anasazi, Inc.  Phoenix, Arizona USA
Date: Mon, 25 Jan 1993 21:18:10 GMT

In article <74011@cup.portal.com> Ted_Eugene_Viens@cup.portal.com writes:
>>
>A local surplus parts house desolders complete boards by heating them is a
>skillet with a shallow layer of oil until the solder melts, taking the board
>out and slamming it down upside down to knock out the components en masse.
>If I was going to do this, I would by a table-top electric thermostatically
>controlled skillet and use some synthetic motor oil.  Put enough oil in the
>skillet to reach the bottom of the board, set it to 450 degrees and desolder
>your buns off...

(Well, I *personally* don't want my buns soldered off, thank you very much! ;-)

Hmm.  Synthetic motor oil, eh?  That might have been better than what
we did - we used cooking oil because of not wanting the (assumed) noxious 
fumes we expected from motor oil.  The main problem with cooking oil was
that it has a very short "hot enough but not so hot to burn" range - you
have to keep it almost smoking but not quite....

I would also think, now that I pause to think about what we were doing
(yeah, pausing to think about 10 years after the deed is done!), is
that the solder pot would have been a MUCH safer way to go about it -
you could clamp the solder pot down, you don't have to diddle with
the stupid pan edges (I remember wearing my leather motorcycle gloves
in order to be able to handle the boards - don't try this at home,
kids!), stuff like that.  I don't remember if we tried to heat only
the board or if we stuck the entire assembly under the oil - I think
the former, and I vaguely recall it was NOT a simple matter to get
enough oil in the pan (NOT exactly the flattest surface around)
to cover the pins in the middle AND the edges...

>I would like to here back from anyone who tries this...
>Bye...  Ted..

Rusty@anasazi.com
-- 
73 de Rusty Carruth, N7IKQ   P.O. Box 27001, Tempe, AZ 85285
      (602) 870-3330         !'s:{ames!ncar!noao!asuvax,mcdphx}!anasaz!rusty
@'s: rusty@anasazi.com       LastResort: rusty%anasaz.UUCP@asuvax.eas.asu.edu
Join the Usenet Un-Net:      1700-1900Z  Saturdays, 28.410 or 28.390 MHz
From: fitzpa@eeel.nist.gov (Gerry FitzPatrick)
Newsgroups: sci.electronics
Subject: Digital Filtering
Summary: how to digital filter ???
Keywords: Digital Filter software
Date: 21 Jan 93 22:34:06 GMT

I need to design a digital filter (either a notch filter or
a low-pass filter).  I will be analyzing data taken from a 
lecroy 7200 scope (in either ascii or binary).  I would like
I would like to look at the 60  Hz component of the waveform.

Any ideas on how to write a subroutine that would perform this
digital filtering on stored data?  Any good books on designing
digital filters?

Thanks,


Eric D. Simmon

simmon@eeel.nist.gov
Newsgroups: sci.electronics
From: gary@mario.inmos.co.uk (Gary Morton)
Subject: Re: what is exactly the TEA1002
Reply-To: gary@inmos.co.uk (Gary Morton)
Organization: INMOS Limited, Bristol, UK.
Date: Fri, 22 Jan 1993 09:40:03 GMT

In article <1993Jan18.150944.3677@cfmu.eurocontrol.be> chris@cfmu.eurocontrol.be (Christophe Paquay) writes:
>
>       I know that the TEA1002 is a PAL encoder but I need more
>    information about it, and I can't find it in my data books.
>    If somebody knows this TEA1002 or has information about it
>    I will appreciate to receive them. 
>
>       What's the pinout, for what is it design, ... ?
>
>       In fact I'm looking for components that can help me to
>     build a converter from RGB video to PAL.
>
I don't know about the TEA1002, but Maplin Electronics in the UK sell the
TEA2000 which appears to do a similar job. It can convert a 6 bit binary
TTL compatible input (providing 64 different colours) into either a PAL
or a NTSC compatible signal. A constructional article using this chip appeared
in the Dec 88/Jan 89 issue of 'Electronics - The Maplin Magazine' (Vol. 8,
no. 29). Maplin sell a PCB and kit for this project. Alternatively they sell
all the parts individually. I don't know whether the TEA1002 has digital or
analogue inputs, so it may not be quite the same. If you are interested in
further details, please email me.

-- Gary
+---------------------------( Gary Morton )-----------------------------+
|Disclaimer: The opinions above are my own personal views etc.          |
|Inmos Ltd, 1000 Aztec West, Bristol, UK         Email : gary@inmos.com |
+-----------------------( +44 454 616616 X526 )-------------------------+
Newsgroups: sci.electronics
From: wrb@cbnews.cb.att.com (wallace.r.blackburn)
Subject: Re: Where do I get a Maxim Max 232 CPE chip?
Organization: AT&T
Distribution: usa
Date: Fri, 22 Jan 1993 17:58:54 GMT

In article <1993Jan22.114641.24921@mr.med.ge.com> szopinsk@picard.med.ge.com (Jerry Szopinski Mfg 4-6983) writes:
>Terry L. Cary (TLC112@psuvm.psu.edu) wrote:
>: 
>: New at this game, outside of the local electronic repair shop and radio shack,
>: I have no idea where to look...  I'm tying to build a RS 422 converter for the
>: Casio SF-8000 to a Macintosh.  Suggestions anyone?
>
>
>
>Terry-
>
>Try your local Hallmark (no, not the card people), Hamilton-Avnet or Newark Distributors.
>They should be listed on your local Buisness Yellow Pages.  I would try Hallmark first,
>I've gotten MAXIM products through them before.
>
>
>Jerry
>

B.G. Micro has the MAX232CPE for $2.30.  Best price I've found.
214-271-5546.  Visa/MC.

I have no connection with 'em.



|*******************************|
| Wally Blackburn		|
| AT&T NSD			|
| wrb@ccsitn.att.com		|
| Amateur Radio Station AA8DX	|
| 614-575-6604			|
|*******************************|
From: keithl@klic.rain.com (Keith Lofstrom)
Newsgroups: sci.electronics
Subject: Re: Hard Disks: Toss them out when they break?
Date: 27 Jan 93 03:45:18 GMT
Article-I.D.: klic.1993Jan27.034518.11046
Organization: Keith Lofstrom Integrated Circuits

In article <15642.2b625d73@ohstpy.mps.ohio-state.edu> garland@ohstpy.mps.ohio-state.edu writes:
>
>The hard disks tend to last about three years before they start to go bad.
>Historically, we've just tossed them out and replaced them. We've not bothered
>with doing a low-level format or otherwise trying to restore them to health,
>the rationale being that the replacement costs are low and extracting another
>six months or so of life isn't worth the bother. 
>
>I'd like to know if this is a sensible policy? What actually goes bad in the
>drive? 

I've worked on about a dozen hard drives.  The failures seem to be:

1)  An extra defect appears.  Shit happens.  Reformatting works fine.

2)  Something major goes wrong in the HDA (the sealed part), like a head
    crash.  Send it out for repair, or save everything that comes loose
    and discard the HDA.  Often caused by mechanical mishandling.

3)  Something goes wrong with the power drive electronics for the motor or
    stepper.  Swap in a board you saved from another drive with a dead HDA.
    Often caused by inadequate ventilation, dust, or power supply failure.

4)  Other.  Blown interfaces from mis-installation.  CDC Wrens have problems
    with bad spindle position sensors - this is a fixable HDA problem.  Bad
    inner or outer tracks - if you are desparate, you can sometimes reformat
    the drive smaller.

In any case, don't throw the drives away.  Reformat them if you can.  If
they don't work after reformatting, sell them to a surplus shop.  Others
can use the parts.



-- 
Keith Lofstrom         keithl@klic.rain.com       Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Power ICs
Newsgroups: sci.electronics
From: bd@cck.coventry.ac.uk (Number 6)
Subject: help !
Organization: Coventry University
Date: Thu, 28 Jan 1993 12:59:01 GMT

From coventry!bd Thu Jan 28 12:53:02 WET 1993


I would need a quartz crystal oscillating at 17.300 Mhz, in order to 
tune a frequency in a satellite receiver.

Any idea what I could replace a crystal by (LC circuit ?), considering
I can't find such a crystal anywhere.

Is there a simple way to make it tunable?

thanks.

   ben.
-- 
---------------------------------------------------------------------------
-bd@uk.ac.cov.cck-                                      ...Be seeing you...
---------------------------------------------------------------------------