HDTenEightyP/NetNews huggingface dataset:
From: billq@ms.uky.edu (Billy Quinn)
Subject: A Question about RAM sizes.
Keywords: RAM,data bus
Date: Mon, 12 Oct 1992 16:36:58 GMT
Organization: University Of Kentucky, Dept. of Math Sciences

	I am not sure if I understand the way RAM's are catagorized in my
electronics catalogs.  When a RAM chip is defined as 16K x 1, does that
mean that it has 1 bit data bus?  If so, then a 2K x 8 chip would
hold the same amount of data (bits) as a 16K x 1 chip, but would only be 
able to address one *BYTE* at a time, while the 16K x 1 chip would be able 
to address 1 *BIT* at a time.  Let me know if I am thinking of RAM    
sizes the correct way.
-- 
*-----------------------------------------------------------------------*
*	Bill Quinn			billq@ms.uky.edu		*
*-----------------------------------------------------------------------*
Newsgroups: sci.electronics
From: klimasewski@fccvde.enet.dec.com (My name is...)
Subject: Sat receiver problem,vert. roll
Organization: Digital Equipment Corporation
Date:  7 OCT 92 07:45:26    

I have a Chapperal Serria II satellite receiver that as a slight vertical
jitter on non-scrambled channels. It also has a rapid vertical roll with 
some distortion to the color and waviness to the picture when fed a signal
into the video input of the receiver.

One Tech at Chapperal told me to change every coupling cap from the dectector
chip to the rf modulator. Another tech told me to look at the sync board.

Has anyone had this problem with this model receiver that could give me a 
better clue?
                                     Ken
From: markr@hpwala.wal.hp.com (Mark Ramberg)
Newsgroups: sci.electronics
Subject: Inverters for Fluorescents
Date: 13 Oct 92 20:29:15 GMT
Reply-To: markr@hpwala.wal.hp.com (Mark Ramberg)
Organization: Hewlett-Packard Waltham Division

I am currently designing a low voltage DC lighting system to run off a wind
generator. I would like to use regular fluorescent bulbs, so I have been
researching electronic ballasts.

the conclusions so far are: run the bulbs between 20KHz and 25KHz for best
effeciency, voltage across the bulb is around 90V AC, and fluorescent bulbs
exhibit a negative impedence.

My question is: does anyone have any information about the design of 12 volt
DC in to 110 volt high frequency AC out electronic ballasts.
Simple inverter circuits work
poorly due to the impedence characteristics of the lamps (I've experimented).
I have built up a simple single transistor "ringing choke" type inverter that
works well but is running around 60% effecient. The literature suggests that
designs exists that can reach 85 -90 % efficiency but do not elaborate on
design topologies. I'm looking for any info, from schematics to design
descriptions. Any help would be appreciated. This is a G-job and my time for
experimentation is limited.
From: covingc@ee.tamu.edu (Mouse)
Newsgroups: sci.electronics
Subject: Re: DC rail capacitors
Date: 16 Oct 92 16:13:57 GMT
Article-I.D.: tamsun.1992Oct16.161357.8139
Organization: Texas A&M University

In article <1992Oct16.061636.692@ryn.mro4.dec.com> paulman@hkmeg1.enet.dec.com (Paul Man) writes:
>
>When I look at some circuit schematics,  I frequently notice that
>a pair of capacitors are being connected to the DC rail.  One cap
>is always at least 100 times greater than the other, say 10uF and
>100nF.  I guess the cap with smaller value is to prevent the power
>supply from being loaded down by the AC current, but what is the
>purpose of the other one?  Any general purpose?  
>
>---
>Paul P. Man                      Internet: paulman@hkmeg1.enet.dec.com
>Digital Equipment Corporation    UUCP:  ...!decwrl!hkmeg1.enet.dec.com!paulman
>---
The large capacitor (probably electrolytic) is for filtering low frequency
noise - the small one (a capacitor with good high-frequency performance) for
eliminating high frequency noise.

Eric Covingcton
covingc@ee.tamu.edu
From: pierson@cimcad.enet.dec.com (Dave Pierson)
Newsgroups: sci.electronics
Subject: Re: fluoresent lighting
Date: 11 Oct 92 18:40:43 GMT
Organization: Digital Equipment Corporation

>In article <718623068.4@mailbox.bison.mb>, Jason.Goga@mailbox.bison.mb.ca
>(Jason Goga) writes: 
	(inquiring about DC and fluorescent lamps)
	The lamps are quite happy on DC, except....  With all the currrent flow 
	in one direction, the eletrodes "wear out" more quickly at one end.
	Also, the tube "blackens" assymetrically.

	Additionally, the easiest way to do the current limiting on DC is with a
	reistor, which is more lossy than the ballast used (inductor) usable
	with AC operation.


thanks
dave pierson			|the facts, as accurately as i can manage,
Digital Equipment Corporation	|the opinions, my own.
146 Main St			|I am the NRA.
Maynard, Mass		01754	pierson@msd27.enet.dec.com
"He has read everything, and, to his credit, written nothing."  A J Raffles
From: pauls@trsvax.tandy.com
Date: 06 Oct 92 10:02 CDT
Newsgroups: sci.electronics
Subject: Re: signal generator CD
Message-ID: <288200014@trsvax>
Nf-ID: #R:alsys1.aecom.yu.edu:1193:trsvax:288200014:000:588
Nf-From: trsvax.tandy.com!pauls    Oct  6 10:02:00 1992


There are several, depending on the quality.

1. For #1 top quality, you cant beat the A-BEX TCD-781. This is the
world-wide test CD for digital audio. Rather expensive, around $150.

2. For non-critical applications, there are a whole ton of them. Some are
the Sony Test CD, the CBS CDs, and the Prosonus SRD. The Prosonus has alot
of good stuff, but BEWARE!! It it NOT accurate in terms of level, and it
has rather high THD (in fact, I thought it was defective at first).

3. Stereophile magazine has one that was real cheap, like $10. Can't
comment on the quality.

Hope this helps.
From: pbaleme@joule.elee.calpoly.edu (Paul Baleme)
Newsgroups: sci.electronics
Subject: PSpice for Windows
Date: 16 Oct 92 05:12:56 GMT
Organization: California Polytechnic State University, San Luis Obispo


  I recently started using MicroSim (Pspice for Windows) and was wondering
if anyone knew of a program that would convert the .cir files from
PSpice to Spice3 format.  We have a few DEC 5000's at school and would
like to run some of my longer analysis on the DEC's while I continue
working with MicroSim.  

  Also, does anyone know of an e-mail address for a customer rep at
MicroSim?  I have a physical address for them but I'd rather use e-mail.
thanx.  pbaleme@joule.calpoly.edu
From: zzang@stat.ufl.edu (zzang)
Newsgroups: sci.electronics
Subject: HELP! op-amp problem
Date: 8 Oct 92 16:04:44 GMT
Article-I.D.: eng.1992Oct8.160444.15278
Distribution: usa
Organization: University of Florida
Originator: zzang@manta

Hello,
I have a hard time in analyzing op-amp circuit.
I recently come across an exercise in a book.
the following is from the spice program I use to
solve my problems.(but, sure it doesn't :-{)

Simple Circuit Analysis
*
*                     
*               +-----www----+     
*  V            |    -       |         +------||-------+ 
*  o----www-----+----|\ 6    |         |    -          |
*  1            2    |  >----+---www---+----|\ 7       |
*                   0|/ 0    3         4    |  >-------+-----o y(t)
*                                          0|/ 0       |5
*                                                     www
*                                                      |
*                                                      x
* all resistances are equal to R, the capacitance is C, and R*C=1
* 0 means ground
the question is when you connect node x to the node 2,
what is the voltage output y(t) ?
the answer in the book is y'(t)= -y(t) + V
but my solution is y'(t)= y(t) + V

here is how my solution comes out:
we consider the voltage at the node 3 V(3)
and assume the op-amp is ideal, so the inverting voltages
V(2) and V(4) are 0.
1. look to the right
V(3)/R = -Cy'(t)
2. look to the left
V/R + y(t)/R = -V(3)/R
combine 1. and 2., we have y'(t) = y(t) + V

my 2nd question is what the y(t) will be if we connect x to 4 ?
following the above argument, I got y'(t) = -y(t) + V
but if the op-amp are ideal, node 2 and 4 are considered grounded,
why these two connections come out different solutions?

could someone give me some helps on this?

Thanks in advance!
.WIDTH OUT=80
.TEMP 35
R1 1 2 5K
R2 2 3 5K
R3 3 4 5K
R4 5 4 5K
C1 4 5 0.0002F
X1 0 2 0 6 3 LM324
X2 0 4 0 7 15 LM324
V1 1 0 DC .006
.PRINT DC V(3)
.LIB EVAL.LIB
.END

-- 
Zhuo Zang[~{j0WA~}]
Department of Statistics
University of Florida            Email: zzang@stat.ufl.edu
From: dplatt@ntg.com (Dave Platt)
Newsgroups: sci.electronics
Subject: Re: C Cross Complier for 68HC11
Date: 14 Oct 92 17:01:49 GMT
Organization: New Technologies Group, Inc.  Palo Alto CA

>P S.  I've always wondered if they had a way to use GNU's
>gcc as a cross compiler for embedded systems

Try calling the folks at Cygnus Support (the people who provide
commercial-grade support for GNU tools, at a reasonable price) at 
+1 415 322 3811.  When I spoke with Rob Savoye at the Embedded Systems
Conference a few weeks ago, I mentioned that I'd love to see gcc for the
8051 family;  he replied that a lot of the work needed to put gcc on
smaller-than-32-bit machines had already been done as part of another
project, and that it probably wouldn't be too hard to retarget the
compiler to produce code for embedded controllers.  All it'd take is
money, from some customer who wanted to pay Cygnus to finish the port.

-- 
Dave Platt                                                VOICE: (415) 813-8917
              Domain: dplatt@ntg.com      UUCP: ...netcomsv!ntg!dplatt
 USNAIL: New Technologies Group Inc. 2468 Embarcardero Way, Palo Alto CA 94303
From: paulman@hkmeg1.enet.dec.com (Paul Man)
Newsgroups: sci.electronics
Subject: DC rail capacitors
Date: 16 Oct 92 18:01:47 GMT
Organization: Digital Equipment Corporation


When I look at some circuit schematics,  I frequently notice that
a pair of capacitors are being connected to the DC rail.  One cap
is always at least 100 times greater than the other, say 10uF and
100nF.  I guess the cap with smaller value is to prevent the power
supply from being loaded down by the AC current, but what is the
purpose of the other one?  Any general purpose?  

---
Paul P. Man                      Internet: paulman@hkmeg1.enet.dec.com
Digital Equipment Corporation    UUCP:  ...!decwrl!hkmeg1.enet.dec.com!paulman
---
From: etxansk@garbo.ericsson.se
Newsgroups: sci.electronics
Subject: 65816 Description
Date: 16 Oct 92 10:50:10 GMT
Distribution: sci
Organization: Ericsson
Originator: etxansk@garbod20


 I need to know if there are good books on the 65816 CPU (hardware and
assembler specs including a machine instruction code listing). 

 This CPU is used in the Super Nintendo (SNES) video game system, and
I think I've heard it's used in the (by now) old Apple IIGS computer.

 Thanks in advance,
 Anders Skelander
Newsgroups: sci.electronics
From: Hans Ridder <ridder@zso.dec.com>
Subject: Re: Thunderstorms
Originator: ridder@zowie.zso.dec.com
Organization: Digital Equipment Corporation - DECwest Engineering
Date: Thu, 8 Oct 1992 01:03:03 GMT

In article <1687984FF.FC138001@ysub.ysu.edu> FC138001@ysub.ysu.edu (Phil Munro) writes:
>  We've seen lots of theory, but only a few experiences, of lightning
>doing damage to computer equipment.  Would anyone have some details
>about damage done to equipment?  This might give us a better idea of
>how much of a problem lightning actually is, direct hits, EMP, etc.

On the other side of the coin, I lived until recently in Colorado
Springs, Colorado for 8 years.  This is one of the lightning capitols of
the world.  (I heard a legend that Tesla built his lab there for this
reason!)  Several people get hit by lightning there each year.

People there always talked about how they scrambled all over the house
unplugging stuff at the first kaboom.  I *never* unplugged any
computers, modems, TV's, stereo equipment, or telephones for any
oncoming lightning storm.  Had some close hits too.  When the hair on
the back of your neck stands up, followed closely by the simultaneous
flash and boom, it's pretty close.  The only fatality was a Telco
lightning protector -- doing its job.

I don't recommend that you try this at home, but that's how it worked
for me.

>  FC138001@ysub.ysu.edu  Phil Munro       Youngstown State University

-hans
-- 
  Hans-Gabriel Ridder				Digital DECwest Engineering
  ridder@rust.zso.dec.com			Bellevue, Washington, USA
  {pacbell,pyramid,uunet}!rust.zso.dec.com!ridder
From: bob@kc2wz.bubble.org (Bob Billson)
Newsgroups: sci.electronics
Subject: solar/wind power mail list?
Summary: mail list devoted to these topics?
Keywords: solar wind power
Date: 13 Oct 92 08:01:00 GMT
Distribution: na
Organization: Color Computer 3: Tandy's 'game' machine

Are there any mail lists devoted to the topics of solar and/or wind power
generation?  I am aware of the electric vehicle mail list; however, I am
looking for something more along the line of power for homes.  Any pointers
will be welcome.

ADVthanksANCE.

     Bob
-- 
  Bob Billson, KC2WZ                          | internet: bob@kc2wz.bubble.org
  $nail:  21 Bates Way,  Westfield, NJ 07090  | uucp:     ...!uunet!kc2wz!bob

  "Professional ear piercing--while you wait!"  --sign in local jewelry store
From: pi@sharon.isi.edu (Jen-I Pi)
Newsgroups: sci.electronics
Subject: Re: Dolby Surround
Date: 13 Oct 92 08:19:43 GMT
Distribution: world
Organization: MOSIS Project, USC/ISI

In article <1992Oct12.012501.167@tplrd.tpl.oz.au>, derbyc@tplrd.tpl.oz.au (Derby Chang) writes:
|> Hi all,
|> 
|> Does anyone have an idea how they encode multiple tracks on two stereo
|> tracks using Dolby Surround Sound encoding (Pro-Logic or otherwise)?

If I remember it right, the Pro-Logic scheme for encoding the audio
signals onto two stereo tarcks is

 (1) *Left* and *Right* are recorded directly onto the L & R channels
     respectively.
 (2) *Center* is recorded 3db down and added in-phase in both left and
     right channels.
 (3) *Surround* is recorded 3db down and phase shifted by -90 degree
     for the left channel and +90 degree for the right channel.

Regards,

Jen-I pi@lepton.isi.edu :-)
From: dhi00@ccc.amdahl.com (mofo )
Newsgroups: sci.electronics
Subject: Re: 25 ohm coax cable
Date: 12 Oct 92 17:56:55 GMT
Reply-To: dhi00@juts.ccc.amdahl.com (mofo )
Organization: Amdahl Corporation, Sunnyvale CA

regarding the following figure:


                50 ohm
           =============
25 ohm  //               \\   25 ohm
========  A             B  ============
        \\               //            |
          ===============             ---
              50 ohm                  | |
                                      | | 25 ohm
                                      | |
                                      ---
                                       |
                                      GND


i think this is what you have when you launch a wave down the
coax:

a signal of voltage v and current i travels down the first
length of coax.  it encounters the 25 ohm 'T' splice and sends
a signal of voltage v and current i/2 down each branch with
no reflection.  

if the two branchs are equal in length, the signals travel
and meet at splice B.  this gets a little tricky.  a wave front
traveling along the south branch would approach splice B and
see an approx. 17 ohm impedance (50 and 25 in parallel).  the
reflection generated from a 50 to 17 ohm mismatch is about 
1/2 the incident wave so at the splice, the signal is reflected
back down the south branch with voltage 1/2 v.  as it happens,
the other branch has provided a boost of 1/2 v as well at precisely
the same time and therefore a signal of v is created at splice
point B (works the same from either branch).


that boost is because of the mismatch, i.e., half of the signal was
reflected, half transmitted.  the reflected signal is exactly cancelled
by the other branchs transmitted signal.  at splice B, your left with
the newly created copy of the signal which is free to travel down
the 25 ohm coax in its original form (+/- capacitive/inductive effects
due to bad solder job.

d
From: v064mb9k@ubvmsb.cc.buffalo.edu (NONE)
Newsgroups: sci.electronics
Subject: Need customer service # for sherwood
Date: 16 Oct 92 03:06:00 GMT
Article-I.D.: acsu.Bw71yv.1y3
Organization: University at Buffalo
News-Software: VAX/VMS VNEWS 1.41



 I need a replacement motor for an old cassette deck manufactured
by sherwood. Does anyone know a telephone # in which I can get
in contact with? Any help will be greatly appreciated.
From: george@gill.micro.umn.edu (Rogers George)
Newsgroups: sci.electronics
Subject: audio mixer plans wanted
Summary: wanted plans mixer audio
Keywords: president Clinton
Date: 16 Oct 92 01:17:05 GMT
Reply-To: geor0007@student.tc.umn.edu
Distribution: usa
Organization: University of Minnesota CIS


I am doing sound for a friend's band on a semi-regular basis, and
the mixer their regular gig provides is of, mmm, marginal quality.
So, I proposed to them that I try to build us one, and I am
curious to know if anybody knows of plans for a good, clean, DURABLE
mic/line audio mixer, for live use with a separate power amp. I have
poked through back issues of R-E and popular electronics, to little
(not entirely no) avail, and all the plans I see in my books are
a bit primitive (read: circa 1970's.) Ideal features would be:
switchable stereo/mono operation
2+ fx or tape loops
monitor out
meters on each channel
and clean enough to be used, in a pinch, for recording.

is there an FTP site with bunches o' plans I could peruse?
is there a good book I don't know about that has all my answers?
is there a good-natured EE in the Mpls/StPaul area who tosses this sort
of thing together in their sleep?

Vielen Dank for any help or hints.

(the band is a nifty techno-pop trio.. guitar, bass, singer,
an Amiga and a wall o' keyboards. /Cafe Fnord/.. if you're around
the Twin Cities, look for them.)

Rogers George
geor0007@student.tc.umn.edu
Newsgroups: sci.electronics
From: frank@rover.uchicago.edu (Frank - Hardware Hacker - Borger)
Subject: Re: Thunderstorms
News-Software: VAX/VMS VNEWS 1.41    
Reply-To: frank@rover.uchicago.edu
Organization: Joint Center for Radiation Therapy
Date: Wed, 7 Oct 1992 23:30:00 GMT

>   We've seen lots of theory, but only a few experiences, of lightning
> doing damage to computer equipment.  Would anyone have some details
> about damage done to equipment?  This might give us a better idea of
> how much of a problem lightning actually is, direct hits, EMP, etc.

	Several years ago lightning hit the top of Main Reese, about
	200 feet away from the computer system we were using. It hit
	hard enough to break loose a several-hundred pound piece of
	masonry coping, which fell 8 stories and landed on the chief
	of police's car, (personal,) totalling same.

	Most of the 32 terminals on our PDP11/45 saw a couple of spurious
	characters, but other than that, the only permanent damage was to
	our egos. (Man, that boom was LOUUUUUD, and scared the xxx out of us.)

   Frank R. Borger - Physicist    __       Internet:  Frank@rover.uchicago.edu
Michael Reese - Univ. of Chicago |___      Phone : 312-791-8075 fax : 567-7455
  Center for Radiation Therapy   | |_) _   
                                   | \|_)  Water, taken in moderation, cannot
    "Birthplace of Softball"          |_)  hurt anyone. - Mark Twain
From: ah335@cleveland.Freenet.Edu (Richard Banks)
Newsgroups: sci.electronics
Subject: RFI/EMI shielding of a plastic box
Date: 9 Oct 92 13:38:55 GMT
Reply-To: ah335@cleveland.Freenet.Edu (Richard Banks)



a
I have a plastic housing to put my circuit into but I'm worried about
RFI interference.  I am going to try using aluminum foil, my question is
how many layers do I need.  I know just one will not work.  I remember
from chemistry I when rutherford discovered electrons they passed
right through one layer of aluminum foil, or was that gold foil?
At any rate could someone give me a good idea of how many layers to
use to line the box with.   Thanks.  Richard Banks
Newsgroups: sci.electronics
From: tchannon@black.demon.co.uk (Tim Channon)
ReplyTo: tchannon@black.demon.co.uk
Subject: Re: HC/CO sensor?
Distribution: world
X-Mailer: cppnews $Revision: 1.18 $
Organization: null
Date: Sun, 4 Oct 1992 00:13:27 +0000

> would give an accurate reading of CO/HC levels in automobile
> exhaust.  Does anyone know of a source for such sensors that are able
> to accurately measure CO/HC levels or alternatively what sensor 
> technology is used in commercial emissions inspection machines?
> 

Many use Infra Red absorbsion and I don't think it is a good candidate for 
DIY. A stable means of detecting suitable IR after the signal has been 
filtered (good luck sourcing the filter material) is not easy. Then there is 
the significant mechnical engineering aspect including eliminating 
condensation of water inside the chamber.

An old technique is to use two chambers one air, one ex. gas. A chopper wheel 
and IR. optical system can then provided a relative signal which allows most 
drift errors to be processed out. (sometimes four signals or more -- air, 
air HC lines, air CO lines, exgas, exgas HC lines, exgas CO lines)

How would you calibrate it? (I used to use reference gas which came in a 5ft 
cylinder at some cost)

Using these systems makes jobs like tuning (non cat.) engines with 3+ carbs 
easy as opposed to damn near impossible. A portable gauge allows diagnoses of 
a variety of faults if a chassis dynamometer is unavailable.

Now a question from me. Can Nox be measured using IR?

  TC. 
    E-mail: tchannon@black.demon.co.uk or tchannon@cix.compulink.co.uk
Organization: Penn State University
Date: Wed, 7 Oct 1992 19:37:28 EDT
From: <DMH132@psuvm.psu.edu>
Newsgroups: sci.electronics
Subject: cd player

     My friend has a sony stero with a cd player (one piece). It seems to have
a very strange problem. It seems to just stop playing then start again.  The di
sk keeps spinning. Sometimes when it does this it starts the cd over again.
Could this be some sort of extended skipping?  Thanks for any and all help you
can provide.
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Newsgroups: sci.electronics
Subject: Overgrown software; was: Re: Bad customer relations; was: Re: archive server for pa
Date: 8 Oct 92 20:32:55 GMT
Organization: AI Programs, University of Georgia, Athens

In article <Bc4asB5w165w@toz.buffalo.ny.us> cyberman@toz.buffalo.ny.us (Cyberman) writes:
>mcovingt@aisun3.ai.uga.edu (Michael Covington) writes:
>
>> It's been done before.  Remember a little software company 
>called Borland
>>
>Oh yeah the poeple who made a full blown pascal compilor that 
>was only 64k! :)
>
>Cyberman - they do need to SHRINK thier products though  

YES! YES! YES!  I can't install their latest Pascal compiler until I get
a new hard disk.  But I keep Turbo Pascal 3.0 around and run it from a
diskette on my laptop.

There is a REAL NEED for SMALL software that has the RIGHT features,
rather than trying to put in everything but the kitchen sink.
Yes, there's a market for big development systems too, but it's not
the ONLY software market that exists!


-- 
:- Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
:- Artificial Intelligence Programs       phone 706 542-0359
:- The University of Georgia                fax 706 542-0349
:- Athens, Georgia 30602 U.S.A.          amateur radio N4TMI
From: grove@tension.UUCP (SYSOP HIGH-TENSION)
Newsgroups: sci.electronics
Subject: Looking for (e(e))prom programmer info
Date: 8 Oct 92 07:44:10 EST
Organization: High Tension BBS

Hi!

I'm looking for Names and Addresses of companies that build programmers.

Currently I am using eeproms, but may switch to other varieties, and would like
to have a programmer that will handle many types of 'proms'.

I would like to use a PC->programmer type setup, so robust sw for the PC (Ibm)
is a major concern.

Any help greatly appreciated!

                             thanks


-----  -----  -----  -----  -----  -----  -----  -----  -----  -----  -----
                                                               
                             High Tension BBS                 /  
                             uunet!tension!grove            \/