HDTenEightyP/NetNews huggingface dataset:
Organization: The Pennylvania State University
Date: Sun, 15 Nov 1992 13:12:33 EST
From: Ernie Oporto <EAO102@psuvm.psu.edu>
Newsgroups: sci.electronics
Subject: Need help with 256K x 1 bit DRAMs

I have 8 256K x 1 bit DRAMs that I'd like to use for memory in a project.
      The data will be an 8-bit digital representation of a voice signal.
      I don't have spec sheets for these chips, and I can't begin to imagine
      where to look for them.  They are commonly used in Commodore 64 and 128
      Ram Expansion Units, and I've heard that they're also used in older
      286 machines.  What I need is a brief description of the pins and
      timing.  Here is the info I have so far:

The chip looks like this:

              _16_15_14_13_12_11_10__9_
             |        9005 B USA      |\        On a couple of the chips,
             |                        | |       the 9005 is an 8936 instead,
             |      *MT   1259-12     | |       but the rest is the same.
             |________________________| |
              \________________________\|
                1  2  3  4  5  6  7  8

Pin 8 is +5V, pin 16 is GND, and pins 1,3-7,9-13,15-16 are common to all the
      chips in one bank of a Commodore Ram Expansio Unit.  I suspect that
      pin 14 is some sort of column select, and pin 2 may be the data line.
      The remaining pins must make up a WR line, 8 1/2-address lines, and
      an RAS line.  Since they are delicate chips, I am reluctant to
      hook them up to find out what the lines do.  I think they may be 41256
      chips, bit I'm not sure.

      I plan on connecting the chips to some sort of counter system to cycle
      through the addresses, with reffreshing going on in between clock
      pulses, but I'm not sure if this is the correct way to do it.

      Any info would be greatly appreciated.
---
"Can someone get this walking carpet out of my way?"  "No reward is worth
this."
  _____)           ______        _)       _)  EAO102@PSUVM.PSU.EDU
                               __       __    OPORTO@CORVETTE.ECE.PSU.EDU
______    ______            ___      ___      Ernie "SHOKK" Oporto
                               __       __    Computer Lab Attendant
(_______ _      _ ________ _     _) _     _)  for PSU's CAC Department
From: mitrache@gringo.usc.edu (Traian Mitrache)
Newsgroups: sci.electronics
Subject: Power supply
Date: 23 Nov 1992 12:05:26 -0800
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: gringo.usc.edu


	I am new here in this newsgroup and I,m not sure if this is the corect 
place to ask this question, so please do not flame me if I,m wrong.
	I need to buy a power supply of 5V 250Amps.Could somebody give me some
names of companies where I could purchase such an item?
	Please email ,thanks

Traian
-- 


mitrache@gringo.usc.edu
Newsgroups: sci.electronics
From: billq@ms.uky.edu (Billy Quinn)
Subject: Re: 8-bit video chip needed
Distribution: usa
Date: Mon, 23 Nov 1992 05:41:08 GMT
Organization: University Of Kentucky, Dept. of Math Sciences

sad@camelot.bradley.edu (Shrijay Dalal) writes:

>Hello,

>Anyone know which are good 8-bit video chips to use to display to a
>composite screen (TV) and is relatively easy to use and come by?

>Thank you,
>Shrijay

I have had a lot of success with the USC1852.  Its is an 8-bit video DAC
which takes horizontal sync, blanking and a clock.  The 8 bits are sent to
the screen at the clock freq.  It is easy to use - I ordered mine directly
from the company. 1-408-463-1906.

Hope this helps!


-- 
*-----------------------------------------------------------------------*
*	Bill Quinn			billq@ms.uky.edu		*
*-----------------------------------------------------------------------*
Newsgroups: sci.electronics
From: dag@col.hp.com (David Geiser)
Subject: Re: police laser radar
Date: Tue, 17 Nov 1992 16:46:33 GMT
Distribution: usa
Organization: HP Colorado Springs Division

> sees at least ond diode.  Modulate the power supply with a little noise (like
> ignition noise) and the officer won't be able to get a reading that makes any 
> sense to his machine.

On second thought, it's fairly easy to descriminate the
reflections.  In fact, it's probably really necessary given all
the regular IR stuff out there like your fan blade chopping the
engine heat, vibrations of the car body due to resonance or 500W
woofers, etc.

Maybe the best defence is a good offence like a Sidewinder.

Maybe the best defence is good detection.

Maybe somebody has already invented the best IR absorbing paint,
but Dupont, in collusion with your Local Finest, has purchased the
patent to suppress it.
-- 

 Boycott Colorado.
From: Robert_La_Ferla@hot.com
Newsgroups: sci.electronics
Subject: Re: Possible to upgrade PC from FCC Class B to A?
Date: 17 Nov 92 15:01:35 GMT
Article-I.D.: hot.1992Nov17.150135.5926
Reply-To: Robert_La_Ferla@hot.com
Organization: Hot Technologies

No. No. No. No.

Class B is stricter than Class A.  You can upgrade a Class A to a Class B  
but there is no reason to downgrade to Class A unless you are developing a  
product for commercial use and want to cut costs.

From FCC Part 15:

Class A digital device.  A digital device that is marketed for use in a  
commercial, industrial or business environment, exclusive of a device  
which is marketed for use by the general public or is intended to be used  
in the home.

Class B digital device.  A digital device that is marketed for use in a  
residential environment notwithstanding use in commercial, business and  
industrial environments.

I don't see any mention of any Class C in the CFR book either.

Robert La Ferla
Newsgroups: sci.electronics
From: kehoe@netcom.com (Thomas David Kehoe)
Subject: Re: Tone frequencies on telephone
Organization: Netcom - Online Communication Services (408 241-9760 guest)
Date: Thu, 19 Nov 1992 17:46:29 GMT

>or the USA equivalent should be easily obtainable.  Basically, each
>digit (as well as the * and # functions) are composed of 2 frequencies
>sounded together.  All keys in the same Column share the same lower tone
>(with the lower tone ascending across columns) ... and similarly for the
>rows.

Which means that there are 16 tones available on a keypad,
although telephones have only 12 keys.  You could easily
build a keypad with 0-9, #, *, and A-D.  What you'd do
with the A-D keys I don't know...
-- 
"Why my thoughts are my own, when they are in, but when they are out
they are another's." - Susannah Martin, hanged for witchcraft, 1692.
Thomas David Kehoe          kehoe@netcom.com         (408) 354-5926
Newsgroups: sci.electronics
From: deanr@sco.COM (Dean Reece)
Subject: Re: Voltage to PWM for DC motor control?
Organization: The Santa Cruz Operation, Inc.
Date: Fri, 20 Nov 1992 17:50:36 GMT
Keywords: PWM

tod@cco.caltech.edu (Tod Edward Kurt) writes:
>
>Hey everyone,
>
>	Here's my dilemma:  I've got a voltage that varies (say from 0-5v) and
>I'd like to have this voltage control a DC motor via Pulse-Width Modulation.
>I've got the actual high-current motor driver (MOSFETs) done, I just need some
>pulses for it.
>	It seems like there should be a chip that does all this, has an
>adjustable PWM frequency, and provides a way to drive the motor both forward
>and reverse (2 seperate outputs, one for forward, one for reverse)
>	Any ideas?  Surely this must have been done thousands of times.  All 
>help appreciated.  BTW, this is for an Electronic Speed Control (ESC) for an
>RC car.
>					Thanks,
>						Tod
>tod@sandman.caltech.edu
>tkurt@vlsi.caltech.edu

There are several ways of doing this, but the most straightforward that
I can think of is using a DAC and a binary "up" counter to generate a
voltage sweep (very accurate sawtooth wave) covering the range of voltages
you are interested in and with a period equal to the desired PWM frequency.

Use a simple comparator to compare the sweep signal to the variable voltage
and use the output to drive the MOSFETs.  If you find that the motor speed
isn't as linear over the control range as you like, you can play around
with modifying the top and bottom voltages of the DAC (this effectively
changes the minimum and maximum duty cycle of the PWM)

I know Radio shack used to sell a real low cost 7 bit (I think) ADC which
was really an 8 pin chip with a DAC, a 7 bit counter, and a comparator
(Just what you want!).  All you gave it was the Voltage to be measured,
a clock reset signal, a clock signal, and power.  As an output, it gave
you the comparator output.  I don't have the exact part number, but it
was something like ADC080?.  So, this chip and a 555 should be all you
need to do what you want.  If I can find the spec sheet for this ADC,
I'll e-mail you (the original poster) the exact number.  Now that I
think about it, it might have even included an ap note on using it as
a PWM generator...  If so, I'll include that info.

Cheers,
 Dean Reece (deanr@sco.COM)
From: brunetm@JSP.UMontreal.CA (Brunet Martin)
Newsgroups: sci.electronics
Subject: 4x12 -> 2x12
Date: 17 Nov 92 20:05:34 GMT
Distribution: usa
Organization: Universite de Montreal

Hi there,

      I have a little problem. I got a speakers cabinet (4x12" speakers) and I want
to change it for a 2x12". I know there are 2 pair of speakers in series and the 2 pair 
are in parallel to make a total of 8 ohms. Each speakers is 8 ohms. Can I put 2 speakers
in serie with a 16 ohms resistance in parallel ? Thanks to all answer!

{Electric CountryMan}
Newsgroups: sci.electronics
From: sad@camelot.bradley.edu (Shrijay Dalal)
Subject: 8-bit video chip needed
Organization: Bradley University
Distribution: usa
Date: 22 Nov 92 19:31:03 GMT

Hello,

Anyone know which are good 8-bit video chips to use to display to a
composite screen (TV) and is relatively easy to use and come by?

Thank you,
Shrijay

--
Shrijay Dalal                       | "Sometimes I think the surest sign that 
sad@camelot.bradley.edu             | intelligent life exists elsewhere in the
Student Computer Trainer            | universe is that none of it has tried
Bradley University                  | to contact us." -- Calvin of C&H
From: dino@inqmind.bison.mb.ca (Tony stewart)
Newsgroups: sci.electronics
Subject: Re: calculating bandwidth for op amps
Date: Sat, 14 Nov 92 18:21:25 CST
Organization: The Inquiring Mind BBS  1 204 488-1607

ah335@cleveland.Freenet.Edu (Richard Banks) writes:
> I need some general formulas for calculating the overall signal
> bandwidth of chained op amps.
> 
> The only formula I have now is:
> 
> 'f_A = f_t/(1 + R_2/R_1)
> 
> Does anyone have anything simpler than this?
> Thanks.

yes... BW = BW(open loop)/Gain(closed loop)
since each opamp will give a 1st order response, and each stage is 
independent, overall response i easy to figure out.
ie if all the same then the BW is same but higher order rolloff.

dino@inqmind.bison.mb.ca
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607
From: cstadbg@csv.warwick.ac.uk (Mr M J Brown)
Newsgroups: sci.electronics
Subject: IR DETECTOR TUBES SUMMARY (emil@lamisun2 read this!)
Date: 17 Nov 1992 09:37:42 -0000
Organization: Computing Services, University of Warwick, UK
Distribution: world
NNTP-Posting-Host: clover.csv.warwick.ac.uk

******* EMIL@LAMISUN2.EPF1.CH ***********

Here is a summary of the information I received. Check Prices before ordering
though:-

IR TO LIGHT CONVERTER TUBES
===========================

FMGST+@PITT.EDU says
                     "Try OATLY Electronics, 5 Lansdowne Parade,Oatley
                      SYDNEY,NSW AUSTRALIA 2223. They do an IR NIGHT VIEWER
                      for $189 (PSU/KIT/CASE/OPTICS/FILTERS also available"
dnwangus@flash.lakeheadu.ca
                     "Try RCA 6032 Tube. Available from :-
                      Information unlimited
                      DEPT REH12
                      BOX 716
                      Amherst
                      NH 03031 USA (Tube and plans $99.50 KIT of all parts $299

LIGHT TO LIGHT (IMAGE INTENSIFIERS)
===================================

doherty@melpar - "New Image intensifiers $1500 plus, second hand $800 from
                  MWK inc." Mail doherty@melpar if you want an address.

 Also $450 18mm Intensifier from Oatly (as above)

CCD DEVICES
+++++++++++

Just about any monochrome/color CCD will be sensitive to IR to some extent.
>From messages I have seen, a cheap kiddy camera, minus filters, will allow
viewing of IR..Use a composite color/b/w monitor to view the picture.
(sysrick@starbase.spd.louisville.edu mentions this)

Hope you find the above useful ... I will check out some of these when I get
the cash!....

Sorry I did not mail the above (mail system bounced it.)

=============================================================================  
     _/      _/   _/   _/  _/   _/_/_/_/   |
    _/_/  _/_/   _/   _/_/     _/          |         Michael Brown
   _/  _/  _/   _/   _/       _/_/         |
  _/      _/   _/   _/_/     _/            |   cstadbg@csv.warwick.ac.uk
 _/      _/   _/   _/  _/   _/_/_/_/  _/   |
=============================================================================


Newsgroups: sci.electronics
From: johnh@macadam.mpce.mq.edu.au (John Haddy)
Subject: Re: Anyone have Protel for Windows PCB Cad?
Organization: Macquarie University, Sydney
Date: Sun, 15 Nov 1992 22:37:52 GMT

In article <BxJK26.K2r@acsu.buffalo.edu>, v064mcqs@ubvmsb.cc.buffalo.edu (NEIL GANDLER) writes:
|> 
|>  I am an electrical engineering student here at the University at Buffalo.
|> I do some small cad work and design circuits. I was very impressed with
|> the Protel Easytrax, the free shareware from Protel. Their new version
|> for Windows looks amazing. I am starting to get into double layer and complex
|> board design and am looking for someone who happens to have a copy. $4000
|> is a little steep for my budget. I would appreciate any help.
|> 
|> 	Neil Gandler

Unfortunately, Protel for Windows requires a hardware dongle.

It may be worth approaching your school - Protel has a much easier-on-the-budget
policy with regard to student laboratory versions (10 license pack).

Email me if you want details of PFW's operation and usability.

JohnH

----------------------------------------------------------------------------

      |  _  |_   _   |_|  _   _|  _|              Electronics Department
    |_| (_) | | | |  | | (_| (_| (_| \/           School of MPCE
    ---------------------------------/-           Macquarie University
                                                  Sydney, AUSTRALIA 2109

    Email: johnh@mpce.mq.edu.au, Ph: +61 2 805 8959, Fax: +61 2 805 8983

----------------------------------------------------------------------------
Newsgroups: sci.electronics
From: smisra@eos.ncsu.edu (SAURABH MISRA)
Subject: VOICE RECOGNTION INFO WANTED - Please!
Organization: North Carolina State University, Project Eos
Distribution: na
Date: Wed, 18 Nov 1992 04:23:49 GMT


Recently, I requested anyone having any chip numbers for voice recogntion
chips to send me some info.  All the email I got was from other users 
requesting that I send them a summary of my findings (which I will when
I get some info)

I have not gotten any leads yet.  Specifically the voice recognition chip
(notice chip, not board) should recognize the numbers 0 - 9 and another
keyword.  Anything more is fine, but just recognizing those 11 words will
be perfect.  I know there are chips out there that do this, but I can't find
them.  Please help me out if you have any information.

Saurabh

PS:  I have checked the EEM 91-92 directory but could not come up with anything.
From: jronnau@kuhub.cc.ukans.edu
Newsgroups: sci.electronics
Subject: Re: does dbuV = uV ???
Date: 20 Nov 92 08:04:05 CST
Organization: University of Kansas Academic Computing Services



dBuV is a logarithmic-relative measure defined as follows:






     dBuV = 10*log10( x uV / 1 uV)
          where x is the voltage in microvolts.

This relationship yields:
     1 uV => 0 dBuV
     2 uV => 3 dBuV
    10 uV => 10 dBuV
   100 uV => 20 dBuV

dBuV is a nice shorthand way of describing wide dynamic range measurments.

Jim Ronnau
JRONNAU@KUHUB.CC.UKANS.EDU
From: smisra@eos.ncsu.edu (SAURABH MISRA)
Newsgroups: sci.electronics
Subject: VOICE RECOGNITION Chip Question
Date: 15 Nov 92 21:18:17 GMT
Article-I.D.: ncsu.1992Nov15.211817.7815
Distribution: na
Organization: North Carolina State University, Project Eos

Could anyone pass me information as to part numbers and manufacturer
of voice recognition chips.  Specifically, I need one that recognizes
the numbers 0-9 and maybe one other word such as "Ready" etc.  I only
need it to recognize the above words and anything more would be extra
though still usable.  Thanks a bunch for your help.  Also, if you could
also send me names and #'s of vendors who have a fast turnaround for ordering
these chips, I would also appreciate that much.

Saurabh
Newsgroups: sci.electronics
From: "Gary A. Woodward" <p00140@psilink.com>
Subject: Re: IC lithography and manufacture.
Organization: Performance Systems Int'l
Date: Mon, 23 Nov 1992 12:37:56 GMT
X-Mailer: PSILink (3.2)

>DATE:   Mon, 23 Nov 1992 05:32:59 GMT
>FROM:   Andrew William Jackson <ajackson@ernie.Princeton.EDU>
>
>In article <2931439971.1.p00140@psilink.com> "Gary A. Woodward" <p00140@psilink.com> writes:
>>Ihave an idea.  I am sorry but I am not too technical with electronics(I 
>>have a degree in econ-probably the best if more economists would find 
>>something other to do also:)).  Is there a source that will tell me the 
>>basics on micro etching of items such as the lithography that allows IC 
>>circuts to be made?  I am looking specifically for 5-20 micrometer 
>>resolution. What would the cost of such equipment be-even used obsolete
>>equipment would work.  The wafers would not to be clean room quaility.
>>Would it be possible to make these micro etched items in my basement?
>>I can not discuss now-but after patent pending I will be willing to discuss.
>>
>
>Getting a patent on a "new" idea is not so easy.  If you dont even 
>know the basics of microlithography, why do you think that you
>are the first to think of this idea?
>
>ajackson@ernie.princeton.edu
>
I've already gotten one patent in another area.  What are your thought 
processes, I'm interested?

GW
Organization: Central Michigan University
Date: Wednesday, 18 Nov 1992 19:41:58 EST
From: John Goggan <34II5MT@CMUVM.CSV.CMICH.EDU>
Newsgroups: sci.electronics
Subject:    DTMF Decoder (I know -- "AGAIN?")

This comes up now and then and I'm always interested, but no one ever
seems to come up with a definate answer.  I'm looking for a schematic
for a touch-tone decoder circuit.  Something that simply takes audio
input and lights an appropriate LED for 0-9,#,*,A-D when it "hears"
it on the audio line.  I've done this project with a bunch (12-16)
seperate tone decoders and then used AND gates, but as everyone knows,
it's not a very good design and it is very sensitive to false readings.

I'd almost given up hope and forgotten about the project for a while when
I recieved the new All Electronics catalog (#492)...  One of the items
offered is some "revolutionary toner-transfer paper" or something.
Anyways, the picture included next to that ad is one side of a pc board
etching -- and the title is etched on it -- "TONE DECODER."  If you
look real close, you see that they are using one main chip (24 pins) to
decode everything (include 0-9,#,*,A-D), so it must specifically be for
decoding DTMF!  Now, if anyone happens to know what this chip is (and
can provide me with a nice schematic since I'm just a beginner and even
with the chip I would have a difficult time making anything useful), I
would _GREATLY_ appreciate it!  I've been wanting to have such a device
for quite a while now and have heard from many people along the way
stateing that they are also very interested.  (Note!:  Please don't
mail me and ask for me to forward any answers to you -- when this
happens, the only responses I receive end up being 20 requests for
teh schematic that I never get... -- In any case, I don't mean this to
be rude, it just won't help any -- I PROMISE that I WILL POST a summary
of all the valid responses that I receive.  So, everyone can get the
answers just by reading my final summary without having to post to
request that I mail it directly to you!)

Advanced thanks to anyone who can get me any information about this
project!

Talk to you all later...

 - John Goggan (34ii5mt@cmuvm.csv.cmich.edu)
               (or NeXT-Mail at:  john@opus.csv.cmich.edu)
Newsgroups: sci.electronics
From: johnh@macadam.mpce.mq.edu.au (John Haddy)
Subject: Re: CD4514 4-16 decoder
Organization: Macquarie University, Sydney
Date: Sun, 22 Nov 1992 23:13:19 GMT

In article <1992Nov21.024740.19971@csusac.csus.edu>, chenh@neptune.ecs.csus.edu (H. Philip Chen) writes:
|> rky57514@uxa.cso.uiuc.edu (Tall Cool One ) writes:
|> : Does anyone know about the CD4515 4-bit latched/4-16 line decoder?  I have one
|> : connected to a 4-bit binary counter.  The idea is a sequencer or chaser light.
|> : Problem is that the LEDs light correctly sometimes, and other times, not at
|> : all.  I have the data sheets, and it doesn't tell me anything useful.  I just
|> : want to use th 4514 as a decoder.  I really don't need the latch part of it..
|> : Any suggestions would be greatly appreciated!  Thanks!
|> 
|> Well, I don't claim to know the CD4514/5 that well, but since you 
|> have the datasheets handy, check the max output current of each pin.
|> (I suspect it's not high enough to drive each the LEDs and if so,
|> you'll need to add some line drivers in there.)  Good luck.
|> 
|> 
|> -phil


For driving LEDs, usually the 74C/HC series is better than 4000 series CMOS. The
pin drivers are rated for more current.

The 4515B can source a maximum of 2.4mA when driven from a 15V rail. This reduces
to 0.9mA at 10V and 0.36mA at 5V.

The 74C154 4-16 decoder (unlatched) can drive 8mA at 10V and 1.75mA at 5V.

The 74HC154 can drive a maximum of 25mA per pin (provided total current to chip
<50mA - easy with a one-of-sixteen decoder) at 5V.

JohnH

----------------------------------------------------------------------------

      |  _  |_   _   |_|  _   _|  _|              Electronics Department
    |_| (_) | | | |  | | (_| (_| (_| \/           School of MPCE
    ---------------------------------/-           Macquarie University
                                                  Sydney, AUSTRALIA 2109

    Email: johnh@mpce.mq.edu.au, Ph: +61 2 805 8959, Fax: +61 2 805 8983

----------------------------------------------------------------------------
From: CT64@music.mus.polymtl.ca (Nicolas Gauvin)
Newsgroups: sci.electronics
Subject: How can a radar detector bedetected?
Date: 18 Nov 92 17:47:47 GMT
Organization: Ecole Polytechnique de Montreal

A friend of mine recently got arrested because he was using a radar
detector. The cops actually used some kind of device to detect its
radar detector. How is this possible? Isn't a radar detector something
that only receives but emits nothing?


                        Nicolas Gauvin
                        gauvinn@info.polymtl.ca
Newsgroups: sci.electronics
From: davidg@lightnin.Columbia.NCR.COM (David Greene)
Subject: WANTED:  stationary bike (circuit) to power TV
Originator: davidg@lightnin
Organization: NCR Corp, E&M-Columbia, Columbia, SC
Date: Wed, 18 Nov 92 19:02:29 GMT

The real objective which I'm trying to accomplish is that I would
like to acquire a circuit description so that I may use a 
stationary bike to provide power to my television. (ie. I want to 
HAVE to peddle a bike in order to watch TV.)

Upon first thought, it seems somewhat easy (generator/motor + 
converter), but I'm afraid that I'm overlooking some critical
details.

If anyone has info./advice regarding such a circuit, please send e-mail.

Thanks in advance,
David Greene

____________________________________________________________________________
                                          
 David A. Greene                           
 Surface Mount Operations Center                 NCR MCPD -- Columbia
 phone: (803) 739-6161                           Operations & Distribution
   fax: (803) 739-7362                           3325 Platt Springs Road
 email: david.greene@ColumbiaSC.NCR.COM          West Columbia, SC 29170
____________________________________________________________________________