HDTenEightyP/NetNews huggingface dataset:
Newsgroups: sci.electronics
Date: Wed,  9 Sep 1992 15:40:15 -0400 
From: Jason Ari Goldstein <jg3o+@andrew.cmu.edu>
Subject: NEED: TTL controlled 115V 5A Switching

Hey now,

The subject pretty much says it all.  I need to switch some light
switches with TTL signals (I am building a controller for my
fraternities dance floor lights).  Basically, I have heard you can use
relays, triacs, etc.  Unfortunately, no one seems to have a circuit
design to show me.  I would like to use triacs because they are
non-mechanical and less likely to blow than relays.  I have seen some
circuits for using triacs but NONE that showed how I can use TTL logic
to do the switching.

BTW, I have looked into solid state relays but $17-$25 each is way too
much.  So, if someone could send me a circuit diagram or point me to a
good book (especially for triacs) it would make me very happy.

If you want to send a circuit you can:
    - do it up on a computer and e-mail it to me. giff, tiff, poscript,
macpaint, etc. is fine.
    - fax it to me at 412-268-2798
    - mail it to me at:
            Kappa Delta Rho
            1071 Morewood Ave.
            Pgh, PA 15213

PS.  The sooner the response the better.  Right now the lights are
switched manually because part of the previous circuit was stolen and
the other part is broken.  There is no diagrams of the previous circuit.
Later...

Jason A. Goldstein
___________________________________________
I'm a peripheral visionary...
I can see the future but only off to the sides.

Over, Finished, Gone, Done, Out.  (Finally)
From: jb@falstaff.MAE.CWRU.Edu (Jim Berilla)
Newsgroups: sci.electronics
Subject: Re: Inquiry: What is the best way to permanently label Panels ?
Date: 13 Sep 1992 17:41:13 GMT
Organization: Case Western Reserve University, Cleveland, Ohio, USA
Distribution: usa
NNTP-Posting-Host: falstaff.mae.cwru.edu

In article <12SEP199214411151@lims01.lerc.nasa.gov>, tidedu@lims01.lerc.nasa.gov (WILLIAM DEDULA) writes:
|> 
|> Hello All;
|> I am preparing to build a project which I want to turn out really neat. I'd
|> like to know if anyone has any ideas about what is the BEST and NEATEST way
|> to permanently label a control panel, or a chassis. I would require 
|> alphanumeric characters as well as straight lines. Anyone have any system 
|> which works great for them, or any ideas ??? Thanks !!!

Assuming that you have the artwork already, there are a number of ways to
do this.  The BEST way is to have someone else do it.  Send it to a silk
screen place that's experienced in printing control panels.  They will
print it in an epoxy ink (in the color of your choice) that will resist
scratching, cleaning, etc.  From what I remember, the cost was about $100
for a single 10.5 x 19 inch panel.  The cost per piece goes way down as
the number of pieces goes up.

For in-house work, there is a product called Fotofoil or Photofoil or
PhotoPhoil or something.  This is aluminum with a photosensitive coating
on it.  It is processed like circuit boards, but instead of removing
copper, you remove the color.  It is available in thicknesses from
about .005" to .125", and a variety of colors.  Depending on how you
process it, you can end up with colored letters on an aluminum background,
or aluminum letters on a colored background.

-- 
      Jim Berilla / jb@falstaff.MAE.cwru.edu / +1 216 368 6776
Newsgroups: sci.electronics
From: johnh@macadam.NoSubdomain.NoDomain (John Haddy)
Subject: project design time (repost)
Organization: Macquarie University
Date: Sun, 6 Sep 1992 23:00:36 GMT

I tried posting this a week or two ago (twice). Since the only response I got
was from within Australia, I'm trying again. I would seriously appreciate any
and all replies.

Note: don't attempt to use whatever garbage address turns up in the header!
Please reply to the address in my .sig; or post here if you think there would be
sufficient general interest.

Thanks.

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


I would like to ask for opinions on this issue:

How long, on average, would you consider a project design/construction to take?
i.e. how many man-weeks?

I refer to a project capable of being designed by one engineer and constructed by
two technical staff.

I know this is an open ended question, with not enough details to answer
precisely; but I'm after a "gut-feel", not a project plan. Projects are
non-trivial (trivial means a circuit that can be knocked up in under a week or
two with no worries) and require an engineer's skill (i.e. they're not the sort
that an experienced technician would be expected to handle), often with
background research required (e.g. magnetic properties of toroid materials, ECL
circuit design, high voltage electronics [10kV-20kV at several amps] etc).

Project design time in this case refers to:

1	Project specification
2	Design and schematic capture, with simulation and breadboarding where
		necessary
3	Printed circuit artwork design (on a CAD system)
4	Printed circuit fabrication, drilling and loading (assume in-house
		fabrication takes one day)
5	Circuit test and revision/modification
6	Chassis work (hole drilling, PC mounting, etc)
7	Front panel design and fabrication (Scotchcal or similar)
8	Final test and shipment ('out the door')

Also, how long would a repeat build take. That is, use an existing design. This
would be equivalent to steps 4..8 above, without the circuit revision or front
panel design elements.

My reason for asking is that a director here is under the impression that the
output of one engineer and two technicians here has been lower than it should.

Personally, I believe that their output has been beyond expectation. However, so
as not to bias your opinion, I'll not quote the details now.

I will summarise if there is enough interest.

John Haddy

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

      |  _  |_   _   |_|  _   _|  _|              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: john@anasazi.com (John R. Moore)
Newsgroups: sci.electronics
Subject: Re: Sources for Motorola Chips !!
Date: 5 Sep 92 15:47:39 GMT
Reply-To: john@anasazi.com
Organization: Anasazi Inc, Phoenix AZ USA

Keywords: 

In article <1992Sep4.170404.4222@cis.ohio-state.edu> rubin@glockenspiel.cis.ohio-state.edu (Daniel Rubin) writes:
]Does anyone know of a good and economical suppliers of Motorola chips?  I am
]looking for linear and microprocessors for the most part!  I have the Digikey
]and Mouser catalogs and neither one sells Motorola?

Arrow Catalog Sales is a good source - they are a branch of a regular
distributor. They take VISA. Try 1-800-93ARROW.

Circuit Specialists has a fair amount of Motorola analog, but no uP's.
They can be reached at 1-800-528-1417.


-- 
John Moore NJ7E, 7525 Clearwater Pkwy, Scottsdale, AZ 85253  (602-951-9326)
john@anasazi.com ncar!noao!asuvax!anasaz!john anasaz!john@asuvax.eas.asu.edu
- - "May you have the wealth of a Republican, and the sexual prowess - -
- -  of a Democrat." - Johnny Carson's joke writers
Xref: sparky sci.electronics:15585 rec.video:11218
From: strike@steam.rome.ny.us (Strikemaster)
Newsgroups: sci.electronics,rec.video
Subject: Re: Macrovision
Date: 13 Sep 92 18:07:39 GMT
Organization: Iron Horse InfoSys

killeen@spcvxb.spc.edu (Jeff Killeen) writes:

>Keep in mind 8mm and Hi8mm units are _not_ effected by Macrovision.  Owners of 
>Sony GV-8/200/300/500's have long ago discovered this happy fact.  Also I 
>believe all Beta units are safe from Macrovision.

Hmmm.  If "The Addams Family" is Macrovision encoded, then I beg to differ
with you.  Recorded from a JVC S-VHS deck to the CCD-V700 camcorder, I get
the same brightness/contrast changes I expect from a VHS tape.

>And if case you are thinking of it...

>	VHS tape -> 8mm tape -> VHS tape

No, this was (VHS tape -> 8mm tape), then playback 8mm tape.

Probably a FAQ, but what "copy guard" formats are there besides
Macrovision?


-- 
      Timothy B. Bowser; Sysadmin,       | strike@steam.rome.ny.us or try
    Chip Socketer & Tape Twiddler of     |    batcomputer!steam!strike
   The Iron Horse Information Service    |--------------------------------
----> "Advanced technology is indistinguishable from a rigged demo." <----
Newsgroups: sci.electronics,ut.ee
From: tgk@cs.toronto.edu (Todd Kelley)
Subject: Help/advice sought on computer controlled rheostat project
Followup-To: sci.electronics
Organization: Department of Computer Science, University of Toronto
Date: 8 Sep 92 20:32:23 GMT

Hello electronics experts,

Consider a generator (electric motor) that will be driven at various
speeds.  I want to be able to control by computer (through a serial
port or whatever) the load on the generator, independent of its rpms.

The purpose of all this is to build a stationary bike that can
emulate the loads experienced by a cyclist when riding on flat stretches,
up hills, against various winds, etc.  The kinetic energy of the spinning
generator should equal the energy of a moving cyclist, since riding
slowly up a hill is different from riding fast on a flat stretch.

I expect what I will need is some sort of voltage-controlled rheostat
or something, which can disapate heat.  I roughly estimate that a 
cyclist can generate as much as 500 watts peak, and maybe 100 watts
sustained over hours.  I have a book that tells me how to build
a voltage controlled resistor with op-amps, but I suspect such a device
could not handle loads of 100-500 watts.

I would appreciate any advice about what I need and where to look to buy it,
and if it can't be bought, then what to build it out of.  Ideally I would
be able to just adapt some device that can be bought off the shelf and
plugged into a serial port.  I'm just a student, so cost is an issue.

If I get some replies and there seems to be enough interest, I'll
post a summary.

Todd
-- 
Todd Kelley                                 tgk@cs.toronto.edu
Department of Computer Science              (416)922-9326
University of Toronto
Xref: sparky sci.electronics:15261 rec.video:10950
From: brown@vidiot.UUCP (Vidiot)
Newsgroups: sci.electronics,rec.video
Subject: Re: Macrovision
Date: 4 Sep 92 05:06:46 GMT
Reply-To: brown@vidiot.UUCP (Vidiot)
Organization: Vidiot's Hangout

In article <1992Sep2.133450.18671@panix.com> schuster@panix.com (Michael Schuster) writes:
<In article <1992Sep2.041037.347@u.washington.edu> bunky@milton.u.washington.edu (Mike) writes:
<>
<>     
<>     Does anyone know how macrovision allows a video tape to be watched on
<>     a television but not on a vcr?  I recently looked at a copy protected
<>     videotape and it appeared that there were 4 white bars on the last
<>     8 or 9 lines in the vertical interval that periodicly (every 15 or 20
<>     sec) faded in and out.  It looks like it's changing the average level
<>     of the picture to mess up the vcr.  If that's the case could this be
<>     fixed with a clamping circuit or some kind of dc restorer circuit?
<>     If anyone knows the technical details of how the copy protection scheme
<>     works I would be very interested. 
<
<Macrovision inserts very bright pulses in the vertical blank interval.
<Most VCR's use this when setting AGC video level, and get fooled into
<thinking the video levle is much brighter than the picture area really
<is. Most TV's don't. Dunno why.

Why is everyone forgetting the extra horizontal sync pulses BEFORE the
extra white pulses?

If it was only white pulses everything would work just fine.
-- 
      harvard\                          spool.cs.wisc.edu!astroatc!vidiot!brown
Vidiot  ucbvax!uwvax..........!astroatc!vidiot!brown
      rutgers/            INTERNET:vidiot!brown%astroatc.UUCP@spool.cs.wisc.edu
                                   brown@wi.extrel.com
From: steve@testeng.ksc.nasa.gov (Steve Schindler)
Newsgroups: sci.electronics
Subject: Re: Can you Modify an OLD Pager to a new frequenc
Date: 15 Sep 92 17:12:24 GMT
Organization: Voice Systems Engineering, Kennedy Space Center

As far as changing a pager to a new frequency, as long as you stay in the same
band (ie- VHF-Low, VHF-High, UHF, etc), it's not to difficult. You will need a
new crystal and may have to change some components in the RF circuitry. Service
manuals are available from Motorola. They contain all of the information that
you will need. You will probably have to retune the receiver to get the best
results.

As far as activating a pager on non-commercial frequencies, pagers that require
two tones to activate are easy. 5/6 tone pagers are more difficult. Pagers 
that use digital addressing (Golay Sequential Code used to be popular) would
be a challange. The big kicker is that the transmitter that broadcasts to
the pager must be licensed. If you are an amateur radio operator, you're in
good shape. It might be a good excuse to get licensed if you aren't already.

Steve


-- 
---------------------------------------------------------------------------
Steve Schindler                      steve@vulture.ksc.nasa.gov
Voice Systems Branch
NASA - Kennedy Space Center
Newsgroups: sci.electronics
From: wa2ise@cbnewsb.cb.att.com (robert.f.casey)
Subject: Re: Impedance match 50 to 75 ohms
Organization: AT&T
Distribution: na
Date: Sat, 12 Sep 1992 01:56:31 GMT

Many years ago I built a device to do this.  But I don't remember clearly
what exactly I did, but it was something like this:  wrap 5 turns of wire
around a toroid core.  tap at 4 turns.  the tap is 50 ohms, top of coil
is 75.  Bandwidth was something like 20 to 300 Mhz, maybe even higher.
Loss was about 1/2 to 1 db (had access to a network analyzer back then).
Believe there is something on this in the ARRL handbook.
From: smithj@hpsad.sad.hp.com (Jim Smith)
Date: Fri, 11 Sep 1992 20:42:27 GMT
Subject: Re: project design/build time (repost)
Organization: HP Signal Analysis Division - Rohnert Park, CA
Newsgroups: sci.electronics

In sci.electronics, johnh@macadam.mpce.mq.edu.au (John Haddy) writes:

>I suspect that the local news feed chewed up my last attempt to post this. If it
>didn't then please forgive the repeat post!
>If you've seen this before, I promise that this will be the last time! I truly
>expected that the the topic would arouse at least _some_ interest, however I've
>only had one reply (from nearby), leading me to suspect that the original post
>did't get very far.

I saw the original post, but didn't respond because of the difficulty of
answering the question.  You essentially ask, "how long will it take to
build a project that takes longer than a week or so to build?"  My flip
answer is, of course, longer than a week or so.  The problem of scheduling
is always a difficult one, and it's not something that can be determined
simply, or usually with much accuracy at all.  Projects that I have worked on 
take anywhere from a few hours to years.  Clearly, your question excludes
the "trivial" tasks, but the range is still huge.  So the question is
almost impossible to answer in the general terms in which you're asking it.
I think it might be possible for people reading this group to estimate
how long it might have taken for them to do something if given more details
than you've given.  Perhaps if you would give more details of the projects
in question, without giving any expected or realized times, someone might
have a chance of estimating it.  Frankly, though, it sounds like your
organization is in need of better methods of evaluating employee's
performance.
		 - Jim

Newsgroups: sci.electronics,sci.engr
From: bkg@ssd.kodak.com (Ben K Gibson)
Subject: Info Wanted on Adac 5532DMA or 5532TTL Boards
Originator: bkg@earth
Organization: Eastman Kodak
Distribution: usa
Date: Wed, 9 Sep 92 14:26:33 GMT

I am looking for information on the Adac 5532DMA or 5532TTL boards.
I am having a problem getting the board to transfer data after an
interrupt is generated. If you have had any success integrating one of
these boards, please e-mail me your phone number. I would like to talk
with you. BTW I get the same symptoms with the ADLIB software as I get
with my own polling software. Adac insists it has to be the SW.

Thanks in Advance,


-- 
KKK  KKK  Ben K. Gibson                           E-mail: bkg@ssd.kodak.com
KK Kodak  Eastman Kodak Company                   Phone:  (716)588-4313
KKK  KKK  Rochester, NY 
----------------- Opinions Expressed are my own, Not EK Co. -----------------
From: mdgoodma@CRDEC8.APGEA.ARMY.MIL (Mack Goodman Have Goals and Faith)
Newsgroups: sci.electronics
Subject: Can you Modify an OLD Pager to a new frequency??
Date: 14 Sep 92 15:37:30 GMT


I have an old Motorola pager model A03AGC1568A
FREQ is 152.240 

I had hoped to take this thing apart, change the freq to a local fire dispatch
freq, and use this as a sortof mini scanner.

Do I have a shot at doing this???

It also has a code plug chip in it.

Please reply by email, thanks for any insight

mdgoodma@crdec8.apgea.army.mil
From: batavia@phakt.usc.edu (Parag Batavia)
Newsgroups: sci.electronics
Subject: DC-DC Converters
Date: 11 Sep 92 22:39:37 GMT
Distribution: usa
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: phakt.usc.edu

Hi...Anyone know of any manufacturers which carry DC-DC converters which 
convert from +5V to +12V and +5V to -12V? Thanks

Parag Batavia
USC Robotics Lab

parag@mensa.usc.edu
From: cgordon@vpnet.chi.il.us (gordon hlavenka)
Newsgroups: sci.electronics
Subject: Re: Filtering TV Commercials
Date: 4 Sep 92 15:40:22 GMT
Organization: Vpnet Public Access


 rmintz@ecst.csuchico.edu (Rich Mintz) writes:
>First, I was told that the audio during commercial 
>announcements on tv is boosted higher than that used for 
>normal programs (for obvious reasons).

This is not _always_ the case.  In fact, I recently watched a
commercial which appeared to have been deleberately processed in such
a way as to make the words _difficult_ to understand.  The overall
volume (composite power) was reduced, and the high frequencies were
noticeably rolled off.  The product?  Beltone hearing aids :-)
(Their 800 number was on the screen in large print throughout...)


-- 
----------------------------------------------------
Gordon S. Hlavenka           cgordon@vpnet.chi.il.us
  Don't forget:  Dave Barry/Joe Walsh in November!
Newsgroups: sci.electronics
From: hpoppe@ncar.ucar.edu (Herb Poppe)
Subject: Re: Re : 68HC705KICS Worth of try ?
Organization: National Center for Atmospheric Research
Date: Wed, 9 Sep 1992 15:51:29 GMT

In article <1992Sep8.123622@btmp24.be> prob@btmp24.be (Pascal Roobrouck 
SH53) writes:

> I don't use the 68HC05 but I do work with the ST62T15.

Who makes this device?

Is its instruction set patterned on some other well-known device?

How many pins does it have.

Peripherals? (Timers, A/D, D/A etc.)

Other family members; devices with EEPROM?

Herb Poppe                 National Center for Atmospheric Research (NCAR)
hpoppe@ncar.ucar.edu       1850 Table Mesa Dr.
(303) 497-1296             Boulder, CO  80303
Newsgroups: sci.electronics
From: feiges@cae.wisc.edu (Howard Feiges)
Subject: Phone line bleeding - help
Organization: U of Wisconsin-Madison College of Engineering
Date: 6 Sep 92 02:37:26 CDT


Hello people - its feiges here - with yet another dillemma with the
phone lines.....

first of all, I would like to publically thank all the poeple who have
spent the time to help me build phone in-use lights.....   WE still have
to get the parts to build them, but once they are built - they will
really be helpful

thanx again...

Now, we have two phone lines...  It seems to me that when people are on
both lines - the person on one line can faintly hear the person on the
other line talk - and visa versa...    

We have a  lot of wiring around our apartment - and usually, both phone
lines are carried through the same wire (ya know - one line on the inner  
two leads and one line on the outer two)

It seems that the less wiring we have around the house (we've done some 
expirements) the more the problem seems to go away (the other voice gets
fainter) ----  so I figured that it might be that a conversation going
on on one line can be "inducing" an electric current to get the echo on
the other line...... but then, all I had to do was add a lot of wire to
JUST ONE LINE of our two phone lines and that also made the problem worse..
so I dunno what the deal is...

anyways.... is this a common  problem?????   Is there a common solution???
if its not a common problem is there still a solution????

Its kinda annoying whne one person is talking on one line while the modem
is on the other ---- it doesnt seem to affect the modem though --- not so
far anyways.....  Also, we have had two modems going on both lines - and
it seems to me that nothing is affected as well....  real wierd

please let me know what you think.... and thanx much

Howard Feiges

feiges@cae.wisc.edu

TPK

Newsgroups: sci.electronics
From: sdavis@laforge.ksc.nasa.gov (Steve Davis)
Subject: Re: Audio Cassette Deck Maintenance - Suggestions Wanted
Organization: NASA
Distribution: usa
Date: Tue, 8 Sep 1992 20:46:31 GMT

Jon Noring writes
> I'd like to get feedback from the Usenet as to the current state-of-the-art
> of audio cassette deck maintenance.  The two areas of maintenance that I
> see are head and capstan cleaning, and head demagnetization.  I've seen
> devices that make this job easier than getting in there with a cotton swab
> and alcohol for cleaning.

  These devices may make the job easier, but they won't do it better.  If  
you're maintaining a standard home tape deck, there's no good reason not to use  
cotton swabs and alcohol.  Use 99% isopropyl alcohol on the heads, capstan, and  
everything else in the tape path other than the rubber pinch roller(s).  Clean  
the deck once for every 10 hours of use.  Also, you can minimize oxide build-up  
between cleanings if you avoid using cheap tapes, such as the three-for-$1  
variety.

  There are lots of demagnetizers on the market, but they all do basically the  
same thing.  I've used a $5 Radio Shack wand for years without any problems.   
Just make sure that the wand you buy will physically fit into the tape well of  
your deck.  Demagnetize the tape path almost as often, more if you play metal  
tapes.  This avoids a magnetic buildup that, if unchecked, will act like an  
erase head while you play your tapes.  This effect is not always obvious right  
away; the first sign is usually a loss of high frequencies on often-played  
tapes.

  Hope this helps... happy listening!

Regards,

Steve
--
+----------------------------------------------------------------+
| Steve Davis                      | sdavis@laforge.ksc.nasa.gov |
| NASA, DL-DSD-32                  | (NeXT Mail preferred)       |
| Kennedy Space Center, FL  32899  |                             |
| (407)867-7582  fax:(407)867-2173 | #include <disclaimer.h>     |
+----------------------------------------------------------------+
From: myers@hpfcso.FC.HP.COM (Bob Myers)
Date: Tue, 8 Sep 1992 02:41:34 GMT
Subject: Re: Complete B&W NTSC timing ???
Organization: Hewlett-Packard, Fort Collins, CO, USA