HDTenEightyP/NetNews huggingface dataset:
From: chrz@tellabs.com (Peter Chrzanowski)
Subject: Re: Help Wanted: Sound detecting circuit
Organization: Tellabs, Inc.
Date: Mon, 25 Jan 1993 18:37:20 GMT

In article <1993Jan20.104438.5447@ucc.su.OZ.AU>, andy@extro.ucc.su.OZ.AU (Andrew Miehs) writes:
> G'day,
> 
> I'm not much in the know about electronics (but I'm learning) and so I'd 
> appreciate anybody's help in designing the following:
> 
> I need a circuit that reacts to a certain high-frequency sound, in order to
> activiate another circuit. Is that clear? In other words, when a microphone
> picks up the sound wave from a nearby source, it turns some auxilary circuit
> on and it stays on until the sound wave ceases.
> 
> Please e-mail me with any suggestions or references.

Look at the schematic (Howard Sams, etc.) of a TV made sometime before the
late '70s.  Old TVs used remote controls that used unmodulated ultrasonics:
just provide enough energy at the right frequency and the function would
be triggered.

The circuits were pretty simple: a piezo microphone followed by a preamp
followed by bandpass filters (L-C) followed by actuators/drivers for the
solenoids or motors.  Frequencies used were in the range 20-40kHz.

These old remotes were very prone to false triggering, as there are many
sources of ultrasonics: electomechanical-bell telephones, jangling keys,
squeaky garage doors would often trigger these things.

Because of the false triggering problem it makes much more sense to use
some sort of modulation and encoding, as is done with modern IR remotes.

> 
> Malcolm Ryan
> 
> (care of Andrew Miehs - email andy@extro.ucc.su.OZ.AU)
> 
> -- 
> +-------------------------------+---------------------------------------------+
> | Andrew Miehs                  |                                             |
> | Mail: andy@extro.ucc.su.oz.au |       $$$ THIS SPACE FOR RENT $$$           |
> | NB:   Don't call me andy!     |                                             |


Xref: sparky sci.electronics:23497 rec.audio:19546 rec.audio.car:5884 rec.audio.pro:2871
From: lancer@wpi.WPI.EDU (Stephe Lewis Foskett)
Newsgroups: sci.electronics,rec.audio,rec.audio.car,rec.audio.pro
Subject: Re: 12V Power Amplifier Design
Date: 27 Jan 93 07:08:11 GMT
	<1993Jan27.000515.19195@parc.xerox.com>
Organization: ZikZak Corporation
NNTP-Posting-Host: wpi.wpi.edu
In-reply-to: tapscott@parc.xerox.com's message of 27 Jan 93 00:05:15 GMT

>>>>> "tapscott" == Peter Tapscott <tapscott@parc.xerox.com> writes:
tapscott> You have to be cautious about accepting wattage ratings from
tapscott> car amps. The manufacturers frequently exceed the laws of
tapscott> physics with their ratings.

You mean my new Sparkomatic "Hi-Power" amp doesn't really deliver 100
watts per channel?

.s.

PS: *grin* for the humour impaired
--
- so spake lancer@wpi.wpi.edu -   - so says the Beautiful South: -
-  Im walking through these pastures, Im picking up sweet fruit  -
-      Im shaking hands with people that previously Id shoot     -
-Nothing will disuade me, nothing will dilute - I want to execute-
Organization: Queen's University at Kingston
Date: Sun, 24 Jan 1993 16:48:22 EST
From: <LEEK@QUCDN.QueensU.CA>
Newsgroups: sci.electronics
Subject: Re: Crystals!
 <C1Cx1r.MIv@ccu.umanitoba.ca>

>In article <1993Jan21.183404.1534@mnemosyne.cs.du.edu> rduta@nyx.cs.du.edu
>(Radu) writes:
>>Can someone please tell me some more info about crystals.  I need to make
>>a electronic switch to select between two crystlas (2MHz, and 8MHz -about),I
>>tried using a 4016 (IC switch), and it didn't work.  Can someople please
>>give me another solution.  I'm desperate.

A quick hack to do it is to use the following Oscillator/Multiplexor
circuit that I used to switch clock frequency on my pocket computer back
in high school days...

Use 74HC00 as                      +------------------------------+  __
the 4 nand               4.7M      |                  4.7M        +-|  \o
gates.            +----/\/\/\/\----+           +----/\/\/\/\----+---|__/|
                  |        _       |           |       _        |       |
Xtal1             +------|| ||-----+           +-----|| ||------+       |
Xtal2             |        -  Xtal1|           |       -   Xtal2|   Clock
are the 2         |       __       |           |       __       |    out
crystals          +------|  \o-----+           +------|  \o-----+
2, 8 MHz          |   +--|__/      |           |   +--|__/      |
            20pF ===  |  nand     ===  20pF   ===  |           ===
                  |   |  gate      |           |   |            |
             __   V   |            V Gnd       V   |            V
Select ---+-|  \o-----+                            |
          +-|__/                                   |
          +----------------------------------------+

(Some of you might want to add a series resistor to limit the current
through the crystal and change the capacitor or whatever.) The circuit
has the lowest components count because it combines the oscillator with
the multiplexor circuit and it does work nicely and it might take
a little bit of time for the oscillator circuit to start after you pull
the select line high/low to select the clock source.  If you don't want
that delay, you might want to build 2 oscillator circuits and feed the
outputs to a 2-1 mulitplexor.  These days I would use a GAL16V8 to
implement the whole thing.  The CMOS inputs works nicely for a simple
oscillator.

In article <C1Cx1r.MIv@ccu.umanitoba.ca>, shad04@ccu.umanitoba.ca (Dan Fandrich)
says:
>
>The 4016 can have a fairly high internal resistance (2k).  Why not use the

More likely the high capacitance is going to cause trouble.

>8 MHz crystal and selectively divide the output by 4 or use a PLL?

Could use the 8MHz and divide by 4 to get 2 MHz.  Less components than
a PLL.  (Since your PLL needs a /4 circuit and a PLL chip)

>>>> Dan

K. C. Lee
Elec. Eng. Grad. Student
Newsgroups: sci.electronics
From: moy@cae.wisc.edu (Howard Moy)
Subject: How to make 24db passive bandpass filter?
Organization: U of Wisconsin-Madison College of Engineering
Date: 25 Jan 93 13:15:36 CST


Hi

Can anyone tell me how to make a passive band pass
filter with a 18 to 24 db slope?  Is it just like
putting two 12db filters in series with proper input/output
impedences of the respective filter to make it 24db slopes?
Can it be that easy?  Since I have articles on how to make
passive crossovers.  I assume to use a three way crossover
for the band pass.

Any input is appreciated.  Please e-mail me if possible,
else posting here is fine.


Thanks in advance,

Howard

moy@cae.wisc.edu

-- 
-Howard
_________________________________________________________
!                    Howard Moy				!
!                  (608) 255-6379			!
Newsgroups: sci.electronics,rec.audio,rec.audio.car,rec.audio.pro
From: ebe+@pitt.edu (Elmer Beachley)
Newsgroups: sci.electronics
Subject: Re: Closed Captions
Date: 24 Jan 93 03:06:57 GMT
Organization: University of Pittsburgh


John:

You ask about closed caption codes.  These were somewhat an industry
"secret" until the decoders were mandated to be part of most tv receivers.

Now, you can find the codes in the U.S. Federal Register, Vol. 56, No. 114
Thursday June 13, 1991.

BTW, what are you building?

Elmer Beachley ebe+@pitt.edu etb@cs.pitt.edu
Newsgroups: sci.electronics
From: mada@electrum.kth.se (Marcus Davidsson)
Subject: XILINX
Organization: The Royal Institute of Technology, Stockholm, Sweden
Distribution: sci
Date: Tue, 26 Jan 1993 08:23:17 GMT

Hej!
Does anybody know if the XILINX bbs, where you can download info and
LCA-programs have an internet connection?

Thanks.

Marcus Davidsson
mada@it.kth.se
Newsgroups: sci.electronics
From: rusty@anasazi.com (Rusty Carruth)
Subject: Re: Recording from/playing onto phone line
Organization: Anasazi, Inc.  Phoenix, Arizona USA
Date: Mon, 25 Jan 1993 21:10:20 GMT
Keywords: phone record play 

In article <jaegerwl.727341219@wckn.dorm.clarkson.edu> jaegerwl@wckn.dorm.clarkson.edu (Bill Jaeger) writes:
>At my university's cable TV station we're working on putting together
>a program that involves a viewer call-in.  Unfortunately, none of us are
>really sure how to go about 1) injecting a signal into the phone line, and
>2) recording the signal from the phone line.
...
>Can anyone tell me how to make one of these things?  Or at least point me
>in the right direction?

Even better - get a Phone Patch.  Hams use them all the time, check
with Ham Radio Outlet (or check the back of QST, 73 amateur radio,
CQ, or any other amateur-radio related magazine you can happen to
run into, for vendors of ham-related equipment).  Our church recently
ran a phone patch for the entire church (!) using a phone patch and
the existing sound system.  Seems to me that the person talking to the
people on the remote phone connection used a mic connected to the
audio system....  If all else fails, I can get you in touch
with one of the people involved here (all I did was talk to
him about what they had done ;-)

Advantages - cheap, they work, and you don't have to build it yourself ;-)

Rusty@anasazi.com
>Thanks!
>
>-Bill
>
>
>------------------------------------------------------------------------------
>-Bill Jaeger
> jaegerwl@logic.camp.clarkson.edu	Clarkson University, Potsdam New York
> jaegerwl@wckn.dorm.clarkson.edu        WCKN Television, Potsdam New York
>
> "Only by attempting the absurd can we achieve the impossible"
>					- Pyro to The Illuminator, 1990
>------------------------------------------------------------------------------
>


-- 
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
Newsgroups: sci.electronics
From: cees@bongo.htsa.aha.nl (Cees Keyer)
Subject: Manufacturer name wanted
Date: Mon, 25 Jan 1993 08:50:03 GMT
Organization: Hogeschool van Amsterdam, the Netherlands, E.E. & C.S. dept.
Keywords: VN10KM

Hello,
I am looking for the manufacturer of the power mosfet VN10KM,
On the casing the symbol is a H but i don't think it's a harris transistor
could someone give me a pointer to the manufacturer.

TNX in Advance

Cees Keyer


-- 
# I am more up and down than a pair of kangaroo's in the mating season.
# Cees Keyer, HVA-TMF, Europaboulevard 23, 1079 PC  Amsterdam, Holland
# Dept of Electrical Engineering.  quote from: Kryton, red Dwarf.
# cees@tamtam.htsa.aha.nl  Voice: (+31)20-6429333, Fax: (+31)20-6443215
Newsgroups: sci.electronics
From: cook@barleywine.atd.ucar.edu (Forrest Cook)
Subject: Re: Recording sound on chip
Organization: Atmospheric Technology Division/NCAR Boulder, CO
Date: Tue, 26 Jan 1993 01:56:22 GMT

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.
>Sivaram

I would suggest that you look into CVSD chips from Harris.
Motorola may also make such a beast.  Look in the Harris Telecom
products manual.  The CVSD (Continuously Variable Slope DeModulator) chips
convert voice signals into a serial bitstream at a very slow bit rate,
something like 400 bytes/Second if I remember correctly.  The CVSD also
goes the other way, bitstream in, audio out.  The bitstream can be fed
into your favorite micro/memory combination or you could even do it with
a RAM chip and mux/counter hardware if you prefer working in the wire
domain over working in the software domain.  Don't forget to add some
lowpass filters on the audio i/o lines.  Fidelity is not great, but
the memory requirements are minimal.  I always wanted to build an all digital
answering machine with one of those and a simm.

--
 ^   ^  Forrest Cook - < Is that a REAL network or is it a SEARS network? RCD >
/|\ /|\ cook@stout.atd.ucar.edu WB0RIO (This posting is my OPINION)
/|\ /|\ {husc6|rutgers|ames|gatech}!ncar!stout!cook
Newsgroups: sci.electronics
From: kayshav_dattatri@taligent.com (Kayshav Dattatri)
Subject: Source for Electronic Ballasts for Fluorescent lamps
Organization: Taligent
Distribution: usa
Date: Tue, 26 Jan 1993 00:23:20 GMT

I'm looking to study electronic fluorescent lamp ballasts from different
manufacturers (GE, Sylvania etc). Can the experts recommend

 1. Sources for these gizmos (both 110v and 220 v versions)
 2. Any books for the schematic/diagrams and information
 3. approximate prices
 4. Address/phone of manufacturers that can give me this information

Thanks in advance

Respond by mail or post to group

Kayshav

Kayshav_Dattatri@taligent.com

Newsgroups: sci.electronics
From: dcovell@hfglobe.intel.com (David Covell)
Subject: Re: QUESTION: The R is out on my RGB monitor
Organization: Intel Corporation
Date: Thu, 21 Jan 1993 16:15:10 GMT

mcovingt@aisun3.ai.uga.edu (Michael Covington) writes:

>In article <digdug.727455954@pv6f02.vincent.iastate.edu> digdug@iastate.edu (Doug V Tran) writes:
>>Well, the Red has left my VGA monitor the other day so I no longer have
>>any colors with red it it.
>...
>>What would be the most like cause of this problem?

>By far the most likely is a break in the cable (at either end).  Second
>most likely would be a video output transistor, I'd guess.


Another strong possibility is a bad solder joint for the red drive connection
to the small pcb mounted at the rear of the CRT. It should be labelled "r" or
"red". For some reason there's a high failure rate for solder joints on this
pcb, possibly caused by vibration of the CRT. I fixed a color TV that I scrounged from the neighbor's trash by locating and resoldering two bad solder joints
on this pcb, one of which was the red drive.
Newsgroups: sci.electronics
From: dannyb@panix.com (Daniel Burstein)
Subject: making 110V into 220v
Organization: PANIX Public Access Unix, NYC
Date: Fri, 22 Jan 1993 18:06:13 GMT

someone or another (I don't have original posting) wrote that he was
moving from the UK (220V)  to canada (11oV) and asked about running his
equipment.

It's -somewhat-doable if you are VERY careful, and check things out
extremely minutely.

In the United States and Canada, most residential electrical supplies are
designed with two separate 110V feeds.  the vast majority of appliances in
the house are plugged into standard outlets, which use a single leg of the
110 line, and go to ground for the other.  hence actual voltage will be 110V.

For various electrical purposes, the house should be wired so that the
loac on each leg will be approximately equal, but that's not too critical
an issue here.

Heavy duty appliances, such as electrical dryers, stoves, ovens, or
(large) air conditioners will run on 220V.  They get this by feeding both
legs of the electrical supply (which are 110V in opposite phase) to the
outlet.  so as leg #1 "pushes" 110v, leg #2 "pulls" and you get an
effective 220V supply.

Reason for this use is that net wattage ("power") is based on
voltage*amperage.  so if you double the voltage, you can get twice the
power through (roughly) the same wiring.

ANyway, what this means is that yes, in most cases, you can get a 220V
supply in your residence in the US/Canada.  But you have to be VERY
careful that you tap the right wires, etc.

ALso, the outlets used for 220V are DIFFERENT than the ones for 110V (for
obious safety reasons)...

If having 220V is important to you, then the simplest (from building code
and electrical code purposes) way is to simply tell them to install a
22V circuit for an airconditioner/heater, etc.  You can then use standard
extension cords and outlet taps, although you will have to replace the
110V sockets with the 220 ones.

(many years ago, long enough for the statue of limitations to protect me,
I had a shortage of outlets in my dorm room.  However, there was this nice
220 volt circuit just sitting there, designed for a heavy duty air
conditioner.  So I replaced the 220v physical outlet with a 110 volt one,
and plugged in various appliances I had that were dual voltage, like my
electric shaver, radio charger, and radio power supply.  NOT receommended
for children and other healthy living things <g>)

danny (zap/slash/singe) burstein

dannyb@panix.com

Newsgroups: sci.electronics
From: solomon@rocdec.roc.wayne.edu (Orson Scott)
Subject: Multiple VGA displays over long distances.
Organization: Wayne State University, Detroit
X-Newsreader: Tin 1.1 PL3
Date: Fri, 22 Jan 1993 05:02:13 GMT

I wish to take a VGA signal and display it on many monitors at the same
time. This would be very similar to the Queue display in use at the
airport which displays arrivals and departures.

Anyone have an ideas? I have a circuit design which will multiply the
signal but I am unsure how the signal will degrade over distance.

PLEASE EMAIL ME IF YOU HAVE ANY IDEAS........

-Solomon

solomon@rocdec.roc.wayne.edu or solomon@146.9.2.3
From: sdoyle@eniac.seas.upenn.edu (Scott Doyle)
Newsgroups: sci.electronics
Subject: HP 400D for sale
Date: 27 Jan 93 18:45:21 GMT
Distribution: usa
Organization: University of Pennsylvania



*****************  FOR  SALE  ********************

Hewlett-Packard Model 400D AC Voltmeter

**  0.001 to 300 volt range
**  10 Hz to 4 MHz freq. bandwidth
**  12 selectable ranges
**  Amplifier with output terminals to
    amplify small input signals.

  Excellent Condition
  Manual included

Own this classic for only $90 plus shipping.


***********************************************************************
Scott Doyle
sdoyle@eniac.seas.upenn.edu
215-898-4473
Newsgroups: sci.electronics
From: bill@thd.tv.tek.com (William K. McFadden)
Subject: Re: My TV is in a funny spot.
Organization: Tektronix TV Products
Date: Fri, 22 Jan 1993 20:14:08 GMT

In article <1jp9c2INNb7s@coral.bucknell.edu> rose@bucknell.edu (philip rose `94) writes:
>The VCR rabbit doesn't broadcast the signal.  The signal is sent through 
>a narrow bandwidth pair of wires (called miniwire or something like that).

The original Rabbit transmitted over a broadcast channel.  The wired version
came later (after the FCC clamped down).  Recent wireless systems use 900
MHz.

-- 
Bill McFadden    Tektronix, Inc.  P.O. Box 500  MS 58-639  Beaverton, OR  97077
bill@tv.tv.tek.com, ...!tektronix!tv.tv.tek.com!bill      Phone: (503) 627-6920
How can I prove I am not crazy to people who are?
From: myers@hpfcso.FC.HP.COM (Bob Myers)
Date: Fri, 22 Jan 1993 19:08:48 GMT
Subject: Re: cheap, reliable oscillator
Organization: Hewlett-Packard, Fort Collins, CO, USA
Newsgroups: sci.electronics


Uh, howzabout the NE555?

Seriously, you're going to have to give a little more information before
you can expect any meaningful answer.



Bob Myers  KC0EW   Hewlett-Packard Co.      |Opinions expressed here are not
                   Systems Technology Div.  |those of my employer or any other
myers@fc.hp.com    Fort Collins, Colorado   |sentient life-form on this planet.
Newsgroups: sci.electronics
From: hoffman@cmf.nrl.navy.mil (Eric Hoffman)
Subject: 68HC11 and 68681
Organization: Connection Machine Facility, NRL
Date: Mon, 25 Jan 1993 04:02:48 GMT


Is it true that the 68HC11 EVB comes with a 68681 or a 2681 DUART onboard?

I have one of the smaller EVBUs and I attached a 68681 to the bus in 
expanded mode. I can write to it fine, even though the DTACK line never
goes low. I cannot read from it all. 

I am concerned because quite a bit of the bus timing of the DUART
seems to be dependent on the X1 input, to which I have attached to a
271ns crystal as recommended. The CS line as decoded from the HC11 is
only 300ns long.  Is is possible that the bus cycle of the HC11 is too
fast for the 68681?  

If there is one on the EVB, would anyone be willing to fax me a copy of
the schematic? I've been poking around for some time with no success,
so even an assurance that the DUART can keep up with such a slow bus
cycle would be helpful.  

The data sheet claims that the maximum time from CS going low to 
data being asserted on the bus is 175ns, but this also seems to be
a factor of the phase of the X1 clock. 

thanx

Eric Hoffman
hoffman@cmf.nrl.navy.mil
(202) 767-1683 fax
From: naiming@eng.umd.edu (Naiming Shen)
Newsgroups: sci.electronics
Subject: Any cheap speech synthesizer board and library for PC?
Date: 28 Jan 1993 15:13:31 GMT
Organization: Electrical Engineering, University of Maryland
NNTP-Posting-Host: bagend.eng.umd.edu


I'm looking for a speech synthesizer board for IBM/PC/AT machine which
can transfer English into words prononced on a speaker. Further I would
like to have a 'C' library goes with it. Do you netters have any
info on this? thanks in advance.

Naiming Shen

Newsgroups: sci.med,talk.politics.medicine,talk.politics.misc
From: gld@cunixb.cc.columbia.edu (Gary L Dare)
Subject: Re: Robert Bourassa
Followup-To: talk.politics.medicine
Reply-To: gld@cunixb.cc.columbia.edu (Gary L Dare)
Organization: Deep Space Nine (DS9)
Date: Sun, 24 Jan 1993 22:25:21 GMT


During debates on public/private health insurance, socialized
medicine, etc. over the past year it had been pointed out by a number
of critics that Quebec Premier Robert Bourassa had been treated at the
National Cancer Institute in Washington, D.C. -- apparently a negative
in the eyes of those opposed to universal public health insurance and/
or socialized medicine (a la the UK).  Many commentators speculated
that it was merely a cover for diplomatic briefings with the U.S.
State Department's Western European and Canadian Affairs desk.  
Maybe that's partly true; the rest turns out to be real.

"Ici Canada This Week" on PBS, a show of CTV (largest private English
network in Canada) newsclips covered the story last week; apparently,
Boo-Boo has a very rare and odd form of skin cancer whose experimental
treatment by an international research team at NCI involving thoracic
surgery techniques not common to the usual cancer specialists (the
cancer is on his chest wall and "roots" downward into his torso) plus
an experimental drug which sounds a little like "interferon", i.e.,
the federalist hope of Quebec is also a guinea pig for Planet Earth.
Thus, Bourassa's case turns out not to be that of a wealthy person
crossing the US-Canada border to avoid the mythical medical queues.

gld
--
~~~~~~~~~~~~~~~~~~~~~~~~ Je me souviens ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Gary L. Dare
> gld@cunixb.cc.columbia.EDU 		Carnaval de Quebec (City)
> gld@cunixc.BITNET			February 4 - 14
Newsgroups: sci.med
From: szikopou@superior.carleton.ca (Steven Zikopoulos)
Subject: Re: What's Lorazepam
Organization: Carleton University
Date: Tue, 26 Jan 1993 23:46:31 GMT

In <18230@pitt.UUCP> geb@cs.pitt.edu (Gordon Banks) writes:

>In article <szikopou.727038286@cunews> szikopou@alfred.carleton.ca (Steven Zikopoulos) writes:
>>
>>I don't see how you can use the fact that one can suffer from seizures
>>after withdrawing from an benzodiazepine as a mark of addiction.  BZ's
>>supposedly potentiate GABA functioning (right?) and GABA is
>>inhibitory.

I haven't posted anything to this chain in ages.  A lot of stuff is
missing and I am (again) being misrepresented.  My comments are being
taken out of context and thus, no longer reflect my opinions.

Again I have to remind people to use [...] or [stuff deleted] to make
others aware that more was stated


Thank you
SZ
Newsgroups: sci.med