magnetic field

[Frithiof Andreas Jensen]

<timinohio@gmail.com> wrote in message
news:1165429325.322963.66490@n67g2000cwd.googlegroups.com...

My wife brought home a flat iron, used for straightening hair, from a
woman she works with. It would turn on, but not get hot. I opened it
up and discovered that a resistor (one lead blown off the board) and a
triac (case had a chunk missing) had failed.
Questions:
What would have had to happen to cause this?

heater shorts, then triac shorts, then triac gate resistor gets blown by the
mains voltage on it and finally the controller, if any, dies. The whole
appliance is shot - just get rid of it. A new one will probably cost about the
same as a new triac in retail prices.

What likely failed first? Did the resistor fail, causing the triac to
fail, or vice versa?
The resistor is tiny, about 6mm x 3mm, and the 5 color bands are very
hard to read. My DMM reads 1.2 Mohm. Is the reading from a failed
resistor accurate enough to get a replacement? If you had a resistor
that you couldn't read the color bands on, how would you replace it?

Thanks in advance.

Tim

 

[Chris Jones]

psdayama wrote:

cbarn24050@aol.com wrote:
If you feed your signal to a phase sensitive rectifier you get zero
volts out when the reference is at 90deg. If you use your micro to
generate the reference (square wave is fine) and feedback the psr
output (error voltage) back to the micros ADC you can lock the
reference to the signal. Repeat for the other signal. Since your micro
is now producing both reference waves it knows what the phase shift is.

Main problem again is to get squared output for PSD(not my initials
! )-
Phase sensitive detector requires squarewave to switch the signal's + &
- ve
So same problem roundabout! I think that now only solution is to take
40K samples per cycle that is 2M samples/second. Then detect the
zeros of ADC and use it as zerocrossing signal. After that micro will
decide the difference and cycle time and give phase angle down to
0.5 minutes. Also then micro will find the peak amplitude of signal at
checking abt 90 degrees.

If you just detect the zeros in the waveform, it is no better than using an
analogue comparator. If you are sampling the waveform with an ADC, then it
is much better to measure the phase by multiplying the samples by a sine
wave and averaging, and multiplying the samples by a cosine wave and
averageing, and finding arctan of the ratio of these two averages. You
could also use a FFT, though in this case I am not sure that it would be
the quickest to run.

Chris

 

[Clever Monkey]

Pete Verdon wrote:

Meat Plow wrote:
On Wed, 20 Dec 2006 02:00:39 -0800, John E. Has Frothed:

Hmm... according to this paper, both the USB and FW supplies output
12vdc:

http://docs.info.apple.com/article.html?artnum=60939

Which begs the question: how can you plug the iPod-to-USB cable into
either a computer (which outputs 5vdc) and the USB AC adapter (which
outputs 12vdc) and have no problems?
I must have some incorrect information... ?

Yes you do. USB is 5 vdc.

It is, but that doesn't imply that the USB-shaped output on Apple's
charger only provides 5v. Presumably the iPod is designed to handle the
higher voltage; perhaps it results in a faster charge? On the other
hand, it seems like a problem waiting to happen as far as plugging in
other USB-powered devices is concerned.

It depends on the charger, but the simplest design would have the higher

voltage offering less milliamps for charging. This might mean that the
12VDC source actually charges slower. Whether or not this is actually
noticeable or not is another question.

 

[Michael Kennedy]

I believe that they use an SMPS for the charger.

"Clever Monkey" <clvrmnky.invalid@hotmail.com.invalid> wrote in message
news:XZcih.47579$43.17564@nnrp.ca.mci.com!nnrp1.uunet.ca...

Pete Verdon wrote:
Meat Plow wrote:
On Wed, 20 Dec 2006 02:00:39 -0800, John E. Has Frothed:

Hmm... according to this paper, both the USB and FW supplies output
12vdc:

http://docs.info.apple.com/article.html?artnum=60939

Which begs the question: how can you plug the iPod-to-USB cable into
either a computer (which outputs 5vdc) and the USB AC adapter (which
outputs 12vdc) and have no problems?
I must have some incorrect information... ?

Yes you do. USB is 5 vdc.

It is, but that doesn't imply that the USB-shaped output on Apple's
charger only provides 5v. Presumably the iPod is designed to handle the
higher voltage; perhaps it results in a faster charge? On the other hand,
it seems like a problem waiting to happen as far as plugging in other
USB-powered devices is concerned.

It depends on the charger, but the simplest design would have the higher
voltage offering less milliamps for charging. This might mean that the
12VDC source actually charges slower. Whether or not this is actually
noticeable or not is another question.

 

[NudoWhacker]

On 24 Dec 2006 10:38:09 -0800, "duty-honor-country"
<dutyhonorcountry2@hotmail.com> wrote:

http://cgi.ebay<snip

HELP GET A SPAMMER'S EBAY ACCOUNT TERMINATED!

This spammer, Charles M. Nudo, Jr. of Drums, PA, is a well-known
scammer and fraudster, selling counterfeit dupes of 8 tracks as well
as worthless crap to unsuspecting buyers on eBay for years now. He
has consistantly violated eBay's Terms of Service
regarding Usenet spam, to wit:

http://pages.ebay.com/help/usenet_policy.html

Nudo now uses four "google groups" accounts from which to spam:

dutyhonorcountry2@hotmail.com
elkhound68@yahoo.com
prshgry@yahoo.com
backthetowerlines@yahoo.com

Here's a recap of his latest spam efforts, almost all of which are in
groups that explicitly do NOT allow eBay spamming, especially for any
off-topic item:

http://groups.google.com/groups/search?q=author%3Adutyhonorcountry2%40hotmail.com+OR+author%3Aelkhound68%40yahoo.com+OR+author%3Aprshgry%40yahoo.com+OR+author%3Abackthetowerlines%40yahoo.com+%22VINTAGE+SANSUI%22&start=0&scoring=d&hl=en&lr=&safe=off&num=10&as_drrb=q&as_qdr=w&filter=0&

Please take the time to take this spammer's original post at the top
of the thread, forward it WITH HEADER to:

abuse@epix.net
groups-abuse@google.com
spam@ebay.com

You may get a "bounce" from eBay, as they like to make it difficult to
rat out their sacred cow sellers, but there will be a link for which
to forward the report.

HELP WIPE OUT A FRAUDSTERING SPAMMER TODAY!

 

[Fred Kemper]

Ah, I forsee the first flamefest of 2007coming.....



--
Fred
TX
CARGPB#8
******************
"Art M - Artfromny" <artgames@nycap.rr.com> wrote >I got this as a working unit from a repair depot but have not tested it,

selling as is, no probes pods or other accessories included. Price is for shipping in the contiguous 48 states; AK HI PR higher.
Email for overseas shipping quote.

--
Art

 

[Michael Kennedy]

Well I know that the newer ipods don't support firewire, but they will still
charge from it.

- Mike

"James Sweet" <jamessweet@hotmail.com> wrote in message
news:1uFmh.3083$T%3.1644@trndny08...

By the way,Does anyone know how to get a 2nd Gen. Nano to charge from a
USB port *without* a host controller?
(IE,just +5V and GND connected to a USB jack.)
I tried the pull-up/pull-down resistor thing on the Data+ and Data-
lines,Nada.Leave them floating,Nada.
It charges for ~3 seconds,then stops once it discovers that there's no
host to negotiate with.

I wonder if it needs to negotiate with the host over the Firewire
connection also? Wish I had the firewire cable to try it!

IIRC the Nano does not support FireWire as the earlier iPods did.

 

Marc Guardiani wrote:

rbezona@nefcom.net wrote:
I wish to burn old 78 rpm records to CDs.
I have an old Stereo with a 78 rpm player but it has no output jacks.
There are external speaker jacks the old
full size ones.

What would be the best way to connect to a PC to record from the
phonograph?

Any suggestions will be appreciated.

Thanks

If you have access to the phono output, you can try this
http://www.dak2000.com/Reviews/2020Story.cfm

Let the DAK flames begin...

Marc

Thanks Marc,

This looks like a great solution.

 

[John]

On 20 Jan 2007 18:56:45 -0800, doc@sympatico.ca wrote:

While attempting a home-charge of a set of NiCd batteries, they were
left unattended and consequently exploded (relatively high current was
flowing through them). The basement area in which the explosion took
place is currently being ventilated overnight.

Does anyone have any recommendations for further safety precautions or
clean-up procedures?

Thanks

Sounds like you need a haz-mat suit, a pressure washer, a wet-dry
vacuum and some 55 gallon drums in which to dispose of the stuff you
wash off the walls, ceiling, and floor...

Unless you have proper voltage and current limiting, plus temperature
sensing, NEVER charge nicads (or other rechargeable cells) at a rate
greater than C/10 (1/10 of the cell's AH rating). If charging
unattended, even the C/10 rate may cause loss of capacity after more
than 14 hours (less if the cell is only partially discharged).

I have a HeathKit adjustable supply ( 50V 1.5A ) with both voltage and
current limiting. I use it to charge all types of rechargeables
(yes, even lithium cells) but only when the battery specs are
available for setting the proper charging conditions.

I've been using rechargeables (nicad, NiMH, SLA, lithium) for more
than 20 years with NO catastrophic failures.

John

 

[John]

On 21 Jan 2007 08:38:21 -0800, rbezona@nefcom.net wrote:

I wish to burn old 78 rpm records to CDs.
I have an old Stereo with a 78 rpm player but it has no output jacks.
There are external speaker jacks the old
full size ones.

What would be the best way to connect to a PC to record from the
phonograph?

Any suggestions will be appreciated.

Thanks

Make a voltage divider of a couple of resistors (1000ohm and 330ohn)
for each speaker line. --1000--330--
connect the open end of the 330 to the ground side (usually the
sleeve) of the speaker connector and the open end of the 1000 to the
other side.
Connect the ground side to the ground side of the sound card's LINE
INPUT connector and the junction of the 1000 and 330 to the other side
(center).

Enable the LINE INPUT on the sound card. Adjust the level as needed.

John

 

[Don Bruder]

In article <1169348204.959697.308040@q2g2000cwa.googlegroups.com>,
doc@sympatico.ca wrote:

While attempting a home-charge of a set of NiCd batteries, they were
left unattended and consequently exploded (relatively high current was
flowing through them). The basement area in which the explosion took
place is currently being ventilated overnight.

Does anyone have any recommendations for further safety precautions or
clean-up procedures?

Thanks

Sounds to me like you just created yourself a fairly serious
toxic-hazard site... Smooth move!

Better hope the EPA doesn't get wind of it, or you may find that you're
the proud owner of a hole in the ground and a big cleanup bill.

(And no, I'm *NOT* kidding - Nickel is no big deal, but cadmium is one
of those items on the lists of things that can get the EPA and similar
outfits *REALLY* nervous - nervous to the point of "knock down the
building and scrape the debris and the top 6 feet of dirt into sealed
barrels, then truck it to a hazardous materials storage facility - it's
the only way to be sure.")

--
Don Bruder - dakidd@sonic.net - If your "From:" address isn't on my whitelist,
or the subject of the message doesn't contain the exact text "PopperAndShadow"
somewhere, any message sent to this address will go in the garbage without my
ever knowing it arrived. Sorry... <http://www.sonic.net/~dakidd> for more info

 

[Homer J Simpson]

<rbezona@nefcom.net> wrote in message
news:1169397501.777660.121740@s34g2000cwa.googlegroups.com...

What would be the best way to connect to a PC to record from the
phonograph?

Any suggestions will be appreciated.

Buy a TEAC GF-350

or Microsoft Plus! For WinXP

or Nero Wave Editor

 

Don Bruder wrote:

....

Sounds to me like you just created yourself a fairly serious
toxic-hazard site... Smooth move!

....

Thanks for the suggestions guys.

FWIW, this happened because I was doing a fast charge.
I'm usually very careful to stop the process as soon as there
is any heat.

But this time I got called to dinner when I should have been
watching the stew. Actually more like pop-corn!

On a more serious note, I am reminded about how familiarity breeds
contempt and can often lead to compromising safety.

Anyway, cleaned up the mess. No real harm seems to have been
done except I prolly blew up about $60.00 worth of nicad cells.


DOC
Have robots. Will travel. http://www.robot-one.ca

 

[John Fields]

On 18 Apr 2006 05:40:08 -0700, lweauthors@mfx.net wrote:

Hello,

My name is Victoria Roberts and I am the Acquisitions Administrator for
Lone Wolf Enterprises, Ltd., a book producer. McGraw-Hill has asked us
to produce books on the following general topics: signal processing,
emerging communications technologies, cutting edge digital design
techniques, and optical engineering. The prospective author should
have significant standing in his professional community and/or a strong
promotional platform.

If you are interested in becoming a published author, please reply with
your credentials to me.

---
If I were interested in authoring a book for McGraw-Hill why would I
want to go through an intermediary?

--
John Fields
Professional Circuit Designer

 

[JoeBloe]

On Fri, 24 Nov 2006 17:11:49 -0500, "John Doe" <hgorden@adelphia.net>
Gave us:

Do NOT post binary files into non binary groups, you IDIOT!

 

[Luhan]

Charles Jean wrote:

Is there a way to play a wav file over an open telephone line? Can
the earphone output of a sound card be used? Would it need to be
amplified or attenuated? Capacitance coupled?

A 600-600 ohm transformer is the usual way. The headphone level is a
pretty good match, but if you pump too much signal into the phone line,
you will piss-off the phone company.

Luhan

 

On Feb 12, 6:10 am, "Geronimo Stempovski"
<geronimo.stempov...@arcor.de> wrote:

I think transmitting high-speed signals is very easy when you have a
360-degree ground reference, round conductors,
and no other nearby signals like in coaxial cables. My aim is to design PCB
tracks as much like a coaxial cable as
possible. Anyone tried this before? Is it possible with regular FR4, anyway?
Thanks for your help.

Gero

You can build a wave guide out of a multi-layer board with lots of
micro vias. The performance gain was non-existent vs traditional micro/
strip/line, and cost a lot of money. These days you can satisfy
yourself of this reality with a 3D field solver. Back when we tried
this, workstations were as slow as building it "for real", and more
expensive.
Just break out to a connector, use a coax assembly, and connect back
in. Easy peasy.

 

[Fred Bloggs]

a7yvm109gf5d1@netzero.com wrote:

On Feb 12, 6:10 am, "Geronimo Stempovski"
geronimo.stempov...@arcor.de> wrote:

I think transmitting high-speed signals is very easy when you have a
360-degree ground reference, round conductors,
and no other nearby signals like in coaxial cables. My aim is to design PCB
tracks as much like a coaxial cable as
possible. Anyone tried this before? Is it possible with regular FR4, anyway?
Thanks for your help.

Gero


You can build a wave guide out of a multi-layer board with lots of
micro vias. The performance gain was non-existent vs traditional micro/
strip/line, and cost a lot of money. These days you can satisfy
yourself of this reality with a 3D field solver. Back when we tried
this, workstations were as slow as building it "for real", and more
expensive.
Just break out to a connector, use a coax assembly, and connect back
in. Easy peasy.

There is such a thing as microcoax, so he can chisel out a little groove
in a thick pc and stuff that in there.

 

[MassiveProng]

On Mon, 12 Feb 2007 14:17:50 GMT, Fred Bloggs <nospam@nospam.com> Gave
us:

a7yvm109gf5d1@netzero.com wrote:
On Feb 12, 6:10 am, "Geronimo Stempovski"
geronimo.stempov...@arcor.de> wrote:

I think transmitting high-speed signals is very easy when you have a
360-degree ground reference, round conductors,
and no other nearby signals like in coaxial cables. My aim is to design PCB
tracks as much like a coaxial cable as
possible. Anyone tried this before? Is it possible with regular FR4, anyway?
Thanks for your help.

Gero


You can build a wave guide out of a multi-layer board with lots of
micro vias. The performance gain was non-existent vs traditional micro/
strip/line, and cost a lot of money. These days you can satisfy
yourself of this reality with a 3D field solver. Back when we tried
this, workstations were as slow as building it "for real", and more
expensive.
Just break out to a connector, use a coax assembly, and connect back
in. Easy peasy.


There is such a thing as microcoax, so he can chisel out a little groove
in a thick pc and stuff that in there.

Semi-rigid is the term, and if it is in coax, it doesn't need to be
IN the PCB from point to point.

I wish you guys would stop cross posting all over the place. Many
ISPs have group inclusion limits.

It is also not considered proper Usenet practice.

 

[werty]

On Feb 12, 2:30 pm, "john jardine" <j...@jjdesigns.fsnet.co.uk> wrote:

"Geronimo Stempovski" <geronimo.stempov...@arcor.de> wrote in message

news:45d04b34$0$27624$9b4e6d93@newsspool2.arcor-online.net...> I think transmitting high-speed signals is very easy when you have a
360-degree ground reference, round conductors,
and no other nearby signals like in coaxial cables. My aim is to design
PCB
tracks as much like a coaxial cable as
possible. Anyone tried this before? Is it possible with regular FR4,
anyway?
Thanks for your help.

Gero

Had trouble with crosstalk on a mass of video signals. Cured with a
multilayer board where each signal was 'boxed in' by ground plane to the
sides, above and below. Sort of square coax.

--
Posted via a free Usenet account fromhttp://www.teranews.com

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

Boxed ! the wavelength is far greater than
your dimensions , thus higher modes can not
exist , thus you do NOT need sides .
When you reach 10 Ghz , then maybe
you need sides in ur boxed "coax" .

But the big joke , is in the real world ,
they use cheap PCB to xmit 2.5 Ghz .
No strip line , no microstrip , nada ..
It works well , so quit arguing reality .

BTW , i saw some novice , trying to
use juice cans to launch WiFi .
He figured the more cans , the more
gain . He had 3 cans , T'd .
to divide the power .
Gain is not in cans , its in size of
the dish .

Another book worm said all i needed
was $26 for 100 meters of blah blah
coax at 2.5 Ghz ..

10 times that price !
and 1.8" dia hard line !

At these wavelengths , its lower loss
to send it TEM and thru the air ,
not thru a coax .

This is goin to FPGA ? Do those relics
still exist ?! Oh well , i supose ya gotta
try to "protect" your firmware by reinventing
the CPU !