magnetic field

On Wed, 02 Mar 2005 12:00:51 -0500, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

On Wed, 02 Mar 2005 09:19:17 -0700, the renowned Jim Thompson
thegreatone@example.com> wrote:


Yep, Canadian cities.

Actually we should just send all the beef back, quoting Spehro, that's
the way democracy works ;-)

...Jim Thompson

Don't "forget" to send all the oil, gas and electricity back too. ;-)
OK, we'll just take back our Fritos and Oreos and Velveeta and
microwave popcorn and Bud Light and "Sex And The City" and you'll be
sorry.

John
 
On Wed, 02 Mar 2005 17:05:16 -0800, the renowned John Larkin
<jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:

On Wed, 02 Mar 2005 12:00:51 -0500, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Wed, 02 Mar 2005 09:19:17 -0700, the renowned Jim Thompson
thegreatone@example.com> wrote:


Yep, Canadian cities.

Actually we should just send all the beef back, quoting Spehro, that's
the way democracy works ;-)

...Jim Thompson

Don't "forget" to send all the oil, gas and electricity back too. ;-)



OK, we'll just take back our Fritos and Oreos and Velveeta and
microwave popcorn and Bud Light and "Sex And The City" and you'll be
sorry.

John
At least we'll still have Cheezies and ketchup Doritos.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
On Wed, 02 Mar 2005 17:05:16 -0800, John Larkin
<jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:

On Wed, 02 Mar 2005 12:00:51 -0500, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Wed, 02 Mar 2005 09:19:17 -0700, the renowned Jim Thompson
thegreatone@example.com> wrote:


Yep, Canadian cities.

Actually we should just send all the beef back, quoting Spehro, that's
the way democracy works ;-)

...Jim Thompson

Don't "forget" to send all the oil, gas and electricity back too. ;-)



OK, we'll just take back our Fritos and Oreos and Velveeta and
microwave popcorn and Bud Light and "Sex And The City" and you'll be
sorry.

John
Sno-o-o-o-o-ort!

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
"Gabriel" <dupuis_gabriel@yahoo.ca> writes:

Hello,

Recently, I had a big power surge problem involving both my brand new
laptop and my less than two years old TV. Two total looses.

My main concern is that I don't really understand what happened and,
thereof, can't see a way to prevent it in the future.
I just can give quesses also...
To giv definitive answer, I would need to be in place with
some measurement instruments...


Here's the story :

I bought a few weeks ago an HP notebook with an S-Video output. I used
my laptop (on battery and AC power) a week and a half before trying the
S-Video output and did not have a single problem.

So, someday, I decided it was time to try to connect my laptop on my TV
by using the S-Video output. I bought a S-Video-to-RCA cable at
Radioshack because I thought it would be more practical to have my
laptop connected to the front RCA jacks of my TV.
Generally sounds OK.
The safest idea is to do the connection while the components
are turned off and not plugged to wall...
Sfest bet in connection is to make sure your PC is
not connected to mains, connect the video cable and then
plug it to wall if needed...

As soon as the contact was made, both my laptop and TV went off and I
could smell a light odour of burnt electronic components. The TV did
not seem to be damaged because I could turn it on almost immediately.
As for the laptop, I simply had to reinsert the battery to make it
start.
Sounds like you got quite a surge to the system....

Maybe it was very stupid, but I thought that the problem could be the
cheap RadioShack cable. So I decided to buy a true S-Video cable.
Most propably the problem here was not in the cable construction itself..

For my second try, I choose to not plug the laptop into the AC outlet
and just use the battery. After connecting the laptop to the TV, all I
see is a black screen. By the way, I did not feel like there was a
power surge problem this time.
The surge could have damaged the video output on your PC or
the input on the TV.. A surge through RCA connector can
cause this.. RCA connector is a very stupid connector
for audio/video connection because normally it connectes the
center pin that carries the signal before the signal ground,
allowing the potential difference between the different equipment
to enter the equipment as surge! This has damaged many equipment
in systems where there are ungrounded PCs or other grounding problems...
I know people who have damaged for example PC sound cards, PC video
cards, TV audio/video inputs, AV amplifier audio/video connections etc..
And the real life experiences (few damaged components) have teched
me to become careful.

In the computer connections there would be lots of less
damaged equipment if proper connections for the applications
are used... Professional audio/video world prefers
XLR and BNC connectors for their connections, both of those
guarantee that ground gets always connected first...
Lots of less fried equipment and more reliable connections.


If things are correct, meaning the cable is correct and still working, computer
settings are correct, TV video input still working and TV settings correct
you should get picture when you run the computer from battery.
Generally with a laptop it is safest to run the computer from
battery on its own (not connected to anything else connected
to mains power or anything else). When you have just the computer
running with batteries it is harver to fry it...

Days later, I really wanted to make my S-Video port work. So, I
downloaded the latest devices drivers for my graphic card and gave the
S-Video output a new try with the laptop connected to the AC outlet.
Not a good idea.
Again, as soon as the contact was made, both my laptop and TV went off
and I could smell a strong odour of burnt electronic components. This
time the damage was terrible. Both my laptop and TV are completely
fried. There is just no way to make'em work anymore.
I would have tried the computer running at batteries without mains
connection. Your sirge problems are most proplably somehow related
to AC power connection.

So my questions are :

1) What happened ?
There was some form of surge formed when you do the connection.
There are varuous possibilities. Some possibilities:
- your TV is conencted to cable TV system that is not properly
grounded and there is some energu there that gets through
your cable and equipment to mains ground
- your ungrounded TV + DVD system is not connected to cable TV outlet,
but some equipment inside it is damaged to that the mains power
gets to the equipment case + AV conenctor ground, when you
do connection to grounded PC you will create a short circuit
(this will generate huge surge and generally burn fuse on mains panel),
- Your TV system is connected to properly grounded cable TV connection
(or properly grounded antenna on your roof) but the is something
wrong in the grounding of your mains outlet grounding (miswired etc..)
so you mains outlet ground has some power on it, when you equipment
chain makes link to cable TV ground you get a large current surge
through your wiring and equipment (might not burn any fuses..)
- your TV + DVD system is not connected to cable TV or other ground,
the ungrounded properly working equipment "leak" some small amount
of power to their cases (this is normal), so the cases are
not at ground potential (usually at around 30-60V AC potential
if you measure them agains ground with a modern multimeter),
when you do the connection with RCA connector, this voltage
difference causes a surge to both equipment on the end of cable
(before the voltage difference gts nulled when groudn gets connected)
- laptop computer power supply is damaged and leaks mains power to PC
case, this gets though your witing to cable TV ground

2) How could I prevent this kind of surge ?
Here are few tips:

- do the connections only when equipment are not powered up and
not plugged to wall
- run your PC preferably with it's internal battery only and not
connected to anything else (modem and Ethernet with UTP cable are OK,
USB connection to equipment with its own power supply is not a good idea)
- do the connections so that you always the ground gets connected
before the signal itself (might need you to used special RCA
connectors or adaters to BNC connections etc..)

Best if yuo can use all of those tips... Sometimes you can only
follow some of them and you need to take your changes...

3) Should I never try to connect a laptop to a TV ?
With a properly caefully done connection will work well...

I made a diagram of my living room electrical setup. You can see it at
this URL : http://home.ca.inter.net/~gdupuis/livingroomsetup.jpg

I don't think that the problem is from my TV since it is almost new and
because it never fried my DVD player or VCR. I guess the problem comes
from my laptop, but I still don't really understand.
The problem could in any equiopment or your house wiring
(antenna/cableTV/mains).

Any help would be greatly appreciated. I really need to understand
since I don't know much about electricity.
Thank you very much.
Hopefully my tips have helped you.

(By the way, I am very sorry for the poor English. It is not my
language.)
Your message was very well readable and understandable English.

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/
 
"Neil" <neilwrites2@hotmail.com> wrote in message
news:1109892001.019432.35700@l41g2000cwc.googlegroups.com...
Hello

For anyone who has burned CD's for Music, or Data, I've found VERBATIM
CD'S are the worst. The average seek time is > 7 seconds for newly
burned discs. I thought I had a problem with my CD-RW Drive, so I
cleaned the optical laser with a cleaning CD, then lightly cleaned it
out with compressed air. I tried other brands from TDK, Maxell,
Imation, CD-R's and they all work fine.

I also looked at the model of my player to make it was MULTI-READ
COMPLIANT, and it is. It appears that the stamped out( bright silver
surface type) CD's from the Software Companies work the best. The
average seek time is less then a couple seconds. These VERBATIM CD-R's,
the surface refectivity is very low, so the laser takes longer for it
to read the CD. If there was a mechanical problem with my drive, it
would of showed up on ALL the discs, not just Verbatim
CD-R's but it doesn't. My friend had the same problem with a burned
CD I gave him from the stack, and he has a Brand new SONY CD_RW/DVD
Writer Drive on his system.

Avoid them like the plague! I'm thinking of dumping these CD-R's and
buying some others to replace them. You might have better luck with
your machine,model,make etc, but I will never buy these again!!

For those who are wondering which ones I'm refering to, on the side of
the blue and white packaging, there is a reorder number# 95028

I wrote Verbatim a Email,I notified them that there could be
manufacturing flaw with the CD-R's I got at christmas.

No Reply!!

-Neil
Ive not found a single DVD-RW which works yet, got 4 or 5 different makes,
tried on 3 seperate makes a DVD drives, all failed a basic format. binned
about 50 of them not to long ago, not even been used, got a load of them
left unused aswell, using them for costers at the moment......

chris
 
On 3 Mar 2005 15:20:01 -0800, "Neil" <neilwrites2@hotmail.com> wrote:

Hello

For anyone who has burned CD's for Music, or Data, I've found VERBATIM
CD'S are the worst. The average seek time is > 7 seconds for newly
burned discs. I thought I had a problem with my CD-RW Drive, so I
cleaned the optical laser with a cleaning CD, then lightly cleaned it
out with compressed air. I tried other brands from TDK, Maxell,
Imation, CD-R's and they all work fine.

I also looked at the model of my player to make it was MULTI-READ
COMPLIANT, and it is. It appears that the stamped out( bright silver
surface type) CD's from the Software Companies work the best. The
average seek time is less then a couple seconds. These VERBATIM CD-R's,
the surface refectivity is very low, so the laser takes longer for it
to read the CD. If there was a mechanical problem with my drive, it
would of showed up on ALL the discs, not just Verbatim
CD-R's but it doesn't. My friend had the same problem with a burned
CD I gave him from the stack, and he has a Brand new SONY CD_RW/DVD
Writer Drive on his system.

Avoid them like the plague! I'm thinking of dumping these CD-R's and
buying some others to replace them. You might have better luck with
your machine,model,make etc, but I will never buy these again!!

For those who are wondering which ones I'm refering to, on the side of
the blue and white packaging, there is a reorder number# 95028

I wrote Verbatim a Email,I notified them that there could be
manufacturing flaw with the CD-R's I got at christmas.

No Reply!!

Like most cdr mfgs, Verbatim make premium cdrs and cheap, shit cdrs.
You've got a pack of their cheap, shit cdrs.

I use the premium ones (they call 'em datalifeplus) a lot and never
have any problems.
 
Ol' Duffer <DontSend@MeSpam.net> writes:

In article <W8SZd.19761$d5.149287@newsb.telia.net>, bos@hack.org says...
As stated above, I'm using veroboards (stripboard and breadboard is a
synonyme for the same thing, i think) for building my circuits. I also
own a licence of Electronic Workbench (Multisim and Ultiboard are the
ones I use most frequently). However, since I do not own any etching
equipment Ultiboard is of less use for me since it can only do
PCB-layout/routing. I have contacted the developers to hear if there was
any possibility to make Ultiboard output to veroboards, but regretfully
enough UB is designed for PCB only, was the answer.

I am not familiar with that package, but have used commercial
routing programs to do veroboard and thought it was a piece of
cake. At least compared to pencil, eraser, and graph paper.
Just snap to a 0.100" grid and remember that the traces on the
bottom only run one direction. No it won't tell you where to
make cuts, but is that really so hard to figure out?
LochMaster claims to be a developers tool for strip board
(VERO) projects for designing, documenting and testing a board.
This is a commercial program.

LochMaster 3.0
http://www.abacom-online.de/html/lochmaster.html

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/
 
Jon G. wrote:

Hi,

I dont understand how the latching relay works. Here is the diagram:


V2309-B1208-B301

|-\ -|
*-------* | \ | *-----*
| | | | | | |
| r *-----------------* r |
s -|+ e |12 10 9 8 7 | e -|+ s
e === s | | s === e
t +|- e | 1 3 4 5 6 | e +|- t
| t *-----------------* t |
| | | | | | |
*-------* | / | *-----*
|-/ -|

contacts in reset position. Both coils can
be used as either set or reset coil.

pins 1,12 are one coil, pins 6,7 are the other coil.

For instance, does this mean? (below)

pins
time,sec 12 10,9 9,8
--------------------------------
1 1 closed open
2 0 open closed
3 1 open closed
4 0 closed open

pins
time,sec 6 3,4 4,5
--------------------------------
1 1 closed open
2 0 open closed
3 1 open closed
4 0 closed open

can I just leave one coil open and only use the other?

Jon

you have keep smething in mind: latching relay means
mechanically latched. To change the relay state you have to use
a pulse on either coil. never leave power on steady or you will not
be able to change the state
rw
 
Hi Jon,
Take a look at this data sheet. It shows the internals of the 2 coil
latching relay.
http://rocky.digikey.com/scripts/ProductInfo.dll?Site=US&V=255&M=DS4E-SL2-DC24V
The relay contains a magnet that latches the points. If you meter the
points and pass a strong magnet over the relay it will transfer
depending on the orientation of the magnet.
Dave

Jon G. wrote:
Hi,

I dont understand how the latching relay works. Here is the
diagram:


V2309-B1208-B301

|-\ -|
*-------* | \ | *-----*
| | | | | | |
| r *-----------------* r |
s -|+ e |12 10 9 8 7 | e -|+ s
e === s | | s === e
t +|- e | 1 3 4 5 6 | e +|- t
| t *-----------------* t |
| | | | | | |
*-------* | / | *-----*
|-/ -|

contacts in reset position. Both coils can
be used as either set or reset coil.

pins 1,12 are one coil, pins 6,7 are the other coil.

For instance, does this mean? (below)

pins
time,sec 12 10,9 9,8
--------------------------------
1 1 closed open
2 0 open closed
3 1 open closed
4 0 closed open

pins
time,sec 6 3,4 4,5
--------------------------------
1 1 closed open
2 0 open closed
3 1 open closed
4 0 closed open

can I just leave one coil open and only use the other?

Jon
 
The USB to serial adaptor is really a virtual port. It lacks the full
compliment of connections. It is really a very basic RX / TX coupling. There
are many devices that require the DTS, and or RTS, and or DSR.

I have a TI calculator, and a few other devices. I bought for my laptop a
USB to serial adaptor. There devices did not work with it. I found that my
serial modem did work with it, if I configured it to work in its most basic
connection requirements. I also found that some models of GPS's will work,
and a number of them will not.

In the end, I bought a PCMCIA serial adaptor. This gives a real serial port
to the laptop. This works with everything, as it should. It was a lot more
money than the simple USB to serial port, but it works.

--

JANA
_____


<cwynnes@hotmail.com> wrote in message
news:1111757184.126400.74120@o13g2000cwo.googlegroups.com...
Hey,
I'm doing a project that requires a USB to Serial Converter and the one
I have been provided with is made by comfile, i have it all set up but
the only problem is that the link been given by lextronic.fr does not
work and the user manual given on the comfile site states that i can
download the driver from their site but unfortunately this does not
seem possible, i have tried e-mailing comfile twice about this problem
but have not recieved a reply in over a week, i also tried emailing
lextronic.fr but still no reply, could anybody please help me on where
i could possibly get this driver, Has anybody any experience with this
component, Any help would be greatly appreciated,
Regards,
Colm
 
"kl1k" <kl1k@hotmail.com> wrote in message
news:1112168974.396591.311780@f14g2000cwb.googlegroups.com...
I'm looking to build a NiCd charger to charge 2 or 4 1.2V NiCd's

The only circuit I've come across is for a 9V battery
(http://www.uoguelph.ca/~antoon/circ/nicd.htm)

Has anyone tried to convert this to change 2 or 4 cells. Or can anyone
point me to another free circuit.
Why not look at Microhip's website they have charger chips (NiCd and NiMh
cell compatible) and application notes with example circuits.

Chris
 
In article <1112227155.640695.247970@o13g2000cwo.googlegroups.com>,
Andre / testing_h@yahoo.com wrote:
Hi group.

I had an interesting idea that perhaps the reason why science has yet
to duplicate the anomalous long lifetime of natural ball lightning is
simply that the scale is wrong.
<SNIP>

Feel free to comment :)
I think more lightly ball lightning is mostly either of these:

1. Afterimages of a bright spot where lightning hits - such as a spot
where metal or salts vaporize. Or an afterimage of a "bright spot" caused
by a segment of lightning stroke being nearly parallel to your line of
sight.

2. Drops of molten metal falling from where lightning hits. Molten metal
does not wet most nonmetallic materials and sometimes fails to wet
metallic objects, so drops of molten metal roll along things very easily.
It is fairly common for drops of molten metal to only mildly and/or
intermittently scorch things they roll over if they move fast enough. And
they can be fairly large due to the high surface tension of many molten
metals. In addition, sometimes aluminum can burn in a manner like that of
magnesium, and is at least sometimes more easily ignited by an arc than by
a flame.

- Don Klipstein (don@misty.com)
 
On 31 Mar 2005 06:08:10 -0800, googlemike@hotpop.com wrote:

I'm a PHP web developer working with Linux by day, and I tinker with
side projects at home to see if I can get something off the ground. I
need someone to give me advice on a webcam project where I need to use
wired, not wireless, cameras to build a video surveillance arrangement
that can be used in large offices. I got excited about the idea when I
found out that my office paid $30K for their video surveillance system.

The first part of this is the wiring of the video cam. I understand
that USB requires repeater extender things to run it over long
distances, and these may require an AC input. But has anyone
experimented with switching the signal to CAT 5 and then putting it
back onto USB again? Shouldn't it then be able to go longer distances?

Before I start tearing apart a web cam's USB cable in my garage to do
this experiment to see how long the video signal can run with CAT5, I'd
like to know if someone has advice on this.
USB has an inherent limit of around 5M.
I have seen USB repeaters that use cat5, e.g.
http://cpc.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=CS11725&N=401

Of course you could just use composite analogue and a multi-channel capture card at the PC end.
 
I suggest you get some terms straigned out...
googlemike@hotpop.com wrote:

The first part of this is the wiring of the video cam. I understand
that USB requires repeater extender things to run it over long
distances, and these may require an AC input. But has anyone
experimented with switching the signal to CAT 5 and then putting it
back onto USB again? Shouldn't it then be able to go longer distances?
Cat5 aint a signal. It is a cable. The cable can carry whatever signal
you want, but it is a twisted pair (TP) cable, thus not suited for some
signals.
USB is _not_ made for TP cable, and would probably give worse results
than using a loooong usb cable.

Before I start tearing apart a web cam's USB cable in my garage to do
this experiment to see how long the video signal can run with CAT5, I'd
like to know if someone has advice on this.
It ain't a video signal as such. It is digital information, whatever
this information is a video format, a word document, sound or whatever,
it has to be undamaged when arriving into the pc.

What I guess you're looking for is some way to convert the USB signals
to Ethernet signals, which can run 250M on CAT5E cable by the
specification.




--
MVH,
Vidar

www.bitsex.net
 
Assuming AA-size cells, you can buy these in the UK, with 4 LEDS, a
Test/Discharge meter function and it optionally does AAA sizes, C sizes, 2 x
9V accumulators as well, with 4 AA-size NiCd cells for about Ł12. Why design
one?



"kl1k" <kl1k@hotmail.com> wrote in message
news:1112168974.396591.311780@f14g2000cwb.googlegroups.com...
I'm looking to build a NiCd charger to charge 2 or 4 1.2V NiCd's

The only circuit I've come across is for a 9V battery
(http://www.uoguelph.ca/~antoon/circ/nicd.htm)

Has anyone tried to convert this to change 2 or 4 cells. Or can anyone
point me to another free circuit.
 
In article <1112278089.874159.95440@o13g2000cwo.googlegroup
s.com>, googlemike@hotpop.com says...

Before I start tearing apart a web cam's USB cable in my
garage to do this experiment to see how long the video
signal can run with CAT5, I'd like to know if someone
has advice on this.
There are devices for converting USB to a form which allows
transmission over CAT5 over fairly long distances. Here's
one (the URL probably won't wrap right. Sorry.):

http://www.usbgear.com/computer_cable_details.cfm?sku=171632
&cats=137&catid=137%2C140%2C120

Extends any USB device up to 150 feet away the computer.
The mini USB-2 extender extends any USB device including
keyboard and mouse up to 150 feet away from the location
of your computer, eliminating the 17.5 feet distance
limitation of USB. The mini USB-2 send and receive units
use one CAT-5 cable for extension and is optimized for
applications where two devices, such as the keyboard and
mouse, must be operated remotely. Category 5-cables to
go with this device Starting from $7.06 for 75FT. Cable
How it works: The mini USB-2 extender send unit is
placed next to the computer. A USB cable connects the
computer to the mini USB-2 extender send unit. A
category-5 (CAT-5) cable is used to link the mini USB-2
send unit to the mini USB-2 receive unit. The USB
peripherals are connected to the mini USB-2 receiver
unit. The USB-2 extender can even be used to extend
surveilance cameras for security purposes.
Google on USB extension, or USB extender.
 
<googlemike@hotpop.com> wrote in message
news:1112278089.874159.95440@o13g2000cwo.googlegroups.com...
The first part of this is the wiring of the video cam. I understand
that USB requires repeater extender things to run it over long
distances, and these may require an AC input. But has anyone
experimented with switching the signal to CAT 5 and then putting it
back onto USB again? Shouldn't it then be able to go longer distances?
Why not use network based cameras?
http://www.tomsnetworking.com/Reviews-68-ProdID-AXIS205.php
 
If you want to mess with sending video over CAT 5 (eg rather than digital
data)...
http://www.smarthomeusa.com/Shop/Home-Network/channelvision/CV-Baluns/Item/VBS78-SP/
 
"kl1k" <kl1k@hotmail.com> wrote in message
news:1112168974.396591.311780@f14g2000cwb.googlegroups.com...
I'm looking to build a NiCd charger to charge 2 or 4 1.2V NiCd's
Why bother. Two and four cell chargers are very cheap.

If you are designing a product then perhaps you should think again and
employ someone who knows what they are doing....

a) NiCads are being phased out because they are bad for the environment (See
NiMH).
b) Have you ever seen an abused NiCad explode ?
 

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