magnetic field

[Watson A.Name - \"Watt Su]

<googlemike@hotpop.com> wrote in message
news:1112278089.874159.95440@o13g2000cwo.googlegroups.com...

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.

Well, you can stop at 300 feet or 90 meters. If the cat5 has been
installed to the EIA/TIA 568 specifications, it will not be longer than
that. Of course you can pull a fast one, and put a jumper cable from
jack to jack at the patch panel. That will make the maximum 181 meters
( about1 meter for the patch cable). Or you could just say that your
product must have a gizmo to amplify the signal at the patch panel to do
that. Make more money that way. ;-)

I did a google search for cat5 security camera and got 90 thousand hits,
so it looks like you've got a lot of competition. :-(

 

[CWatters]

<esantoro@poczta.onet.pl> wrote in message
news:1112435995.576498.231740@l41g2000cwc.googlegroups.com...

I have a compact FM transmitter that runs on three AA batteries. I'd
like to get an AC adapter for it but am not sure what specs are
necessary.

Three ordinary Alkaline batteries will provide 4.5V DC not AC

If you were to remove the batteries and connect the output of the mains
adaptor to the battery terminals then the spec you need would probable be
4.5V DC @300mA . A current rating of 300mA should be ok because it's
unlikely the output power is more than 1W.

 

[Jerry G.]

I was about 120 miles north of Montreal. It was during the summer, right
after a heavy thunder shower. I stopped at a dining place to have some
lunch. The area had a very strong smell of ozone, probably because of the
heavy thunder showers.

I happened to look up and saw a sort of glowing circle of light. It was not
very bright. It appeared to be like a transparent reddish blue ball. There
appeared to also maybe have some traces of some yellow and green in it. The
colour seemed to vary a little as if it was unstable. I would think that
most of the colour that I saw was from reflections or just the ambient light
in the area. This ball lasted about maybe 20 to 30 seconds if that long at
all. It seemed to float towards some power lines near to a telephone poll.
At that point it simply faded or vanished.

I know of someone else who also has seen ball lightning. He was over in
Europe when he saw this.

I know of a story that someone had one come in to his house through an
opened window. It floated around in his kitchen for about 30 seconds, and
then disappears with a sort of snapping noise.

Was these some type of electrical build-up from charges that were in the
air? Each time these occurred, it was right after severe thunder showers.

--

Jerry G.
=====

<testing_h@yahoo.com> wrote in message
news:1112378183.407901.9100@o13g2000cwo.googlegroups.com...

Jerry G. wrote:
You sound like your involved in some heavy physics. A number of years
ago, I read some similar theories. About 15 years ago, I had the
experience of seening ball lightning. It was an interesting thing to
see.

Cool! what did it look like/lifetime/etc?

re. the post about submarines. It would certainly make sense, the
smaller balls might be a lower energy version produced by spinning
metal plasma blobs held together by electrostatics, instead of
full-blown pm=lasma toroid clusters.

Regards,
-A



Jerry G.
=======

 

[Dave Baker]

On Sat, 2 Apr 2005 18:08:38 -0500, "Jerry G." <jerryg50@hotmail.com> wrote:

I know of someone else who also has seen ball lightning. He was over in
Europe when he saw this.

When I was in the Air Force, one of my technicians made ball lightning
accidentally.

We had these massive power supplies - called Invertrons if I remember
correctly. Can't really remember what they did, but they had 3 phase input &
3 phase output, and each phase had 40 high power transistors on a massive
heatsink. I think it created very clean 3 phase power.

Anyway, one of the techs was replacing a transistor - they died reasonably
regularly. When putting it back in the 19" rack he wired the input to the
output & vice-versa.

At turn-on, a ball of lightning about the size of a tennis ball came straight
out of the front panel & floated around in the air a little for about 5 to 10
seconds, in front of about 5 technicians including some of the bosses. Quite
impressive.

The mistake also blew out all 120 power transistors which took quite a
rebuild!

Dave

The email address used for sending these postings is not valid.
All replies to the group please.

 

[CWatters]

<esantoro@poczta.onet.pl> wrote in message
news:1112486126.455336.70850@l41g2000cwc.googlegroups.com...

Thanks so much for your reply.

I'm quite sure that the transmitter is less than 1 watt. It has a
range of about 100-120 ft.

Ok, then , I'll go ahead and try my universal regulated mains adapter.
I have one that is something like 1.5v, 3v, and 6v at 300mA,

but no 4.5V? That's what you need if you plan on connecting to the battery
terminals. If the transmitter has a socket on it for a mains adaptor you
need to check the specs for what that requires. Without more info we can't
help.

 

[CWatters]

<googlemike@hotpop.com> wrote in message
news:1112500401.249741.288660@l41g2000cwc.googlegroups.com...

I see it comes with a built-in web server and built-in MPEG display
playback. The question I have now is how can I download Axis 205 data
from the unit to a PC so that it can store this and allow a security
guard to review it backwards in time?

You would have to look at the manual. There are many program that can
record streaming video but I suspect this camera may come with something to
do just that.

 

[CWatters]

"CWatters" <colin.watters@pandoraBOX.be> wrote in message
news:ZbP3e.53764$2R1.4203613@phobos.telenet-ops.be...

googlemike@hotpop.com> wrote in message
news:1112500401.249741.288660@l41g2000cwc.googlegroups.com...

I see it comes with a built-in web server and built-in MPEG display
playback. The question I have now is how can I download Axis 205 data
from the unit to a PC so that it can store this and allow a security
guard to review it backwards in time?

You would have to look at the manual. There are many program that can
record streaming video but I suspect this camera may come with something
to
do just that.

Actually now that I've scanned the review I see it says...

"Axis does not offer the ability to directly capture video streams from the
205. However Axis does offer the "Axis Camera Recorder" application, which
allows you to capture and save video. This is professional security level
software and, according to what we were able to find out, it is not
currently compatible with the 205. Since the software is expensive and the
205 is an entry level product, don't expect support for this feature anytime
soon."

In which case you might want to look at other models from their range or
other manufacturers products.

 

[CWatters]

<esantoro@poczta.onet.pl> wrote in message
news:1112523756.392879.68640@l41g2000cwc.googlegroups.com...

Oops, It also has 4.5v. I'll give it a try.

the transmitter has only the battery compartment, no socket for a mains
adapter. I'll rig something like alligator clips to the mains adapter.
By chance is there some kind of plug I can put in two of the AA slots
that conveniently can connect to the adapter?

I've seen dummy AA cells in the past but no idea where to get them. They are
designed for use in a four cell battery holder whan you only want to use
three cells. If you use three of these remember to cut the metal link in one
of them or you will short out your mains adaptor.

 

[CWatters]

<googlemike@hotpop.com> wrote in message
news:1112533043.441353.326180@z14g2000cwz.googlegroups.com...

Darn. I knew there had to be a catch. Any other camera would be out of
my price range for this very inexpensive (but functional) system

You might find cheaper..

Wired network cam $94
Wireless network cam $149

http://kingofgadgets.com/Products/security.html

 

[Michael]

hartlyuk@yahoo.com wrote:

http://www.concord-camera.com
Can't get any useful specs. from above website on their 3045 camera.
I want to run it from a cheap rechargable external long life battery.
It uses 4x1.5 volts one-use batteries,but I don't know for sure if
they are alighned to give 6 volts or not.
I think they are in series so camera must use 6 v.
What does anyone think it uses?.
If it takes 6v,what is the best/cheapest rechargable battery to use. I
prefer lead-acid cuz. I get the impression the other types don't last
long on each charge.
What do you recommend I use.?.

http://www.ripmax.com/FS_PriceList2003.html
O-PRP0610 6v 10A Power-Peak SLA Battery Ł9.99

Why doesn't the above battery info. state it's ampere/hours,while the
other manufacturers does?.
Thanks, Hartly.

The first thing you want to do is determine exactly - *exactly* - how those
cells are wired. Otherwise it will be you-bet-your-digicam.

Maybe seller wants battery to sound heftier than it actually is. I assume "10A
Power-Peak" means "10A, peak" ... and therefore the battery's AH rating is lower
than 10.

(By the way, the term is "ampere-hour". Not "ampere/hour".)

 

[Tomi Holger Engdahl]

googlemike@hotpop.com writes:

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?

There are some products that claim to be able run USB signals through CAT5
UTP wiring. They go somehow longer distance than normal USB cables,
but I don't think they can extend the maximum lengthof USB network.

If you really want some longer distance than few meters, I would
recommend to use some technology that is designed to work over
the needed distance in the beginning, rather than pushing the
USB techology that is originally designed for short distances only.

Technologies that are suitable for longer distances over CAT5 wiring
are webcams with Ethernet interface (normal Ethernet networking
limits) and CCTV cameras designed for UTP wiring signal transfer
connected to video digitizing card/device on the computer end
(works well up to several hundred meters).

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 real technical reasons why USB cables have their
distance limits, and why the cable used with USB devices is
different that CAT5 cable. CAT5 cable is not the optimum
medium for USB signals... Maybe not worth to take apart
an expensive web camera.

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

 

[Don Bruder]

In article <b8805d0c.0504060742.724405c6@posting.google.com>,
bobr05@yahoo.co.uk (bobr05) wrote:

Hi,
Does anybody know if I use a 5V, 0.8A adaptor plugged into my car's
cigarette lighter to charge my MP3 player (that is supposed to be
charged with a 5V, 1.6A charger), will it do any damage, to either the
MP3 player or the charger?

You'll cook off the charger. You're asking a unit tagged for 0.8 amps to
supply twice its rated output. Not a good situation no matter how you
look at things.

My guess is it should be OK, since the current output from the charger
is less than what the player can take,

Your guess is totally wrong, in every way that it possibly can be - It's
exactly the reverse of reality.

The *DEVICE*, not the supply, determines how many amps will be drawn
from the supply. The supply's rating is an "I am capable of pushing up
to this many amps if you need it, but no more" number. The device's
rating is an "I'm going to try to pull this many amps from the supply"
number. If the device's number is higher than the supply's number, the
result is going to be a fried supply. How the supply cooks off is going
to be a function of how overloaded it is - A slight overdraw may just
quietly go "pfft" and let out a wisp of smoke. A major overdraw can
literally turn the supply into a bomb.

When choosing a supply for a device, the specified voltages must always
match, or the device is likely to be either damaged (if volts too high)
or non-functional (volts too low), and the amp rating of the supply must
be equal to or greater than the amp rating of the device, or the supply
will likely be damaged.

but a colleague reckons that
the player will try to draw more current from the supply and do some
harm to either it or the charger.
What do the experts think?

Your colleague is correct. You're almost certain to fry the charger if
you make the attempt.

--
Don Bruder - dakidd@sonic.net - New Email policy in effect as of Feb. 21, 2004.
Short form: I'm trashing EVERY E-mail that doesn't contain a password in the
subject unless it comes from a "whitelisted" (pre-approved by me) address.
See <http://www.sonic.net/~dakidd/main/contact.html> for full details.

 

[CWatters]

"bobr05" <bobr05@yahoo.co.uk> wrote in message
news:b8805d0c.0504060742.724405c6@posting.google.com...

Hi,
Does anybody know if I use a 5V, 0.8A adaptor plugged into my car's
cigarette lighter to charge my MP3 player (that is supposed to be
charged with a 5V, 1.6A charger), will it do any damage, to either the
MP3 player or the charger?
My guess is it should be OK, since the current output from the charger
is less than what the player can take, but a colleague reckons that
the player will try to draw more current from the supply and do some
harm to either it or the charger.

No your colleague is correct. The current sucked out of the charger depends
on the load. The MP3 player spec says it needs 1.6A so your 0.8A charger
would be overloaded.

 

[CWatters]

<hartlyuk@yahoo.com> wrote in message
news:1112636954.186799.52920@o13g2000cwo.googlegroups.com...
http://www.concord-camera.com

If it takes 6v,what is the best/cheapest rechargable battery to use. I
prefer lead-acid cuz. I get the impression the other types don't last
long on each charge.
What do you recommend I use.?.
http://www.ripmax.com/FS_PriceList2003.html
O-PRP0610 6v 10A Power-Peak SLA Battery Ł9.99

I probably wouldn't go with a lead acid battery. Lead acid batteries don't
really like being repeatedly deep discharged or being left empty for a few
days. A 10AH lead acid battery is also going to be quite big and possibly
heavy. You would also need a charger suitable for 6V Lead Acid cells -
perhaps one designed for charging 6V motorbike batteries.

http://www.maplin.co.uk/Module.aspx?ModuleNo=27698&TabID=1&source=15&WorldID=&doy=6m4

Can you use rechargable cells in your camera (eg NiCad or NiMH) AA cells?
If so then I would use something like these in the camera itself..

Sanyo 2100 mAh ni-mh
http://www.overlander.co.uk/detail.asp?categoryid=64&ID=271
These are standard AA size cells. Note that some other cells from Overlandar
look like AA but are slightly bigger physically. Check the physical
dimensions!

There are lots of chargers available for the above.. eg...
http://www.maplin.co.uk/Module.aspx?ModuleNo=31769&TabID=1&source=15&WorldID=&doy=6m4

 

[Watson A.Name - \"Watt Su]

<alondra101@hotmail.com> wrote in message
news:1112824555.472068.130380@l41g2000cwc.googlegroups.com...

It looks as if they have essentially lifted the pages out of the ol'
GE
Miniature Lamp Catalog and put them into this .PDF, which is nearly 3
megs. But this is _the_ definitive lamp catalog, with all those old
specialty lamps like #47 lamps used in the old radois, etc. Every
bookshelf should have this on it, or at least saved on their hard
disk.
It's a classic.

http://www.sunraylighting.com/pdf/Catalog.pdf

Is anyone getting my Google postings? The last one I did hardly anyone
postd a followup. I'm thinking that Google has an excellent inbound
news system, but for outbound messages it sucks.

 

[Michael A. Terrell]

"Watson A.Name - \"Watt Sun, the Dark Remover\"" wrote:

alondra101@hotmail.com> wrote in message
news:1112824555.472068.130380@l41g2000cwc.googlegroups.com...

It looks as if they have essentially lifted the pages out of the ol'
GE
Miniature Lamp Catalog and put them into this .PDF, which is nearly 3
megs. But this is _the_ definitive lamp catalog, with all those old
specialty lamps like #47 lamps used in the old radois, etc. Every
bookshelf should have this on it, or at least saved on their hard
disk.
It's a classic.

http://www.sunraylighting.com/pdf/Catalog.pdf

Is anyone getting my Google postings? The last one I did hardly anyone
postd a followup. I'm thinking that Google has an excellent inbound
news system, but for outbound messages it sucks.

The one about the lamps showed up on Earthlink, but I think Google
groups are starting to be black holed for excessive spam.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

"Watson A.Name - \"Watt Sun, the Dark Remover\"" wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:4254C718.52BD4BC7@earthlink.net...

The one about the lamps showed up on Earthlink, but I think Google
groups are starting to be black holed for excessive spam.

Maybe so; I noticed that there were a lot of adverts in their posts.

Last year at work, when CSU shut down their news servers, I asked our
netheads what the IP was for the replacements. They said, sorry, it's
gone; just use Google. So I was SOL at work. Sometimes I've run across
something that I want to post, and I'll use Google. Sometimes I'll just
email it to myself and later at home I'll cut and paste the URL or
whatever into a post. I guess that's what I'll have to do and forget
about using Google to post.

There are a number of free news servers still available. I have a
couple links, somewhere to web pages comparing the different ones but
you can do a search and find most of them.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

 

[CWatters]

"spudnuty" <spudnuty@lycos.com> wrote in message
news:1112854127.384074.47500@z14g2000cwz.googlegroups.com...

Hmm is it just me but I don't seem to find an external power plug on
this camera and the manual doesn't mention an external supply. If so
you'll be opening the camera anyway to put your own in. Then you'll
figure out exactly how the batteries are wired. Most likely 6V.

...and I note that it says the internal cells AAA size- so ignore my previous
recommendation for AA cells.

 

[CWatters]

"spudnuty" <spudnuty@lycos.com> wrote in message
news:1112854127.384074.47500@z14g2000cwz.googlegroups.com...

Hmm is it just me but I don't seem to find an external power plug on
this camera and the manual doesn't mention an external supply. If so
you'll be opening the camera anyway to put your own in. Then you'll
figure out exactly how the batteries are wired. Most likely 6V.
Richard

Review here says "no AC adaptor" and "short battery life"....
http://ecoustics.epinions.com/pr-Concord_Eye_Q_3045_Digital_Camera/linkin_id_~3035301/display_~reviews

Now that I look again the spec clearly says "NiMH cells recommended" which
means it will work on 4 x 1.2V cells = 4.8V

 

[CWatters]

"hartly" <hartlyuk@yahoo.com> wrote in message
news:1f73b571.0504080734.42689bd1@posting.google.com...

"spudnuty" <spudnuty@lycos.com> wrote in message
news:<1112854127.384074.47500@z14g2000cwz.googlegroups.com>...

I will use dead batteries with wires soldered to the inner end to
touch the camera's terminals.

Make sure they aren't in circuit - eg insulate the "unused" end.

Also watch out for leakage.

I'll have to use a sealed lead acid batt. of about 4Ah.in my jacket
pocket or rucksack as larger are too heavy.

I'd be surprised if a 4AH lead acid were lighter than the nearest NiMH cell
but whatever you say.