xena wrote:
My horse is due to foal any day now, so I bought a wireless CCTV system so I
could keep an eye on her. I specifically needed one that could run off a
battery as there is no power in the stable.

I set it all up and it worked fine for a few minutes, then it stopped, and
it looks as though the camera battery has run out. It was also supplied
with an adaptor, which says Output 8V - 500mA. Well as the rechargeable
batteries I have are 160mAh, would I be right in thinking that these
batteries will last all of about 20 minutes?? If so, I'm absolutely
seething, that's no good at all. I'm waiting for a response off the company
that sold me the kit (they know exactly what it was being used for...)

Yes, those batteries should run it for about 20 minutes or so.


Is there any way I can get the camera to run off a 12v leisure battery
instead?

Yes. First, find out what voltage range the camera can run off. Many
have quite a wide range, of 5V-12V. If this is the case, then you can
just power it straight off your 12V leisure battery.

If it has a narrower range, you need a suitable power supply to drop the
12V to 8V. Something like this:

http://www.maplin.co.uk/Module.aspx?...supply&doy=4m7

and a trailing cigar lighter socket:
http://www.maplin.co.uk/Module.aspx?...socket&doy=4m7


--
Grunff
Low temperature Stirling engine:
http://www.shinyshack.com/product.php?prid=211027

My horse is due to foal any day now, so I bought a wireless CCTV system so I
could keep an eye on her. I specifically needed one that could run off a
battery as there is no power in the stable.

I set it all up and it worked fine for a few minutes, then it stopped, and
it looks as though the camera battery has run out. It was also supplied
with an adaptor, which says Output 8V - 500mA. Well as the rechargeable
batteries I have are 160mAh, would I be right in thinking that these
batteries will last all of about 20 minutes?? If so, I'm absolutely
seething, that's no good at all. I'm waiting for a response off the company
that sold me the kit (they know exactly what it was being used for...)

Is there any way I can get the camera to run off a 12v leisure battery
instead?

Cheers.

"xena" wrote in message
...
My horse is due to foal any day now, so I bought a wireless CCTV system so
I could keep an eye on her. I specifically needed one that could run off
a battery as there is no power in the stable.

I set it all up and it worked fine for a few minutes, then it stopped, and
it looks as though the camera battery has run out. It was also supplied
with an adaptor, which says Output 8V - 500mA. Well as the rechargeable
batteries I have are 160mAh, would I be right in thinking that these
batteries will last all of about 20 minutes?? If so, I'm absolutely
seething, that's no good at all. I'm waiting for a response off the
company that sold me the kit (they know exactly what it was being used
for...)

Is there any way I can get the camera to run off a 12v leisure battery
instead?


It might even run off 12V anyway - modern power inputs are quite tolerant -
but it would be risky. You could buy a 12V inverter which would provide 240V
power up to 150W for £25 from www.towsure.co.uk (for example) and plug your
mains adapter into that. This would be of perhaps more use long term and
wouldn't require any work and would be quick!


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

xena wrote:

Thanks for that. The camera says it wants 8v, so do you think it would
prefer 7.5v or 9v?

I doubt it will care either way. Start at 7.5V, and if that doesn't
work, switch to 9V.


I don't think I have the luxury of waiting for delivery
now, so I guess it'll be whatever Halfords have.

I'm sure they'll have a suitable one.


I've found an old
multi-voltage adaptor like the one you linked to, but none of the 4 adaptors
will fit the camera

Snip the lead and wire it straight to the camera, observing polarity.


Many thanks for your help.

YMW.



--
Grunff
Low temperature Stirling engine:
http://www.shinyshack.com/product.php?prid=211027

xena wrote:

Interesting idea. I need one fast, but Halfords are doing them for £27.99
according to their website. They should be safe around horses, shouldn't
they? It's not got the oomph of a normal 240v supply, after all. What
about the fact that it would be outdoors in an unfavourable climate, i.e.
misty and windy, would it mind that?


The main issue with using an inverter is the losses - the inverter + PSU
combination will add a lot to your current draw, so you'll need to
recharge your leisure battery fairly frequently.


--
Grunff
Low temperature Stirling engine:
http://www.shinyshack.com/product.php?prid=211027

"Grunff" wrote in message
...
xena wrote:

Is there any way I can get the camera to run off a 12v leisure battery
instead?

If it has a narrower range, you need a suitable power supply to drop the
12V to 8V. Something like this:

http://www.maplin.co.uk/Module.aspx?...supply&doy=4m7


Thanks for that. The camera says it wants 8v, so do you think it would
prefer 7.5v or 9v? I don't think I have the luxury of waiting for delivery
now, so I guess it'll be whatever Halfords have. I've found an old
multi-voltage adaptor like the one you linked to, but none of the 4 adaptors
will fit the camera

Many thanks for your help.

"Bob Mannix" wrote in message
...

"xena" wrote in message
Is there any way I can get the camera to run off a 12v leisure battery
instead?

You could buy a 12V inverter which would provide 240V power up to 150W for
£25 from www.towsure.co.uk (for example) and plug your mains adapter into
that. This would be of perhaps more use long term and wouldn't require any
work and would be quick!

Interesting idea. I need one fast, but Halfords are doing them for £27.99
according to their website. They should be safe around horses, shouldn't
they? It's not got the oomph of a normal 240v supply, after all. What
about the fact that it would be outdoors in an unfavourable climate, i.e.
misty and windy, would it mind that?

Many thanks.

xena wrote:
My horse is due to foal any day now, so I bought a wireless CCTV system so I
could keep an eye on her. I specifically needed one that could run off a
battery as there is no power in the stable.

I set it all up and it worked fine for a few minutes, then it stopped, and
it looks as though the camera battery has run out. It was also supplied
with an adaptor, which says Output 8V - 500mA. Well as the rechargeable
batteries I have are 160mAh, would I be right in thinking that these
batteries will last all of about 20 minutes?? If so, I'm absolutely
seething, that's no good at all. I'm waiting for a response off the company
that sold me the kit (they know exactly what it was being used for...)

Is there any way I can get the camera to run off a 12v leisure battery
instead?

Are you sure the adaptor is not (also) a charger? If you plug in the
camera with the batteries in and leave for a few hours, what sort of
battery life do you get then?

Chris

--
Spamtrap in use
To email replace 127.0.0.1 with btinternet dot com

In article ,
xena wrote:
You could buy a 12V inverter which would provide 240V power up to 150W
for £25 from www.towsure.co.uk (for example) and plug your mains
adapter into that. This would be of perhaps more use long term and
wouldn't require any work and would be quick!

Interesting idea. I need one fast, but Halfords are doing them for
£27.99 according to their website. They should be safe around horses,
shouldn't they? It's not got the oomph of a normal 240v supply, after
all.

It's got more than enough oomph to kill anyone, if 240 will kill a horse.

With a human, a few watts are enough, and these are capable of hundreds.

What about the fact that it would be outdoors in an unfavourable
climate, i.e. misty and windy, would it mind that?

The ones I've seen ain't weatherproof.

--
*Eat well, stay fit, die anyway

Dave Plowman London SW
To e-mail, change noise into sound.

"Chris Hodges" wrote in message
...
xena wrote:

Is there any way I can get the camera to run off a 12v leisure battery
instead?

Are you sure the adaptor is not (also) a charger? If you plug in the
camera with the batteries in and leave for a few hours, what sort of
battery life do you get then?

Yup, there's an adaptor coming out of the camera, into which you either plug
a 9v battery (on an adaptor cable) or the 240v plug. In any case, if the
max capacity of the battery is 160mAh, then it's only going to work for 19
minutes, as I work it out.

I've started the butchery, and it will hopefully be connected to the leisure
battery within the next hour after my cuppa

On Wed, 4 Jul 2007 17:55:52 +0100, "xena"
wrote:

"Chris Hodges" wrote in message
...
xena wrote:

Is there any way I can get the camera to run off a 12v leisure battery
instead?

Are you sure the adaptor is not (also) a charger? If you plug in the
camera with the batteries in and leave for a few hours, what sort of
battery life do you get then?

Yup, there's an adaptor coming out of the camera, into which you either plug
a 9v battery (on an adaptor cable) or the 240v plug. In any case, if the
max capacity of the battery is 160mAh, then it's only going to work for 19
minutes, as I work it out.

I've started the butchery, and it will hopefully be connected to the leisure
battery within the next hour after my cuppa

Let's hope all goes well for the horse...

--
Frank Erskine

"Frank Erskine" wrote in message
...
On Wed, 4 Jul 2007 17:55:52 +0100, "xena"
wrote:

I've started the butchery, and it will hopefully be connected to the
leisure
battery within the next hour after my cuppa

Let's hope all goes well for the horse...

Well with regard to the electrics, it's protected by a 5A fuse at the
battery, and they would have to stretch very high to reach the cables, which
are all tacked down very securely.

xena expressed precisely :
My horse is due to foal any day now, so I bought a wireless CCTV system so I
could keep an eye on her. I specifically needed one that could run off a
battery as there is no power in the stable.

I set it all up and it worked fine for a few minutes, then it stopped, and it
looks as though the camera battery has run out. It was also supplied with an
adaptor, which says Output 8V - 500mA. Well as the rechargeable batteries I
have are 160mAh, would I be right in thinking that these batteries will last
all of about 20 minutes?? If so, I'm absolutely seething, that's no good at
all. I'm waiting for a response off the company that sold me the kit (they
know exactly what it was being used for...)

Is there any way I can get the camera to run off a 12v leisure battery
instead?

20 minutes would be about right.

If the 8v needed is 8v DC, then you could run it from a 7808 series
regulator. Get a 1amp version of the 7808 from perhaps Maplin. It has
three terminals + in, ground, + output at 8v. Mount in on an heat sink
because it will need to be kept cool.

An 85amp hour battery will last around 130 hours continuous running.

Another solution might be to get hold of a long 240v extension and take
care where you place the cable.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

on 04/07/2007, Dave Plowman (News) supposed :
It's got more than enough oomph to kill anyone, if 240 will kill a horse.

With a human, a few watts are enough, and these are capable of hundreds.

1mA at 240v is enough to kill a human - animals are supposedly even
more sensitive.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

In article , Harry Bloomfield
writes
on 04/07/2007, Dave Plowman (News) supposed :
It's got more than enough oomph to kill anyone, if 240 will kill a horse.

With a human, a few watts are enough, and these are capable of hundreds.

1mA at 240v is enough to kill a human - animals are supposedly even
more sensitive.

Cite?
--
fred
Plusnet - I hope you like vanilla

On Wed, 04 Jul 2007 19:39:57 +0100, Harry Bloomfield
wrote:

on 04/07/2007, Dave Plowman (News) supposed :
It's got more than enough oomph to kill anyone, if 240 will kill a horse.

With a human, a few watts are enough, and these are capable of hundreds.

1mA at 240v is enough to kill a human - animals are supposedly even
more sensitive.


It's the mills that kills but the volts that jolts.

My lecturer at Uni had a research project that involved passing
currents through the hearts of aneasthetised animals to see what
current would make them die. He said it was about 10 mA

DG

"Harry Bloomfield" wrote in message
...
on 04/07/2007, Dave Plowman (News) supposed :
It's got more than enough oomph to kill anyone, if 240 will kill a horse.

With a human, a few watts are enough, and these are capable of hundreds.

1mA at 240v is enough to kill a human - animals are supposedly even more
sensitive.

I don't get this leccy thing at all. 12v doesn't hurt if you touch both
terminals. My electric fence at 8,200V (yes 8.2KV) stings a bit but doesn't
kill, yet somewhere in the middle, 1mA at 240v can kill??

"Harry Bloomfield" wrote in message
...
xena expressed precisely :

Is there any way I can get the camera to run off a 12v leisure battery
instead?

If the 8v needed is 8v DC, then you could run it from a 7808 series
regulator. Get a 1amp version of the 7808 from perhaps Maplin. It has
three terminals + in, ground, + output at 8v. Mount in on an heat sink
because it will need to be kept cool.

Thanks, but she could literally foal any hour now, I can't risk waiting for
stuff to turn up. I've tried to set it up using the 12v DC adaptor but
haven't found a way of finishing the connections off just yet.

Another solution might be to get hold of a long 240v extension and take
care where you place the cable.

Not possible, the lane to next door goes between the house and the field,
and I've been warned before by the kind folk on here that mains leccy near
my horses ain't good.

Cheers for your advice tho.

xena wrote:
"Chris Hodges" wrote in message
...

xena wrote:


Is there any way I can get the camera to run off a 12v leisure battery
instead?

Are you sure the adaptor is not (also) a charger? If you plug in the
camera with the batteries in and leave for a few hours, what sort of
battery life do you get then?


Yup, there's an adaptor coming out of the camera, into which you either plug
a 9v battery (on an adaptor cable) or the 240v plug. In any case, if the
max capacity of the battery is 160mAh, then it's only going to work for 19
minutes, as I work it out.


I see. Obvious enough when you know how it's connected. The adaptor is
probably slightly overspecced, but it's going to be minutes not hours
certainly (and might even be worse than the 19 depending on the
discharge curve at high cuurents (which it is for a small 9V)

I've started the butchery, and it will hopefully be connected to the leisure
battery within the next hour after my cuppa

If it was me I'd rig 6 D cells in series to a spare 9V battery lead
(remembering that the colours will be the wrong way round). The
rechargeable D in front of me is 2300mAh, a duracell will be much more.


--
Spamtrap in use
To email replace 127.0.0.1 with btinternet dot com

On Jul 4, 9:20 pm, "xena" wrote:
"Harry Bloomfield" wrote in message

...

on 04/07/2007, Dave Plowman (News) supposed :
It's got more than enough oomph to kill anyone, if 240 will kill a horse.

With a human, a few watts are enough, and these are capable of hundreds.

1mA at 240v is enough to kill a human - animals are supposedly even more
sensitive.

I don't get this leccy thing at all. 12v doesn't hurt if you touch both
terminals. My electric fence at 8,200V (yes 8.2KV) stings a bit but doesn't
kill, yet somewhere in the middle, 1mA at 240v can kill??

Hi,

You'd be best off talking to an electrician qualified and experienced
in agricultural installations, maybe a local farmer or stable owner
could recommend one.

If they say a 30mA 30 millisecond RCD is good enough protection for a
supply for use with horses, then it most probably is...

cheers,
Pete.

xena explained on 04/07/2007 :
I don't get this leccy thing at all. 12v doesn't hurt if you touch both
terminals.

It does if the voltage is enough to overcome the resistance of your
body. The highest resistance is normally that of your skin. Try the 12v
on your tongue - on second thoughts perhaps not. Try the 12v via a
couple of pins in your skin.

The voltage has to be enough to overcome your body resistance...

My electric fence at 8,200V (yes 8.2KV) stings a bit but doesn't
kill,

...and the current enough and for a long enough period to do damage.

yet somewhere in the middle, 1mA at 240v can kill??

It can, but it depends upon the individual, the exposure conditions,
the current path through the body and of course the length of time of
exposure to the current.

The worst possible route for the current is in one arm and out the
other, via the heart - hence the good working practise of working with
your spare hand in your pocket body covered and well insulated dry
shoes. The worst you can then suffer is a belt across your hand.

An old party trick I used to do was to allow the 30Kv spark from a
colour CRT TV, to arc across to my finger tip. Very high voltage, but
very little actual current - due to my normaly dry skin I don't usually
feel much.

Even the 10mA RCD's are not certain to prevent death and or injury, but
they do limit the time of exposure to a very short time period. They
are a delicate balance between protection and nuisance tripping due to
normal circuit leakage currents.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Wed, 4 Jul 2007 21:24:32 +0100, "xena"
wrote:


"Harry Bloomfield" wrote in message
...
xena expressed precisely :

Is there any way I can get the camera to run off a 12v leisure battery
instead?

If the 8v needed is 8v DC, then you could run it from a 7808 series
regulator. Get a 1amp version of the 7808 from perhaps Maplin. It has
three terminals + in, ground, + output at 8v. Mount in on an heat sink
because it will need to be kept cool.

Thanks, but she could literally foal any hour now, I can't risk waiting for
stuff to turn up.

Do let us know how she gets on, will you?

--
Frank Erskine

fred used his keyboard to write :
In article , Harry Bloomfield
writes
on 04/07/2007, Dave Plowman (News) supposed :
It's got more than enough oomph to kill anyone, if 240 will kill a horse.
With a human, a few watts are enough, and these are capable of hundreds.

1mA at 240v is enough to kill a human - animals are supposedly even
more sensitive.

Cite?

You will find a citation somewhere in the URL copied in my sig. Sorry I
don't remember the actual page, but it was based upon valid research
done upon the subject of such risks.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

In article ,
xena wrote:
"Harry Bloomfield" wrote in message
...
on 04/07/2007, Dave Plowman (News) supposed :
It's got more than enough oomph to kill anyone, if 240 will kill a
horse.

With a human, a few watts are enough, and these are capable of
hundreds.

1mA at 240v is enough to kill a human - animals are supposedly even
more sensitive.

I don't get this leccy thing at all. 12v doesn't hurt if you touch both
terminals. My electric fence at 8,200V (yes 8.2KV) stings a bit but
doesn't kill, yet somewhere in the middle, 1mA at 240v can kill??

The current flow in amps depends on two things - the voltage and
resistance.
V
The formula is I (amps) = -
R

So if you increase the voltage or reduce the resistance the current
increases.

The electric fence will have a large value resistor in series with it to
limit the maximum current to a safe value.

Your skin when dry has quite a high resistance. Try putting the
terminals of a PP3 (9 volt) battery across your tounge. You'll feel
that. ;-)

--
*Drugs may lead to nowhere, but at least it's the scenic route *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,

The current flow in amps depends on two things - the voltage and
resistance.
V
The formula is I (amps) = -
R

So if you increase the voltage or reduce the resistance the current
increases.

Got ya, thanks

"Harry Bloomfield" wrote in message
...

The worst possible route for the current is in one arm and out the other,
via the heart - hence the good working practise of working with your spare
hand in your pocket body covered and well insulated dry shoes. The worst
you can then suffer is a belt across your hand.

Never heard of that, but makes sense. One of the horses in the same field
as mine many years ago was killed by lightning. Apparently it hit his ear,
went through his heart and to ground through his shod feet. Poor boy

Thanks for explaining.

On 4 Jul, 17:03, "xena" wrote:
"Grunff" wrote in message
...
xena wrote:

Is there any way I can get the camera to run off a 12v leisure battery
instead?

easy

Thanks for that. The camera says it wants 8v, so do you think it would
prefer 7.5v or 9v? I don't think I have the luxury of waiting for delivery
now, so I guess it'll be whatever Halfords have. I've found an old
multi-voltage adaptor like the one you linked to, but none of the 4 adaptors
will fit the camera

Many thanks for your help.

You could simply use 5 diodes in series to drop the 13v to 8v. Basic
1N4001 diodes would do fine. Cost a few p each.


NT

wrote in message
ups.com...

You could simply use 5 diodes in series to drop the 13v to 8v. Basic
1N4001 diodes would do fine. Cost a few p each.

Interesting idea, never heard of those before, but a few on ebay for next to
nothing. The camera's actually up and running now, using an old car voltage
adaptor, and some fancy wiring. However, it's enlightening to see other
potential solutions as it may well help the next time I want to do something
clever with a 12v supply!

On 2007-07-05 22:24:19 +0100, "xena" said:

wrote in message
ups.com...

You could simply use 5 diodes in series to drop the 13v to 8v. Basic
1N4001 diodes would do fine. Cost a few p each.

Interesting idea, never heard of those before, but a few on ebay for next to
nothing. The camera's actually up and running now, using an old car voltage
adaptor, and some fancy wiring. However, it's enlightening to see other
potential solutions as it may well help the next time I want to do something
clever with a 12v supply!

Voltage droppers. Potential solutions. Shouldn't meet much resistance
in the current form.

On Thu, 05 Jul 2007 13:03:37 -0700, wrote:

On 4 Jul, 17:03, "xena" wrote:
"Grunff" wrote in message
...
xena wrote:

Is there any way I can get the camera to run off a 12v leisure battery
instead?

easy

Thanks for that. The camera says it wants 8v, so do you think it would
prefer 7.5v or 9v? I don't think I have the luxury of waiting for delivery
now, so I guess it'll be whatever Halfords have. I've found an old
multi-voltage adaptor like the one you linked to, but none of the 4 adaptors
will fit the camera

Many thanks for your help.

You could simply use 5 diodes in series to drop the 13v to 8v. Basic
1N4001 diodes would do fine. Cost a few p each.


It's probably a bit short notice for a horsey that's about to give
birth any minute though...


(Xena) - any news yet?

--
Frank Erskine

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "xena"
saying something like:

Never heard of that, but makes sense. One of the horses in the same field
as mine many years ago was killed by lightning. Apparently it hit his ear,
went through his heart and to ground through his shod feet. Poor boy

Not just that, there've been many cattle killed by nearby strikes when
the ground potential between their front legs was enough to cause a
current to flow, stopping the heart. I'd assume horses would be
similarly sensitive.
--

Dave

"Frank Erskine" wrote in message

It's probably a bit short notice for a horsey that's about to give
birth any minute though...

(Xena) - any news yet?

No, nothing yet. Horses are notoriously difficult to predict though, so
whilst she has all the signs of dropping it at any minute, she could still
hold onto it for another week or even two if she wants/needs to - hence the
need for the cctv. For instance, she might want to wait until the weather
is a little better. With the amount of stuff that can go wrong with a
foaling though, and the often catastrophic results, I have much more peace
of mind now Was fantastic being able to watch them last night from the
comfort of my bed!!

I really appreciate all the help you people have given me, not just with
this topic, but the others I've put up before, like best way to illuminate
the shelter, putting a ceiling fan up (though the weather made that
unnecessary in the end!) so I'll let you know when she drops it and stick a
pic link up

In article , Harry Bloomfield
writes
fred used his keyboard to write :
In article , Harry Bloomfield
writes
on 04/07/2007, Dave Plowman (News) supposed :
It's got more than enough oomph to kill anyone, if 240 will kill a horse.
With a human, a few watts are enough, and these are capable of hundreds.

1mA at 240v is enough to kill a human - animals are supposedly even
more sensitive.

Cite?

You will find a citation somewhere in the URL copied in my sig. Sorry I
don't remember the actual page, but it was based upon valid research
done upon the subject of such risks.

That's a bit lazy isnt it :-?

The request for cite was the politest possible suggestion that ******** was
being spake.

Wikipedia's summary is pretty much as I understand it:
http://en.wikipedia.org/wiki/Electric_shock

In brief (human):
1mA threshold of perception
5mA maximum current which would be harmless
snip
100-300mA ventricular fibrillation. Can be fatal.
snip

Human fatality at 1mA seems extremely unlikely but yes I did read the
microshock link: http://en.wikipedia.org/wiki/Microshock
--
fred
Plusnet - I hope you like vanilla