Re: Outdoor Webcams
Brian Cryer
news:4a9ce59d-cade-4cdf...@k8g2000yqn.googlegroups.com...
>I am looking to purchase a webcam to monitor my hive. I require one
> for outdoor use and one that works on batteries or solar - any ideas
> or suggestions would be greatly appreciated. Thanks
It might be worth asking this on alt.comp.hardware, as its probably a
relevant question for that group and it probably gets far more visitors than
this one. You could also try alt.comp.periphs.webcam. I've cross-posted my
reply to both of those groups.
Something else to throw into the mix: Do you have any idea how you are going
to get the signal back to your PC? If its somewhere where you can run a
cable then you won't need batteries. If its somewhere not easily accessible
(so you can't run a cable, which is quite likely given the places I know
where bee hives are kept), then you are either looking at recording the
video or transmitting it. I think there are cameras that work on wifi, but
all of this adds to the total cost.
Hope you find something suitable.
--
Brian Cryer
www.cryer.co.uk/brian
kony
Indeed. If ethernet cable is ran then power delivery can be
by POE, power over ethernet. If it's a wifi network cam
without any cables then it will require the solar power.
The OP will have to purchase the webcam found desirable
without regard for power source then a separate POE module
or separate solar power module including battery pack, solar
panels, and regulation circuitry to arrive at the webcam's
input power voltage (and of course capable of it's current
needs for the duration of the time... it was not made clear
whether it needs be able to work in the dark, a typical
webcam won't do that anyway it would need be infrared if
what needs monitored shows up on infrared which bees might
not).
Paul
There are plenty of bad camera devices out there. My expectation
would be, you'll spend some money, and be disappointed.
Cameras can be connected by
1) Coaxial cable. For example, many security cameras use composite
output (baseband video), which can be digitized cheaply with
a BT848/BT878 or similar PCI capture cards. The coax cable would
not be protected against lightning.
2) USB. You can purchase active USB cables (they have a one port USB hub
at the end of the cable). The USB standard allows perhaps five of these
to be concatenated. The total cable length is not really that useful.
There are also devices, which allow the signal to go further, because
they change the physical layer protocol. Again, the issue is the
fact there is a cable outside, and a lightning strike could blow
the computer up. And if you used fiber optics for the physical layer,
the cost is astronomical.
3) Wireless or IP cameras. There are cameras that connect to Ethernet.
(Yet another wire.) There are also cameras that are wireless and use
WiFi. You view the output with a web browser. The solution may use
an ActiveX plugin (i.e. only works on Internet Explorer), or perhaps
some Java plugin. The Wifi solution provides protection from
lightning. On the computer end, you'd need a Wifi access point dongle,
or perhaps a Wifi router, if you have need of that anyway (for
wirelessly sharing Internet with multiple computers).
The power requirement at camera end, could be significant,
at least with respect to solar power. To do solar, you'd need a storage
battery which can hold enough power for multiple days of usage, in
no-sunlight situations. The remote hardware might be using several
watts continuously.
So a wireless camera would appear to be the safest, but may not have
a lot of flexibility in the viewing department. Based on reading a
few reviews, the cameras seem to have just dreadful silicon sensors
for the camera part. It is tough to get "all good ingredients in
the same cake".
I bought a camera solution years ago, and was disappointed with the
quality. This past Christmas, I bought a USB2 webcam for $99, and
was similarly disappointed with the results (5 frames per second,
needed lots of light). As far as I'm concerned, camcorders are
closer to state of the art, than webcam technology. Webcams are
just "more of the same", over and over again. I don't particularly
like encouraging people to use these technologies, when I know
a large percentage of them are going to throw money away, and
be less than satisfied.
So it boils down to, "should you throw away a little money, or
throw away a lot of money".
Try reading some reviews here. Many of these have Pan/Tilt/Zoom (PTZ),
and you want optical zoom, rather than digital zoom. Optical zoom
preserves the capture quality, while digital degrades it.
This one is $740.00 . It runs from a 12V 1.5A DC wall wart.
I don't know how long a car battery would last at that rate.
You'd need a car battery, plus a regulator to drop that to
the required 12V value. Probably part of the power consumption,
is from the pan and tilt motors, but continuously running
Wifi is probably good for a few watts too. It would need a
pretty large solar array, to keep the battery charged.
ftp://ftp.dlink.com/Multimedia/dcs6620G/Manual/DCS6620G_manual_100.zip
I got a little more data here.
Power Consumption:
# 5.5W (Still)
# 8.0W (Moving)
So while the camera is panning or tilting, you'd need 12V @ 0.66 amps.
Or about half an amp if the camera remained still. For a four day
run on a car battery, that would be 96 hours times half an amp hour,
or 48AH battery capacity.
Sensitivity is listed as 0.05 Lux, which I find a bit hard to
believe. In any case, with that kind of listed value, you might
not have too many problems in daylight conditions.
So is it worth spending $740.00 on a toy ?
As for the computer end, it looks like wireless routers are
more available than the "access point" version. So buy a
wireless router, to be able to receive the signal from the
camera.
802.11b/g router, should work with 802.11g camera.
http://www.newegg.com/Product/Product.aspx?Item=N82E16833127158
That example camera is likely not protected against the elements,
so you may want to prepare a housing for it. The housing will
need sufficient ventilation, so that the 5.5W the thing is
wasting, doesn't cook it.
Paul
h...@40th.com
>This one is $740.00 . It runs from a 12V 1.5A DC wall wart.
A dlink 6620 is a rebranded vivotek 6000 line. The plastic
is a little different, but the guts and optics are the
same. 4Xem sells a similar camera, as does/did LevelOne.
These things are very old. Vivotek did the 6000 line back in
2005 or so. While these do "640x480", they are CCD devices, and
320x240 (352x240) ones at that. The image appears scaled when
larger than 320x240, so no real detail gain over what you get if
you just did a 2x scale. That price is odd; LevelOne had sold
their brand of it (FCS-1040/WCS-2040) for as low as $350 (at
Provantage, years ago even). I've noticed the Taiwan-based
cams have gone up the past year, though.
The Vivo/dlink/4xem/LevelOne/et al. 6000 does okay in low light
but the FPS goes very low, to a blur when movement is in the
frame (B&W in low-lux mode, too). It is old tech (but standard
mpeg-4, which is good so long as there's a clean picture). For
that price you can get a Panasonic 580A which will does full speed
in low light, with a much better image (still noisy, but full
color) than the old tech stuff. If you can deal with low FPS,
there's a slower shutter (about 4 FPS) which gets a near-
daylight-like image (very little noise, and very bright) out
of that Panasonic camera. It's a lot newer tech than the dlink.
Differences:
Smoother PT (Pana: sub-degree absolute positioning;
dlink: only (easily) left/right/up/down movement, so you can't
tell the camera to move 45.42 degrees right, etc.)
Zoom is 21x optical versus 10x on dlink/vivo/etc. Zoom can
also be set to an absolute mag (say, 4.5x) while dlink has to
increase/decrease, and with odd speed limitations (i.e., how
fast it moves in its zoom range) too complex to go into here.
Pana has an SD card to store events on-camera (may be useful if
the connection goes down).
Pana's image is quite a bit better. It's not mega-pixel camera
quality - not by a long shot, but if you zoom 21x, you can
read a book a quarter-mile away. Well, you could probably
tell it's a book, anyway. Not too useful in a small building,
unless you like looking up people's noses.
BTW, Vivotek has (soon to) replaced this with a 7000-line version
of this 6000-line camera. It looks the same on the outside,
but has the newer board electronics like the rest of their 7000
cams (which have been around a while already). I think Vivotek
makes good cameras (I have several). The 6000-line is old tech,
though, only because it IS old tech. D-link would be the last
choice for me, even though the camera itself is basically the
same. Most of the cameras dlink sells for over $100 are made
by Vivotek. They have difference plastic, but inside are the
same as standard vivo cams (I think dlink still sells a Vivo
3000-line cam - that dates to 2003 or so).
- - -
These things usually go by "network camera" or "IP camera".
A "Web cam" is a thing you pick up for $15 (seldom worth more),
and are USB-based. Network/IP cams, like the name suggests,
are ethernet/wifi-based. And yes, they cost a lot, never have
an image that their price would suggest they do, but are cool,
and hardly "toys". I've got a more than a dozen, and custom
software to make them work.
--
40th Floor - Software @ http://40th.com/
PhantasmX3 - The finest sound in the world
phantasm.40th.com ppc netbook
Paul
>
> These things usually go by "network camera" or "IP camera".
> A "Web cam" is a thing you pick up for $15 (seldom worth more),
> and are USB-based. Network/IP cams, like the name suggests,
> are ethernet/wifi-based. And yes, they cost a lot, never have
> an image that their price would suggest they do, but are cool,
> and hardly "toys". I've got a more than a dozen, and custom
> software to make them work.
>
So how would a person reliably pick a product, and
get value for money ? Do we rely on other users,
to have taken the goods apart, to find out how
cheesy they are ? It all looks like a giant scam.
Paul
terryc
> So how would a person reliably pick a product, and get value for money ?
go to exactly the same stuff used industrially four outdoors. The cheep
usb cams are all crud, end of story.
You start off by looking at you distance to the object and width of field
required, which gives you your lens.
Then you look at illumination, (sun only, IR boos, etc) and that just
about defines the camera you want.
The time/money wasters are autofocus, zoom and movement
Then you look for a suitable housing and mount.
Then you look at how you are going to get the picture back to base.
Total up all your power requirements and work what you need.
Then die of shock at the price.
Then go back to defining your requirements, aka all I want is a picture
of the bastard who keeps robbing my hives and their vehicle, so you jst
want a still camera that activates on movement.
> Paul
Hewson Jack
> "Hewson Jack" <gamese...@googlemail.com> wrote in message
Brian
Thanks for taking the time.
The cross posting to the other groups is a great lead - I would never
have thought of that.
I had been thinking wireless WiFi as I can't get to the area by cable
- price may kill this project from the start but I'll take what you
say on board and keep going.
Best Hewson
Hewson Jack
> On Mon, 29 Jun 2009 12:55:02 +0100, "Brian Cryer"
>
>
>
> <not.here@localhost> wrote:
Thanks for the reply - looks like my project may not get off the
ground...
Hewson Jack
>
> This one is $740.00 . It runs from a 12V 1.5A DC wall wart.
> I don't know how long a car battery would last at that rate.
> You'd need a car battery, plus a regulator to drop that to
> the required 12V value. Probably part of the power consumption,
> is from the pan and tilt motors, but continuously running
> Wifi is probably good for a few watts too. It would need a
> pretty large solar array, to keep the battery charged.
>
> ftp://ftp.dlink.com/Multimedia/dcs6620G/Manual/DCS6620G_manual_100.zip
>
> I got a little more data here.
>
>
> Power Consumption:
> # 5.5W (Still)
> # 8.0W (Moving)
>
> So while the camera is panning or tilting, you'd need 12V @ 0.66 amps.
> Or about half an amp if the camera remained still. For a four day
> run on a car battery, that would be 96 hours times half an amp hour,
> or 48AH battery capacity.
>
> Sensitivity is listed as 0.05 Lux, which I find a bit hard to
> believe. In any case, with that kind of listed value, you might
> not have too many problems in daylight conditions.
>
> So is it worth spending $740.00 on a toy ?
>
> As for the computer end, it looks like wireless routers are
> more available than the "access point" version. So buy a
> wireless router, to be able to receive the signal from the
> camera.
>
>
> That example camera is likely not protected against the elements,
> so you may want to prepare a housing for it. The housing will
> need sufficient ventilation, so that the 5.5W the thing is
> wasting, doesn't cook it.
>
> Paul
Paul
Thanks for all this - whoh!!! so comprehensive - I think my project is
going to be a no no but I'll look at some of the suggestions you have
made and costs which in the end will determine the viability of the
project.
So Kind of you
Best Hewson
Jon Danniken
>
> Your origional post didn't make my news server, so I'll reply as
> a followup to another post. Below are some important questions to
> fill in some important gaps concerning what you want to do. If
> you like to tinker then your project may be doable for a
> reasonable cost.
>
> 1) What type of monitoring of the hive do you have in mind?
> Inside, outside, periodic or full time? Do you have to have color
> or will BW be ok?
>
> 2) How far is the hive from a structure with power? How far is
> the hive from the structure that will house the computer
> connecting to the web?
>
> 3) How much $$$ do you have to spend on the project? DYI is a lot
> cheaper than an off the shelf solution.
>
> My DIY pan/tilt web cam:
> http://www.geocities.com/zoomkat/wc2000-PT-script.htm
Wow, that is impressive. I had toyed with playing around with cams using
stepper motors, but it was a bit beyond my skills. That servo chip looks
like it really makes this thing workable.
Thanks for documenting your work, I might just have to start thinking about
this again!
Jon
Hewson Jack
> On Tue, 30 Jun 2009 00:26:25 -0700 (PDT), Hewson Jack
>
> <gamese...@googlemail.com> wrote:
> >Thanks for the reply - looks like my project may not get off the
> >ground...
>
> a followup to another post. Below are some important questions to
> fill in some important gaps concerning what you want to do. If
> you like to tinker then your project may be doable for a
> reasonable cost.
>
> 1) What type of monitoring of the hive do you have in mind?
> Inside, outside, periodic or full time? Do you have to have color
> or will BW be ok?
>
> 2) How far is the hive from a structure with power? How far is
> the hive from the structure that will house the computer
> connecting to the web?
>
> 3) How much $$$ do you have to spend on the project? DYI is a lot
> cheaper than an off the shelf solution.
>
> My DIY pan/tilt web cam:
> http://www.geocities.com/zoomkat/wc2000-PT-script.htm
I'M VERY VERY IMPRESSED - BUT THAT IS ALL BEYOND ME ON THE TECHNICAL
SIDE - UNLESS YOU LIVE ACROSS THE ROAD OF COURSE !!!!
I CAN RUN A WIFI LAPTOP FROM THE BEE SITE NO PROBLEMS - THE CAMERA IS
TO MONITOR THE OUTSIDE OF THE HIVE [ SOUNDS BORING DOESN'T IT ? ]
I WAS THINKING COLOUR AND EVERY 15 SECS OR SO - MAYBE MOTION CONTROL.
AS TO $$$$ - I AM A RETIRED MILLIONAIRE BUT SOMEONE 'MADE OFF' WITH MY
MONEY - SO AS CHEAP AS POSSIBLE WITHOUT CONSTRUCTING ONE.
I'M IN THE UK SO UP TO STERLING 125 ISH
THANKS FOR THE CONTRIBUTION
terryc
> I CAN RUN A WIFI LAPTOP FROM THE BEE SITE NO PROBLEMS - THE CAMERA IS TO
> MONITOR THE OUTSIDE OF THE HIVE [ SOUNDS BORING DOESN'T IT ? ]
So, you want a big umbrella and a cheap USB cam that plugs into the
laptop. All the stuff sits under the umbrella, including the inverter and
battery big enough for 24hr of lappie power.
You will need a pair of humungous deep discharge lead acid batteries. One
battery is at the hive site providing power for the lappie. the other is
back at home being recharged. You could probaly use a cheap hand trolley
to cart the fresh battery in and the old battery out.
--
Great advances in Debian Linux; post a bug report and get spam in three
days.
Hewson Jack
> > "Hewson Jack" <gamese...@googlemail.com> wrote in message
>
> This one is $740.00 . It runs from a 12V 1.5A DC wall wart.
> I don't know how long a car battery would last at that rate.
> You'd need a car battery, plus a regulator to drop that to
> the required 12V value. Probably part of the power consumption,
> is from the pan and tilt motors, but continuously running
> Wifi is probably good for a few watts too. It would need a
> pretty large solar array, to keep the battery charged.
>
> ftp://ftp.dlink.com/Multimedia/dcs6620G/Manual/DCS6620G_manual_100.zip
>
> I got a little more data here.
>
>
> Power Consumption:
> # 5.5W (Still)
> # 8.0W (Moving)
>
> So while the camera is panning or tilting, you'd need 12V @ 0.66 amps.
> Or about half an amp if the camera remained still. For a four day
> run on a car battery, that would be 96 hours times half an amp hour,
> or 48AH battery capacity.
>
> Sensitivity is listed as 0.05 Lux, which I find a bit hard to
> believe. In any case, with that kind of listed value, you might
> not have too many problems in daylight conditions.
>
> So is it worth spending $740.00 on a toy ?
>
> As for the computer end, it looks like wireless routers are
> more available than the "access point" version. So buy a
> wireless router, to be able to receive the signal from the
> camera.
>
>
> That example camera is likely not protected against the elements,
> so you may want to prepare a housing for it. The housing will
> need sufficient ventilation, so that the 5.5W the thing is
> wasting, doesn't cook it.
>
> Paul
Thanks Paul
I'm slowly going off the idea - it sounded so simple at first - your
contribution is much appreciated though
Hewson Jack
Any ideas as to where I can get the batteries?
Si Ballenger
<game...@googlemail.com> wrote:
>> Your origional post didn't make my news server, so I'll reply as
>> a followup to another post. Below are some important questions to
>> fill in some important gaps concerning what you want to do. If
>> you like to tinker then your project may be doable for a
>> reasonable cost.
>>
>> 1) What type of monitoring of the hive do you have in mind?
>> Inside, outside, periodic or full time? Do you have to have color
>> or will BW be ok?
>>
>> 2) How far is the hive from a structure with power? How far is
>> the hive from the structure that will house the computer
>> connecting to the web?
>>
>> 3) How much $$$ do you have to spend on the project? DYI is a lot
>> cheaper than an off the shelf solution.
>>
>> My DIY pan/tilt web cam:
>> =A0http://www.geocities.com/zoomkat/wc2000-PT-script.htm
>
>I'M VERY VERY IMPRESSED - BUT THAT IS ALL BEYOND ME ON THE TECHNICAL
>SIDE - UNLESS YOU LIVE ACROSS THE ROAD OF COURSE !!!!
>
>I CAN RUN A WIFI LAPTOP FROM THE BEE SITE NO PROBLEMS - THE CAMERA IS
>TO MONITOR THE OUTSIDE OF THE HIVE [ SOUNDS BORING DOESN'T IT ? ]
>
>I WAS THINKING COLOUR AND EVERY 15 SECS OR SO - MAYBE MOTION CONTROL.
>
>AS TO $$$$ - I AM A RETIRED MILLIONAIRE BUT SOMEONE 'MADE OFF' WITH MY
>MONEY - SO AS CHEAP AS POSSIBLE WITHOUT CONSTRUCTING ONE.
>
>I'M IN THE UK SO UP TO STERLING 125 ISH
>
>THANKS FOR THE CONTRIBUTION
You can get cheap wireless cams like below and make directional
antennas to improve performance. The one below would need to have
the IR LEDs deactivated to save power if it were to be run off of
battery/solar panel power .
http://www.geeks.com/details.asp?invtid=NIGHT-WIRELESS&cat=VID
Nick Cramer
> On Jul 2, 1:18=A0am, terryc <newssevenspam-s...@woa.com.au> wrote:
> > [ . . . ]
> > You will need a pair of humungous deep discharge lead acid batteries.
> > One battery is at the hive site providing power for the lappie. the
> > other is back at home being recharged. You could probaly use a cheap
> > hand trolley to cart the fresh battery in and the old battery out.
> Any ideas as to where I can get the batteries?
\Check out an RV dealer or a chandlery.
--
Nick, KI6VAV. Support severely wounded and disabled Veterans and their
families: https://www.woundedwarriorproject.org/ Thank a Veteran!
Support Our Troops: http://anymarine.com/ You are not forgotten.
Thanks ! ! ~Semper Fi~ USMC 1365061
terryc
> Any ideas as to where I can get the batteries?
Well, depending on the calcs*** you do, better electronic suppliers or
fork lift battery supplies. These are the best value in my experience.
Places like 4WD shops and Battery world are relatively expensive.
I buy new Trojans for my needs, but everytime I've been over there, he is
always offering refurbed fork lift batteries. If I had a non-critical
stationary need(and can afford a decent amount of solar panels), then
I'd jump at the fork lift.
*** You really need to get minimal power requirements. Hopefully a simple
cmos camera with a wifi video link will suffice. Trying to run a standard
lappie through an inverter could see you lugging in up to 100kg each day.
caveat, I've only ever had ancient lappies (5A @ 17V is OUCH).
Hopefully one day, Someone will crack the job of directly replacing
laptop batteries with a solid lead acid battery. The problem is defeating
the charging controls and sensors (that is what all the pins are for).
kony
<newsseven...@woa.com.au> wrote:
>On Thu, 02 Jul 2009 00:42:37 -0700, Hewson Jack wrote:
>
>> Any ideas as to where I can get the batteries?
>
>Well, depending on the calcs*** you do, better electronic suppliers or
>fork lift battery supplies. These are the best value in my experience.
>Places like 4WD shops and Battery world are relatively expensive.
That may be a bit excessive. Consider a webcam that can run
from USB, that's 500mA max current. Next consider that USB
wifi adapters may use about 300mA, let's assume for the
moment the total current is 800mA @ 5V or 4W.
Next we can reasonably assume a buck regulator taking the
12V from one battery to be 85% efficient. 4W/.85 = 4.7W,
but let's round up to 5W.
No matter how good or poor the sun is, the average charge
rate for the battery must slightly exceed the average
currrent draw of the webcam. No matter how large the
battery the solar panel capacity remains a separate factor
but let's spec for two days of runtime with the battery
starting at full charge.
48 hours * 5W = 240WH
240WH/12V = 20AH.
(>=) 20AH is not a particularly large SLA battery pack,
something for a forklift would be massive overkill. Even if
we assume charging inefficiency, we don't necessarily need a
full 24 hours of runtime as there are not days where the sun
puts out no light at all... it's all a matter of determining
the capacity of the solar charger from that point forward,
the charger & solar panel(s) probably being the most
expensive part of the project.
>*** You really need to get minimal power requirements. Hopefully a simple
>cmos camera with a wifi video link will suffice. Trying to run a standard
>lappie through an inverter could see you lugging in up to 100kg each day.
>caveat, I've only ever had ancient lappies (5A @ 17V is OUCH).
Laptops are not suitable for 24/7 outdoor use, but if they
were, it would not be expected to consume 5A @ 17V
regardless of what the power brick is spec'd for. With the
screen & it's backlightling off, mostly idling in an ACPI
power management capable OS, it would probably idle closer
to 30W, or about 2A.
Regardless, as you wrote a wifi video camera would be the
best option of one can be found that is both affordable and
with reasonable enough quality, that will be the challenging
part to find, though the cumulative cost of batteries,
regulation and solar panels won't be cheap either.
>
>Hopefully one day, Someone will crack the job of directly replacing
>laptop batteries with a solid lead acid battery. The problem is defeating
>the charging controls and sensors (that is what all the pins are for).
Not necessary, simply get an automobile lighter adapter
(DC-DC laptop specific PSU), wire a lighter socket to the
battery terminals, and plug that PSU into the lighter socket
and laptop PSU socket. It'll be a little less efficient
than hacking into the main charging circuit, but since it
stays with the original design and doesn't void the laptop
warranty (besides the part about leaving it outside), there
are few things to go wrong.
Paul
> On 02 Jul 2009 14:41:31 GMT, terryc
> <newsseven...@woa.com.au> wrote:
>
>> On Thu, 02 Jul 2009 00:42:37 -0700, Hewson Jack wrote:
>>
>>> Any ideas as to where I can get the batteries?
>> Well, depending on the calcs*** you do, better electronic suppliers or
>> fork lift battery supplies. These are the best value in my experience.
>> Places like 4WD shops and Battery world are relatively expensive.
>
> That may be a bit excessive. Consider a webcam that can run
> from USB, that's 500mA max current. Next consider that USB
> wifi adapters may use about 300mA, let's assume for the
> moment the total current is 800mA @ 5V or 4W.
>
There are some pretty looking toys out there.
For example, this one has the *looks*. Fortunately,
it is discontinued, so there is no danger of them
selling more of them.
http://www.smarthome.com/69010/2-4GHz-Solar-Color-PIR-Camera-Receiver-6C128U-6EVSP000/p.aspx
The reviews tell the story.
http://www.smarthome.com/asp/ReviewRead/ReviewRead.asp?itemnumber=69010
"Review: WORKS OK BUT IT KICKS ME OFF WIRELESS INTERNET AND XBOX LIVE."
What that means, is the unit is 2.4GHz, but it doesn't use WiFi protocol.
It interferes with Wifi operation though.
And that product, needs a PCI or PCI Express capture card in the host computer,
as the video coming out of the receiver, is composite video on an RCA jack.
The 2.4GHz is carrying the analog version of the video. It isn't digital
packets ready to view in a web browser.
Still, it is getting closer to something usable. By only running the
video camera for 40 seconds, after someone is detected in the area,
it reduces battery waste. Whether this is useful, really depends on
whether the detector works reliably.
PIR is Pyroelectric InfraRed, which isn't necessarily reliable with sunlight
present. PIR detectors can be very sensitive. I have one which can sense
me at 50 feet. And when it was mounted in my basement, it triggered when a
mouse ran across the basement floor (at first, I couldn't figure out what
was triggering it, since I don't have any pets). But outdoors, there might
be more nuisance detection events.
http://en.wikipedia.org/wiki/Passive_infrared_sensor
If a separate PIR detector was tied to a camera system, it would at least
allow the unit to be "sleeping" when no-one was present. The PIR I've got,
flattens a 9V transistor radio battery, in about one week of usage, to give
some idea how much power it uses while "watching" a room.
Such a system, might not have the convenience of "always on" monitoring.
At the receiver, you'd need a means for the receiver to tell the computer
that the signal was valid. Or for the capture card in the computer, to not
capture an empty video signal if no signal was present.
Paul
terryc
> On 02 Jul 2009 14:41:31 GMT, terryc
> <newsseven...@woa.com.au> wrote:
>
>>On Thu, 02 Jul 2009 00:42:37 -0700, Hewson Jack wrote:
>>
>>> Any ideas as to where I can get the batteries?
>>
>>Well, depending on the calcs*** you do, better electronic suppliers or
>>fork lift battery supplies. These are the best value in my experience.
>>Places like 4WD shops and Battery world are relatively expensive.
>
> That may be a bit excessive.
As you are illustrating, it depends on the kit you can use.
> Consider a webcam that can run from USB,
> that's 500mA max current. Next consider that USB wifi adapters may use
> about 300mA, let's assume for the moment the total current is 800mA @ 5V
> or 4W.
Good.
>
> Next we can reasonably assume a buck regulator taking the 12V from one
> battery to be 85% efficient. 4W/.85 = 4.7W, but let's round up to 5W.
>
> No matter how good or poor the sun is, the average charge rate for the
> battery must slightly exceed the average currrent draw of the webcam.
> No matter how large the battery the solar panel capacity remains a
> separate factor but let's spec for two days of runtime with the battery
> starting at full charge.
>
> 48 hours * 5W = 240WH
> 240WH/12V = 20AH.
>
> (>=) 20AH is not a particularly large SLA battery pack, something for a
> forklift would be massive overkill.
Okay, first trap, maybe. If it is a lead acid anything battery, you want
at least double capacity. Basically, the lower you sip, the longer the
life(cycles) from the battery. So that 20Ah becomes 40Ah. At this point a
75Ah deep discharge lead acid battery from SuperCheapAuto for $75(sale)-
$125 becomes a better buy than a 40Ah sealed lead acid battery from
Jaycar. ($AUS and local stores for comparison purposes only.)
> Even if we assume charging
> inefficiency, we don't necessarily need a full 24 hours of runtime as
> there are not days where the sun puts out no light at all... it's all a
> matter of determining the capacity of the solar charger from that point
> forward, the charger & solar panel(s) probably being the most expensive
> part of the project.
And the real gotcha. If you have no idea of the weather at the site, then
you have no idea how much uptime Vs size of panel. For me,any project
involving solar panels are very expensive suck it and see proposals. Many
people assume that any solar panel is unlimited power.
In ~90% of the project solar power installations I cost up, the cheapest
and most practical option turns out to be dumping the biggest battery you
can get on site, then dragging out a battery charger generator once a
week for a top up.
> doesn't void the laptop warranty (besides the part about leaving
> it outside), there are few things to go wrong.
Drool, a lap top in warranty. {:-). I have actually never purchased
one***. As I repair computers, I inevitably get asked about repairing
them and decline and end up being given them for bits or trading them for
some old part.
***My computers are like the good old axe; three heads and seven handles.
kim
Ballengers second point...IE how far away is the hive from power and or
place that will do the monitoring?
kony
<newsseven...@woa.com.au> wrote:
>> 48 hours * 5W = 240WH
>> 240WH/12V = 20AH.
>>
>> (>=) 20AH is not a particularly large SLA battery pack, something for a
>> forklift would be massive overkill.
>
>
>Okay, first trap, maybe. If it is a lead acid anything battery, you want
>at least double capacity. Basically, the lower you sip, the longer the
>life(cycles) from the battery. So that 20Ah becomes 40Ah. At this point a
>75Ah deep discharge lead acid battery from SuperCheapAuto for $75(sale)-
>$125 becomes a better buy than a 40Ah sealed lead acid battery from
>Jaycar. ($AUS and local stores for comparison purposes only.)
While you have a point, I don't necessarily agree the
battery has to be oversized by 2X. Given 48 hours of
runtime there is some margin already, more a matter of
having the solar panel amply sized so that it provides
enough recharge power even on overcast days.
I don't think it needs be something exotic and expensive.
While I had calculated for 12V, a 3 pack of $15, 7.5AH cells
as commonly found in low-end UPS would suffice. The
thinking here is that such a battery is more easily found
locally... the battery from SuperCheapAuto may be a good
deal for what it is but I am not familiar with this retailer
and don't know if one is local to the OP.
>
>
>
>> Even if we assume charging
>> inefficiency, we don't necessarily need a full 24 hours of runtime as
>> there are not days where the sun puts out no light at all... it's all a
>> matter of determining the capacity of the solar charger from that point
>> forward, the charger & solar panel(s) probably being the most expensive
>> part of the project.
>
>And the real gotcha. If you have no idea of the weather at the site, then
>you have no idea how much uptime Vs size of panel. For me,any project
>involving solar panels are very expensive suck it and see proposals. Many
>people assume that any solar panel is unlimited power.
That's why it's good to select a charger with a fairly large
input voltage range capability, and instead of one large
panel to buy multiple smaller panels so if the original spec
is off, addt'l panels can be added without loss of the value
of the original panel(s).
>
>In ~90% of the project solar power installations I cost up, the cheapest
>and most practical option turns out to be dumping the biggest battery you
>can get on site, then dragging out a battery charger generator once a
>week for a top up.
While it may be cheaper, 800mAH isn't a terribly large
amount of power... and that is merely a conservative peak
estimate. I'll speculate that a typical wifi netcam will
use less than this... not only because these were derived
from USB upper limits, but also because if it were 4W in a
small enclosed plastic 'cam, it would get really hot which
they don't so obviously the average current is lower.
>
>
>> doesn't void the laptop warranty (besides the part about leaving
>> it outside), there are few things to go wrong.
>
>Drool, a lap top in warranty. {:-). I have actually never purchased
>one***. As I repair computers, I inevitably get asked about repairing
>them and decline and end up being given them for bits or trading them for
>some old part.
>
>***My computers are like the good old axe; three heads and seven handles.
Depends on what laptop and how old it is? Lots of them now
have only 1 year warranty and an entire mainboard can be
replaced for $250 or less if you happen to find one on
ebay. Then again some of the more common repairs are things
like a loose power jack, sometimes it can be soldered back
on, or epoxied in place and jumper wires used to replace the
broken traces. I enjoy coming up with new ways to fix
damaged goods so the time isn't really much of a factor...
so long as the owner isn't really anxious to get it done
ASAP to the point where I'm supposed to drop everything else
to work on it.
terryc
> While you have a point, I don't necessarily agree the battery has to be
> oversized by 2X. Given 48 hours of runtime there is some margin
> already, more a matter of having the solar panel amply sized so that it
> provides enough recharge power even on overcast days.
Totally irrelevant. You can not run lead acid batteries flat*. It
permanently screws them about. It isn't my recommendation, but all the
old farts who have worked with these things for decades.
There is a Bill *arden Lead acid FAQ floating around somewhere on it all.
* Actually, you can not run any battery flat due to the danger of a cell
(batteries are made up of cells) going reverse charge.
kony
<newsseven...@woa.com.au> wrote:
>On Fri, 03 Jul 2009 07:44:32 -0400, kony wrote:
>
>
>> While you have a point, I don't necessarily agree the battery has to be
>> oversized by 2X. Given 48 hours of runtime there is some margin
>> already, more a matter of having the solar panel amply sized so that it
>> provides enough recharge power even on overcast days.
>
>Totally irrelevant. You can not run lead acid batteries flat*. It
>permanently screws them about. It isn't my recommendation, but all the
>old farts who have worked with these things for decades.
You wouldn't be running them flat. Remember, the suggestion
was 48 hours of _reserve_ capacity, the average current plus
some margin has to be supplied by the solar panel(s) either
way.
Generally what this means is at most the pack is powering
the cells from evening until dawn, perhaps 14 hours in the
winter out of 48.
Further, the step-down supply for the cam can be selected
with a cutoff at a threshold above the minimal desired
battery pack voltage, but with amply sized solar panel(s)
that threshold should never be reached.
>
>There is a Bill *arden Lead acid FAQ floating around somewhere on it all.
>
>* Actually, you can not run any battery flat due to the danger of a cell
>(batteries are made up of cells) going reverse charge.
>
>>
Agreed, that's why the details of having 48 hours plus amply
sized solar panels were suggested. There should never be a
time when one needs to go out and trickle charge the panels
from an alternate source, nor double the capacity for this
project *except* if the ambient temperatures drop very low
then the SLA batteries may not be the right alternative,
perhaps NiCad or even better one of the Lithium
formulations.
terryc
> On 03 Jul 2009 13:11:05 GMT, terryc
> <newsseven...@woa.com.au> wrote:
>
>>On Fri, 03 Jul 2009 07:44:32 -0400, kony wrote:
>>
>>
>>> While you have a point, I don't necessarily agree the battery has to
>>> be oversized by 2X. Given 48 hours of runtime there is some margin
>>> already, more a matter of having the solar panel amply sized so that
>>> it provides enough recharge power even on overcast days.
>>
>>Totally irrelevant. You can not run lead acid batteries flat*. It
>>permanently screws them about. It isn't my recommendation, but all the
>>old farts who have worked with these things for decades.
>
> You wouldn't be running them flat. Remember, the suggestion was 48
> hours of _reserve_ capacity, the average current plus some margin has to
> be supplied by the solar panel(s) either way.
Umm, do you actually have any experience with this type of kit?
And I'll say again, 48Ah of deep discharge lead acid battery capacity is
not 48Ah of usable capacity. Read it and learn http://www.batteryfaq.org/
> Generally what this means is at most the pack is powering the cells from
> evening until dawn, perhaps 14 hours in the winter out of 48.
Do you have any experience to backup your previous claim that the solar
panels will produce some meaningful amount of power every day?. Which is
the fundamental shaky claim you are now making.
> Further, the step-down supply for the cam can be selected with a cutoff
> at a threshold above the minimal desired battery pack voltage,
Yep, absolutely necessary. Do you have a device recommendation for the
original poster or a circuit for the constructor? How does it affect
efficency?
> amply sized solar panel(s) that threshold should never be reached.
Aah,"amply sized". A vague quantity that means absolutely nothing.
>
>>There is a Bill *arden Lead acid FAQ floating around somewhere on it
>>all.
This looks like it. http://www.batteryfaq.org/
kony
<newsseven...@woa.com.au> wrote:
>On Fri, 03 Jul 2009 16:08:03 -0400, kony wrote:
>
>> On 03 Jul 2009 13:11:05 GMT, terryc
>> <newsseven...@woa.com.au> wrote:
>>
>>>On Fri, 03 Jul 2009 07:44:32 -0400, kony wrote:
>>>
>>>
>>>> While you have a point, I don't necessarily agree the battery has to
>>>> be oversized by 2X. Given 48 hours of runtime there is some margin
>>>> already, more a matter of having the solar panel amply sized so that
>>>> it provides enough recharge power even on overcast days.
>>>
>>>Totally irrelevant. You can not run lead acid batteries flat*. It
>>>permanently screws them about. It isn't my recommendation, but all the
>>>old farts who have worked with these things for decades.
>>
>> You wouldn't be running them flat. Remember, the suggestion was 48
>> hours of _reserve_ capacity, the average current plus some margin has to
>> be supplied by the solar panel(s) either way.
>
>Umm, do you actually have any experience with this type of kit?
>
>And I'll say again, 48Ah of deep discharge lead acid battery capacity is
>not 48Ah of usable capacity. Read it and learn http://www.batteryfaq.org/
>
>
I never suggested it was. The 48Ah is to take this into
account, that it is already more than needed. Let's look at
it the other way, instead of saying we need to double the 48
hours, what the 48 hours is, is double 24 hours.
>
>> Generally what this means is at most the pack is powering the cells from
>> evening until dawn, perhaps 14 hours in the winter out of 48.
>
>Do you have any experience to backup your previous claim that the solar
>panels will produce some meaningful amount of power every day?. Which is
>the fundamental shaky claim you are now making.
Solar panels will product some meaningful power every day,
unless you know of days the sun doesn't rise in the sky.
Again, the issue is amply sized solar panels, that they
don't just provide barely enough power on a nice sunny,
cloudless day, that they provide enough on overcast, shorter
winter days.
>
>
>> Further, the step-down supply for the cam can be selected with a cutoff
>> at a threshold above the minimal desired battery pack voltage,
>
>Yep, absolutely necessary. Do you have a device recommendation for the
>original poster or a circuit for the constructor? How does it affect
>efficency?
There is no efficiency difference, with any reasonable solar
charging circuit you will need a regulator, and with one
designed for battery power it will have a low voltage
shutoff. Recommendations would of course depend on the
battery pack voltage, for example whether it is one large
~12V pack, or some other voltage or series of batteries.
>
>> amply sized solar panel(s) that threshold should never be reached.
>
>Aah,"amply sized". A vague quantity that means absolutely nothing.
Absolutely wrong. It is the exact thing that needs
considered, and only vague because we don't have an actual
product to take the input power figure from, nor the site
solar levels which will probably have to be determined
experimentally which is why I suggested a modular approach
where more panels are added if the ones purchased don't
provide enough power.
>
>>
>>>There is a Bill *arden Lead acid FAQ floating around somewhere on it
>>>all.
>
>This looks like it. http://www.batteryfaq.org/
Great, and it does not conflict at all with what I've
written, just what you wanted to imagine instead.
terryc
> I never suggested it was. The 48Ah is to take this into account, that
> it is already more than needed. Let's look at it the other way, instead
> of saying we need to double the 48 hours, what the 48 hours is, is
> double 24 hours.
The figure came from early figures. Argue about it all you. See comment
below.
>>> Generally what this means is at most the pack is powering the cells
>>> from evening until dawn, perhaps 14 hours in the winter out of 48.
>>
>>Do you have any experience to backup your previous claim that the solar
>>panels will produce some meaningful amount of power every day?. Which is
>>the fundamental shaky claim you are now making.
>
> Solar panels will product some meaningful power every day, unless you
> know of days the sun doesn't rise in the sky.
Right, at this point, I'll bow to your obvious greater practical on your
planet.
toodle pips.