Power for IR lights
- Thread starter ps0303
- Start date
It all depends on acceptable voltage drop (not over 5%) calculated from device amperage draw, applied voltage, distance and wire gauge, so:
Here's a great online calculator ==>> Voltage Drop Calculator
Select the middle tab "Estimated Resistance", plug in your figures then "calculate" and if the voltage drop (results shown at top of calculator) goes above 5%, go to the next larger conductor, find its resistance (Ohms) per 1,000 ft. in the chart toward the bottom of that page and plug that in then re-calculate. Try to keep the drop below 5% by either shortening the wire distance, lowering the current draw (less devices) or using a larger wire size.
- Total device(s) current draw?
- Voltage?
- Distance?
- Wire gauge?
Here's a great online calculator ==>> Voltage Drop Calculator
Select the middle tab "Estimated Resistance", plug in your figures then "calculate" and if the voltage drop (results shown at top of calculator) goes above 5%, go to the next larger conductor, find its resistance (Ohms) per 1,000 ft. in the chart toward the bottom of that page and plug that in then re-calculate. Try to keep the drop below 5% by either shortening the wire distance, lowering the current draw (less devices) or using a larger wire size.
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CanCuba
Known around here
Are the IR lights close to the cameras? If so, you can buy POE splitters which split the data and power into the two separate connectors (RJ45 and DC barrel connector). From there, you can further split the DC power between camera and an illuminator.
Yes they would be close to each other.
Something like this???
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Just be aware that if you want to use an existing POE cable that's supplying POE + data to a POE camera and you want to derive the 12VDC for an LED emitter AND supply POE + data to that POE cam you unplugged for that purpose that many, if not most, of the more readily advertised and less expensive (< $20) POE-to-12VDC splitters do not supply POE out on the RJ45, only data.
This device will pass-thru the data and POE power to a POE camera and supply 12VDC @ 15W but it is not cheap ==> Tycon Power Systems - POE-MSPLT-4812P-F - PoE Splitter. 48VDC 802.3af PoE input and passthru RJ45 Socket output. 12VDC 15W output on 5.5x2.1mm DC connector. 6 inch cables
This device will pass-thru the data and POE power to a POE camera and supply 12VDC @ 15W but it is not cheap ==> Tycon Power Systems - POE-MSPLT-4812P-F - PoE Splitter. 48VDC 802.3af PoE input and passthru RJ45 Socket output. 12VDC 15W output on 5.5x2.1mm DC connector. 6 inch cables
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CanCuba
Known around here
That's perfect. You'll need the POE splitters:
Then the y-cable to split the DC power between the cam and the IR light:
The linked splitter will provide up to 24 watts of power @ 12v (2amps). I'm assume you have the barrel connector for DC power on your cam and the IR light has the same connector.
Connect the POE splitter to the cable coming from the switch/NVR. Plug the RJ45 male from the POE splitter into the RJ45 female of the cam. Then connect the y-cable to the barrel connector of the POE splitter and then the two ends of the y-cable to the cam and IR light.
Only thing to check is the combined wattage of the cam and the IR illuminator. Both should be listed on each device. Make sure the total watts (cam + IR light) don't add up to more than 24 watts.
This is the easier way and avoids running power just for the IR light.
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Also, insure you protect any of the aforementioned, recommended devices from direct exposure from the elements, use dielectric grease on plug/receptacle connections and wrap the final, tested connections with self-fusing tape, over-taped with electrical tape. Methods and supplies listed here.
Thank you for the input.
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Parley
Known around here
CanCuba
Known around here
I think it's @wittaj who has the down low on that. I measured the voltage one day and it read 11.5v but apparently that's what's leaking from the diode that's supposed to STOP people from feeding another DC device directly off the camera.
My only complaint is that the POE splitters are a bit bulky and I've had to install a junction box just for the POE splitter. I just mount it beside the junction box for the camera and have a very short piece of conduit between the two.
CanCuba
Known around here
I'll let someone else explain it. From my understanding, it's not designed to have power coming out of the camera.
Parley
Known around here
A camera can power an external illuminator, with a few qualifications:
If you meet all these requirements it's an easy modification to the camera, bridging a single diode with a wire. There's also the catch that I can only speak for the specific 8 or so Dahua models I've done this to. Also, I use a POE switch, not an injector, and it could work differently with an injector.
- Accept the risk of breaking the camera by opening and modifying it.
- Able to do fairly small geometry soldering.
- Camera's built-in IR lighting shut off.
- Load on camera's power plug limited to 4 watts.
If you meet all these requirements it's an easy modification to the camera, bridging a single diode with a wire. There's also the catch that I can only speak for the specific 8 or so Dahua models I've done this to. Also, I use a POE switch, not an injector, and it could work differently with an injector.
Yeah you really should use a splitter and "Y" cable or run a separate cable. I have had good luck with these:
As it stands from the factory, no you cannot use the 12VDC cable from the camera to power the IR. It is not designed that way and you will probably blow out the camera board. Maybe not immediately, maybe a few days from now or next week or next month. Just not worth as there are other ways.
The camera is designed to accept power from either the ethernet cable or the 12v cable, but not provide power from one to the other.
Now if you take a reading on the 12v, you will see some voltage (most see like 11.5v or so), but what you're reading is voltage leaking through the diode that is there to prevent drawing power from that connector and would fail under load. The PoE converter in the camera is designed to support the camera only and no external devices.
We have seen a few guys like @tigerwillow1 that have opened up a camera and bypassed things to get 12VDC out on that connector, but I would not suggest doing that and risk overloading and ultimately blowing the PoE board in the camera and then you are stuck with a bad camera. But he lays out the caveats and if you are comfortable with that, it is a possibility.
As it stands from the factory, no you cannot use the 12VDC cable from the camera to power the IR. It is not designed that way and you will probably blow out the camera board. Maybe not immediately, maybe a few days from now or next week or next month. Just not worth as there are other ways.
The camera is designed to accept power from either the ethernet cable or the 12v cable, but not provide power from one to the other.
Now if you take a reading on the 12v, you will see some voltage (most see like 11.5v or so), but what you're reading is voltage leaking through the diode that is there to prevent drawing power from that connector and would fail under load. The PoE converter in the camera is designed to support the camera only and no external devices.
We have seen a few guys like @tigerwillow1 that have opened up a camera and bypassed things to get 12VDC out on that connector, but I would not suggest doing that and risk overloading and ultimately blowing the PoE board in the camera and then you are stuck with a bad camera. But he lays out the caveats and if you are comfortable with that, it is a possibility.
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Parley
Known around here
I do not want the cameras IR lighting to shut off. Also, if the camera might fail down the road it is not worth it. Thank you everyone for the replies. With one of my license plate cameras I am getting most of the plates with good resolution. However, with the retro plates available here in California and a couple of "dirty" plates, I was thinking that with a little extra IR light I could pick those up too and approach 100%.
Edit: I am running 23 gauge solid copper Cat 6 cable.
Edit: I am running 23 gauge solid copper Cat 6 cable.
To clarify @wittaj 's schema, here's an image at bottom I copied from someone in another thread this morning but for the life of me can't find his post or even his name....but kudos to him.
EDIT: I found it here. Thanks @Mark_M !
And BTW, if you can get the one wiitaj linked, here another 2AMP version ==>> Gigabit PoE Splitter 12V 2A Output with IEEE 802.3af/at Standard Compliant 10,100,1000Mbps Power Over Ethernet Splitter Adapter for Security Camera CCTV Surveillance 5.5x2.1mm DC Plug Cable(PS5712TG)
EDIT: I found it here. Thanks @Mark_M !
And BTW, if you can get the one wiitaj linked, here another 2AMP version ==>> Gigabit PoE Splitter 12V 2A Output with IEEE 802.3af/at Standard Compliant 10,100,1000Mbps Power Over Ethernet Splitter Adapter for Security Camera CCTV Surveillance 5.5x2.1mm DC Plug Cable(PS5712TG)
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Solving one issue but creating another one. Now I am faced with finding a way to protect the 12v splitter as it won't fit inside the box I have the camera mounted to.
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You said earlier that the cam and the IR emitter are close to each other.
You could mount the IR on a box, put the splitter in there and extend the 12VDC and Ethernet from the splitter to the cam; keep all connections protected inside boxes and waterproof all connections ==>> LeMotech ABS Plastic Dustproof Waterproof IP65 Junction Box Universal Electrical Project Enclosure White 5.9 x 4.3 x 2.8 inch
There are Carlon boxes at HD and Lowes but they are all pretty big and cost a lot more. Sounds like more work and expense I know but certainly it's your call.
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