Dahua camera mod to power external IR light

tigerwillow1

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I've made an easy modification to 2 popular chinese market cameras to provide 12 volt power from their external power input jack (models HFW4431M-I2 and HFW4431R-Z). The same power components are in at least one model international starlight I looked at, so I'd expect the modification to be the same. The prerequisites are (1) Willing to open up the camera, (2) Small geometry soldering capability, and (3) Assuming the risk of destroying the camera.

Inside the camera, its internal poe-powered 12 volt supply and the external 12 volt input are hooked in parallel, with the exception of a diode in the external power input line that prevents POE power exiting the power input jack, and provides reverse polarity protection. Merely bridging this diode allows the camera's 12 volt POE power to be available at the power input jack. I'd expect powering the camera through the input jack to still work, with reverse polarity protection lost.

Starting with the 4431M, this is a picture of its main board. The diode is already bridged:
4431m-board.jpg
A closeup of the power input area shows the bridged diode on the right:
4431m-hack.jpg
The component 3 positions to the left is a 15 volt transient suppression diode. The green "150" component is a "polyfuse", which is roughly a non-mechanical automatic reset circuit breaker. This one is manufactured by CYG Wayon, and opens up between 1.5 and 3 amps at 25 deg C. With the 4431M I've not seen an initialization problem that crops up with the 4431R-Z, but it's something to be aware of. You then need a "double male" cord to connect the camera to the IR light. The cable you already have to split a POE splitter's power output works as a temporary substitute.

The modification is the same on the 4431R-Z's board:
4431rz-board-1.jpg 4431rz-hack.jpg

Even with the internal IR light turned off in the camera's setup, both cameras turn it on full blast for a few seconds during startup. With the 4431R-Z, the camera won't successfully boot up if the external IR light is active. It just keeps looping, attempting to get started. This was solved by forcibly disabling the 4431R-Z's internal IR lights by cutting the wire that goes to pin 1 of the IR array:
4431rz_ir-cut_2 (Medium).jpg

I've been running the 4431M with a 6 watt external light, and the 4431R-Z with a 4 watt external light, and so far, so good.

These are voltage measurements of the camera's 12 volt supply:

4431M:
no IR - 11.86
internal IR at 100% - 11.66
4 watt external IR - 11.49
6 watt external IR - 11.45
6 watt external + internal at 100% - 10.58

4431R-Z:
no IR - 11.66
internal IR at 100% - 11.40
4 watt external IR - 11.23
6 watt external IR - 11.14
4 watt external + internal at 100% - 11.18
6 watt external + internal at 100% - 11.11, with possibility of shutdown

I'm not doing this to avoid the cost of POE splitters. It's to fight the war on spiders without adding a bunch of cords and connectors exposed to the elements.
 
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handinpalm

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Great job on implementation. Thanks for the tip! Glad I bought POE+ switches.
 
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100 td

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Can you enlighten me to make/model of external IR, and how far away are you placing it from the camera?
 

tigerwillow1

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Can you enlighten me to make/model of external IR, and how far away are you placing it from the camera?
I'm happy to share with the caveat that I'm a beginner with this in learning mode. Aside from spider web issues, I'm generally disappointed with the dahua camera built-in IR, mainly because of its uneven coverage (i.e. hot spot in center). The built-in IR is also not particularly powerful. As an example I have a 4321 turret and a 4231 bullet, and measured the power draw increase from 0% to 100% IR as 2.3 watts in the turret and 3.5 watts in the bullet. I've also only tried the illuminators with small numbers of high power IR lights, as opposed to those with larger numbers of small LEDs. All of the ones Ive tried are constant power devices, drawing very close to 1 watt per LED, with the current ramping down as the supply voltage ramps up. So far I've mounted the emitters within a few feet of the camera and plan on experimenting with some further away. Most everything I've tried has a center hotspot problem. I've had the best luck using two smaller emitters with one camera, with the hotspots distributed.
There are pictures in other threads. This is what I've tried:

cmvision IR3 (3 leds): I got 2 of these. Liked them at first, then one failed, followed by the other failing. It was the actual LEDs that went out, and I got one working again by swapping the still good LEDs into one unit. After another month, that one failed. No more of these for me!

cmvision IR40 (4 leds) - Working fine for me so far, using 2 per camera. Maybe the same as jcheng security JC 4-led?

univivi u6r (6 led) - Working ok so far

tendelux AI4 (4 led) - Advertised as no hotspot. While generally true, it also has less light output than the other 4-led models I have.

Here are some other links:
5231- External IR Help
Compensating for narrow IR lighting
IR light - 5 model comparison
Univivi IR Illuminator 6 Leds
Any suggestions on a wide-angle coverage IR Illuminator
IR Cannon w/Adjustable Focus
Inexpensive IR illuminator
IR blasters - do you use them?
 

tigerwillow1

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I applied the modification to an international HDW-4231EMP-ASE, 2 megapixel starlight fixed focus turret camera. It has been running ok for about 2 weeks driving a 4 watt external IR light. The internal supply voltage is 11.36 with no IR light, 11.28 with built-in IR at 100%, and 10.90 driving the external 4 watt IR light. The isolation diode that gets jumpered is right next to the SD card slot. It wasn't necessary to cut the wire to the internal IR light as with the 4431r-z. This camera doesn't turn on its IR light during startup as all my other models do (controlled by the firmware I assume).
4231-turret-board.jpg 4231-turret-hack1.jpg
 
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