Dahua keeps rebooting
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sebastiantombs
Known around here
Crunching numbers, and assuming the table I found saying that 1.5mm2 wire is equivalent to 16 AWG:
Round trump wire length is 160 meters
Resistance of copper 16 AWG is 0.0132 ohms/meter
Resistance over 160 meters 2.112 ohms
Current at 6 watts = 0.5 amps
Voltage drop at 6 watts 1.056 (wire only, not considering connectors or splitter)
I don't know offhand what the allowable minimum camera voltage is.
sebastiantombs
Known around here
I have a feeling the Foscam was operating right at the edge of failure due to voltage drop between the cable and the splitter drops. With the Dahua needing another amp, nominal operating current, and probably two or three more during boot it's just too big a voltage drop.
We'll see guys. Appreciate the help. Tomorrow I'm going to remove that splitter and measure voltage. Will be continued.
@tigerwillow1 So POE would also not work for these distances right? I mean, those cable pairs are much much much smaller.
@tigerwillow1 So POE would also not work for these distances right? I mean, those cable pairs are much much much smaller.
sebastiantombs
Known around here
PoE actually supplies 48VDC on those wires. That reduces current demand to one fourth what it would be at 12VDC. You would need a PoE+ switch or a PoE injector capable of 12V@30 watts or more.
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alastairstevenson
Staff member
3A is a great deal for a camera - is that really the current that's drawn?
If so, check this out -
No, Dahua says a 12V/3A adapter should be provided.
But at max it draws 21W (IR on/Moving). Which is not even 2A (if i'm right). See sheet:
I dont know a lot about electricity but I thougt that if it would need 3A and there was a voltage drop due to cable length it would just push more amps at the batttery side, but that is clearly wrong haha
.
If the length of the cable is the problem. Would a solution be to have 2 x 12V batteries in serie pushing 24V to the other side, and there use a 12V regulator that brings it down to 12V again?
But at max it draws 21W (IR on/Moving). Which is not even 2A (if i'm right). See sheet:
I dont know a lot about electricity but I thougt that if it would need 3A and there was a voltage drop due to cable length it would just push more amps at the batttery side, but that is clearly wrong haha
.If the length of the cable is the problem. Would a solution be to have 2 x 12V batteries in serie pushing 24V to the other side, and there use a 12V regulator that brings it down to 12V again?
sebastiantombs
Known around here
A decent regulator, buck/boost, would be the easiest solution.
With nominal 48 volt POE the current would be divided by 4, and the voltage drop would be divided by 4 after it's reduced from 48 volts to 12 volts (most cameras convert 48 to 12 volts for their internal operating power). Plus, with POE, each side of the power is carried by 2 of the smaller conductors.
If I didn't mess up the math (always possible), POE smokes the direct 12 volt connection with a 12 volt drop of about 0.2 volts. Additionally, the camera's 48-to-12 volt conversion could possibly be more tolerant of lower voltage than the direct 12 volt connection.
Resistance of 160 meters 16 AWG =2.1 ohms, current for 6 watts@12 volts=0.5 amps, voltage drop=1.05.
Resistance of 160 meters 23 AWG =10.7 ohms, divided by 2 for parallel conductors = 5.4 ohms, current for 6 watts@48 volts=0.125 amps, voltage drop=0.675@48 volts, or 0.17@12 volts.
Resistance of 160 meters 24 AWG =13.5 ohms, divided by 2 for parallel conductors = 6.7 ohms, current for 6 watts@48 volts=0.125 amps, voltage drop=0.838@48 volts, or 0.21@12 volts.
You guys were right. The problem is clear. But not how to fix it. Bt I guess/hope/know you guys can give me the best advice.
Test with empty battery
First of all, I went to the location. Measured the (at that moment) empty battery.
Voltage at the battery: 12.08V
Voltage after 80M cable 10.43V
So there you have it. The resistance in the 80m cable is so high the voltage drops to low. It loses rougly 1.65 volts.
Test with full battery
Then I tried a "fresh" battery from the charger.
Voltage at battery: 13.04V
Voltage after 80M cable: 11.65V
Voltage after barrel power splitter: 11.58V
So there is also a loss of 1.39 volts.
First solution: Epic Fail
So I thought to be smart. I had a voltage stabilizer. Input: 9V - 34V. Output 12V
I thougt: at the end the voltage is 11.65V. which is in the input range of the stabilzer. So I attached the stabilizer.
I measured and expected it to output 12V. But wtf... output was 0V. And the voltage before the stabilizer dropped to 4.05.
So that sollution did not work. How can the voltage drop? I'm a noob.
Next solution:
My trust is in you guys. Who knows what I can do to have a stable 12V at the bottom of the pit where the camera is.
Thanks
Thanks to all of you to point me in the right direction. Awesome feeling when you finally find the problem. Now, help me find a solution
Test with empty battery
First of all, I went to the location. Measured the (at that moment) empty battery.
Voltage at the battery: 12.08V
Voltage after 80M cable 10.43V
So there you have it. The resistance in the 80m cable is so high the voltage drops to low. It loses rougly 1.65 volts.
Test with full battery
Then I tried a "fresh" battery from the charger.
Voltage at battery: 13.04V
Voltage after 80M cable: 11.65V
Voltage after barrel power splitter: 11.58V
So there is also a loss of 1.39 volts.
First solution: Epic Fail
So I thought to be smart. I had a voltage stabilizer. Input: 9V - 34V. Output 12V
I thougt: at the end the voltage is 11.65V. which is in the input range of the stabilzer. So I attached the stabilizer.
I measured and expected it to output 12V. But wtf... output was 0V. And the voltage before the stabilizer dropped to 4.05.
So that sollution did not work. How can the voltage drop? I'm a noob.
Next solution:
My trust is in you guys. Who knows what I can do to have a stable 12V at the bottom of the pit where the camera is.
Thanks
Thanks to all of you to point me in the right direction. Awesome feeling when you finally find the problem. Now, help me find a solution
sebastiantombs
Known around here
You didn't mention how you connected the voltage stabilizer, actually a regulator. Is that connected directly to the cable bringing the 12VDC in? If not connect it that way without ANY connectors involved other than what may be on the stabilizer. Next question is what is the input voltage with the stabilizer connected and also what is the current draw with the stabilizer connected? That device will draw current even with no load which can cause more voltage drop and cause it not to work if the voltage falls too low.
I know you said there's significant snow cover right now, but maybe an inspection of the cable, itself, is in order. Is the cable overhead, attached to trees or poles, laying on the ground or buried? A crushed or sharply bent section can also play havoc. DC behaves differently than AC when "transmitted" over significant distances.
I know this is getting a little complex and detailed, but trouble shooting from continent to continent can be a little difficult. I'm just trying to offer as many possibilities as possible.
As a solution, from what I can gather your battery/charger, probably a solar charger, are located remotely from the camera. This is requiring getting power, at some current level, to the camera. It may be a better solution to locate the battery with the camera and "transmit" the lower current of charging to the battery rather than the higher current being "transmitted" for the camera. Just a quick thought.
I know you said there's significant snow cover right now, but maybe an inspection of the cable, itself, is in order. Is the cable overhead, attached to trees or poles, laying on the ground or buried? A crushed or sharply bent section can also play havoc. DC behaves differently than AC when "transmitted" over significant distances.
I know this is getting a little complex and detailed, but trouble shooting from continent to continent can be a little difficult. I'm just trying to offer as many possibilities as possible.
As a solution, from what I can gather your battery/charger, probably a solar charger, are located remotely from the camera. This is requiring getting power, at some current level, to the camera. It may be a better solution to locate the battery with the camera and "transmit" the lower current of charging to the battery rather than the higher current being "transmitted" for the camera. Just a quick thought.
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With the added load, the voltage drop increases.
I would look at all of the connections and see if you can find a bad connections.
Including along the entire length of the wire. Any number of rodents can chew on wire,
thinking it is good to eat. Some wire is made from organic material.
Really, since you are using a buck boost converter, you can increase to 24 volts (2 batteries)
and will be over the voltage needed for the converter (as long as the wire has no bad connections).
I would look at all of the connections and see if you can find a bad connections.
Including along the entire length of the wire. Any number of rodents can chew on wire,
thinking it is good to eat. Some wire is made from organic material.
Really, since you are using a buck boost converter, you can increase to 24 volts (2 batteries)
and will be over the voltage needed for the converter (as long as the wire has no bad connections).
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@sebastiantombs
The voltage stabilizer is this one It has an in and an out. It says input 6-36V and out, 12V. I had it wired up directly to the battery with the 80m cable in between.
So: Battery => 80M cable => Stabilizer. I had nothing ON the stabilizer. Just measuring the blank cables that come from the output. Input voltage was 11.65V (before attaching the stabilizer). Stabilizer connected it said at that same point 4.05.
I have checked the wire. It is about 3 meters high in the trees. Doesn't look damaged at al. It is a pretty thick outdoor wire.
The reason why the wire is 80M long is because of the terrain: The camera is in a large pit. It has no 4G network coverage. The sides of the pit are steep and hard to get through due to vegetation. The top of the pit is 100m from the road.
So it is pretty easy to get a battery to the top of the pit near the router and the directional antenna then to climb down every day or two. The thing is 22Kg.
Otherwise placing the battery next to the camera would be the easiest solution indeed. But it is not an option as you might understand now
@Old Timer So if i'm reading it right: I could place two batteries, increase the voltage to 24V (which will be around 22V or so at the bottom). Then attach this stabilizer and convert it back to 12V.
But now, with 1 battery and the stabilizer attached, voltage dropped from 11.65 to 4.05. Wouldnt it then go from 23.2v to 8.10v and still would not work?
The voltage stabilizer is this one It has an in and an out. It says input 6-36V and out, 12V. I had it wired up directly to the battery with the 80m cable in between.
So: Battery => 80M cable => Stabilizer. I had nothing ON the stabilizer. Just measuring the blank cables that come from the output. Input voltage was 11.65V (before attaching the stabilizer). Stabilizer connected it said at that same point 4.05.
I have checked the wire. It is about 3 meters high in the trees. Doesn't look damaged at al. It is a pretty thick outdoor wire.
The reason why the wire is 80M long is because of the terrain: The camera is in a large pit. It has no 4G network coverage. The sides of the pit are steep and hard to get through due to vegetation. The top of the pit is 100m from the road.
So it is pretty easy to get a battery to the top of the pit near the router and the directional antenna then to climb down every day or two. The thing is 22Kg.
Otherwise placing the battery next to the camera would be the easiest solution indeed. But it is not an option as you might understand now
@Old Timer So if i'm reading it right: I could place two batteries, increase the voltage to 24V (which will be around 22V or so at the bottom). Then attach this stabilizer and convert it back to 12V.
But now, with 1 battery and the stabilizer attached, voltage dropped from 11.65 to 4.05. Wouldnt it then go from 23.2v to 8.10v and still would not work?
How are you getting power for your Mifi and Uno? I will assume it is 5volts.
If you go 24v batteries, then you will need a 5v converter to feed the MiFi and dUno.
Then you can wire the 24 volts to the wire going into the canyon, and put another 12v
converter at the bottom to run the camera and microphone.
This will allow you to have up to half the voltage lost in the wiring, and the converter at the bottom
will regulate the voltage at 12volts.
I will draw up a little schematic / pictorial for you in a bit.
What bugs me is the setup worked with a different camera for a while, yet your voltage drop is so
much it has only 4 volts at the bottom. I still worry about a loose connection or bad wire somewhere.
If you go 24v batteries, then you will need a 5v converter to feed the MiFi and dUno.
Then you can wire the 24 volts to the wire going into the canyon, and put another 12v
converter at the bottom to run the camera and microphone.
This will allow you to have up to half the voltage lost in the wiring, and the converter at the bottom
will regulate the voltage at 12volts.
I will draw up a little schematic / pictorial for you in a bit.
What bugs me is the setup worked with a different camera for a while, yet your voltage drop is so
much it has only 4 volts at the bottom. I still worry about a loose connection or bad wire somewhere.
sebastiantombs
Known around here
Looking at your sketch I'm guessing that you have both the 12 volt cable and an ethernet cable running to the camera. If that's the case, the easiest thing I can think of would be to buy a four port PoE+ switch and not use the 12 volt cable at all. Use the PoE on the network cable. That assumes, and we know what that can do, that the network cable is solid copper and 23 gauge wire. That one PoE switch would eliminate all the other electronics you have running there other than what is needed to power your RF link which is right at the battery anyway.
As a side note, make sure you leave plenty of slack between each tree the cable is anchored to. Trees sway, a lot, even though we normally don't notice it that much unless you mount a camera on one. Trees also grow in diameter as well as height. Make sure the cable is not getting buried in the bark as the tree adds girth. I know this from personal experience, and problems, with wire strung using trees as poles and by having two cameras mounted in trees on the main trunk about 2.5 meters from the ground. They sway and rotate in the wind despite the trees being well over a foot in diameter. I also had to make heavy aluminum brackets to support the flex conduit I switched to after losing cable to the tree sway and growth. It happens faster than you may anticipate or even realize.
As a side note, make sure you leave plenty of slack between each tree the cable is anchored to. Trees sway, a lot, even though we normally don't notice it that much unless you mount a camera on one. Trees also grow in diameter as well as height. Make sure the cable is not getting buried in the bark as the tree adds girth. I know this from personal experience, and problems, with wire strung using trees as poles and by having two cameras mounted in trees on the main trunk about 2.5 meters from the ground. They sway and rotate in the wind despite the trees being well over a foot in diameter. I also had to make heavy aluminum brackets to support the flex conduit I switched to after losing cable to the tree sway and growth. It happens faster than you may anticipate or even realize.
This would be a good second way to go. The biggest thing would be to find a PoE+ switch with a 12v input, or find a converter
that will take 12v in and what ever voltage the switch needs ( usually 48v).
Then use a 5v converter for the top electronics and the PoE+ to feed the bottom stuff.
sebastiantombs
Known around here
I think the small PoE switches use a wall wart and usually a 12 volt one. Alternately a PoE injector would work, but there you'd be in trouble finding one that uses 12 volts in.
@Old Timer , the router and the arduino both have an inbuild voltage regulatie. So they run on the 12V. The arduino is a self build device that measures the voltage and sends it through wifi (to the router) to a server so I can see when I need to replace the battery.
If I go 24 volts I indeed need an extra regulator because that is to much for the arduino.
It aslo bothers mee that it worked with the other camera. But as someone in this topic already said, it was probably on the edge. This cam uses a litttttle more power but it is probably just a little over the edge. It works with a fully charged battery, but when it empties 20% it is getting in trouble.
I do not think the wire is damaged. There is (afaik) just a 1,3v lost because of the resistance in the wire. Which bring the 12,8+ volt down in the canyon to < 12v.
I have looked at your drawing and this is also what I was thinking of. I already have all the gear to test this if it would work.(Except the 5v converter, but I can test the camera). It also adds another battery so the battery lifetime would increase (right?). Which gives me a little more time to go back and replace the thing.
Other point to mention is, that ik the future I might add a 410Wp solar panel. And those things also require 24V. So it would be ready for that.
@sebastiantombs you are right, I have two wires going down. An ethernet and a powerline. I first wanted to go for WiFi. But in the end the camera was repositioned, and distance was to large for wifi and I added a network cable.
That brings us to the Poe. I dont know much about electricity but even less about poe . But what I read is that there are multiple versions Poe.
I have a security camera at home which is powered by Poe. It uses a adapter that outputs 12v. But the Dahua requires Poe+ and the plus stands for more watts.
Now the 12v adapter output 1A, which is not enough.
That said the poe adapter I have is just a passive one. So maybe if I add it to the battery it just increases the ams. (Dunno).
This is a picture of the poe injector I have.
So the adapter is not good enough but if I just cut the barrel connector and attach it to the battery, it might inject enough amps... (Maybe?)
The poe injector is probably worth a shot isnt it?
But I cannot measure at the bottom with Poe, can I? Just plug in and see if the cam works?
If I go 24 volts I indeed need an extra regulator because that is to much for the arduino.
It aslo bothers mee that it worked with the other camera. But as someone in this topic already said, it was probably on the edge. This cam uses a litttttle more power but it is probably just a little over the edge. It works with a fully charged battery, but when it empties 20% it is getting in trouble.
I do not think the wire is damaged. There is (afaik) just a 1,3v lost because of the resistance in the wire. Which bring the 12,8+ volt down in the canyon to < 12v.
I have looked at your drawing and this is also what I was thinking of. I already have all the gear to test this if it would work.(Except the 5v converter, but I can test the camera). It also adds another battery so the battery lifetime would increase (right?). Which gives me a little more time to go back and replace the thing.
Other point to mention is, that ik the future I might add a 410Wp solar panel. And those things also require 24V. So it would be ready for that.
@sebastiantombs you are right, I have two wires going down. An ethernet and a powerline. I first wanted to go for WiFi. But in the end the camera was repositioned, and distance was to large for wifi and I added a network cable.
That brings us to the Poe. I dont know much about electricity but even less about poe . But what I read is that there are multiple versions Poe.
I have a security camera at home which is powered by Poe. It uses a adapter that outputs 12v. But the Dahua requires Poe+ and the plus stands for more watts.
Now the 12v adapter output 1A, which is not enough.
That said the poe adapter I have is just a passive one. So maybe if I add it to the battery it just increases the ams. (Dunno).
This is a picture of the poe injector I have.
So the adapter is not good enough but if I just cut the barrel connector and attach it to the battery, it might inject enough amps... (Maybe?)
The poe injector is probably worth a shot isnt it?
But I cannot measure at the bottom with Poe, can I? Just plug in and see if the cam works?