Extending IP Web Cam DC Power Wiring

[rockcrawler]

Hello,

I hope this is the right place. First time posting, but it seems like some people out there may have some ideas for me.

I need some help. I'm just a hobbyist and I'm trying to setup some cheap wireless PTZ IP Cams. Setup is not the issue. They work fine as delivered. I'm trying to do something a little more unique. I want to mount them were there is no electrical outlet for 100 feet. Essentially around the roof line of my 2 story house.

So far I've tried cat 5 and 18 gauge speaker wire with no luck. So before I get into all the details, let me give you some specs.

The camera came with a 5VDC 1.5 amp power supply. The draw is less than 6 watts. I metered the power supply and it puts out between 4.9 and 5.2 volts. I was not able to test the volts with a draw, or measure the amps.

Test 1
So the first thing I tried was to get some injectors and try POE with Cat5. I get an image, but it is a still frame, and no servo control. With this I concluded that at 5 volts, the voltage drop over cat 5 was too much at 50 or 100 feet.

Test 2
My second thought was to get a 5 volt 3 amp 15 Watt transformer, connect it to a distribution block, and wire in a barrel connector. First I tested with a 10 foot 18 gauge wire. It worked fine. So the transformer was good. When I metered the transformer, it put out 4.88 volts, and after a draw, 4.6 volts. I then added 50 feet of wire. The result was the same as the cat 5. Just a still image and no servo control. When metered at the source, it was 4.88VDC. At the end of the 50 foot wire it was 4.88 VDC. After I put a load on it (Connected the camera), VDC dropped to 4.25.

Test 3
So again, I figured I needed more power. Since I have about 100 DC adapters laying around, I found 2 to test. One was 7.5 volts at 1 amp, and the other was 6 volts at 3 amps. Both metered without a load, were putting out over 11 volts. But neither would work. The 7.5 VDC adapter dropped to around 5.8 to 6.5 VDC with a load. But nothing, not even an image. I removed the 50 foot wire and connected directly to the adapter. Nothing. I tried the 6 VDC 3 amp next. Similar results, although when connecting directly to the adapter (without the 50 wire) this adapter dropped to 4.2 VDC with only the original 3 foot wire attached.

So now I'm confused. I'm not sure what to do next. My thought was to use an old computer power supply and send 12 VDC over the wire, and attach a 5VDC voltage regulator right next to the camera. But test 3 suggests that might not work either.

Can anyone tell me what I'm doing wrong. I thought DC was DC, and it would be simple. Obviously not. How ideas on how to make this happen without spending a fortune. A true POE PTZ camera is way too much for my simple application.

Any assistance would be greatly appreciated.

Thanks.
Crawler

 

[Modelworks]

5VDC running for 100 feet requires some fairly large wires. The reason is that DC voltage drops fairly fast over distance and if you only have 5 volts to start with you can't afford to lose much.

You have two options.
Use a much heavier gauge of wire.
Use a higher voltage and regulate at the camera.

The first one is pretty straightforward.
For 100FT and 5VDC you need 8AWG wire. That would allow 4.7VDC @ 1.5A on the other end. That is fairly large wire and it would need to be solid wire or 6AWG if stranded. One of the reasons AC is used to distribute power is due to the losses DC has over distance.

If you raise the voltage to 12VDC then you can use a 5v regulator to produce 1.5A at the camera site. You will need to supply 12VDC at about 1A at the source so that by the time the voltage reaches the regulator it is at least 1.2 volts over what you need to output from the regulator. The wire size minimum for 12VDC is 16AWG that will provide 9V to the regulator. You could go even smaller for wire size but I wouldn't because things like outdoor temps will effect the capacity of the wire.

Personally if it were me I would send AC over the wire, rectify and filter it at the destination and not have to worry about the losses. You would need a transformer to convert the 120VAC to at least 4VAC at the source and a bridge rectifier, capacitor, 7805 regulator at the other end.

 

[rockcrawler]

Thanks for the response Modelworks. That helps a bit:


So part of my confusion is POE. 12 volts over Cat5 works up to 300 feet or so. Is it that with a 12VDC device, a voltage drop of 2VDC is a smaller percentage drop than 1VDC for a 5VDC device?

Also, during one of my test, with the 7.5 adapter, shouldn't the device have worked at 5.2VDC? The only thing I can think of with that particular adapter is that it was only capable of `1amp, so maybe it was not able to supply the amperes required for the device to run.

Other than those questions, I'm leaning towards the higher output transformer with a voltage regulator at the device. The reason being is that I want all the power in one spot for troubleshooting. Running AC everywhere would be cool, but then I'd have to get on a ladder at each connection to troubleshoot or reboot the devices, not to mention costs for conduit, outdoor gang boxes, installing another breaker on my panel.... Lots of work there to do it properly.

Running VDC home runs to each device from a distribution block in a closet allows me to cycle the power for each device individually.

One final question, would it make sense to have a 12VDC transformer capable of supplying 30 watts and 10 amps. Assume I have 8 camera attached. That's MAX watts = 8 x 6 = 48 and MAX amps = 8 x 1.5 = 12.

I expect that the only time the camera draws the max is when I'm using the servo. I will never have ALL 8 cameras panning and tilting to draw the max for all cameras simultaneously.

Rockcrawler

 

[Modelworks]

So part of my confusion is POE. 12 volts over Cat5 works up to 300 feet or so. Is it that with a 12VDC device, a voltage drop of 2VDC is a smaller percentage drop than 1VDC for a 5VDC device?

POE doesn't use 12VDC, it uses a minimum of 37VDC and up to 44VDC, a big difference when you are going the distance. CCTV cameras have a 12VDC supply but they accept anywhere from 6-12VDC internally so they can be run off a common source voltage over long distances.

Running VDC home runs to each device from a distribution block in a closet allows me to cycle the power for each device individually.

One final question, would it make sense to have a 12VDC transformer capable of supplying 30 watts and 10 amps. Assume I have 8 camera attached. That's MAX watts = 8 x 6 = 48 and MAX amps = 8 x 1.5 = 12.

You can run DC but the problem becomes getting the 5.2VDC at the end. If you run 12VDC then you will need a regulator at the camera. Regulators come in two types linear and switching. Linear are cheap but regulate by diverting all the excess power into heat. If a linear regulator is supplied 9VDC to make 5VDC @ 1A then it will waste 4VDC @ 1A, or 4 watts of power that becomes heat, that can be an issue if the regulator is placed in a hot location like outside in the summer. The other type is a switching regulator and the downside of those is cost. Probably looking at $15 per camera to purchase one that will have enough output and then you will also need some type of enclosure.

I have no connection with the below seller, just bought stuff before and it arrived as described.

Switching regulator:
http://www.ebay.com/itm/AX3022-Base...ltDomain_0&hash=item2304922dab#ht_2293wt_1163

Linear regulator:
http://www.ebay.com/itm/LM317-Adjus...ltDomain_0&hash=item53dbecd57b#ht_2438wt_1163

At a $3 difference get the switching regulator.

You will need 8 watts for each camera so that is 64 watts total. Or 12VDC@6A .

 

[bobdole369]

Thanks for the response Modelworks. That helps a bit:


So part of my confusion is POE. 12 volts over Cat5 works up to 300 feet or so. Is it that with a 12VDC device, a voltage drop of 2VDC is a smaller percentage drop than 1VDC for a 5VDC device?

Also, during one of my test, with the 7.5 adapter, shouldn't the device have worked at 5.2VDC? The only thing I can think of with that particular adapter is that it was only capable of `1amp, so maybe it was not able to supply the amperes required for the device to run.

Other than those questions, I'm leaning towards the higher output transformer with a voltage regulator at the device. The reason being is that I want all the power in one spot for troubleshooting. Running AC everywhere would be cool, but then I'd have to get on a ladder at each connection to troubleshoot or reboot the devices, not to mention costs for conduit, outdoor gang boxes, installing another breaker on my panel.... Lots of work there to do it properly.

Running VDC home runs to each device from a distribution block in a closet allows me to cycle the power for each device individually.

One final question, would it make sense to have a 12VDC transformer capable of supplying 30 watts and 10 amps. Assume I have 8 camera attached. That's MAX watts = 8 x 6 = 48 and MAX amps = 8 x 1.5 = 12.

I expect that the only time the camera draws the max is when I'm using the servo. I will never have ALL 8 cameras panning and tilting to draw the max for all cameras simultaneously.

Rockcrawler

Wall warts (those cubes) are often poorly if at all regulated. While it "says" 7.5VDC, in reality its anywhere between 6 and 9VDC. Also as power draw increases on cheap unregulated power supplies, its voltage decreases. You don't mention if you had 5.2V at the camera, or at the power supply. It would have to be 5.2V at the camera. However, without enough power to run the device - esp when the motor kicked in, it won't work.

Also this isn't exactly highly technical, but I digress.

The largest power draw for a smallish camera is the image sensor. It runs 100% of the time. PTZ's have inductive loads so they need a LOT of power available (often 3-5x the rated input power req) at motor start. Rule of thumb is to have 3x the power available for each camera. SO you would typically need 18W for each camera. While you might have a wall wart that "says" 5V 1.5A - I bet theres a nice big cap in there to account for the motor draw (inductive load).

SO the fix - Add power, add capacitors. A computer power supply won't cut it - it isn't used to an inductive load, and one is likely to trip the PS crowbar circuit. However with a small load like that - who knows.

12VDC transformer capable of supplying 30 watts and 10 amps

Such a thing doesn't exist. 12V at 10 amps is 120W.

 

[uclabachelor]

You might be spending more resources on getting power to your current camera than to just buy one that supports POE.

 

[rockcrawler]

You might be spending more resources on getting power to your current camera than to just buy one that supports POE.

Update:

Been playing with the 5vdc regulator. Ran 12v off an old computer power supply, hooked the 5vdc regulator within inches of the camera, and it worked perfectly. Threw in 500 feet of speaker cable and it still worked perfectly. This is excactly what I wanted to accomplish. I am now only limited by the wireless signal distance.

Thanks for all the input.

 

[heymrdj]

Update:

Been playing with the 5vdc regulator. Ran 12v off an old computer power supply, hooked the 5vdc regulator within inches of the camera, and it worked perfectly. Threw in 500 feet of speaker cable and it still worked perfectly. This is excactly what I wanted to accomplish. I am now only limited by the wireless signal distance.

Thanks for all the input.

Watch loading a computer PSU in such a way, they aren't really meant for a single rail to be taxed. It would be better (and safer) to grab a hobby psu that just has a 12v rail. They can be had a few bucks used on the bay.

 

[rockcrawler]

Watch loading a computer PSU in such a way, they aren't really meant for a single rail to be taxed. It would be better (and safer) to grab a hobby psu that just has a 12v rail. They can be had a few bucks used on the bay.

I'm not completely understanding the issue here. What do you mean by "single rail to be taxed"? These cameras draw a MAX of 1.5 to 2 amps. Could that really draw too much from the PSU. A mother board, and all the other things hooked up to it draw way more.....

So what is the difference between say an HP PSU and a hobby PSU?

Thanks much.

 

[bobdole369]

I'm not completely understanding the issue here. What do you mean by "single rail to be taxed"? These cameras draw a MAX of 1.5 to 2 amps. Could that really draw too much from the PSU. A mother board, and all the other things hooked up to it draw way more.....

So what is the difference between say an HP PSU and a hobby PSU?

Thanks much.

An ATX PSU has a number of voltage outputs. Often these are pulled off the same switching output but at different taps for certain voltages. SO say +5V and +12V are on the same output and -12V and +3.3V are on another. Since they share a transformer (with diff windings) the power pulled by 1 of the legs will increase the voltage on the shared output and cause the supply to reduce the output on your 12V...... Thats just one scenario. THis is if you are only using the +12V out and leaving the rest of the supply unloaded (open). COuld it be that you have a running computer that you are pulling +12V from?

A typical hobby power supply has a single output that is the only one monitored (if regulated intelligently, and they often are not).

PC power supplies are very cheaply designed to provide exactly what a computer is going to need. Not necessarily a steady 12V output.

 

[rockcrawler]

COuld it be that you have a running computer that you are pulling +12V from?

A typical hobby power supply has a single output that is the only one monitored (if regulated intelligently, and they often are not).

PC power supplies are very cheaply designed to provide exactly what a computer is going to need. Not necessarily a steady 12V output.

Hmmmmmm.... Okay, sounds like I'm still safe, unless I'm misreading.... I have the PSU standing alone for only this purpose (Mounted in a cabinet all by itself). I took 1 yellow lead (12vdc), and the black. All others are tied off and not being used. As long as it sends anything over 5 volts, each regulator will limit it, and allow 2amps to be drawn. As I add more cameras to this single 12v output, I will meter it to make sure I'm not over drawing the supply.


I realy apprecuate the input. I'm just trying to figure this out as I go, and it seems I have it. A fall back is a hobby PSU if this CPU PSU turns out flakey.

Thanks

Or am I completely missing your point?

 

[bobdole369]

Hmmmmmm.... Okay, sounds like I'm still safe, unless I'm misreading.... I have the PSU standing alone for only this purpose (Mounted in a cabinet all by itself). I took 1 yellow lead (12vdc), and the black. All others are tied off and not being used. As long as it sends anything over 5 volts, each regulator will limit it, and allow 2amps to be drawn. As I add more cameras to this single 12v output, I will meter it to make sure I'm not over drawing the supply.


I realy apprecuate the input. I'm just trying to figure this out as I go, and it seems I have it. A fall back is a hobby PSU if this CPU PSU turns out flakey.

Thanks

Or am I completely missing your point?

If its working well - more power to you .

 

[stormkroe]

Have you thought of buying some 14/2 TEK 90 and just running 120 to each camera? PVC and xLink might be cheaper, but either way could be cheaper than trying to finagle low voltage DC that far.

 

[PsiStar]

Stop screwing around with the DC side & just extend 110VAC out to the camera. I don't know ... an extension cord maybe?

The real issue is environmental protection. The power is an issue there, but the camera more so but you don't seem to concerned about that.

 

[Bryf50]

The real issue is environmental protection. The power is an issue there, but the camera more so but you don't seem to concerned about that.

Cameras are bad for the environment?

 

[Fayd]

wtf is wrong with people that they feel the need to use some different font and size than what is standard to the forum? it's very disruptive to my trying to read the damn thread.

in regards to the op:

voltage drop is something that you can calculate for certain.

http://www.csgnetwork.com/voltagedropcalc.html

for a given distance, with a given wire type, and a given input voltage and draw, you can calculate the voltage drop over that distance.

now, in regards to your specific use. I've installed a system of 12v DC power flowing through my house to IP based surveillance cameras. this works exceptionally well. i can't remember what the gauge was that i used, though. voltage drop was limited to .25v or so, at 12v. that's barely noticeable.

 

[sm625]

The 7.5 VDC adapter dropped to around 5.8 to 6.5 VDC with a load. But nothing, not even an image. I removed the 50 foot wire and connected directly to the adapter. Nothing. I tried the 6 VDC 3 amp next. Similar results, although when connecting directly to the adapter (without the 50 wire) this adapter dropped to 4.2 VDC with only the original 3 foot wire attached.

So now I'm confused. I'm not sure what to do next. My thought was to use an old computer power supply and send 12 VDC over the wire, and attach a 5VDC voltage regulator right next to the camera. But test 3 suggests that might not work either.

Test 3 doesnt make a whole lot of sense. You must have missed something. Maybe your 6 Volts was triggering some kind of overvoltage protection.

 

[PsiStar]

Cameras are bad for the environment?

Ha! Keep it in perspective. He is using the cameras to observe & record his environment.

DC is the wrong thing to use. This argument was argued nearly a century ago between Edison & Tesla.

 

[PsiStar]

wtf is wrong with people that they feel the need to use some different font and size than what is standard to the forum? it's very disruptive to my trying to read the damn thread.

in regards to the op:

voltage drop is something that you can calculate for certain.

http://www.csgnetwork.com/voltagedropcalc.html

for a given distance, with a given wire type, and a given input voltage and draw, you can calculate the voltage drop over that distance.

now, in regards to your specific use. I've installed a system of 12v DC power flowing through my house to IP based surveillance cameras. this works exceptionally well. i can't remember what the gauge was that i used, though. voltage drop was limited to .25v or so, at 12v. that's barely noticeable.

Your eyes are exceptionally sensitive to font size.

It is entirely possible that noise is getting coupled into his long runs of unshielded wire. Again, stop screwing around with DC & just string up an extension cord.

 

[Fayd]

Your eyes are exceptionally sensitive to font size.

It is entirely possible that noise is getting coupled into his long runs of unshielded wire. Again, stop screwing around with DC & just string up an extension cord.

only if he's running unshielded data/12v power wire for long stretches (3 feet+) right next to 120v ac power cables...

hell, i run ethernet cords carrying the video signal right next to the 12v cords for the bulk of 50-100 feet, and no problems.

besides, it makes more sense to have centrally supplied power. i just have to buy a single transformer, in the wall jack i'm using i set up 5 ethernet jacks and 1 barrel plug. plug a 12v transformer into the barrel plug, and the 5 ethernet jacks go off to their respective cameras. the 12v lead goes up the wall to the attic, then splits into 5 leads to go to their respective cameras.

(this is how it'll work in theory. i only have 2 cameras thus far.)

 

[Colt45]

There's a reason real POE uses 48V. I2R losses are a bitch at low voltages.

 

[stormkroe]

hell, i run ethernet cords carrying the video signal right next to the 12v cords for the bulk of 50-100 feet, and no problems.

You could run it 35 kajillion feet next to 12v cords, there is no induction to speak of for creating interference.

 

[Howard]

You could run it 35 kajillion feet next to 12v cords, there is no induction to speak of for creating interference.

Ever see a super-ripply DC supply?

 

[PsiStar]

There is also a lot of electrical noise such as 60 Hertz floating around. Long runs of wire are just antennas & can couple to anything. There are exceptions.