HDCVI and power over coax

[oh6hfx 0]

Installing a new Dahua HD-CVI system for a client with old analog cameras.

 

He has power-over-coax solution so there is a big power supply inside the room and

only one coax going out to each camera.

 

I'm afraid I have to add +12V for every new HD-CVI camera now as they don't support

power over coax.

 

Or is there power-over-coax splitters available I can just plug in the camera end of coax and

separate video and +12V sockets?

[oh6hfx 0]

This is what I mean:

 

http://www.viewtech.co.nz/cctv-and-surveillance-systems/biwave-2100-2200-video-sender

 

But I should just need the isolator in the camera end. (2100 sender)

 

Would it be ok to plug the coax in the camera and then just take +12v parallel from the coax?

There was no harm to HDCVI camera when I plugged the coax in even it has +12V in it.

[tomcctv 190]

Hi no you need both ends and you also need the power supply that is used for that kit

 

 

If you are doing this for a client...... How many cameras will need the bi-wave kit because they are not cheap.

 

You would be best using power from camera area

[oh6hfx 0]

Yes, he has already power supply in the office, and I can measure +12V in the camera end of the coax. So I should only need

a cheap isolator which pulls +12V from the coax and does not let it in the camera BNC plug.

 

I'm also considering feeding a separate power +12V for every camera (8 cameras), maybe that would be the wisest solution.

Anyway it is a big work, almost the same as changing the coaxs to ethernet. Anyway HD-CVI system is a lot cheaper than 8 x IP system...

[tomcctv 190]

Yes, he has already power supply in the office, and I can measure +12V in the camera end of the coax. So I should only need

a cheap isolator which pulls +12V from the coax and does not let it in the camera BNC plug.

 

I'm also considering feeding a separate power +12V for every camera (8 cameras), maybe that would be the wisest solution.

Anyway it is a big work, almost the same as changing the coaxs to ethernet. Anyway HD-CVI system is a lot cheaper than 8 x IP system...

 

 

Local power is also an option..... And no point in going cat cable for cvi

[oh6hfx 0]

Well, yes, I meant semi-local power. There is no wall socket near every camera, but I can do it with 3-4 power supplies around the site. Maybe

a DIN-standard DC supply inside IP66 box.

 

And of course no cat for hd-cvi, I was just comparing doing the whole system with IP cameras, but as present cables are physically difficult accessible,

partially under ground, there is indeed no point.

 

Still, a best solution would be a simple power splitter before the camera, but there seems to be not very much such things on the market.

 

Found this now, the principle is just what I need and the price also ok. It's just that the feed voltage should be +24V. I should go on the site and

check if the PS has adjustable voltage, then this could be the solution.

 

http://www.alibaba.com/product-detail/Newest-HD-POC-PVT-Power-Over_60439120049.html?spm=a2700.7724857.29.37.bC0Snv

[oh6hfx 0]

I was today on the site and checked voltages.

 

Coax power supply is feeding around +30V for the cameras. When camera is not connected, I can measure

the same in the other end of each line. And when camera is connected, I can measure +13,6V parallel

on the coax. So it seems that old cameras have broad voltage range and regulator inside?

 

Anyway, now it seems that I could use those splitters linked above. Just need to find out where from I can buy them, as that

link seems to be for big trades...

[tomcctv 190]

on the coax. So it seems that old cameras have broad voltage range and regulator inside?

 

Anyway, now it seems that I could use those splitters linked above. Just need to find out where from I can buy them, as that

link seems to be for big trades...

 

A lot of the old power over coax was 24v AC

 

Your cvi will be 12v DC . Not a match.

 

Cvi cameras unlike tvi all data is done at camera end then sent to recorder. You you need a cvi solution.

 

Your link only shows the power over coax but it does not show you that you need a power supply for each camera ...... And the power supply has to be variable 12-15-18-24v DC

[oh6hfx 0]

Well, if you read the specs of the link, you can see

 

"- Compatible with HDCVI/ HDTVI/ AHD/ CVBS

- Input voltage:DC24-36V , output power max to 12VDC,12W"

[tomcctv 190]

Well, if you read the specs of the link, you can see

 

"- Compatible with HDCVI/ HDTVI/ AHD/ CVBS

- Input voltage:DC24-36V , output power max to 12VDC,12W"

 

 

I DID READ THE SPEC

 

And it says DC which is right

 

Now read my last post

 

Is your coax boxs giving ac or DC ? Like I said your cameras are DC

 

Installing a new Dahua HD-CVI system for a client with old analog cameras.

 

Am giving you basic advice .... Cvi is done at camera end unlike analog and tvi ..... If you don't use cvi comparable components then your letting your client down with a simple plug and play system

[oh6hfx 0]

Yes, the power supply is giving DC +29V out. Just measured today with a multimeter.

 

Sorry I did not first pay close attention that you wrote that old PoC was 24 AC.

 

Not a lot information I can get by looking power supply.

 

There is one with 4 x outs and then 4 x these you can see in the picture:

 

https://www.dropbox.com/s/ppc7pzpfa28qe9x/2016-05-04%2009.51.04.jpg?dl=0

 

The one with 4 outs is TS-6020PS4N, but cannot find brand name anywhere.

[oh6hfx 0]

Ordered 8 x those POC splitters from Alibaba. Took a while but arrived well in ~ 14 days.

 

Well, I can say it works! I can use the old power supplies for the cameras and

the voltage is dropped to 12v dc in the camera end.

 

Just one of the old power supplies is not compatible with the splitter. Don't know why,

tested with many channels but no luck. Have to get separate 24V dc power for that channel.

 

I had problems with two cameras because there was stupid thing done in old system: there was need of 2 cables more to put under ground for 10m length, so installer was used just single CAT cable to feed 2 cameras video. Well, worked with old resolution but with HDCVI there was almost picture over picture when signals were "heard"

trough CAT wires...