Baluns for Video and Power at 1000ft ?

[eahheretik 0]

(Sorry for the double post in the wrong forum)

 

Hello all,

 

I'm a broadcast video engineer trying to build a small CCTV system for myself to look over a property I maintain.

 

I'm hoping someone can tell me how far I can power a 12VDC Swann Camera on a Cat5 balun.

 

I'm using two pairs of a 1000ft 24AWG Cat5E - one pair for power, one pair for video.

 

I've been looking at this balun kit which says 900ft(300m) for video and power.

http://www.cctvcamerapros.com/Cat-5-Video-Balun-p/balun-pv5.htm

 

I'm very curious if any of you have experience with running both power and video at a long distance (I'm trying to go a full thousand feet).

 

Any Balun recommendations?

[GrouchoBoucho 0]

first, i'd recommend one active balun and one passive for that distance. you *might* be okay with both passive, but an active unit at either end will be more reliable.

 

second, i'd strongly recommend using all three other pairs for power. how much loss you might see will depend on the actual current draw of the camera - if it has ir (something swann probably does), that's going to cause a lot more draw, a lot more voltage drop, and probably cause the camera to drop out at night when the ir switches on.

 

assuming ir then, it's a safe assumption the camera will draw at least 500ma with ir on... based on this calculator, at 500 feet (the highest distance it will accept) and using three pairs, you see about 1.5v loss at the camera end. double that for 1000', and you'll have to feed 15vdc into the run to end up at 12vdc at the camera. some cameras will handle that (some dual-voltage cameras will work with anything between 10-30v ac or dc), but i wouldn't count on this one having that kind of latitude.

 

looking at the page you linked, that shows two pairs for power... not sufficient at that distance. the balun doesn't really do anything with the power - it just connects the wires from the power jack direct through to two of the spring terminals. power distance is affected by nothing other than ohm's law.

 

what i'd recommend, if you have the space at the camera end, is sending 24vac over the wires, then adding a 12v regulator at the camera end to knock the voltage down. something like this will work nicely: http://www.electronicproductonline.com/catalog/product_info.php?products_id=2237&osCsid=49b51fb1cbae214fe8c0428d9b914bd5

[eahheretik 0]

Thanks for the detailed reply!

 

I have no way of getting power at the camera end, so finding a way to do it over Cat5e is critical.

 

Thank you for the info on the 24vac idea. From searching around I had gathered that this would probably be what I would have to end up doing.

 

I found this:

APS-ACDC-1500, 24vAC to 12vDC Power Converter

http://www.active-vision.com/Power-Converter-p/aps-acdc-1500.htm

 

But I understand this would be used on the camera side, and I would need that 24vAC supply on the receiving end.

 

The product you linked to looks like it might be a bit confusing for me. Do you know of any supply that might be a bit more self contained?

 

Thank you so much for your time.

[hardwired 0]

Same functionality, little easier package- http://www.altronix.com/products/product.php?name=VR3T

[survtech 0]

Same functionality, little easier package- http://www.altronix.com/products/product.php?name=VR3T

That device is 24VDC to 12VDC. Typical camera power supplies are either 12VDC or 24VAC. To convert 24VAC to 12VDC, use any of the Altronix VB/VR products except the VR3T. http://www.altronix.com/products/index.php# - click on "Power Conversion Modules".

 

VR1- Converts 24VAC or 24VDC to a 12VDC @ 1 amp. Modular Connector/Cable Assembly.

 

VR1T- Converts 24VAC or 24VDC to a 12VDC @ 1 amp. Screw Terminals.

 

VR2T- Converts 24VAC or 24VDC to a 12VDC @ .5 amp. Screw Terminals.

 

VR5T- Converts 24VAC or 24VDC to a 12VDC @ 3A.

[hardwired 0]

Same functionality, little easier package- http://www.altronix.com/products/product.php?name=VR3T

That device is 24VDC to 12VDC. Typical camera power supplies are either 12VDC or 24VAC. To convert 24VAC to 12VDC, use any of the Altronix VB/VR products except the VR3T. http://www.altronix.com/products/index.php# - click on "Power Conversion Modules".

 

VR1- Converts 24VAC or 24VDC to a 12VDC @ 1 amp. Modular Connector/Cable Assembly.

 

VR1T- Converts 24VAC or 24VDC to a 12VDC @ 1 amp. Screw Terminals.

 

VR2T- Converts 24VAC or 24VDC to a 12VDC @ .5 amp. Screw Terminals.

 

VR5T- Converts 24VAC or 24VDC to a 12VDC @ 3A.

Oops, sorry, picked the wrong one out of the list. I've used the VR5T in quite a few instances.

[GrouchoBoucho 0]

the unit i linked is not complicated at all. there are four screw terminals - two for ac in, two for dc out - and a jumper to set it for 6, 12, or 24 vdc out. it can also be set as adjustable, but you don't need to worry about that - it comes set to 12v by default, so all you need to do is connect the wires into the terminals.

 

in fact, the connections are pretty much the same as in the active-vision unit, it's just open-frame instead of in a little black box.