Video, UART and DC Power Using Only One Coaxial Cable

[nikkoderic]

Good day eevblog community!

I'm just an ECE undergraduate and only knows basic electronics so please bear with me. I just want to ask how to transmit NTSC composite video, serial data and 12v dc power (enough to power max of 10 "very" bright LED lights, an analog ntsc composite output camera, and a small dc motor) through a single 300m coaxial cable. Is it even possible? I just want some ideas from you guys and how to approach this problem generally. Not necessarily exact circuits etc.

And I'm sorry for my english. XD

Thank you! =)

[Psi]

You could have a 12V DC offset on the composite video signal.
You could also embed some serial data in the unused lines of the composite video signal (kind of like how teletext works)

[T3sl4co1l]

300m is quite a long run to deliver 12V, surely 24V or more would be desirable?  (If your loads are 12V, you'll need a converter.)

What bitrate of UART?  Bidirectional?

Tim

[mikeselectricstuff]

The closed-circuit TV industry has been doing this sort of stuff for decades - you should be able to find info on how it's typically done.
Chances are power is 24 or 48V.
Google "power over coax" for a start