Video camera power
I have worked on a camera system (Sony) that has a rack-mounting camera controller unit (CCU) and a single co-ax lead to the camera, this carries something like 20v DC to the camera (audio people would call this phantom powering), the camera is also synchronised by the CCU so that all cameras can have graphics overlaid (the opposite of genlock?).
The co-ax is something like 100 metres long, the camera has no other leads to it, this must save a few ££ on cable (but a 24v cooling fan in the camera housing is seperately powered :? as are the floodlights :roll: Oh well, that's industry for you.
I would think any camera with a common ground between co-ax screen and power could be 'powered' with a single wire, relying on the screen as power return - with the possible risk of inducing a DC offset into the video signal, this might be fine on short runs but could upset a video monitor on longer runs ?