DC power over coax

[Pine Pienaar]

I wish to provide DC operating power via the coax cable that feeds the video signal from a remote monochrome video camera. The required circuit is not complex but I have no idea of the frequency components in the video signal and hence the size of choke to use.

Assistance or a pointer in the right direction will be highly appreciated.

73 de Pine, ZS6GST

 

[Audioguru]

Doesn't an analog video signal need DC coupling for the proper black level?
Many, many years ago I used a DC-restorer circuit and a coupling capacitor.

 

[Ylli]

Base band video can go all the way from zero to multiple MHz, depending on the sweep rate. I don't think you are going to have much luck trying to feed the DC power down the line.

 

[FuZZ1L0G1C]

Hello Pine.
What connector does your video remote video camera use?
USB, AV with separate DC supply? DIN socket?
If you can supply a clear photo of the business end of the connector, then a solution will be easier to work out.
Regards, Clive.
Afterthought:
By 'remote', do you mean 'cabled' as in coax as mentioned (1 coax plug only) or RF link?

 

[Pine Pienaar]

Hi Clive,
The video output signal is via a BNC connector. I wish to run DC power for the camera down the coax while receiving the video signal via the same coax. I live in a high lightening region and have lost several cameras as a result of a loop being formed with the coax video cable and nearby camera power supply that is tied to the mains. By running one cable to the camera no loop able to pick up induced lightening spikes will be formed.

 

[duke37]

Hi Clive,
. By running one cable to the camera no loop able to pick up induced lightening spikes will be formed.

I have repaired a few electric fencers which have been damaged by lightening. They only have one wire running into them. Of course a loop could be worse.

 

[ramussons]

I wish to provide DC operating power via the coax cable that feeds the video signal from a remote monochrome video camera. The required circuit is not complex but I have no idea of the frequency components in the video signal and hence the size of choke to use.

Assistance or a pointer in the right direction will be highly appreciated.

73 de Pine, ZS6GST

Use a simple video modulator that shifts the video to RF. You can feed DC power to the Camera and the Modulator on the same coax