Pages: [1]   Go Down
Author Topic: Can the ground wire in an analog video cable be shared with other ground wires?  (Read 500 times)
0 Members and 1 Guest are viewing this topic.
0
Offline Offline
Sr. Member
****
Karma: 0
Posts: 340
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

First of all, which wire is ground in an analog video cable? Is it the inner wire, or the outer 'shielding' wire? It is designed similarly to coaxial cable.
Secondly, can I share that ground wire with the ground from a 12v source and still have clear video?
I drawed a picture..
Logged

UK
Offline Offline
Shannon Member
****
Karma: 223
Posts: 12631
-
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I don't know about video signals specifically, but in general the shielding should only be grounded at one end to avoid forming an earth loop.
Logged

I only provide help via the forum - please do not contact me for private consultancy.

Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 618
Posts: 33959
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Yes it has to be grounded but don't pass current down it. It is the outer that is ground, however it has to be connected at both ends in most cases. It is not shielding which should be grounded at one end only.
Logged

Offline Offline
Sr. Member
****
Karma: 9
Posts: 296
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
First of all, which wire is ground in an analog video cable? Is it the inner wire, or the outer 'shielding' wire?
Always the outer braid... it's like a Faraday cage.

Quote
Secondly, can I share that ground wire with the ground from a 12v source and still have clear video?
Of course.


Quote
but in general the shielding should only be grounded at one end to avoid forming an earth loop.
I don't think so, not for single-ended lines.

Now, if this is a balanced/differential line, then you have the HOT and COLD lines, and you have the shield/ground. Then you can connect your shield (pin1 usually on XLR or TRS jacks) grounded to the case immediately at the entry point (use the metal tabs on the XLR jacks provided for this - short pin1 and the metal tab with a glob of solder, then secure XLR jack to metal case with screws.)  
Logged

0
Offline Offline
Sr. Member
****
Karma: 0
Posts: 340
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
First of all, which wire is ground in an analog video cable? Is it the inner wire, or the outer 'shielding' wire?
Always the outer braid... it's like a Faraday cage.

Quote
Secondly, can I share that ground wire with the ground from a 12v source and still have clear video?
Of course.
You are correct. It works now. Thanks.
Logged

Pages: [1]   Go Up
Jump to: