Video signal ground isolation

[Leopoldo]

Hi to everyone,I'm new to the blog but I wanted to know if someone could help me:
I'm working on composite video signal and trying to extract the vertical and horizontal components through an LM1881,but I got stuck in a problem: when I connect the ground of my power supply to the ground of the DVD player which I'm using as the signal source,the two grounds,being connected to the wall outlet,are completely different and I measured that they're about 120Vpp apart. So my question is: is there a way to take the signal from the DVD player with its ground and use it isolated in another circuit with another ground reference? So I don't get sparks... THANKS a LOT!!!

[David_AVD]

The DVD player will be double insulated and the voltage you're seeing is via the small capacitors going from L & N to the DVD chassis.

It is annoying and you may get a tingle, but this very low current leakage is completely normal.

[Leopoldo]

So you say that if I connect the two grounds together I don't do any damage to any circuit? Because I agree with you,I took apart a tv and didn't find any isolation transformer or whatever on the composite video signal input... If it's so,it's perfect! Thank you very much!

[David_AVD]

Most domestic AV gear these days only share a common ground via the signal leads.  You'll be fine.