I have an application which is using a differential transmitter to transmit a video signal(PAL).Transmitter is placed in a remote device which is connected through a long cable.The device is powered up through two conductors(one for 24V and one for GND) which each conductor has 1.8ohms.My doubt is if the device consumes 5 amps I will have a ground difference of about 9V, so from start the common mode voltage on the twisted pair of differential transmitter will be 9V.Is it true ?
Assuming that the differential signals are generated relative to ground, then the answer would be yes, as seen from the other end.
The ground would have floated up by 9V relative to the supply's ground, and the 24V would float down by the same amount - leaving only 6V at the transmitter end.
Not actually relevant to the question asked, but do you really need 5 amps to power what sounds like a camera? If so, you're going to need a higher voltage.
Well the receiver is powered from the start of wires, so the remote device is powered through that resistance of cable.The ground difference at 5 amps is 9V(1.8 * 5).The receiver is powered up from the same supply just that the resistance to ground is almost 0.
Sorry I wanted to be a comment.