Power Injection question

[sck1ng]

I was wondering that if I had a single PSU feeding a string of 200 pixels and had to power inject at the end of the string from the same PSU, do I only need +V connected or should I also connect the GND?

 

[nzlongfellow]

I was wondering that if I had a single PSU feeding a string of 200 pixels and had to power inject at the end of the string from the same PSU, do I only need +V connected or should I also connect the GND?

You need to connect both the +ve and Gnd at each end.

 

[mborg10]

That's right you need +ve and ground to complete the circuit, if easier you could inject in the middle at 100 pixels for same result

 

[Maple]

Im looking at something similar and wondering if this is correct:


6 arches, each with 75 pixels.
Each set of 2 arches will be off a single output of a pixlite, e.g. output x (power and data) to Arch y (y=1, 3 or 5). I need to feed power back in to the ends of each set of 2 (arch 2, 4 and 6). Can I just run a separate feed of + and - for each of these 3 from the same supply as powering the pixlite?

[edit: previous was not entirely clear (or correct - it has been a while since I've put these together.)]