dumb RGB module power injection

nato595

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Feb 20, 2013
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Reno, Nevada
I'm running a string of about 100 dumb RGB 12v rectangular modules and need to inject power every 40 modules or so. My question is can I just run a single wire to inject additional power (same power supply and/or RGB amplifier) directly to the 12V+ wire and continue the R, G, B negatives from the previous 40 modules, or do I need to run an additional 4 wires and inject 12v+, R, G, and B negatives every 40 modules? Is there any downfall to continuing the 3 negatives through 100 lights as long as I'm adding addition +VDC as needed?

Thank you!!
 

nato595

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Feb 20, 2013
Messages
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Location
Reno, Nevada
I mocked up a quick little illustration. Basically I'm wondering if this attached example is an OK way to hook up. I'd like to prevent running extensions of 4 wires when I could potentially just run one (power), but of course want to make sure this way is safe. I've bench tested both ways and the lights appear the same with injecting just power, or power plus 3 negatives, but want to make sure it won't have any ill side affects.example1.jpg
 

David_AVD

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Adding the extra V+ wire will certainly help as it carries the sum of all the RGB - wire currents.

Doubling up on the RGB - wires will also make a difference, but to a lesser degree.
 

scamper

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It is fine to do it that way, as you can only go so far before you need to go to a different controller anyway as the switching current is the limit.
But yes, as you have 4 wires all the same size, theoretically you could power inject twice before you match the load on positive and negative lines anyway.
bare in mind, this is a very rough theory as you need to take into account voltage drop over distance etc..
 
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