Power Injection for Dumb RGB Strips

Bokines

New elf
Joined
Jun 29, 2014
Messages
31
Location
North Gosford, NSW
Hi,

Can anyone advise on power injection on dumb RGB strips.

I understand how to inject power into Smart RGB's.

I am planning to outline part of the house in 6 x 5m Dumb RGB strips. I wish to use one control output to run all the strips connected end to end. Is this possible?
With smart RGB it seems straight forward with a positive and negative connection however with Dumb RGB strips there is a positive connection and separate cables for Red, Green & blue. I can not work out how to inject power into these strips.

If anyone can provide some advise I would appreciate it.

Thank you
 

AAH

I love blinky lights :)
Community project designer
Joined
Dec 27, 2010
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Eaglehawk
Depending on what the specs are on the strip and how long the windows etc are then you may have issues finding a controller that is capable of running that distance. There are a couple of ways that you can go. You can go with an RGB repeater some of which are listed on http://www.aliexpress.com/store/701799/search?SearchText=repeater or you can use 2 dmx dimmers set to the same start address and have each 1 of them doing half of the distance/current if you exceed the current ratings. Provided you're not exceeding the current rating of an output there isn't really any need to attempt anything resembling power injection.
If an controller has sufficient current capability to be able to run the full length strip in 1 go then to prevent voltage drop you can power the strip from the centre with the 2 "tails" of the strip heading out to either side. The choice of strip is a fair governing factor in how you need to power the leds. With 24V 60 led/metre strip you're looking at 0.2A per colour per metre of strip. For 12V it's 0.4A per metre of strip.
To compare what each of the dc boards is capable of you can have a look at http://auschristmaslighting.com/wiki/Controllers#Feature_Comparisons
 

davrus

Silent elf
Joined
Jan 9, 2014
Messages
168
Location
Whitianga
Bokines, you said the three colours, plus positive wire.


Please be aware that for RGB, the colours are positive, and the "common" wire is negative. So you have 3 x positive wires, and one wire negative.
 

AAH

I love blinky lights :)
Community project designer
Joined
Dec 27, 2010
Messages
4,188
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Eaglehawk
Nope
There's 1 positive for 99% of all rgb lights and 3 negatives. The common wire is however often black as that is the leftover colour in standard 4 wire cable. This style of leds are common anode. Common cathode is very very rare.


davrus said:
Bokines, you said the three colours, plus positive wire.


Please be aware that for RGB, the colours are positive, and the "common" wire is negative. So you have 3 x positive wires, and one wire negative.
 

davrus

Silent elf
Joined
Jan 9, 2014
Messages
168
Location
Whitianga
Sorry AAH, I must have had a brain fade. Of course you are correct. One positive wire !!!
 
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