Yet another injection question

[jerrymac]

I have looked at the 101 manual and gone through as many of the injection posts as I can find but...
first the setup: 19 each 12 volt 2811 strips (5 meter) 50 pixel group total of 150 pixels per strip (CCR style). San Device P12R controller and 12 Volt regulated 30 amp power supply. Connected with 18 gauge connectors. and will be strung with 3 srips end to end (zig zag style) for a total of 7 virtual strings (19 vertical strips).
Issue is using a 30 amp power supply or a 600 watt ATX power supply, setting color to white results in white turning to orange and then to red at about mid way through the 3 strip string to the end. (Assume due to voltage drop).
I would expect that the answer to be inject power half way through each 3 strip string which whould be inconveniount?
Due to the setup it would be easier to inject power the the far end of each 3 strip string (near end powered by the P12R).
Do I just connect power and ground to the output side of the 3 strip string? ( can I use the additional connectors on the power supply's (each has 3) for the power injection? I am quezy about applying power to both ends of a string.

 

[barbotte]

witmin i only used the power and negative at the end of the strip ..i left alone the data one .... do a try out on 1 to see if it will fix your color problem ... cheer

 

[dougd]

Do you see this problem with one strip hooked up or all the strips hooked up?

 

[jerrymac]

With only one strip all is fine, with two the color on the second starts to change about the middle of the sencond strip and with three the third strip is nearly all red. (This is only when all three are set for white color at the same time or chased to white). Red, green blue and most other colors seem OK (mabe excelt yellow) but only if the entire string is white at the same time. with small sections white and other colors (mix) white is fine all the way along and same for a chase with 10 of 15 pixels at a time all along the entire length.

 

[dougd]

You will have to inject power at the beginning of every strip. That is what i am planning to do. Only the ground and date will go from on strip to the next.

 

[Trafficman]

I agree with doug but I would try just power and ground at the end of the third strip as you stated middle ways of the second strip you start having an issue. You may get lucky.... Now keep in mind Jerry I am still a rookie at RGB.. LOL


Jeff

 

[ShellNZ]

I would go at least end of every 2nd strip or as doug said, end of every strip.

My tree is only 2.5m (25pix) high, it goes up/down/up/down then has power injection. That only JUST gives it enough power I think.

 

[fasteddy]

With the 12vdc strip you can get away with injecting a between every second strip and back feeding the 2nd strip

So it would be connected this way, you must ensure that the cable used for the injection is rated high enough to take the load of 2 strips (6 amps) and voltage drop considerations on the injection cables is also taken into consideration due to length.


power - strip 1 - strip 2 - Injection - strip 3 - strip 4 - Injection - strip 5 - strip 6 - Injection

 

[jerrymac]

Only 3 strips (connected together with waterproof plugs) run from each socket on the P12R. Each set of 3 run Up the matrix to the top (first strip) and are joined (#1 end to #2 beginning) then run down and are joined (#2 end to #3 beginning) again with waterproof connectors and up the matrix (then end). Second and third strings each from a seperate socket on the same side of the controller do the same. The remaining 3 are the same on the other side of the controller with a single string of only 50 pixel (4th string on this side).
From Eddies suggestion I would inject power where the 2nd and 3rd strips are connected together by running a line from the power supply (same one powering the first strip and the controller) Teeing into the pos and negative lines of the connector, there by refreshing the power up and down the line?

Same for each of the 6 sets of 3 strips. Line run length will be 12 feet between power and strip connector and am planning on using SP2 wire.
Have I got this correct?

 

[dougd]

Good to know I need to only inject power after 2 strips.

 

[jerrymac]

Injected power between strips 2 and 3 in the 3 strip stings from the same power supply ("T"-d into the power and ground wires in the waterproof connects that conect the strips together) and white works fine Apparently the issue was voltage drop rather than insufficiant amperage (should not have been since they are 30 amp supply's).

 

[Beefer]

excellent, same behaviour confirmed here with multiple 100-pixel strings and the fix is the same.