Issue with rectangular modules

[zwiller]

I built a bank of 4 rgb minis each with 20 rectangular modules for a total of 80 which is the max in wiki.  I think you probably know where I am heading with this...  No problems except for white.  There is an obvious issue and it appears to be not enough power.  Tested with another SSC and cable and same result.  What's worse, I made a bank of 2 arches for a total of 64 modules and I am seeing the same thing.  11.28V at the SSC?!  That's low right?  Power supply dying?  One year old Corsair and I did not run it hard at all last year.  How to test PS?  In some strange way I hope it is the PS so I don't need more SSCs/power injection. 

I would like to test a module anyway...  I understand I need to run current through the meter to measure current but unsure the best way to test.  I also wonder if Ray has changed something.  Can someone walk me through testing for current on a module so I can run numbers to make sure 80 is still a good max figure?

THANKS!!!

[Steve Gase]

if you have a multimeter, set it to measure amperage and place it inline between the SSC ground and first pixel.

[zwiller]

Thanks Steve.  Yep have a meter.  When you say "first pixel" do you mean 12V+ to string?  If so, I get 2.7A on full white.  What is interesting is that on a rgb cycle in xlights other colors are pulling slight MORE amps than white, 2.8A.  Shouldn't I closer to 4A? 

[zwiller]

Tried a 4 port and 350W power supply with same results...   Using a 20' cat 5 from monoprice.  Minis are spaced 2.5' from one another and used Ray's 3 wire for splices. 

Took some voltage readings at the end of string and are as follows at VDC:
R=7.95
G=8.61
B=8.91
W=7.20

Seems like a large drop to me...  I am thinking wire size/gauge is a part of this.  Contemplating using another wire to run 12V+ line to end from 3 core connector splice but sure it won't be that simple since I _is_ clueless about power injection. 

[arw01]

Well, there certainly was a lot of opinions on power injection.  Best practice would be the keep the 12v from the SSC from seeing the 12v from the power injection, so at somepoint in the string separate the 12v line, maybe do another set of pigtails with just ground and data connected between them.

Remeasure, retest then.

If it was just me and i was just testing, I'd hook it all together and see what happens  ...

[tbone321]

Power injections is no big deal.  If you are using the same power supply then just run a heavier gauge wire to the end of the string.  I would run both the +12V and the ground as the voltage drop is due to BOTH wires.  There is no need to cut any wires here because if either side fails, the load is still within the max spec and all that will happen is your voltage drop will return.  If you are going to use a seperate supply, then you may want to cut the +12V midway in the string.

[Steve Gase]

the load is still within the max spec

That is not certain...  we've had reports that the TC strings use 5.5A, and the hubs are fused for 4A.


The other reminder is to fuse the injection line.

[tbone321]

Yea, but he actually measured it and is pulling less than 3A max.  Now this may be due to the voltage drop but if one of the connections fails, the voltage drop will return along with the reduction in current.

[zwiller]

Back inside for moving 8" of snow...

Found this researching "power injection"...  You are not allowed to view links. Register or Login  Boy I wish I saw that before...   <fp.  Might be prudent to update the wiki once I end "testing" since I think 80 is max in terms of sending data. 

Took Alan's approach   Tried 12V+ power injection to the end and was a definite improvement and all is white but mini closest to SSC is clearly brighter.  In a fit of "holiday spirit" I cut 2 minis off (before tbone's post).  Mini closest to SSC still brighter.  Added 12V to 2nd mini and improvement but mini closest to SSC still brighter.  Didn't know if ground was needed so tried another and now both are equal in terms of brightness.  After reading tbone's post I will try 12+ AND ground on the entire 4 mini tree bank.  Stupid question: for convenience sake I injected power on the output side, is this cool or a no no?  After some testing I have a module nearest to the output where I applied power (no data) that is flaky or shot.  Might be coincidence.  Probably best to inject to input side?

Seems like we are all having "fun" this year. 

[tbone321]

If you are injecting on the input side, that indicates that the CAT5 really isn't up to the Job.  You can inject from either end and the results vary depending on the cause.  If the lead wire is good, then power injection to the input will have little to no effect.  Injecting at the other end will offer the best power distribution.

[zwiller]

Tried running 12V+ and ground to the 4th mini and was best yet, but the 2 interior minis were less bright.  Probably doable for a lot of guys but not me. (dang OCD)  I suppose I could have run power injection to other 3 but I decided to break them up into group of 2.  1 SSC for 2 minis of 40 modules total with power injection. So in my opinion, the wiki should have some info about power injection for these.  A single SSC will power 20 rectangular modules without power injection and 40 and beyond will require power injection.  In my opinion power injection is needed every 20 modules.   I guess it is no surprise Ray sells these in groups of 20...  Kinda makes sense since the flex strips have 120 leds and 40 rectangular modules have 120 leds as well. 

[arw01]

Has anyone tried another supplier of these?  I was thinking of getting some from Todd just to play with, but those seemed more dmx based than rgb based, and didn't want to go messing with that on top of everything else we mix in on ourselves.

Alan

[caretaker]

I bought the 2811 rectangle modules from Dave at Holiday Coro and they are working fine for me with v3 SSC's. I did have to select rectangle modules when setting the start addresses to get the color order correct.
 

Has anyone tried another supplier of these?  I was thinking of getting some from Todd just to play with, but those seemed more dmx based than rgb based, and didn't want to go messing with that on top of everything else we mix in on ourselves.

Alan