Pixels misbehave - sometimes

[mking0310]

My previous post was about power injection. I'm still not sure I have understood the proper way, but there was some progress.. ( I think )

 

I have successfully exported from SS,  and played a sequence in the Sequence Editor, and it has worked... sort of.  The pixels seem to just stop responding at certain points.  I can unplug the pixels while the show is playing, plug them back in,  and voila - it goes back to working.

 

I have tried moving the power injector to the beginning of the strings, to the middle, and there has been no common or repeatable outcome. 

You can click here to see my 6 strings, a photo of my power injector. https://dl.dropboxusercontent.com/spa/pbm4rut0gwi7qef/rgb_pixels/index.html

 

 I read that you should use the same Negative throughout your entire wiring, and only inject new sources of Voltage. So when I used the same power Source to inject power,  it helped the pixels behave, a little better.

 

Here's my question: Does the Negative Source need to actually come from the Pixel Controller, or is it ok to use the negative from the power source that is powering the pixel controller? 

 

** Is this even the root cause of this at all ?

 

What is misbehaving pixels?

1. When I click All Lights Off in the sequence editor, Pixels don't turn off.  (everything else in my display does)

2. Not all the pixels are white when they should be.  Typically an indication of not enough power, I know - but since I cannot seem to isolate the issues, it is hard to work on two problems at once. (unless they are the same)

 

3. Why can I unplug, plug the pixels and they begin to work properly (for a short time) 

 

Here's some pictures and details:

https://www.dropbox.com/s/mkpco5eaxzm5ryk/TinyPix-from-Holiday-Coro---12-Volt-Power-Supply.jpg?dl=0

 

This is where the DMX comes in from my computer.  DMX goes to the Pixel Contoller,  and out of the controller goes Voltage/Negative/Data.

_{Additionally there is another power cord coming off this power supply to serve as a power injector.}

 

_{I'm not sure if I should move the negative from the power injector cord to the Pixel Controller Negative, or leave it on the actual Power Supply.}

[dgrant]

Why is there only two wires going out to the pixels? There should be three? You should have +, - and Data going to them from that connector and no where else. Power injection is only needed to maintain brightness for say 150 pixel nodes in series. It might not matter if its the negative but still...I would think its best to connect properly upfront then inject power down the line as needed. Have you checked for shorting out wires to whatever frame you have them mounted too?

Edited December 12, 2014 by dgrant

[Ron Boyd]

When doing your power injection, the v+ and ground coming from the power source needs to be added to the line. Basically, what you need is a v+ at the injection point. Your data wire will be unchanged. The ground wire though, will need a "Y". A ground from last pixel, a ground from power supply attached to the ground of the next pixel in line.

You can also y the v+ at this point and back feed power th the first pixels.

[mking0310]

Thank you for the feedback.  Actually, DGrant, I do have V+, V- and Data going to each and coming from each. 

 

Ron, I never thought about brining Data AND Neg from the last pixel, to the next.  I will surely try that with my next power injector cable iteration. Thank you so much.

[dgrant]

The picture didn't show the three wires going out, rather just the two but like I said, electricity-wise, it really shouldn't matter

[mking0310]

I completely tore the box apart where all my wiring was so I could start over and hopefully identify the error. 

As for my power injector cable, I tore it apart too just to confirm the following:  The Y has Neg and Data coming off the last pixel,  the other side of the Y has Voltage + and -

 

There were some changes I tried, that didn't pan out. Instead of powering the pixels right from the OUT of the Pixel Controller, I took only the DATA from the pixel controller and then separate power from the Power Supply (with a fuse inline on the V+ side)

However, that only lit up 2 pixels...  So then I moved the Negative from the PS,  to the OUT of the Pixel Controller and got Nothing.

 

So now I am going back to  Pixel Controller OUT-> data, V+, V -   to get back to "somewhat" working.

I appreciate everyone's input so far...  I thank you in advance for your support.

[mking0310]

Bad news. I tried combining neg from both power supplies and then nothing happened. So back to the garage to test voltage and when it showed 20 volts I got confused how a 12 volt power supply could produce that much. When I hooked everything back up in my original iteration the pixels did not come on at all. I fear they are fried. First year attempting and in my 7th week of working on the display from the time I get off work until bed time. Feeling like Scrooge right now