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Vince4xmas

Pixels not reacting correctly - too long run?

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I have a Pixcon16 operating correctly on all but one channel. This channel is my longest run from the Pixcon16 to the prop.

I have 4 windows outlined using 40 smart pixels on each window. I am power injecting 12vdc between windows 2 & 3 using a separate power supply. The voltage at

the power injection tee connector is 11.9V. So I believe my power is acceptable and not the issue.

My cable from the Pixcon16 to the first window is 24 feet. then 5 feet to next window, then power injection tee, 3 feet to next window and 5 feet to last window.

When my show plays windows 1 and 2 are displaying correctly, however windows 3 & 4 sometimes through the show "pixelates".

Seems to be when a special effect is used.

I am guessing I do not have a power issue, I have a data issue since my length is so long to first window.

Do I need to add a null pixel? If so, where and how, as I have never had to do that anywhere else on my other 15 Pixcon channels.

I could make a shorter cable from the Pixcon16 to the first prop as a test to see if issue goes away but would run at angle and look horrible. Might be able to shorten the length to 18 feet.

Any help would be much appreciated!

Thanks

 

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My guess is you actually are having a power problem.  You have 80 pixels after the power injection point.  Set up a test with all pixels full white and measure the voltage at the end of window 4.

 

 

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You don't need a null if windows 1 & 2 are working correctly.  Controller to window 1 is your longest run and appears to be working properly.  The last pixel on window 2 will regenerate and send the data to window 3.

I would agree, I believe you have a power problem.  80 pixles on a 24 foot connection from your controller, I would guess your power injection is also running a bunch of pixels on window 2, along with 3 and 4

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My power injection is running all 4 windows. Do I need to inject power at the last pixel on window 4?

Please advise.

 

Thanks

 

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20 minutes ago, Vince4xmas said:

But I measured the power at the injection point between window 2 and 3 and it is 11.9V.

 

With all the lights ON? And White (the worst case draw)?

I had 3 strings of 25 with 15' between and could not get above 10.3V at the start of string 3. And that was with my power supply set to 12.6 (5%. splits the 10% tolerance typical for 12V nominal)

BTW I was using 3 core extension cables from the same light vendor. There was no issue, without the extra cables

 

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16 minutes ago, Vince4xmas said:

But I measured the power at the injection point between window 2 and 3 and it is 11.9V.

If I understand, you have a somewhat long cable that is carrying data, ground, and power from the the Pixcon to the beginning of window 1.  From the end of window 1 there is a five foot cable to the beginning of window 2.  At the end of window 2 there is a power injection T fed from a separate power supply with 11.9 volts at the injection point.  Then there is three feet of cable to the beginning of window 3.  From the end of window 3, there is 5 feet of cable to the beginning of window 4.

If my description is correct, from the injection point, there is eight feet of cable and 80 pixels to the end of window 4.  Especially since your injection point is a little on the low side, I'll bet you are getting low voltage on window 4 - particularly the end of it.  By comparison, windows 1 & 2 are never more than 40 pixels from a power source.  As I said earlier, using either a test mode, or a test sequence, set all pixels to full white and measure the voltage between power and ground at the END of window 4.  While you're at it, with all the pixels in full white, measure the voltage at the injection T.

One other thing.  Is there a good connection between the negative of the power supply that is powering the Pixcon and the negative of the power supply that is supplying the injection T.  And no, the data cable between Pixcon and the pixels does not count.  Neither does having the power supply negative grounded to the green wire of the AC power cord (if you do that - I don't BTW).

 

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All negatives on ALL power supplies are connected.

If all window lights are on white and I measure supply at injection point and at end of window 4, what should acceptable voltage be at injection point and at end last pixel on window 4?

If low at window 4 last pixel, I need to inject power there, correct?

Thanks guys!

 

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30 minutes ago, Vince4xmas said:

All negatives on ALL power supplies are connected.

Good.

30 minutes ago, Vince4xmas said:

If all window lights are on white and I measure supply at injection point and at end of window 4, what should acceptable voltage be at injection point and at end last pixel on window 4?

It depends on the pixels.  I know when I first hooked up 94 pixel the far end looked really crappy.  Measured at about 9 volts.  Injected power to the far end and problems went away.  Same thing with my pixel star which has 90 pixel strings.  Had to inject power at the ends.

 

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Dont see a way to measure voltage at injection point (molded tee connector)  but can at last pixel on window #4. What voltage should I see? Obviously, it must be low now.10 Volts minimum?

 

 

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1 minute ago, Vince4xmas said:

Dont see a way to measure voltage at injection point (molded tee connector)  but can at last pixel on window #4. What voltage should I see? Obviously, it must be low now.10 Volts minimum?

 

 

Not to exceed 10% (theoretical) down from 12V or 10.8  (this is why I set the PSU to 12.6.  It give me another 6/10 to play with without the risk of over voltage when all LEDS are off.

BTW use a sewing PIN (pierce insulation) in the power wire at the first pixel to measure with

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48 minutes ago, Vince4xmas said:

So you suggest to inject power at the last pixel on window #4?

That would be the easy place to do it.

 

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Thanks for all your help.

I will check voltage and add an injection point after last pixel on window 4.

Thanks again!

 

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Well, no change. I injected power after the last pixel on window 4 using the same power run (extension cable is 18').

Measure voltage at window 4 last pixel with all white on = 7.5V! Very low!

Think the distance is loo long to get ample voltage from original power supply location.

Should I add a separate 12vdc power supply close to last pixel on window 4 and inject there? And tie negative back to be common with all other power supplies?

Please advise ASAP and I have 3 days until show goes on.

Thanks mucho!

 

 

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3 minutes ago, Vince4xmas said:

Well, no change. I injected power after the last pixel on window 4 using the same power run (extension cable is 18').

Measure voltage at window 4 last pixel with all white on = 7.5V! Very low!

Think the distance is loo long to get ample voltage from original power supply location.

No wonder it's not working well!  Was that 7.5 volts at the end of window 4 with power injected at that point?

4 minutes ago, Vince4xmas said:

Should I add a separate 12vdc power supply close to last pixel on window 4 and inject there? And tie negative back to be common with all other power supplies?

Correct.

 

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7.5 v with out power injection at window 4 last pixel.

Added injection and no change....believe distance is too far from original power supply to get ample voltage to last pixel.

So, add a new power supply closer is what is needed to eliminate major voltage drop I am seeing?

 

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Still not working!

I installed a separate 12v 45 watt power supply and connected to the wires off the last pixel on window 4.

I have 12v wire from pixel connected to +12v on power supply, GND wire from pixel to -12v on power supply and nothing connected to DO wire from pixel.

Help please!

Thanks

 

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25 minutes ago, Vince4xmas said:

Still not working!

I installed a separate 12v 45 watt power supply and connected to the wires off the last pixel on window 4.

I have 12v wire from pixel connected to +12v on power supply, GND wire from pixel to -12v on power supply and nothing connected to DO wire from pixel.

Help please!Thanks

You did break the 12V line between Window 3 and Window 4. 2 different power sources (plus side) should not be connected together. Only the reference (Ground)

Edited by TheDucks

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Broke line between windows and issue remains.

Not sure what to do next. Do I need to relocate the power injection location?

Are we sure its not a data issue?

 

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Up and running! It was actually an intermittent short in the power injection tee. Replaced it and all works.

 

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16 minutes ago, Vince4xmas said:

Up and running! It was actually an intermittent short in the power injection tee. Replaced it and all works.

 

Yea! We were beginning to wonder.

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