Need advice - MegaTree power injection causes lights to behave wonky

Paul Reinhardt

New elf
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Dec 27, 2018
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3
Hi all,
This is my first year putting together a light display. Everything is working great except for the mega tree. Here's a (really bad quality) video of the problem I'm seeing.
View: https://www.facebook.com/HobbiesMostly/videos/427943297891359/


This happens whenever the controller is powered on, regardless of whether the controller is outputting data.
I'm looking for suggestions on how to troubleshoot and resolve this issue.

I'm using a Falcon F16v3 controller and the mega tree is on port 16. However, I'm ONLY using the data output from the controller - not power. I have a separate power supply for the mega tree that provides all the power and power injects at four separate locations on the tree. I'm doing this because I read somewhere not to mix power supplies.

So the video demonstrates that the tree has power to all nodes, so power is working. But I have no idea why it just cycles all lights repeatedly when no data is being sent to the tree.

Any suggestions would be greatly appreciated!
Thanks!
 

Paul Reinhardt

New elf
Joined
Dec 27, 2018
Messages
3
Answered my own question. After I added a common ground between the two power supplies, it worked perfectly. Probably a rookie mistake. but you have to admit, that's some strange and unexpected behavior for simply not having the grounds connected! :oops:

Here's a good article that helped me figure it out.

 

scamper

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Jan 5, 2014
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collie
Good on you for working it out. I was just about to suggest that.
The thing to remember is, when we use the term earth or negative, it is basically a reference. So if you apply a voltage (or data) to something, it is only that voltage with reference to the other line.
So when you have power and data, they must reference to the same earth otherwise, they could be any potential.
 

Paul Reinhardt

New elf
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Dec 27, 2018
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3
@scamper, thanks for the follow up! That's interesting.
I've made some animated Halloween props in the past with Arduino, pneumatic actuators, etc. Not having any background, I've found trying to figure out electricity is a lot harder than I had imagined.

I imagine the two power inputs that come with the Falcon F16 are already grounded together, so I wouldn't have to do anything there. Sound right?
 

scamper

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Jan 5, 2014
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collie
They should be, but a good rule of thumb is to never assume anything. If you have a multimeter, check for continuity to make sure. If you don't have one, it is a good idea to get one. A cheap one will do, you want to be able to check for continuity and voltage a lot in this hobby.
 
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