Why don't these work?

[bobschm]

I've got a bunch of these CPT 5V convertors. When I use them to inject power, I get horrible blinky pixels. Go back to injecting direct from a 5v power supply and it works fine. I'm only testing one string of 50 2811 5V pixels on a SanDevices board. It almost looks like the power coming out is "dirty" with noise and interfering with the data. Has anyone had trouble with these cheap convertors?

[TitusCarnathan]

I used a different brand, I got it off of amazon. I used one to run a 5 volt string on a 12 volt power supply and it worked great.

Here is the one I used. https://www.amazon.com/gp/product/B00CXKBJI2/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1

Edited August 8, 2016 by TitusCarnathan

[EmmienLightFan]

Test with a multimeter.

 

How many pixels are you running?

 

 

You can't have the 5v PSU connected then inject with this at the other. You need to disconnect the + if you are doing this.

[bobschm]

Multimeter looks identical at both ends of a string of 50 lights with either one connected. And no, I didn't run both the drop and the power supply at the same time. I wish I had an oscilloscope so I could see what that 5V looks like with the drop versus the power supply. 

I'll check out the link. Thanks. 

[EmmienLightFan]

What controller are you using and how is it connected?

[Ebuechner]

Number one make sure your negative feeds straight through that regulator without resistance. Number 2 make sure you feed the regulator with 12 volts or more so turn up the voltage on your power supply. Your idea of dirty power may be correct if it doesn't have a high enough Supply voltage