Let’s talk about pixel tape....

[timsabre]

Ah, I have done some stuff with the MY-Semi ones, but they are a nightmare to control, having an SPI-like interface but it triggers on both the rising and falling edges of the clock. And when it outputs the ongoing data to the next chip, it does not give any delay between the clock and the data change so any length of wiring between the chips makes it fail.

 

MY9231 was used to create 16-bit dimmed LED strips for this Rolls Royce launch which I designed the electronics and control software for. I think it was 49 universes of DMX by the end

 

https://www.stageone...phantom-reveal/

Edited January 6, 2020 by timsabre

[pmiller056]

Thank you for the helpful market overview comments from various contributors. I'll have to radically re-think how I'm going to control pixel mapping along with the rest of the show lighting. The changes will have to be made at some point anyway.....

If you have a stock of existing (Pat tested) 12V power supplies for LED tape, but having to use 5V pixel tape, why don't you use small 12V to 5V buck/step-down converters periodically along the length of 5V tape? Using 12V for power distribution keeps wire sizes a bit more manageable for longer runs.

 

[timsabre]

"small" buck converters won't do it unless you really have a lot. 16 pixels gets you to 1 amp.

[pmiller056]

There are widely available, pre-made buck converters based on the LM2596 which are good for a 3A load. These are switch-mode converters, so they don't get hot unless you are using them incorrectly. 5A converters are readily available as well. Most of these converters will work happily with a 24V input which makes power distribution even less bulky.

[timsabre]

Do you install tape with lots of 5v converters like that then? I have never seen it done like that. People seem to prefer home runs to multiple drivers. And don't you get problems with ground noise mucking up the data signal?

[musht]

Seems to be issue with the SPI ,seperately clocked , pixels, APA102 springs to mind, theoretically manage Mhz, in real life not so much.

 

WS2815 12V tape dosen`t come with any substantial cost penalty over 5V strip, cuttable per LED with easier power injection.

 

5V tape for RGB+ , wearable and portable applications. Any USB power bank will give you 2.1A at 5V

 

Power and signal distribution few ways emerging:

 

PSU & Driver in box beside prop, Mains power and ethernet connection to box, or battery and wifi connection.

Keeps data path as short as possible(more than 10` is a long way for unbuffered pixel data) saves V drop on power to prop.

Possibly noisy fan cooled PSU

 

Driver in box with remote data connections. Using RS485 Tx/Rx either end of CAT5 for data, combined with ground isolation and seperate PSU at prop end or data ground return on same line or 24/48V buck convertor from spare pairs. No concerns about data run distance and no bulky boxes beside prop. Advaenttec ;-)

 

PoE , latest standard allows 70W delivered,high power PoE switches are expensive and the chipsets are rare at mo`.

HiPoE + 60W delivered used for CCTV , switches and midspan convertors more available buts its only 60W.

Passive PoE, as above cram 48V down spare pair on Cat5 and mini buck at receiver end.

 

Interesting look at some options:

 

http://www.jdeation.com/

 

Connector options another debate,as long as its not blooming pigtails or just dangling Wagos...

 

How much damage can a incorrectly plugged Speakon do....?