Plugging in and unplugging Pixel strings

nzlongfellow

Dennis from NZ
Joined
Jan 2, 2014
Messages
538
Location
Lepperton, Taranaki
Do you need to power down outputs when connecting strings?Can you destroy a pixel chip by plugging in or unplugging a light string on a running system?
 

battle79

Full time elf
Joined
Dec 8, 2012
Messages
416
Location
Chirnside Park, Victoria, AU
Yes you absolutely can, I've done it a couple of time before I learnt. Just thought I had failing pixels until I was enlightened, haven't had one since. (for that reason anyway)

Cheers,
Rowan
 

SmartAlecLights

Im a SmartAlec what can i say!
Community project designer
Joined
May 4, 2010
Messages
1,279
Location
Murray Bridge, S.A.
i agree 100% that it is a pain in the butt to power down, connect up, then power up..
but i've never had any fail either
 

multicast

Senior elf
Joined
Jul 13, 2013
Messages
715
On our commercial gear, in the instruction manual it says


" Do not connect or disconnect any cables from the device while it is energised "


The reasons for this are not just about destroying pixels, its about safety as well. The most likely time for something to go wrong is when you plug something in our disconnect it. If theres a bad mains connection or a dodgy earth, it might really bite you.


From a pixels perspective, I know you can destroy WS2801's, if you disconnect the Earth before the CLK, DATA and +V, and the driver line doesn't have any resistors in series. Current can find a path through the IC, and seing these paths where only designed for logic levels, they don't do so well if you try to pass a few amps.


Other pixel driver ic's have other fault modes.


It is likely that for the main you will get away with multiple live connect/disconnects, but one day it might just break something.


Make your own mind up.
 
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