Where to cut this strip

Charles Belcher

New elf
Joined
Mar 14, 2012
Messages
45
Location
Dallas, Texas
I have several strips from Ray that I need to cut. They are 2812B 12V. They have both 5V and 12V traces with Buck converters mounted on the rear of the strip.


Because of the converters, they can only be cut every meter beginning from the input end so says Ray's website. Measuring that, I arrive at what looks like a cut joint but on the back of the cut area is a tiny little wire. The wire jumps the 5V trace from the first copper joint to the immediate left of the cut area to the 5V mark on the cut area.


Not sure what to do with this? Anyone know about this that could guide me?

Here is the link to the strip on Ray's site:
http://www.aliexpress.com/store/product/5m-DC12V-WS2812B-addressable-pixel-strip-waterproof-in-silicon-tube-30pcs-WS2812B-M-with-30pixels-36W/701799_32313871852.html



Thanks in advance if so. Attachments


Charles
 

Attachments

  • 2812B front.jpg
    2812B front.jpg
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  • 2812B Back.jpg
    2812B Back.jpg
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Fing

Full time elf
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Muswellbrook
Reading ray wu's site it appears to me that you would have converter, then a metre of strip, then another converter, a metre of strip etc
If this is the Metre mark then you are missing a converter ? the wire looks like a repair job or its a bit of a "fix" to jump the 5v from strip to strip as there is no converter?


it would seem that each converter will drive a metre of strip and you can shorten the strip only at the "output" end. Each strip must start with a converter ?


hope this helps
Cheers
Fing
 

Charles Belcher

New elf
Joined
Mar 14, 2012
Messages
45
Location
Dallas, Texas
smartalec and Fing,


Starting at the input end of the strip and looking at the back of the strip, you have the following in order:
All measurements are from input end of strip:


1) 18"-19" is the first little jumper wire
2) 23"-24" is the first converter
3) 39"-40" second little jumper wire
4) 59"=60" third little jumper wire
5) 61"-62" second converter
6) 78"-79" forth little jumper wire
7) 97"-98" fifth little jumper wire
8.) 100"-101" third converter
9) 116"-117" sixth little jumper wire
10) 136"-137" seventh little jumper wire
11) 138"-139" forth converter
12) 155"-156" eigth little jumper wire
13) 175-176" ninth little jumper wire
14) 177"-178" fifth converter
15) 195" end of strip
______________
Every one of the places that are not marked "cut", but look like cut locations occur on the opposite end of the little jumper wire; for example the first jumper wire is at 18" and ends at 19" and the cut location is at 19" and so on.


Any clues?


Charles
 

Fing

Full time elf
Generous elf
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Messages
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Hi Charles,


Next guess....


it looks like the converters have been mounted the middle of the metre strip instead of the beginning ? This could make sense from a voltage drop point of view ?
your first photo shows that the 5v connection has a white square on it. and no solder pad? so the wire is just a bridge to connect the two ends together.


If each metre strip has its own converter ( mounted in the middle) then I'm assuming that each metre section of 5 volts is disconnected from each other ? If you examine the strip closely can you see this? this could be midway between converters?
Are all your strips the same?
Cheers
Fing
 

Charles Belcher

New elf
Joined
Mar 14, 2012
Messages
45
Location
Dallas, Texas
Fing said:
Hi Charles,


Next guess....


it looks like the converters have been mounted the middle of the metre strip instead of the beginning ? This could make sense from a voltage drop point of view ?
your first photo shows that the 5v connection has a white square on it. and no solder pad? so the wire is just a bridge to connect the two ends together.


If each metre strip has its own converter ( mounted in the middle) then I'm assuming that each metre section of 5 volts is disconnected from each other ? If you examine the strip closely can you see this? this could be midway between converters?
Are all your strips the same?
Cheers
Fing


All strips are identical and converters seem to be mounted in the center of each respective meter. Every cut area has that white square on the 5V without a solder pad. I'm guessing you are right and that it is a bridge which allows the cut at that point. But...I don't really know. I was hoping someone who had these strips would see this post and join in--but lots of views and no one has said they actually use that strip.


I guess I will sacrifice one strip by starting at the output end and work my way to either complete damage of the strip or to a working strip at the length I need. ヽ༼☯﹏☯༽ノ


Charles
 

Charles Belcher

New elf
Joined
Mar 14, 2012
Messages
45
Location
Dallas, Texas
Followup:


The converters are in the center of a meter's worth of pixels. Starting from the input end, you can cut every meter. Still don't know what the little jumper wires are for, but I can cut it where I need to cut it so life is good.


Charles
 
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