How to cut up "BigW" or similar strings?

[Ktag]

I have a few sets of coloured led strings (BigW or similar.. can't remember where they were bought). I would like to chop them up into smaller sections.

I have snipped the controller off the end and confirmed they work and are 2 ch. The wiring starts with 3 then through the LED's expands to 6 and back down to 4. If they got back down to three... no problem I would cut there. But should I cut them when they get down to 4? Or do I need to trace where each wire goes?

 

[aussiexmas]

Normally for 2 channel strings they would go from 3 wires to 5 wires and then back down to 3. The cut point is at 3.

I have seen some odd strings (multi colour) where the red+yellow are on 1 channel and the blue + green are on the other channel and the bulbs/light segment differ - eg red+yellow 15 while blue+green were 10. For these, the cut points were after 60 bulbs when the the wire count dropped to 3 (or 4). These were older lights and did not include in string resistors as in most current designs.

There have also been some strings where the first or last segments included odd bulb numbers to bring the total string count to a round number (eg 200). In these strings the majority of segments dropped to 3 wires, just some funny behavious at the beginning or end.

Hope this helps.

 

[David_AVD]

Some info in the wiki also:

http://auschristmaslighting.com/wiki/LED_String_Wiring

 

[Ktag]

Thanks for that, I had looked at the wiki.. and searched a fair amount before posting.

I have now done the next best thing.... trial and error.

I cut the wires where they dropped to 4.. easy to figure the channel lines or so I thought! Anyway I have managed to work out which wires do what in the 2 sections I cut. There are 2 +ve wires so I just put them together and all is good. As long as I can get them working, understanding how it goes from 3 wires up to 5 then 4, then up to 6 and back down to 4 rotating through the string (about every 2m) is now low on my list of itmes to do.

All is good though.