General > General Technical Chat
Cutting Store-Bought Xmas Light Strand to Length
(1/4) > >>
lothian:
Home Depot sells Home Accents Holiday (HAH) "Super-Bright" 100-ct LED xmas lights. I'm getting an early start on swapping our years-old strands of outdoor lights to these things.

Each LED strand is ~29ft long, and I'd like to save some money by making two individual strands from one. My problem is I can't figure out the wiring of these things in order to cut the wires at exactly the right spot to get two working sets.

With previous LED strands, I've been able to get two strands from one, and the trick is to identify the resistor at either end of a some count of LEDs, then determine the two lamps that are adjacent each resistor and cut the wires there. Resistors are apparent as either a comparatively thick lamp socket or a bulbous in-line thing on the wire, but not so much with these HAH strands.

I'm also confused by the conductor count: The HAH strand has four conductors between lamps with three conductors at each terminator; my older LED strands have three conductors between lamps and two exiting each terminator.

Tracing voltage thru a given wire is frustrating me on a neural level, so I'm posting this S.O.S in the plaintive hope that someone might be familiar with this HAH LED xmas light product and know exactly where to cut the wires.

Better still, buy a set, figure out where to cut the wires in order to get two strands from one and let me know, and I'll reimburse you for your purchase!
IanB:
If you are prepared to reimburse someone to buy a set and figure it out, that will counter your attempts to save money by cutting a strand in half. You might just as well buy two strands instead of one? Unless of course you want to buy and modify lots of them?

If you buy lots of them, they can be chained end-to-end, which surely should be fine unless you need small numbers of lights in all sorts of different places?

Anyway, what I suspect is they have wired the lights up in some kind of series parallel arrangement, which would explain the four wires, and would explain how they can keep working if one lamp fails. For instance, they might have four lamps in parallel, and then 25 of these parallel groups in series, with one or more resistors in appropriate places. But this is just a guess.
lothian:
uh'mm... anyone else?
ataradov:
I would agree. Those things cost $20. Just buy an extra set. Nobody is going to waste their time reverse engineering Chinese junk.
lothian:
uh'mm... anyone else?
Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod