LED seed lights - what to look for when buying long lengths? (avoiding dim bulbs)

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jonathan18

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#295937 6-May-2022 17:02

I'm wanting to purchase a decently long length (at least 20m, ideally 30m if they're decent) of mains-powered copper warm LED seed lights for outside use.

The thing that I want to avoid is the lights getting really dim towards the end thanks to a voltage drop; a run that I bought from Mitre 10 is dire in this regard, making the full length kind of pointless.

While I get one solution is to use two shorter lengths, that's not a terribly practical solution in this case. So what I should be looking for to avoid this; is there a particular design that is less prone to this? Or are there lights that provide a gruntier voltage that will ensure all are decently lit?

This listing comes with a 12v adapter for cables up to 50m, which compared to the following seems pretty low, but I really don't have a clue! https://www.aliexpress.com/item/33033640072.html

This listing says the supplied adapter is 30v, so will this do the trick? https://www.aliexpress.com/item/4000094190703.html

Any tips on what to look for or specific recommendations would be much appreciated.

richms

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#2911110 6-May-2022 17:25

The better ones usually have a third wire to the end and power it from both ends to negate that happening as all LEDs have the same total wire length that they are powered thru. When bare LEDs are in parallel a slight voltage drop will have a signifigant change on the brightness.

As you want mains power, look at higher voltage ones and that will minimize the drop as there will be groups in series across the wires making it have lower current. The cheap USB powered ones are all in parallel and have a single dropper resistor at the plug so not a good way to go.

The longest I have bought has been 7 meters or so to wrap around some wire garden ornaments and when I cut it to length, had to connect 2 of the wires together at the end. It was a "12v" one so there were groups of 4 LEDs in series between the 2 power wires. Even before cutting it was uniform.

Richard rich.ms

Stu1

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#2911112 6-May-2022 17:28

I have just got the Holman ones from Bunnings based on the pics from one of the forums they look Awsum at night can run upto 75m
https://www.geekzone.co.nz/forums.asp?forumid=141&topicid=289955

MarkM536

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#2911122 6-May-2022 18:05

The three wire variants of these copper wire seed lights.

Bottom two diagrams on BigClive's note pad use a technique to keep the string evenly lit.

Although you'll be wanting the high voltage one running at 12v, 24v, which is the bottom diagram

(In case BB code doesn't work:) https://youtu.be/DoRbHYJAwis?t=478

I've had 80 meters with on my large Christmas tree for the past 5 years. These seed lights work very well outdoors, Only note is that the wires lacquer comes off with UV/friction and the wires then corrodes.

https://www.youtube.com/watch?v=kByuz9pRZ5Y

Talk about voltage drop... I'm rebuilding that tree. New one will have 240 meters of addressable RGB seed pixels.