Don't buy Lytworx leds from Bunnings

AAH

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There's nothing wrong with the Lytworx led strings that are sold at Bunnings (and maybe elsewhere) but they have a problem if you try to control them with a DC dimmer board. http://www.bunnings.com.au/lytworx-220-led-festive-budlight-white-_p4351527 in particular and maybe other Lytworx strings are made so that there are 2 channels of lights but in order to control the 2 channels the polarity of the leds is reversed. What this means is that for DC control only half of the lights will turn on. With modification they may be able to work all the leds off DC but realistically it's not worth the hassle.
Short story is that if you are wanting to PC control led strings then stay away from these leds in particular and maybe the Lytworks brand in general.
 

Jamie

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Thanks for the heads up.. Hope u didnt get caught for too many..
 

AAH

I love blinky lights :)
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I didn't get caught at all. I just happened to be in chat and was part of the diagnosing of the issue when another member couldn't get all his leds going on his newly constructed trees and thought that others should be made aware.
 

Christmas on Clarafield

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Thanks for this, I was going to consider getting some of the green strings as I needed them but looks like it was just as well I didn't go ahead with them.
 

ComPeter

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Uh oh. I have 2 x 30m rolls of them. I was hoping to control them by DC. Will put this to the test next week to see if I have the same problem.
 

ComPeter

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I realise that I have the Lytworks LED Ropelight, not the LED strings that you opened the thread with. Have tested the Ropelight on a DC PSU and they come up OK. Will test on a DC PSU with LOR Controller later this month (when my 36v DC PSUs arrive from China) and report back.
 

koolantz

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I have been looking around for cheap low voltage rope light and the Lytworx were the first I have seen at the local shops so I picked 3 up. Bugger! Also got stung with the curtain lights.
Had a look at the drive on the CRO and I agree it looks like to much trouble to get working on a DC-48 etc.
Here are some video's of the included controller AC drive on the CRO:
lytworx ropeligt standard controller both colours on Vimeo
lytworx ropeligt standard controller alternate colours on Vimeo
And some photos of driving with DC each polarity:
[attachimg=1]
[attachimg=2]
[attachimg=3]
 

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David_AVD

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Those waveforms are exactly what I suspected the drive would look like. Interestingly it shows that each LED can only be on for 50% of the time max. What was the CRO timebase?

While it would be possible to make a DC controller to suit those strings, it would not be worthwhile. Similarly, I can't see that modifying the strings to run on a conventional controller would be practical.

It would be interesting to pull the PSU / MFC apart at some stage to see ho the drive circuit was implemented.
 

Boomer#6

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Thanks for the heads up Alan.
I had bought a few 250 count white strings to complete some more elements the same as last year's and found 2 out of 3 were the new style alternating polarity you noted. I was able to return these and hunt through the old stock at the back of the shelf to find the 3 wire (com+, 2 -'ve) tyre. Any with build date 10/04/2014 or older are still ok for DC control.
Great tip Alan.[attachimg=1]
 

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koolantz

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Time base is 1ms/div and 10v/div.
I will keep one rope light to play with and pull apart the controller and go to bunnings today to swap the rest.
 

koolantz

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I also noted with the memory hold controllers there is a noticeable delay between applying power and when the leds light so cant even run these on a 240 AC controller.
 

David_AVD

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Re: Don't buy leds from The Reject Shop

Was just helping someone else get started with a DC controller and what lights he could use.

These ones from The Reject Shop are also 2-wire from controller to string so would not be usable.

He also had a 100m 240V string off eBay ("Kiddie Killers" as I call them) so gave him the bad news on those too.
 

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