T-Shirt Forums banner
1 - 10 of 10 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
I'm currently in the process of converting my garage into a workshop and I'm wanting to build an exposure unit. Got all the bits n pieces but having a bit of an issue with the lights. I'm using UV LED bars that connect together like a daisy chain. For some reason, however, not all lights come on. I've hooked up 5 and 1, 3 and 5 light up but 2 and 4 do not. Does anyone have an idea why this might be happening?

I've tried turning them round and plugged them into the wall rather than just the USB included. All lights work individually, so they all work, but I would rather have one switch rather than 8 separate USBs into a hub.
Stairs Neon Visual effect lighting Electric blue Font

Thanks in advance!
 

·
Registered
Joined
·
3,855 Posts
I've hooked up 5 and 1, 3 and 5 light up but 2 and 4 do not. Does anyone have an idea why this might be happening?
My guess is they all have the output wires conected the wrong way.
#1 gets the correct polarity from the source, but then reverses the polarity so #2 will not light up.
#2 reverses the polarity again, so #3 will light up.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
My guess is they all have the output wires conected the wrong way.
#1 gets the correct polarity from the source, but then reverses the polarity so #2 will not light up.
#2 reverses the polarity again, so #3 will light up.
I’ve tried that. Swapped the direction on the light, swapped the direction of the cables. When unplugging 2 and plugging into 3, ‘3’ will go off and ‘2’ will come on. It’s like the power is skipping ever second connection.🤷‍♂️
 

·
Registered
Joined
·
3,855 Posts
I’ve tried that. Swapped the direction on the light, swapped the direction of the cables.
Have you actually opened the units to reverse the wires internally?
It's not possible without doing so.


It’s like the power is skipping ever second connection.
That's right...
The 1st unit reverses the polarity so the 2nd one will not light up.
BUT that 2nd unit reverses the polarity again, so the 3rd unit will light up.
BUT guess what? The 3rd unit also reverses the polarity, so the 4th will not light up either.
AND of course the 4th unit reverses the polarity again, and the 5th one lights up.

A 6th unit wouldn't light up either, but a 7th one would be OK... and so on.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #5 ·
Have you actually opened the units to reverse the wires internally?
It's not possible without doing so.



That's right...
The 1st unit reverses the polarity so the 2nd one will not light up.
BUT that 2nd unit reverses the polarity again, so the 3rd unit will light up.
BUT guess what? The 3rd unit also reverses the polarity, so the 4th will not light up either.
AND of course the 4th unit reverses the polarity again, and the 5th one lights up.

A 6th unit wouldn't light up either, but a 7th one would be OK... and so on.
So I would need to reverse the wires on all of them then? I’m no electrician so I’m not mucking about with that. (I’ve opened them up and wouldn’t know how to start.)
Surely, if they can be daisy chained you wouldn’t need to rewire them to get them to work???
 

·
Registered
Joined
·
3,855 Posts
Surely, if they can be daisy chained you wouldn’t need to rewire them to get them to work???
They are basically defective.
My guess is that these units were initially made with LED rope type of connectors.
Bicycle part Automotive wheel system Auto part Technology Rim

Polarity is irrelevant with these, because they can be connected in reverse.
Apparently some "genius" in China decided to replace them with USB connectors, which are not reversible.

You just could cut the USB cables and connect black to red (or whatever colors they have).
Eyewear Sunglasses Font Slope Twig
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #7 ·
They are basically defective.
My guess is that these units were initially made with LED rope type of connectors.
View attachment 275910
Polarity is irrelevant with these, because they can be connected in reverse.
Apparently some "genius" in China decided to replace them with USB connectors, which are not reversible.

You just could cut the USB cables and connect black to red (or whatever colors they have).
View attachment 275911
I’m thinking I’ll just need to get a USB hub..connect them all separately. A bit annoying but at least it’ll work.

I can see the +/- on the strips and plugging them in the opposite way should work but as you say, maybe they’re wired up wrong.

Annoying, but you what you pay for.
 

·
Registered
Joined
·
3,855 Posts
I’m thinking I’ll just need to get a USB hub..connect them all separately. A bit annoying but at least it’ll work.
A hub is not necessary, plus you will have to extend the wires anyway.
You could just extend the wires and and connect them together (black to black red to red).
They are always connected in parallel anyway.
Rectangle Font Parallel Slope Number

Annoying, but you what you pay for.
Products with minor defects are usually sold at cost.
I don't mind things like that, as long as they work.
 

·
Registered
Joined
·
25 Posts
I'm currently in the process of converting my garage into a workshop and I'm wanting to build an exposure unit. Got all the bits n pieces but having a bit of an issue with the lights. I'm using UV LED bars that connect together like a daisy chain. For some reason, however, not all lights come on. I've hooked up 5 and 1, 3 and 5 light up but 2 and 4 do not. Does anyone have an idea why this might be happening?

I've tried turning them round and plugged them into the wall rather than just the USB included. All lights work individually, so they all work, but I would rather have one switch rather than 8 separate USBs into a hub.
View attachment 275896
Thanks in advance!
If the strips will light individually then run them individually on a hub or power strip. This will keep them in parallel and will also reduce dimming at the end of the chain.
 

·
Registered
Joined
·
3,855 Posts
If the strips will light individually then run them individually on a hub or power strip. This will keep them in parallel and will also reduce dimming at the end of the chain.
These are always in parallel... even if it looks like they are connected inline.
 
1 - 10 of 10 Posts
Top