as far as I have always worked, I have operated with 5V Addressable LED strips, and when speaking or reading other comments I have generally got the feeling that this is the norm.
However, I was talking to a sales rep from Mean Well power supplies and he gave an off the cuff comment saying that using 5V LED strips is unusual. I appreciate that there can be a lot more to what he said than that, but what is the norm with LED strips power voltage, especially the addressable ones. What do you use?
I did a google serch and realised there are 24 volt ones but I don’t think they are addressable, but there are 12v addressable ones. What is the difference between 12V and 5V for the strips, is it brightness? Also if you get a 12 V one will the voltage drop be greater?
The common 12V ones I’ve seen are either:
a) addressable in blocks of 3 pixels at a time (so addressable, but not individually addressable), or
b) “dumb” RGB strips which have a wiring connection of R,G,B,+ (or R,G,B,-) and setting a color changes every pixel (the entire strip) all together.
All my projects have been 5V except one that used a “dumb” RGB strip provided by the client.
I worked with 12V WS2811 before, I think it’s mostly convenient so you don’t have to inject power every meter (less voltage drop). The data line was 5V though.
I had a similar comment from a MeanWell reseller sales rep recently when I ordered about 10kW of 5V power supplies!
The difficulty with the low voltage and high current is just the voltage drop. You need to take care of the with short and heavy cabling, bus bars, etc. Oh and fusing becomes difficult as a fuse rated to protect the lightest of your wires will add another voltage drop.
For things like signage this is all doable, but 5V wiring doesn’t suit spread out installations. For those I’ve designed a small point of load (POL) converter that goes near each strip segment of a couple of meters, and convert 12-15V in down to 5V at 7A. But that gets costly, especially if you also have to convert from 48V down to 12V because the mains power supplies have to be located at a distance for aesthetic reasons.
All that said, at some point I got some 12V WS2812B strips from Ray Wu (I think) which have a small POL converter on the back of the strip every 500mm. So they locally convert to 5V as close as possible. Very cool, but you have to trade off the extra expense of these strips against extra costs elsewhere. I’ll try dig out a link or photo if others are interested.
All the other 12V strips I’ve seen have groups of 3 LEDs per pixel off a WS2811 chip.
Oh, and to answer your final question, the voltage drop will be lower in any 12V (or 24V, etc) cabling. This is because the current is lower at a higher voltage for the same total power consumption. P=VI
Mind you if you then convert to 5V with a POL converter the current is back to original at that point on and you have some power loss in the converter (maybe 10%).
If I remember correctly the 12V tri-pixel strips are also slightly less efficient as they burn up a little extra power in the current limiting resistors.
@Kean_Maizels 10kW, that is a lot of power! One questions leads to another, but which bus bar do you use? Ive had a problem finding affordable ones as they all come in really expensive.
Would be interested to see those Ray Wu ones which automatically change from 12V to 5V, that would be really beneficial as you could get really long strips going? I assume you would need to inject every meter or so with those, but as the voltage drop would be reduced on 12V cable you can create a longer parallel circuit? Am I understanding that right?
if you have a 50m strip to do, what do you find the best method (Assuming you dont start from the middle and do a sneaky 2x25)?
Yeah, the 10kW is broken across several installations, and includes some redundancy as well. The low voltage busbars we use are often used in marine installations I believe. They’re not cheap especially when you need quite a few. Something like these http://www.marinco.com/en/bb-12w-2nc-fslh-dsp
I only bought one reel each of the 30/m and 60/m strips to check them out, so I never did much testing with these.
You don’t need to inject power every metre, as although the 12V will slowly drop along the length, the buck converter in each segment will generate a new local 5V supply for that segment. I believe the 5V connection doesn’t continue from one segment to the next, but the 12V does.
If I needed to run a really long strip like 50m, I’d still be injecting power at multiple places along it via POL converters of real PSUs. Even with these 12V strips you’ll get a substantial voltage drop on the 12V supply along that length such that the buck converters will begin to struggle (unless you have an animation that draws very little power). There just isn’t enough copper in these flex strips.
Secondly, are you also saying the 12v rail is carried the whole way, and then at intervals, some is ‘taken’ and used in the 5v rail?
However, because of voltage drop, the 12v rail needs to be ‘topped up’?
No problem - there is always something new to learn. POL just means Point Of Load - so it is designed to be put very close to the load and thus minimises voltage drop in cabling. It is usually a buck converter topology.
And yes, in answer to your questions. Having them integrated into the strips makes life so much easier.
I have quite a few LED’s at the moment but I am going to have to look into those when I get my next batch. thats really good to know
thanks. If you dont mind, is there any way I can talk to you with regards to hardware in the future if i have something going on?