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### Topic: Power supply - relating 150 vs 300 LED per strip (Read 3097 times)previous topic - next topic

#### boing2017

##### Nov 07, 2017, 05:39 am
Hello,

I'm having a hard time answering/googling this. I'm working on a project w/ WS2813 5meter strips.  There are two types I'm eyeing:

• 5 meters, 150 LEDs, 5V. At 60mA max for each LED, this would be a total of 9000mA, or in other words, I'd need a 9 amp power supply. Call it 10amps for a little wiggle room.
• 5 meters, 300 LEDs, 5V. At 60mA each, this would be a total of 18000mA, or in other words, I'd need a 18 amp power supply. call it 20amps for a little wiggle room.

My question is this: Can I power (2) x 5 meter 150 LED power strips with a single 20 amp power supply? I know most suggest breaking out each strip into its own power supply. But would this be OK, a total of 300 LEDs on a single 20 amp power supply, but 10 meters long vs. what is already out there and given as acceptable of a single 20 amp power supply for 300 LEDs, but only 5 meters long?

Is it due to voltage drops that I cannot do this? Or would this be OK to do 2 strips?

The overall project will use ~ 5 strips. So I know I'll at least be using 3 power supplies. The question is can I use just 3? (two strips on one power supply, two strips on another power supply, 1 strip on its own power supply) Or do I need to do 5 power supplies?

Thanks all!

#### Grumpy_Mike

#1
##### Nov 07, 2017, 10:20 pm
Quote
Can I power (2) x 5 meter 150 LED power strips with a single 20 amp power supply?
Yes. The current rating of a power supply is what it CAN deliver not what it WILL delver.

Quote
The question is can I use just 3? (two strips on one power supply
You can mix it up however you like.

#### Qdeathstar

#2
##### Nov 08, 2017, 05:06 amLast Edit: Nov 08, 2017, 05:08 am by Qdeathstar
Hi. They do sell high power single power supplies. You'll need to tie all the grounds together if you use different power supplies. Also, if you use one power supply, you will have to "inject" power along the strip. My suggestion is to insert power every 5m.

If you are going to use one large power supply, you should fuse the branches. Low voltage can have a higher fire risk than house wiring.

Another thing to consider is that 25 meters is a long run and depending on how you plan to have everything wired up, apa102s or ws2811s might be more reliable because they have a dedicated clock line an arnt so dependent on tight timing, like ws2812/13.

If you are going to be running jumpers in between the strips i would use twisted pairs with a ground in each of the pairs (one for clock, one for data).

I am using 45 meters of 12v 2811 strip for my project. (eve lighting)  I am running it in a meanwell 100amp power supply. I fused the power supply at 60 amps, then each branch is fused at 5 amps.
stiff against the freezing fog
glares at a tickless watch.

Time has failed him -- all things shall pass.

#### boing2017

#3
##### Nov 08, 2017, 08:02 pm
Thanks @Grumpy_Mike and @Qdeathstar!

After reading Grumpy_Mike's post, but before reading Qdeathstar's post, I picked up 4 power supplies for the 5 strips.

• (3) x RSP-75-5 MeanWell power supplies - destined to handle (1) x 5m strip each w/ 150 LEDs. This is a 5V 15A power supply which I plan on fusing at 10A, a single strip's max consumption on these will be 9A.
• (1) x RSP-100-5 MeanWell power supply - destined to handle (2) x 5m strips w/ 150 LEDs each (300 LEDs in total). This is a 5V 20A power supply which I plan on fusing at 20A for a pair of strips, the pair of strip's max consumption is 18A.

(Purchased from Mouser.)

Keep in mind that strips with 300 LEDs on 5 meters are readily available, I'll basically be doing 300 LEDs on 10 meters for one segment and power supply (2 strips), is the current plan. The vast majority will be 1 strip per 1 power supply. And the reason for this desired setup is pulling power to one particular area would be difficult and I'd prefer to avoid running copper power lines adjacent to one of the strips to power those two destined to be on one power supply individually. I mean, I COULD if I need to. But trying to avoid that which is why I brought up the topic. (And appreciate all the help/advice!) (Please convince me if I really need to run a 5m power copper line segment next to one of the strips for the one area I can't really get a dedicated power supply to after reading this plan.)

That was my initial plan and after reading Grump_Mike's post, I purchased the power supplies.

That said, after reading Qdeathstar's post (and thank you for it!) a few follow up questions?

For the moment, let's assume I'm sticking with ws2813. I'm not opposed to switching to ws2811, but for the sake of this discussion anyways.

Quote
Also, if you use one power supply, you will have to "inject" power along the strip. My suggestion is to insert power every 5m.
Roger that! Do you think that for the one segment I'd be OK to power (2) x 5m segments considering I'm using 150LED/strip lights vs. the 300LED/strip lights? I know I'm introducing distance here... But thoughts? I never plan on blasting these things, BTW. I'm guessing 50-60% is as high as I'd ever run them. But gotta plan for the worst, ya?

Quote
You'll need to tie all the grounds together if you use different power supplies.
Interesting. Thank you for mentioning that, I was unaware. I'll do some more research on it too.

Quote
Another thing to consider is that 25 meters is a long run and depending on how you plan to have everything wired up, apa102s or ws2811s might be more reliable because they have a dedicated clock line an arnt so dependent on tight timing, like ws2812/13.
Interesting. I had avoided the ws2811's for that exact reason thinking an external clock would be better! I had read that the maximum addressable quantity of ws2813's per segment was something well over 1000. (I can't seem to find the article at the moment, but I want to say like over 1,800. I just remember seeing that and knowing I'd be nowhere near that limit.) I'll be around 750 LEDs along that 25 meters. (Probably a bit less as the last segment will be trimmed.) Is this a distance thing vs. a quantity thing?

Quote
If you are going to be running jumpers in between the strips i would use twisted pairs with a ground in each of the pairs (one for clock, one for data).
No jumpers of significance, just enough pigtails/vampires to connect two adjacent strips together. The goal is to present them all as one long segment. (At least at first, I have a feeling this could get addicting and I will have some discontinuous strips which I'd take your advice on, thank you!)

Quote
I am using 45 meters of 12v 2811 strip for my project. (eve lighting)  I am running it in a meanwell 100amp power supply. I fused the power supply at 60 amps, then each branch is fused at 5 amps.
So 9 x 5m strips, or ? If this isn't too much to ask, would you consider drawing the layout out on a napkin and attaching it? I started typing questions based upon a few different layout assumptions and it was getting long. LOL

Thanks!!

#### Grumpy_Mike

#4
##### Nov 09, 2017, 12:10 am
Quote
Please convince me if I really need to run a 5m power copper line segment next to one of the strips for the one area I can't really get a dedicated power supply to after reading this plan.)
You have several options apart from this one. You could site the power supply at the far end, or you could try large capacitor at the far end as well as the near end. But at the end of the day you have to see what works for you. Personally I would split the power supplies up to 20A a piece but I have no very strong conviction about this. Playing with large currents is more electrical engineering that electronic engineering.

#### Qdeathstar

#5
##### Nov 09, 2017, 04:28 amLast Edit: Nov 09, 2017, 04:29 am by Qdeathstar
Using different power supplies isn't a big deal, but the ground need to be tied together to keep everything at the same potential.

My feelings are that you should inject power every 5m irregardless of the power supply. It is a lot easier to do when you are installing it the first time, then to have to do it after everything is installed once you notice your white is a little orange.

The clock line sends a signal to the chips that says "hey, i'm ready to send data now" where as with a 2812, it needs to data to be sent out at a very specific rate so that the chips will receive the data it is expecting, if everything isn't perfect, you get clitches. Ws2812s also take more clock time to write out i believe
stiff against the freezing fog
glares at a tickless watch.

Time has failed him -- all things shall pass.

#### Qdeathstar

#6
##### Nov 09, 2017, 04:44 am

This is set up as one continuous strip, but in the software I have it broken into several zones.
stiff against the freezing fog
glares at a tickless watch.

Time has failed him -- all things shall pass.

#### boing2017

#7
##### Nov 10, 2017, 06:29 am
Very nice!

OK, I think I understand.

Did you run your power lines next to the LED strips? And if so, did you run one bus line off the 60 amp all the way down the strips and then tap in for each 5 amp tap/injection? Or did you run several pairs of 5 amp wires from the power supply (so to speak)?

Or maybe you fed the power in/out of the attic at the various injection points?

#### Qdeathstar

#8
##### Nov 10, 2017, 02:46 pm
Hi, I sent the 60 amp line with 6awg copper to a buss in the attic of the front porch, then fed multiple feeds off that main bus, each protected by. 5 amp fuse. I am using glass fuses.

stiff against the freezing fog
glares at a tickless watch.

Time has failed him -- all things shall pass.

#### Qdeathstar

#9
##### Nov 10, 2017, 02:52 pmLast Edit: Nov 10, 2017, 02:56 pm by Qdeathstar

I ran the wires through the attic.  They are fused at the bus. The numbers show power injection locations and also shows you how the strip data runs.

I was having issues with random "blinks" but I installed ferrite beads on the data and power lines and it solved the issue. It runs on an esp8266. If these where neopixels it would not work at all because of the precise timing need to drive the neopixels and the fact that the esp8266 needs to interrupt every so often to do wifi things.
stiff against the freezing fog
glares at a tickless watch.

Time has failed him -- all things shall pass.

#### boing2017

#10
##### Nov 10, 2017, 06:08 pm
Cool! So it looks like #7, 8, and 9 are sort of under the front porch where #1, 2, 3, 4, 5, 6, and 10 are directly on the Eaves?

Thanks for explaining your power bus and tap/injections. Makes sense. 6awg copper bus. Wow! I'm tucking away that bit of knowledge on the ferrite beads as well.

How do you change patterns? You mentioned the esp8266, and I explored a few options using it. But most looked very static. I.e. take down the Arduino, program it for the pattern you want, then go hook up the Arduino again until the next time you want to change patterns. The only `dynamic` one I found was this project:
https://github.com/jasoncoon/esp8266-fastled-audio

#### Qdeathstar

#11
##### Nov 10, 2017, 08:33 pmLast Edit: Nov 10, 2017, 08:34 pm by Qdeathstar
The esp8266 is capable of running the fastLED library.  In my experience it doesn't work well with ws2812 leds over about 60 leds, it will cause glitching as the esp8266 interrupts the led writeout.

It works fine with leds with a clock line, I am driving about 600 ws2801s. However, each ws2801 drives 3 rgb leds in parallel so it's about 1200 leds. That allows me to use 12v instead of 5v; voltage drop over the power lines is less of an issue.

I have a controller with LCD display for choosing from about 30 different programs and any color.  I also have a switch by the front door that lets me turn the leds on and off and adjust brightness level.

Everything talks to everything else via Mqtt