Powering 600 WS2812B LEDs from one 32A 5V ATX PSU

[2hynu]

I'm trying to power an entire strip of 600 WS2812B LEDs with one ATX PSU which is rated for 5V 32A which should work fine if I assume that one LED draws 50mA of current meaning the entire strip would require 30A 5V. However, when I plugged the strip in to 5V on the ATX connector, Three quarters of the strip was dimmer than the first quarter and when I measured the voltage at the end it showed 2V. The ATX PSU provides the same outcome as my laptop's USB port which is strange considering the ATX PSU is providing much more power. The ATX PSU only has the LEDs and has no computer plugged in so I'm confused in why it is not working.

 

I can use multiple PSUs but I would prefer using one PSU for the entire LED strip since I am running it from one source and running the LED to areas with no power which would make it more convenient to have only one PSU instead of running extension leads.

[HanZie82]

Theres a thing called resistance.
You WILL NOT be able to power that from jsut the 1 end.

You will need to ad power cables in the middle or more to make sure theres 5V all over the line instead of less cus of the resistance.

 

 

(Thats why you use 12V strips for stuff like that!)

You can have more voltage and less amperage wicxh heats up cables/wires less thus easier in power transfer, which means less power addind needed in the middle.

 

 

If you have connectors like thses (standard for aRGB strips) you can put extra power to the wires with the arrow. (Yes you can use the same power suply, just make sure the wire you use is rated for high amps and has little resistance so all the voltage makes it there and you should be good.)

[2hynu]

Oh right, I totally forgot about resistance. Thank you for helping me I might buy 5V voltage regulators and run 12V along with the strip and have it connect to the voltage regulator every meter.

[HanZie82]

3 minutes ago, 2hynu said:

Oh right, I totally forgot about resistance. Thank you for helping me I might buy 5V voltage regulators and run 12V along with the strip and have it connect to the voltage regulator every meter.

If you use for example regular power wire (for 120V or 240V) That would be more than fine. No need for power regulators.
The wire on the ledstrip is just pretty thin and has more resistance.

 

 

ps thinking about it, voltage regulators might not be the way to go, as they would have to be very powerful. It might be easier to get a thicker gauge wire and just run the length. Altho im not sure about its thickness 5V is surely not a lot but 30Amps can be.

 

[2hynu]

1 minute ago, HanZie82 said:

If you use for example regular power wire (for 120V or 240V) That would be more than fine. No need for power regulators.
The wire on the ledstrip is just pretty thin and has more resistance.

Oh yeah that sounds like it would work too, I might also consider trying that since I did notice the wires were very thin. Thank you for helping. 

[mariushm]

The power supply probably can't output 32A of current on 5v .... it's either an ANCIENT design of psu (from around 2000-2005) or they just plain lie about it.

Most modern power supplies output at best around 20A on 5v.

 

Estimate around 30-40mA on each led ... and yeah, you'll have to either inject 5v at various points in the strip,because the strip has a relatively high resistance... the resistance of the strip increases as you move further away from the start of the strip. 

If you can have two thicker wires go along the strip you'd be fine ... the regular power supply wires are AWG18 and they have around 0.02 ohm resistance per meter... even AWG24