Is it possible to overcurrent a light strip?

[Acorn Eyes]

I isolated a ground and a 5v pin on the main motherboard power cable for my PSU, my cable takes 18A at full brightness and white. One 5v rail outputs 20A the aux outputs 3A, I have no clue how to measure how to measure current or resistance with a multimeter so I don't what the current flow is.

 

Now I'm pretty sure 2A can't hurt, but I just want to be sure I wouldn't fry my strip.

[PeachyUwUSenpai]

3 minutes ago, Acorn Eyes said:

I isolated a ground and a 5v pin on the main motherboard power cable for my PSU, my cable takes 18A at full brightness and white. One 5v rail outputs 20A the aux outputs 3A, I have no clue how to measure how to measure current or resistance with a multimeter so I don't what the current flow is.

 

Now I'm pretty sure 2A can't hurt, but I just want to be sure I wouldn't fry my strip.

is this an rgb one did it have built in resistors?

[Acorn Eyes]

Just now, Alaradia said:

is this an rgb one did it have built in resistors?

RGB, addressable, and looking at the strip every LED has a resistor.

[vanished]

That's not how electricity works.  The 20A is what it can provide, the 18A is what it needs.  It's only getting 18 when plugged in.

[PeachyUwUSenpai]

did you accidentally hook the power to the data pins

[PeachyUwUSenpai]

1 minute ago, Ryan_Vickers said:

That's not how electricity works.  The 20A is what it can provide, the 18A is what it needs.  It's only getting 18 when plugged in.

not always there's exceptions to it and one of them is leds if it wasn't in a circuit to protect them like in this case 

[vanished]

Just now, Alaradia said:

not always there's exceptions to it and one of them is leds if it wasn't in a circuit to protect them like in this case 

exceptions to what?  Ohm's law?

[Acorn Eyes]

2 minutes ago, Alaradia said:

did you accidentally hook the power to the data pins

What do you mean? I shorted the motherboard data cable to ground so that the power supply turns on, and I'm using a red wire which I tested for 5v.

 

I haven't cut any cables yet and am using arduino male to male cables to prototype.

[Acorn Eyes]

4 minutes ago, Ryan_Vickers said:

That's not how electricity works.  The 20A is what it can provide, the 18A is what it needs.  It's only getting 18 when plugged in.

I mean, I know that. But I don't want to look like an idiot when it turns out I went about it all wrong and fried my strip. It's a sanity check question.

[PeachyUwUSenpai]

2 minutes ago, Acorn Eyes said:

I mean, I know that. But I don't want to look like an idiot when it turns out I went about it all wrong and fried my strip. It's a sanity check question.

for the rgb strips to turn on you have to send data to it via the data line with the arduino 

[Acorn Eyes]

8 minutes ago, Alaradia said:

for the rgb strips to turn on you have to send data to it via the data line with the arduino 

Yeah thats what I'm doing. 

 

Looks like its working as intended, but it looks like the strip has a kink so it doesn't light up correctly unless I hold the wires in a certain position.

[Elerek]

if the strip has resistors you're fine.

[intender]

You can not over current something.  You can over volt something.  If you try and draw more current than your supply can provide you could burn out the supply.  The device can dynamically draw as much current as it needs up to the max your supply can give at any given time at the fixed voltage provided

[mariushm]

The power supply can provide what says on the label, but the current on the label is when multiple individual wires are used.

 

For example, the power supply could say it can do 20A on 5v, but a single AWG18 wire is only rated for around 10A (if you don't want a lot of voltage drop on the wire and you don't want it to overheat). In order to give up to 20A to something, you should connect together at least 3 pairs of wires (3 red wires which are 5v , and 3 ground wires which should be black)

Also note that some power supplies (the cheaper group regulated ones) don't like to provide a lot of power on the lower voltages (5v or 3.3v) without something using power on the higher voltage (12v). So especially if your light strip has lots of leds (let's say you use more than 10A), with those cheap power supplies you should have something connected to the 12v (maybe at least a couple of 12v fans, but normally should be more)

 

You can measure the current used with a multimeter by placing the multimeter in series with the circuit  :  led strip input voltage  --- meter probe 1 ---- meter  ---- meter probe 2 --- + 5v power supply

Set the multimeter on current measurement and set it on high range (10-100A ) and start the power supply and you should be able to see how much the led strip will use.

 

For a basic idea, the addressable leds are usually around 15-20mA per color at maximum brighness, so for a full white your led will probably use around 60mA or 0.06 A .. just round it down to 0.05A ... so 100 leds would use up to 5A.