All great ideas.
I have 5V ARGB LEDS in my computer that I want to measure. Currently, they are connected to an SATA ARGB hub and the hub is powered by the SATA PSU connection. The data cable comes from the motherboard. That way I can use the software to control the LEDs.
Incidentally, there is a power cable that also comes from the MB. I was getting some weird feed back through the MB or PSU SATA connection that would slowly turn either the PSUs fan or two of the 12V fans, very slowly, when the computer was off. I found that the phenomenon is the way Gigabyte does the ARGB circuitry. It's kind of a feed back from the hub that is powered by the SATA connection.
I traced the power feedback in off mode to the ARGB power lead connected to the MB.
The solution was simple. I just cut the ARGB wire's power connection from the motherboard. That's how I would prefer it anyway, since the MB ARGB riser has it's own set of ARGB LEDs and they are and should be separate from the SATA powered hub.
Anyway, after reading your comments, I think all I need to do is plug the SATA connection into my bench power supply, then read the bench power supply's amp reading. The power can't get to the MB from the bench supply because the ARGB connection's power wire is cut. I think that would be pretty safe.
In short, I'll be using the MB's ARGB controller for the data cable, in order to turn the lights on, and the bench PS to power them through the SATA connection. Then I can just read the current from the bench PS's read out.
The best solution is to have an ARGB controller that I can power directly from the bench supply. I do have one, but it is current limiting, so I can't use it to measure maximum current.
It has been impossible for me to find a simple ARGB 5V controller that does not limit current. Otherwise, I'd use that connected to the bench supply to measure current, leaving the MB out of the loop (which is my preference).
Anyone see any problems doing it like that?