I’m building a qav-xs using a luxv2 fc and matek HUBOSD8-SE pdb which has 5 and 10 volt regulators. I want to run 2 5volt leds for orientation. How many leds can i run off of one 5volt pad. And what would be the best way to run these leds, off of the luxv2 or my pdb. And I have 5volt leds now but I can purchase 12 or 16 volt if there’s a better way to run them. Thanks!
Sounds like a neat project. Those 5050 surface mount leds tend to pull around 20mA and can handle bursts of up to 100mA. The 5V BEC from the matek can put out 1.5A and should be plenty. You should connect each led to the 5V output directly so each led gets an even current and 5V. At maximum you can have 1.5A/0.02A = 75 leds before you see power issues. You can definitely get the orientation leds powered and then some but make sure you have enough space to connect them to that 5V output. You may need an extension from that solder pad to fit more.
Now if you get an led strip, those are usually situated in series and require a higher input voltage(noted on the board). Sadly the matek model mentioned only has a 10V BEC and would likely be insufficient for a 12V or 16V strip.