Power Question Lights and RP4?

Did you mean you want to connect your RPi4 to 5v 30A Power supply together with your 312 LEDs?, if that right, than I think its ok

Guys, I have a question regarding power consumption.

219 leds - SK6812 RGBW - what power brick should I use to power leds and RP3? 30A How to calculate current draw from the leds correctly?

They say ( its not my experience)

that 1 led consumes around 60 miliamps each at full brightness.

so formula would be 219 x 60 miliamps = 219 x 0.060 = 13,14 Amps

but i am using diffrent, 219 x 45 miliamps = 219 x 0,045 = 9,855 Amps

if you are using a Raspi that consumes around 700 miliamps or 0,7 Amps

So you are safe with 75 Watts/15 Amps PSU

look at LRS-75-5 from Meanwell.

SK6812 RGBW per LED 49mA!

SK6812 RGBW Datasheet

219 x 49mA max . 11A

regards pclin

Zitat von Lightning-guy77

if you are using a Raspi that consumes around 700 miliamps or 0,7 Amps

So you are safe with 75 Watts/15 Amps PSU

Thank You Sir!

Unfortunately my PSU has 15amps, rpi screams about undervoltage. As all we know it isn't safe to stress power supply 100% - so in my case there's two possible issues - no enough power for RP3 or wiring issue.

Here's my  

undervoltage warning is normal, PI wants to run under 5.3 volts

you can overrule in config.txt the undervoltage warning

Zitat von Lightning-guy77

undervoltage warning is normal, PI wants to run under 5.3 volts

you can overrule in config.txt the undervoltage warning

True I can do that, but stress test for raspberry shows me that board works at 600MHz only..what indicates power issue.

I mean that the ledstrip doesn't want more (most of them) than 5 volts, so if used one main PSU then that warning is always there.

Only if used separate PSU for Raspi and for ledstrip then you can run the Raspi at slightly higher voltage

You are right about the rest though

Zitat von Lightning-guy77

Only if used separate PSU for Raspi and for ledstrip then you can run the Raspi at slightly higher voltage

Yeah, but both need common ground I believe ;]