Power Management + Fan on SATA HAT

#1

I am planning to build a NAS with 4x 3.5" HDDs and an external case fan, I would like to make sure I understand the power management on the SATA HAT.

My plan is to use power option 2, 12V 5A directly onto the DC jack of the SATA HAT.

  1. Is the Raspberry Pi 4 powered via the 5V pins on the GPIO? If yes, what kind of converter is being used to step the 12V down to 5V? Is any protection given for the 5V rail of the Pi?

  2. If I connect my own fan to the 5V (pin 4) on the 10 pin connector of the HAT, how much current can I draw? I guess this depends on answer 1 and how the 12V is stepped down to 5V.

  3. In order to use the built in fan control, I would need a 5V PWM fan connected to 4, 8 and 7-9 of the 10 pin connector, is that correct? Or alternatively a regular 5V fan with my own transistor connected to pin 8 of the 10 pin section.

Thank you in advance, looking forward to using the product!

#2

Hello,

  1. Yes. Via Switching Voltage Regulators (5V, max 8A). Be protected.
  2. Depends on how much power is left in the power supply and the SVR.
  3. PWM: GND, pin33, 5V. Regular: GND, pin33.
#3

Thank you!

Glad to hear the SVR can handle 8A, this will be plenty to drive an extra fan.

Unfortunately it seems the Noctua PWM fan I plan to use has a 5V pullup inside so driving it directly off the 3.3V GPIO pin would probably be unwise. I will add a 2n2222 transistor in between and control it with the GPIO, allowing the fan to be safely controlled at 5V.

#4

Can you explain more detailed about the wiring of the fan, is correct to asume wiring in pin4, pin 8 and 9 of the 5x2 pin on the Sata Hat? I have been problems controlling the fan speed, always is on 100%

#5

I use on Quad Hat and Penta Hat pin 4, 8, 9 running a 4 pin Noctua NF-A4x10 5V PWM (RPM unconnected)

#6


The wriring looks ok (if yellow is really PWM on yours, as e.g. Noctua uses blue)

Does fan stop if you connect for a short test the fan’s PWM cable to ground?

Heat issue solved by separating SATA HAT and Pi
#8

Solved, update the system at all and disconnecting all the peripherals and then reconecting firstly the fan and the other peripherals later it’s solved. Thanks for your help