1

I have a generic 5V 10A switching power supply with screw terminals, that looks kind-of like this:

Power supply

Is it safe to use the output from here to drive the Pi by cutting a USB cable and connecting the power wires to the terminals? I am already using this power supply to power a set of LED lights (similar to these) and I want to avoid needing an extra power supply just for the RPi if I can help it.

Is there anything in particular that I need to be careful about when doing this, other than accidentally crossing the wires?

2 Answers 2

2

I have used a 12v version of this and then used a linear regulator to drop it down to 5v.

It worked fine for driving the Pi but because it is a switched mode power supply the output is quite "noisy" and even putting it through the linear regulator I still had the noise. I was using the Pi to switch camera outputs and the resulting picture had lots of lines of interference on it.

2
  • 1
    I'm curious about the noise you mention. My DC power supply experience is limited and I was having a tough time assessing why my 5v switch mode PS seemed to be affecting my 3D printer connected to my RP3. Any time I'd send a Gcode command to the Arduino (running Marlin), the USB connection would reset and I'd have to restart the RP for it to properly connect again. I was trying to filter out irregular voltage, but I ended up creating another problem, it would seem.
    – Erutan409
    Nov 2, 2017 at 21:02
  • The average voltage will be fine but the noise I was seeing was related to the switching frequency of the power supply (say 60kHz). Because it had such a fast edge to it, my grounding/filtering wasn't adequate and because it wasn't synchronized to the video camera I got the interference.For the digital case you have it might be more down to the ability of the power supply to supply the necessary current under demand.
    – Kev Scott
    Nov 10, 2018 at 18:44
1

Kind of overkill, but as long as it is 5v it should work. And skip the USB hack. Power through the GPIO connections.

See: Safest way to power a hungry Wifi adapter and the Pi from a single 5V source

and

Suitable power supply for DC power through GPIO

Edit: The USB hack will work. I just think the GPIO pins are easier to connect to.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.