# Powering 3 DC devices from one outlet

I have be trying to research how I would go about powering 3 Raspberry Pi devices using only 1 outlet. The raspberry pi require 5v and a max of 2a. I think I know just enough about electronics in general to apply any answers I find here. I am capable of diy what I need to.

Could I purchase a simple 9v ~1a wall wart power supply and split the dc 9v dc power over 3 buck converters that will step down to 5v? Place a diode in before the buck converter for protection?

Any and all advise os greatly appreciated. Thanks.

• If all 3 devices are 5V, why not just get a 5V power adapter that has enough current output for all 3 devices? (so if each device needs 500mA just use 2A adapter) – I. Wolfe Mar 7 '15 at 15:52
• According to raspberrypi.stackexchange.com/a/1183 it looks like the Pi doesn't need 2A - tests max out around 500mA. Like Wolfe says, any adapter that can source at least 1.5A can supply power for 3 devices (at 500mA each). – Greg d'Eon Mar 7 '15 at 16:19
• More amps are needed for usb addons. I.E. wifi dongle, usb keyboard and mouse. I wanted to create a system that allowd flexibility. – Catalyst09 Mar 7 '15 at 17:39

I have never tried it on my own, but from the looks of it if one Raspberry PI drain 2A then 3 should drain 6A at max, using rough estimation the maximum power needed would be: P = V * I , which is P = 5V * 6A = 30W. Yet the source you use is P = 9V * 1A = 9W. Roughly it's not safe enough in my opinion, unless you could at least get yourself a 12V - 3A power supply, which in my guess won't be that rare

well, I hope it helps, Cheers

• If the PI needs a 5V source, a 9V source will not work. Matching the voltage needs to come before figuring out the power. – Greg d'Eon Mar 7 '15 at 16:17
• @Kynit: The OP has already put buck converters into the scenario, so your comment is irrelevant. – Dave Tweed Mar 7 '15 at 17:06