PSU for Arduino Mega and Arduino Uno

Hi I just read this article: http://playground.arduino.cc/Learning/WhatAdapter

It suggests using a PSU that is 12V DC, 1A, centre positive and 2.1mm plug.

Do either of these fit the bill?: http://www.ebay.co.uk/itm/DC-12V-1A-1000mA-UK-Power-Supply-Adapter-for-CCTV-Cameras-Sky-Netgear-Routers-/180972604036?_trksid=p2054897.l4275

http://www.ebay.co.uk/itm/UK-3-Pin-AC-100V-240V-Adapter-DC-12V-2A-LED-Light-Power-Supply-extention-Line-/160705693329

The second one is 2A instead of 1A. Will that still work? Or will the extra Amperage fry my Arduino?

I am planning on using 16 IR LEDS and 16 IR receiver modules on my mega. and 5-6 IR LEDS and 5/6 IR receiver modules on my Uno. Although on each I only run one LED at a time, I turn each on and off in quick succession. So I guess I really only need the power to drive one IR led lol. But anyways im unsure.

Will the 2A one help as it will guarantee I have the power?

Alternatively I have this for my RPi: http://thepihut.com/products/7-port-usb-hub-for-the-raspberry-pi Is this sufficient? It only gives out 5V and I read the Arduinos need 7-12V.

One final question, they say 7-12? Is 12 the best option, still safe, but lots of power?

Either 1A or 2A adapter will work with Arduino.

If you are only powering one LED at a time, then you will be fine with either one since each LED will have a relatively small current draw.

And the 7-12 recommendation is because the voltage regulator on the Arduino has a drop out voltage so the input needs to be a few volts above output (5v).

A 7V adapter will waste less power cause instead of regulating 12V to 5V it only has to regulate 7V to 5V. You might look at getting a 9V adapter (happy medium).

There is a way to power arduino with 5v but not through barrel jack. You can use Vin pin and connect a regulated 5V and your arduino will work fine. Just don't put over 5V in Vin pin or you could fry arduino. So if you took a USB cable and cut off end and stripped wires and connected 5V and gnd to arduino Vin and gnd you could power it with the pi USB expander

Hi thanks a lot for the answer, probably going to have a look at 9V, if not i think il get the 12V 2a as it comes with a free extension cable :) lol. Thanks for reassuring me on my purchase!

No problem. Have fun!