Look at the underside of your laptop's voltage converter and make sure it includes voltage of 220 at 50Hz. It will says something like "Input: 100 - 240V", states the University of Washington (reference 2). The converter looks like a rectangle, situated in the middle of the plug. On its bottom you will see the voltage range that the converter works with. Most U.S. laptops come with a converter that works with the voltage used in Ireland. You can also find your computer's voltage information in its technical manual.
Buy a voltage converter for your computer. You will only need to buy this converter if your computer specifications state a voltage range that does not include 220 at 50Hz. You computer's manufacturer and electronics stores sell voltage converters.
Purchase a plug adapter. The plug adapter does not convert voltage. Using an adapter with a laptop that does not have the appropriate voltage converter can damage your device. Plug adapters will have slots on one side where you insert your U.S. plug and prongs on the other side that look like an Irish plug. A variety of shops, including Amazon, Walmart, Kmart, Staples and Ace Hardware, sell plug adapters. Adapters usually cost no more than $10.
Put your laptop in your carry-on bag. Putting your computer in your carry-on luggage ensures that it stays with you the entire time and keeps it from getting damaged. Checked baggage gets thrown around and could cause damage to your computer. Airport security will require you to take your laptop out of the bag for screening. You can also carry your computer in a laptop case, however some airlines might consider this bag your one carry-on item. Other airlines will allow a laptop case, plus a normal carry-on bag. Check with your airline before traveling to find out its rules regarding baggage.
