Most of the countries in Asia use the 240 V.
Japan is 100-volt system; the US is 110v so most of the US devices will work in Japan.
Indonesia uses the same plug configuration found in the UK, and some of the countries next to Indonesia use the European Style of plug. Just bring a universal plug adapter that costs hardly anything and you will be fine. I think I bought mine for around US$1.
Some developing countries in Asia do not have a clean power source and some are run on generators. Power changes can cause your device to fry. You may want to consider bringing a portable solar charger with you.
For specific information on countries around the world Click Here
Plug Adapters v. Electrical Converters v. Power Transformers:
Plug Adapters: Know what electrical plugs and voltage the country you will be in uses. Plug adapters do not change the electricity supplied to equipment, they simply allow it to be plugged in to a different type of wall socket or outlet. They are usually cheap to buy and are light to carry. You may want to get two if you think you will need two different things plugged in at once. The adapter I have has little gadgets that pull out that allows me to convert just about anu equipment plug into any outlet worldwide.
Choose an adapter if the equipment you are using supports dual voltage and dual frequency. Look at the equipment you will be plugging in, if it says 110-240v or 120-240v or 120/240v, 50/60Hz you won’t need a converter or a transformer, just an adapter. Make sure the 240v is there; otherwise you will blow out your equipment.
If your equipment only says 110V or 120V, etc. and doesn’t show a dash for example: 110-240v or 120-240v or 120/240v, 50/60Hz, then you’ll need a converter or transformer in addition to a plug adapter.
Before you buy a converter, check to see if a travel charger is available because they are usually dual voltage, you may not need a converter after all. A travel charger with a plug adapter might be the most convenient way to go depending on the type of equipment you have.
Most laptop computers and battery chargers are dual voltage, so all you will need to use them with a different supply is a plug adapter.
Power or Voltage Converters: Also known as electrical converters. They step down the voltage from 240V to 120V, allowing equipment which is not dual voltage to operate at the voltage for which it was designed. Converters do not alter the frequency at which electricity is delivered. 1 to 2 hours at a time is the max it should be plugged in for, it is not designed for continual usage. Always unplug it once you are done!
Choose a converter if you wish to use common electrical equipment which is not dual voltage, such as hairdryers (1875w), clothing irons, hair straighteners, some curling irons, some electrical shavers, and fans, etc. They are used for higher wattage equipment. I have a travel hair straighter that I bought at Bed Bath and Beyond with low watts and it does not require a converter, so check around for travel equipment which may save you from buying a converter. Some hotels will provide converters for your convenience.
If you connect a 120 volt equipment to a 230 volt supply the electrical current will go up 100% and will burn out your equipment almost immediately.
Frequency: If you connect 60 Hertz equipment to a 50 Hertz supply (that isn’t dual voltage or says 50/60Hz) the electrical current goes up by about 17%. Most equipment can deal with this for a short amount of time; however it will lead to a slow burn out of the equipment in the long run. It will also make the equipment run slowly, if you are using it for a clock radio you may lose 10 minutes every hour. By using a converter or transformer then this will take care of the problem.
Power Transformers: Also called “step up, step down converters”. Power transformers will step down the voltage. They are designed to be used with electronic equipment. They alter the voltage of electricity going through equipment to a safe level and can be used continuously or at least for much longer than a power converter. Transformers are heavy and can be expensive.
There is the difference between low wattage and high wattage. If you can’t find the Watts (W), you can use W = Volts (V) x Amps (A). So if your 110V product says 2.0A, you’ll have a 220W product. Transformers are used for low watt products (50W or less), such as iPods, battery chargers, etc. They are also made for extensive use of electronic equipment such as a DVD player, computer, printers or televisions all of which does not support the dual voltage.
Auto-switch Converter: This will automatically switch when you plug in a battery charger or a hair dryer. This with an adapter kit will cover you.
Transformers and converters only change the voltage supplied to equipment, they do not alter the frequency of the electrical supply. Thus long term use of equipment with either a converter or a transformer may damage it.
If you are still confused, follow these steps:
Step 1: If your equipment is dual voltage or says 120v/240v or something similar you won’t need a converter or transformer. You may still need an adapter if the equipment won’t physically plug into the outlet.
Step 2: If your equipment is not dual voltage or it only says 120v or something similar you will need a converter or a transformer; depending on what equipment you need to plug in. You may also need an adapter in addition if it won’t physically plug into the outlet.
Step 3: What are you trying to plug in? Is it high watts like a clothing iron? Is it low watts like an iPod charger? Use a converter for higher watts and use a transformer for lower watts. Or use an auto switch converter for both. Also check with your hotel to see if they provide clothing irons, hair dryers or even converters. Buy a travel charger, travel straightener, or travel curling iron instead.
For more information on specific countries Click Here
General Appliance Voltage:
The information below is a guideline, and it may or may not be correct for your appliance. Make sure to check the label on your appliance:
iPod: You’ll have to check the iPod’s charger. There are too many charger options and they are all different. If the charger only says “120V” then you’ll need a voltage transformer for a 220V power outlet. Better yet buy a new charger that is 100-240 compatible.
Laptops: 100-240V, 50/60Hz, auto-switching. An adapter is all you need.
Cell Phone: The chargers are usually 100-240V Compatible, but double check since there are a lot of brands out there. If it says “100-240V” then a plug adapter is all you need. If it doesn’t say the 240V then get a new plug adapter that is compatible.
PDA/Blackberry/Digital Camera/ Cordless Electric Shavers: Most chargers are usually 100-240V compatible.
Hair dryer/curling iron/flat iron and Plug in Shavers: Most U.S. and Canadian hair appliances are only compatible with 110-120V. Some models have a switch to change the voltage to 220V. If it doesn’t have a switch, then you will need a voltage converter. Voltage converters are usually better than a step down transformer.