If your appliance is dual voltage, you can switch it to work on 220 volts, without a transformer or converter. The electrical outlets outside the United States and Canada are different from those in North America. The plug on the appliance you use in the U.S. won't fit into the outlet in most foreign countries. Therefore, you will need a plug adapter to plug in your electrical device. Electric products are simple heating devices or have mechanical motors.
Examples are hair dryers, steam irons, toothbrushes or small fans.
Converters should not be used for more than three hours at a time. Electronic products have a chip or circuit. Examples are radios, CD or cassette players, shavers, camcorder battery rechargers, computers, computer printers, fax machines, televisions and answering machines. Transformers can also be used with electric appliances and may be operated continually for many days. Converters and transformers are available for appliances of different wattages.