International Plug Adapters



International plug adapters are a necessity when traveling overseas to Europe, Asia, or other foreign countries. This is because the outlets are shaped differently than American outlets, and power that is available at a plug-in wall outlet is comes in different versions; what is delivered to the house by the electric company in America can be far different than that provided in foreign countries. Electricity has various properties that the casual user will never consider in their entire lifetime, but these properties are well known to anyone who is versed in even the basics of electrical power.



The two most important characteristics are voltage and frequency. All electric power sources furnish electricity as either a direct current (DC), or alternating current (AC). AC electrical power is much safer to use in the home than DC, and power losses as a result of transmission from the generating plant are much lower when electricity is transferred in the form of AC. The disadvantage of AC is that it is transmitted at a high voltage and must be converted back to a low voltage in order to be used in the home, and this requires the use of those cylindrical transformers you see at the poles outside the homes, as well as the substations where larger transformers also perform conversions. In the USA, the AC power might be transmitted long distances at a voltage of 100,000 volts, but it is reduced to 120 volts by the time it reaches the house. In between, it is probably between 20 and 30 thousand volts as it is transmitted down the electric line near your home.

The second principal characteristic of home electricity is the frequency. The frequency of an AC current (current refers to electricity that is flowing through a wire) is the rate at which it changes direction, back and forth. It is measured in round trip flips per second. A change in current flow from one direction to the opposite direction, and back, is termed 1 Hertz (Hz). In the USA, electrical power is furnished to the wall outlet at 120 volts at 60 Hz. Note that 120 is an average, not the maximum voltage. The maximum voltage can be calculated by multiplying 120 by the square root of 2 (1.414), which yields approximately 170 volts.

Home appliances in the US are designed to use the 120 volts @ 60 Hz, but other countries use different standards. Great Britain uses 230 VAC @ 50 Hz. China uses 220 VAC @ 50 Hz. Some countries use a voltage that approximates the voltage of the US, and some countries use 50 Hz instead of the 60 Hz used in the USA.