The countries of the world differ in some well-known ways that it’s important for travelers to consider prior to travel: the languages spoken, the foods served, the culture and ethnicities, etc. Smaller, though essential, differences are also the voltage and types of electrical outlets and plugs used. Fortunately, when traveling internationally, a travel plug can bridge the gap between appliances you have and the outlets you find in your travels. A travel plug can refer simply to a plug adapter, a voltage converter or transformer, or a combination of the two.
There are 13 types of plugs used internationally, designated by capital letters A through L. Some of these plugs are variations on a basic type. For example, B is the three-prong counterpart of A, or A with a ground, in other words. If one is traveling to a country with the same voltage as one’s home country, and therefore, the same voltage as one’s appliances, all that is needed is a plug adapter. The plug from the appliance is put into the adapter, and the adapter is plugged into the outlet.
While much of the world operates appliances at between 220 and 240 volts, in a good part of the Americas and Japan, a voltage from 100 to 127 volts is used. There may also be a difference in cycles per second (Hz). Thus, depending on where one is traveling from and to, a converter or transformer may be needed, as well as a plug adapter. The front of the converter or transformer has an outlet appropriate to the country in which it is purchased. It is either plugged directly into the socket in the other country if this happens to work, or it is plugged into the appropriate adapter, which is plugged into the socket.
Travel plugs are sold individually and in kits. A kit may either contain several travel plugs or several plugs along with a converter or transformer. A travel plug kit including a voltage converter or transformer should be purchased in one’s home country for best results, because this will mean that the socket on the front usually will fit one’s appliances.
This is not always the case, however. For example, in the United States, where the plug types are A and B, when one buys a travel plug kit, the converter or transformer may have an A socket — the two-pronged type — on the front and a shape such that the three-prong B plug does not fit. Fortunately, many kits come with an extra A plug that can be plugged into the front of the converter or transformer. The adapter provides enough distance from the converter or transformer that the third prong will fit under it.