There are two main types of travel adapters that can be used with electronic devices. The first type simply converts one type of plug to another, allowing a device from one country to plug into a foreign wall socket. These are simple pass-through units that provide an electrical connection between the proper terminals, but do nothing else. A second category of travel adapters are often referred to as adapter converters because they can also alter the amount of voltage provided to a device. Some electronics can operate using two or more different voltages, though others are single voltage devices that require some type of transformer unit when traveling abroad.
One of the major concerns encountered during travel is whether personal electronic devices will be compatible with the local electrical system, and travel adapters are a common way to deal with the issue. There are over a dozen types of electrical plugs and receptacles that are commonly used in different places around the world. Each country typically has one type that is predominantly used, though some countries use two or more. There are also several different levels of voltage used in different countries in addition to two common frequencies. Both incompatible plug types and voltage levels can be addressed by travel adapters.
The most basic travel adapters are simple pass-through devices that allow a plug of one variety to be inserted into a wall outlet of another. This type of travel adapter can be useful when the plug types differ but the voltages are similar. These adapters can also be used with dual voltage devices. If a device is rated for use in both 110 and 220 volt systems, and the local power mains offer either of those voltages, a simple pass-through travel adapter will typically suffice. In addition to simple one way adapters, it is typically also possible to find universal kits that include many types of plugs and receptacles.
Adapter converters, or transformers, are somewhat more complex than common pass-through travel adapters. In addition to providing an adapter compatible with local wall sockets, these devices can also convert the available voltage to a higher or lower value. Some electronic devices are designed to work with only one input voltage, in which case this type of travel adapter is typically required. Another feature sometimes associated with adapter converters is protection from surges or other events that could damage an electronic device.