Editing Electric power conversion (section)

==Other systems==
{{Main|Three-phase electric power}}

There are also devices and methods to convert between power systems designed for single and three-phase operation.

The standard power voltage and frequency vary from country to country and sometimes within a country. In North America and northern South America, it is usually 120 volts, 60&nbsp;[[hertz]] (Hz), but in Europe, Asia, Africa, and many other parts of the world, it is usually 230 volts, 50&nbsp;Hz.<ref>[http://www.kropla.com/electric2.htm Electric Power Around the World] {{webarchive|url=https://web.archive.org/web/20090906064026/http://www.kropla.com/electric2.htm |date=2009-09-06}}, Kropla.com</ref> Aircraft often use 400&nbsp;Hz power internally, so 50&nbsp;Hz or 60&nbsp;Hz to 400&nbsp;Hz frequency conversion is needed for use in the ground power unit used to power the airplane while it is on the ground. Conversely, internal 400&nbsp;Hz internal power may be converted to 50&nbsp;Hz or 60&nbsp;Hz for convenience power outlets available to passengers during flight.

Certain specialized circuits can also be considered power converters, such as the [[flyback transformer]] subsystem powering a [[cathode-ray tube|CRT]], generating high voltage at approximately 15&nbsp;kHz.

Consumer electronics usually include an [[AC adapter]] (a type of [[power supply]]) to convert mains-voltage AC current to low-voltage DC suitable for consumption by microchips. Consumer [[voltage converter]]s (also known as "travel converters") are used when traveling between countries that use ~120 V versus ~240 V AC mains power. (There are also consumer "adapters" which merely form an electrical connection between two differently shaped [[AC power plugs and sockets]], but these change neither voltage nor frequency.)