In recent years, attention has been given to a feed system (a non-contact feed system, a wireless charging system) that performs non-contact electric power supply (power transmission, electric power transmission) to a CE device (Consumer Electronics Device) such as a mobile phone and a mobile music player. This makes it possible to start charging merely by placing an electronic device (a secondary-side device) on a charging tray (a primary-side device), instead of starting charging by inserting (connecting) a connector of a power-supply unit such as an AC adapter into the device. In other words, terminal connection between the electronic device and the charging tray becomes unnecessary.
As a method of thus performing non-contact electric power supply, an electromagnetic induction method is well known. In addition, in recent years, a non-contact feed system using a method called a magnetic resonance method utilizing an electromagnetic resonance phenomenon has also been receiving attention. Such non-contact feed systems are disclosed in, for example, Patent Literatures 1 to 6.