Foreign object detecting device, wireless power transmitting device, and wireless power transmission system

The invention discloses a foreign object detecting device, a wireless power transmitting device, and a wireless power transmission system. An object detecting device includes a coil array including coils, short-circuit switches connected in parallel with the coils, an oscillator circuit that outputs, to the coils, a voltage including an alternating current component, selection switches connected between the coils and the oscillator circuit, a detecting circuit that detects an object based on a change in a physical value such as voltage, and a control circuit that opens and closes the short-circuit switches and the selection switches. When a first selection switch is closed, a first short-circuit switch, which is connected to the first selection switch, is opened. The other selection switches are opened, and the other short-circuit switches are closed.