Contactless power supply system and power reception apparatus

A contactless power supply system in which supply of electric power from a power transmission apparatus to a power reception apparatus is performed in a contactless manner, the contactless power supply system comprising:

• the power transmission apparatus including
• a primary-side resonant circuit having a primary-side coil for power transmission and a primary-side capacitor,
• an AC power supply apparatus configured to supply AC power of a predetermined operating frequency to the primary-side resonant circuit, and
• a power-transmission-apparatus detection section provided at the primary-side coil or near the primary-side coil;
• and
• the power reception apparatus including
• a secondary-side resonant circuit having a secondary-side coil for power reception, which is to be magnetically coupled with the primary-side coil, and a secondary-side capacitor,
• a load apparatus configured to use electric power outputted from the secondary-side resonant circuit,
• an activation circuit having an activation coil and a pulse generation circuit configured to supply AC current of the operating frequency to the activation coil, and
• a power-transmission-apparatus detecting unit configured to detect the power-transmission-apparatus detection section,
• wherein:
• in response to detection of the power-transmission-apparatus detection section by the power-transmission-apparatus detecting unit, the activation circuit supplies the AC current from the pulse generation circuit to the activation coil;
• and
• the power transmission apparatus further includes a primary-side detection circuit configured to detect a change in a voltage of the primary-side coil, a change in electric current flowing through the primary-side coil or a change in a magnetic field in the vicinity of the primary-side coil, each of the change in the voltage, the change in the electric current and the change in the magnetic field being caused by magnetic flux generated by the activation coil with the supplied AC current.

A power reception apparatus configured to receive, in a contactless manner, electric power transmitted from a power transmission apparatus,

• the power reception apparatus comprising:
• a secondary-side resonant circuit that includes a secondary-side coil for power reception, which is to be magnetically coupled with a primary-side coil for power transmission included in the power transmission apparatus, and a secondary-side capacitor;
• a load apparatus configured to use electric power outputted from the secondary-side resonant circuit;
• and
• a magnetic flux amplifier circuit configured to amplify magnetic flux generated by predetermined standby current flowing through the primary-side coil.

A power reception apparatus configured to receive, in a contactless manner, electric power transmitted from a power transmission apparatus,

• the power reception apparatus comprising:
• a secondary-side resonant circuit that includes a secondary-side coil for power reception, which is to be magnetically coupled with a primary-side coil for power transmission included in the power transmission apparatus, and a secondary-side capacitor;
• a load apparatus configured to use electric power outputted from the secondary-side resonant circuit;
• an activation circuit that includes an activation coil and a pulse generation circuit configured to supply AC current of a predetermined operating frequency to the activation coil;
• and
• a power-transmission-apparatus detecting unit configured to (i) detect a power-transmission-apparatus detection section provided at the primary-side coil or near the primary-side coil and (ii) cause, upon detecting the power-transmission-apparatus detection section, the pulse generation circuit to supply the AC current to the activation coil.