Patent ID: 11936200
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A wireless power supply system comprising:
a power transmitter including a power transmission power conversion circuit configured to convert a power transmission direct-current power supply into high-frequency power, a power transmission resonant circuit including a power transmission coil configuring the power transmission power conversion circuit, and a power transmission control circuit configured to control the power transmission power conversion circuit; and
a power receiver including a power reception resonant circuit that includes a power reception coil and can be electromagnetically coupled to the power transmission resonant circuit, a power reception power conversion circuit configured to convert the high-frequency power received by the power reception resonant circuit into a power reception direct-current power supply, and a battery configured to be charged with the power reception direct-current power supply,
wherein
the power receiver includes a power reception control circuit and a power reception resonance modulation circuit, the power reception control circuit including a charge state detection circuit configured to detect a state of charge of the battery and generate a power transmission stop signal based on a state of charge of the battery detected by the charge state detection circuit, the power reception resonance modulation circuit being configured to change resonance conditions by changing an input impedance when the power reception resonant circuit is viewed from the power transmission resonant circuit in response to the power transmission stop signal,
the power transmitter includes an electric variable detection circuit configured to detect an electric variable from the power transmission direct-current power supply due to a change in the resonance conditions,
the power transmission control circuit is configured to demodulate the power transmission stop signal based on the electric variable detected by the electric variable detection circuit and stop an operation of supplying the high-frequency power in the power transmission power conversion circuit for a predetermined period, and
the power reception control circuit in the power receiver is configured to cause the power reception resonance modulation circuit to perform an operation based on generation of the power transmission stop signal at predetermined time intervals while a full-charge state of the battery is detected.