POWER TRANSMISSION DEVICE AND WIRELESS POWER TRANSMISSION SYSTEM
First Claim
1. A power transmission device that applies an alternating-current voltage to a first power-transmission-side electrode, which is adapted to oppose a first power-reception-side electrode of a power reception device with a gap therebetween when the power reception device is placed in an operative relationship with the power transmission device, and to a second power-transmission-side electrode, which opposes a second power-reception-side electrode of the power reception device with a gap therebetween when the power reception device is placed in the operative relationship with the power transmission device, and transmits power to the power reception device via electric field coupling, the power transmission device comprising:
- a first voltage monitoring unit that monitors a voltage of the first power-transmission-side electrode;
a first change detection unit that detects a change in the voltage monitored by the first voltage monitoring unit at regular time intervals;
a second voltage monitoring unit that monitors a voltage of the second power-transmission-side electrode;
a second change detection unit that detects a change in the voltage monitored by the second voltage monitoring unit at the regular time intervals; and
a power transmission stopping unit that stops transmission of power to the power reception device as a function of the changes detected by the first and second change detection units.
1 Assignment
0 Petitions
Accused Products
Abstract
A power transmission device includes an AC power generator for generating an AC voltage and applying it to first and second power transmission electrodes. A controller controls the AC voltage applied to the first and second power transmission electrodes. To this end, the controller monitors the voltage on the first electrode and determines how that voltage changes at the beginning and end of each of a plurality of predetermined time intervals, monitors the voltage on the second electrode and determines how that voltage changes at the beginning and end of each of the plurality of predetermined time intervals, and determines when to cut off the application of the AC voltage to the first and second power transmission electrodes as a function of the manner in which the voltage on those electrodes changes at the beginning and end of at least one of the predetermined time intervals.
7 Citations
14 Claims
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1. A power transmission device that applies an alternating-current voltage to a first power-transmission-side electrode, which is adapted to oppose a first power-reception-side electrode of a power reception device with a gap therebetween when the power reception device is placed in an operative relationship with the power transmission device, and to a second power-transmission-side electrode, which opposes a second power-reception-side electrode of the power reception device with a gap therebetween when the power reception device is placed in the operative relationship with the power transmission device, and transmits power to the power reception device via electric field coupling, the power transmission device comprising:
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a first voltage monitoring unit that monitors a voltage of the first power-transmission-side electrode; a first change detection unit that detects a change in the voltage monitored by the first voltage monitoring unit at regular time intervals; a second voltage monitoring unit that monitors a voltage of the second power-transmission-side electrode; a second change detection unit that detects a change in the voltage monitored by the second voltage monitoring unit at the regular time intervals; and a power transmission stopping unit that stops transmission of power to the power reception device as a function of the changes detected by the first and second change detection units. - View Dependent Claims (2, 3)
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4. A wireless power transmission system comprising:
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a power transmission device including a first and second power-transmission-side electrodes, and a DC to AC inversion circuit that converts a direct-current voltage into an alternating-current voltage and applies the voltage between the first and second power-transmission-side electrodes; and a power reception device including a first power-reception-side electrode that opposes the first power-transmission-side electrode with a gap therebetween, a second power-reception-side electrode that opposes the second power-transmission-side electrode with a gap therebetween, and a voltage supply circuit that supplies a voltage induced between the first power-reception-side electrode and the second power-reception-side electrode to a load; wherein the power transmission device includes; a first voltage monitoring unit that monitors a voltage of the first power-transmission-side electrode; a first change detection unit that detects a change in the voltage monitored by the first voltage monitoring unit at regular time intervals; a second voltage monitoring unit that monitors a voltage of the second power-transmission-side electrode; a second change detection unit that detects a change in the voltage monitored by the second voltage monitoring unit at regular time intervals; and a power transmission stopping unit that stops transmission of power to the power reception device as a function of the changes detected by the first and second change detection units.
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5. A power transmission device, comprising:
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first and second electrodes for transmitting power to a power receiving device placed in an operational relationship with the first and second electrodes; an AC power generator for generating an AC voltage and applying it to the first and second electrodes; a controller for controlling the AC voltage applied to the first and second electrodes, the controller; monitoring the voltage on the first electrode and determining how that voltage changes at the beginning and end of each of a plurality of predetermined time intervals; monitoring the voltage on the second electrode and determining how that voltage changes at the beginning and end of each of the plurality of predetermined time intervals; and determining when to cut off the application of the AC voltage to the first and second electrodes as a function of the manner in which the voltage on the first and second electrodes changes at the beginning and end of at least one of the predetermined time intervals. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification