Wireless power supply apparatus
First Claim
1. A wireless power supply apparatus comprising:
- a power transmitter unit including a direct-current power source that supplies electric energy and a power transmitter coil electrically connected to the direct-current power source;
a power receiver unit including a load that consumes electric energy and a power receiver coil electrically connected to the load;
a power transmitter resonance circuit composed of an inductive impedance of the power transmitter coil and a parasitic capacitance of the power transmitter coil or a capacitive impedance of a resonance capacitor formed of an external capacitor;
a power transmitter switching circuit including a switch element and a switching control circuit, the switch element being electrically connected to the power transmitter resonance circuit and intermittently applying the direct-current power source to the power transmitter resonance circuit based on an on-and-off switching operation, the switching control circuit controlling the switch element and allowing the power transmitter resonance circuit to create a resonance current therein;
a power receiver resonance circuit composed of an inductive impedance of the power receiver coil and a parasitic capacitance of the power receiver coil or a capacitive impedance of a resonance capacitor formed of an external capacitor; and
a power receiver load circuit that is electrically connected to the power receiver resonance circuit and supplies electric energy due to the resonance current to the load, whereinthe power transmitter unit and the power receiver unit are arranged in separate spaces,the power transmitter coil extracts electric energy from the direct-current power source based on an operation of the power transmitter switching circuit and creates the resonance current;
directly creates an electromagnetic field that periodically varies at a switching frequency fs due to the resonance current; and
forms an electromagnetic resonant field where a space vibrates with energy,the power receiver coil creates a resonance current by obtaining electric energy from the resonant field and further forms a new electromagnetic resonant field based on the resonance current, andthe switching control circuit is configured to control the switch element so that the switching frequency fs is set such that an imaginary part X is 0 or substantially 0, the imaginary part X being an imaginary part of an equivalent input impedance when a whole load side is viewed from an input of the power transmitter resonance circuit, to which the power transmitter switching circuit is connected.
1 Assignment
0 Petitions
Accused Products
Abstract
A power transmitter coil, a power transmitter circuit, and a direct-current power source constitute a power transmitter unit. Further, a power receiver coil, a power receiver circuit, and a load constitute a power receiver unit. Further, a resonator coil and a resonator circuit constitute a resonator unit. In the power transmitter unit, electric energy of the direct-current power source is directly converted into electromagnetic energy, a resonant field is expanded by making resonance currents of the same frequency to flow in the power transmitter coil and the resonator coil, and in the power receiver unit, electromagnetic energy of the resonant field is directly converted into electric energy, thereby transmitting electric power from the power transmitter unit to the power receiver unit.
-
Citations
26 Claims
-
1. A wireless power supply apparatus comprising:
-
a power transmitter unit including a direct-current power source that supplies electric energy and a power transmitter coil electrically connected to the direct-current power source; a power receiver unit including a load that consumes electric energy and a power receiver coil electrically connected to the load; a power transmitter resonance circuit composed of an inductive impedance of the power transmitter coil and a parasitic capacitance of the power transmitter coil or a capacitive impedance of a resonance capacitor formed of an external capacitor; a power transmitter switching circuit including a switch element and a switching control circuit, the switch element being electrically connected to the power transmitter resonance circuit and intermittently applying the direct-current power source to the power transmitter resonance circuit based on an on-and-off switching operation, the switching control circuit controlling the switch element and allowing the power transmitter resonance circuit to create a resonance current therein; a power receiver resonance circuit composed of an inductive impedance of the power receiver coil and a parasitic capacitance of the power receiver coil or a capacitive impedance of a resonance capacitor formed of an external capacitor; and a power receiver load circuit that is electrically connected to the power receiver resonance circuit and supplies electric energy due to the resonance current to the load, wherein the power transmitter unit and the power receiver unit are arranged in separate spaces, the power transmitter coil extracts electric energy from the direct-current power source based on an operation of the power transmitter switching circuit and creates the resonance current;
directly creates an electromagnetic field that periodically varies at a switching frequency fs due to the resonance current; and
forms an electromagnetic resonant field where a space vibrates with energy,the power receiver coil creates a resonance current by obtaining electric energy from the resonant field and further forms a new electromagnetic resonant field based on the resonance current, and the switching control circuit is configured to control the switch element so that the switching frequency fs is set such that an imaginary part X is 0 or substantially 0, the imaginary part X being an imaginary part of an equivalent input impedance when a whole load side is viewed from an input of the power transmitter resonance circuit, to which the power transmitter switching circuit is connected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
-
Specification