Resonant wireless power transmitter circuit and control circuit and control method thereof
First Claim
1. A resonant wireless power transmitter circuit having an input impedance, comprising:
- a driver circuit, which is coupled to a power supply, wherein the driver circuit includes at least a power switch which is controlled by a switching time signal to switch at a pre-determined resonant frequency;
a switching resonant control circuit, which is coupled to the driver circuit, and configured to control the driver circuit such that the driver circuit operates at the pre-determined resonant frequency;
an adjustable impedance matching circuit, which is coupled to the driver circuit, wherein the adjustable impedance matching circuit includes at least one varactor, and has an impedance;
a transmitter circuit, which is coupled to the adjustable impedance matching circuit and the driver circuit, wherein the transmitter circuit includes at least a transmitter coil, wherein the power switch of the driver circuit is configured to switch with the resonant frequency to periodically conduct the power supply to drive the transmitter coil; and
an impedance control circuit, which is coupled to the driver circuit and the adjustable impedance matching circuit, and configured to operably generate an analog impedance control signal to control a reactance of the varactor in continuous analog form so as to control the impedance of the adjustable impedance matching circuit such that the input impedance of the resonant wireless power transmitter circuit is matched at the pre-determined frequency, wherein the reactance of the varactor is continuously adjustable in analog form;
wherein when the input impedance of the resonant wireless power transmitter circuit is matched at the pre-determined frequency, a current of the power switch supplies a half cycle of a resonant sinewave current, wherein the resonant sinewave current flows through the transmitter coil;
wherein the impedance control circuit is configured to operably generate the impedance control signal according to the switching time signal of the power switch and a signal related to the current of the power switch, wherein the switching time signal carries information of the switching time point of the power switch.
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Accused Products
Abstract
The present invention discloses a resonant wireless power transmitter circuit, which has an input impedance. The resonant wireless power transmitter circuit includes: a driver circuit coupled with a power supply, which includes at least a power switch; a switching resonant control circuit coupled with the driver circuit, such that the driver operates at a pre-determined or a variable resonant frequency; an adjustable impedance matching circuit coupled with the driver circuit, which includes at least a varactor; a transmitter circuit coupled with the impedance matching circuit and the driver circuit, which includes at least a transmitter coil; and an impedance control circuit coupled with the adjustable impedance matching circuit and the driver circuit, which provides an impedance control signal to control the reactance of the varactor, such that the input impedance of the resonant wireless power transmitter circuit is matched at the pre-determined or the variable resonant frequency.
9 Citations
19 Claims
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1. A resonant wireless power transmitter circuit having an input impedance, comprising:
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a driver circuit, which is coupled to a power supply, wherein the driver circuit includes at least a power switch which is controlled by a switching time signal to switch at a pre-determined resonant frequency; a switching resonant control circuit, which is coupled to the driver circuit, and configured to control the driver circuit such that the driver circuit operates at the pre-determined resonant frequency; an adjustable impedance matching circuit, which is coupled to the driver circuit, wherein the adjustable impedance matching circuit includes at least one varactor, and has an impedance; a transmitter circuit, which is coupled to the adjustable impedance matching circuit and the driver circuit, wherein the transmitter circuit includes at least a transmitter coil, wherein the power switch of the driver circuit is configured to switch with the resonant frequency to periodically conduct the power supply to drive the transmitter coil; and an impedance control circuit, which is coupled to the driver circuit and the adjustable impedance matching circuit, and configured to operably generate an analog impedance control signal to control a reactance of the varactor in continuous analog form so as to control the impedance of the adjustable impedance matching circuit such that the input impedance of the resonant wireless power transmitter circuit is matched at the pre-determined frequency, wherein the reactance of the varactor is continuously adjustable in analog form; wherein when the input impedance of the resonant wireless power transmitter circuit is matched at the pre-determined frequency, a current of the power switch supplies a half cycle of a resonant sinewave current, wherein the resonant sinewave current flows through the transmitter coil; wherein the impedance control circuit is configured to operably generate the impedance control signal according to the switching time signal of the power switch and a signal related to the current of the power switch, wherein the switching time signal carries information of the switching time point of the power switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 19)
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10. A method for controlling a resonant wireless power transmitter circuit which has an input impedance, wherein the resonant wireless power transmitter circuit comprises:
- a driver circuit, which is coupled to a power supply, wherein the driver circuit includes at least a power switch which is controlled by a switching time signal to switch at a pre-determined resonant frequency;
a switching resonant control circuit, which is coupled to the driver circuit, and configured to control the driver circuit such that the driver circuit operates at the pre-determined resonant frequency; and
an adjustable impedance matching circuit, which is coupled to the driver circuit, wherein the adjustable impedance matching circuit includes at least one varactor, and has an impedance; and
a transmitter circuit, which is coupled to the adjustable impedance matching circuit and the driver circuit, wherein the transmitter circuit includes at least a transmitter coil, wherein the power switch of the driver circuit is configured to switch with the resonant frequency to periodically conduct the power supply to drive the transmitter coil;
the control method comprising;generating an analog impedance control signal; and controlling a reactance of the varactor in continuous analog form according to the analog impedance control signal so as to control the impedance of the adjustable impedance matching circuit such that the input impedance of the resonant wireless power transmitter circuit is matched at the pre-determined frequency, wherein the reactance of the varactor is continuously adjustable in analog form; wherein when the input impedance of the resonant wireless power transmitter circuit is matched at the pre-determined frequency, a current of the power switch supplies a half cycle of a resonant sinewave current, wherein the resonant sinewave current flows through the transmitter coil; wherein the impedance control signal is generated according to the switching time signal of the power switch and a signal related to the current of the power switch, wherein the switching time signal carries information of the switching time point of the power switch. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
- a driver circuit, which is coupled to a power supply, wherein the driver circuit includes at least a power switch which is controlled by a switching time signal to switch at a pre-determined resonant frequency;
Specification