CHARGE CURRENT MONITORING OR CONTROL IN A RESONANCE-TUNED INDUCTIVE CHARGER
First Claim
1. A battery charger for magnetically transferring power from a power source to a battery, the battery charger comprising:
- a driver circuit couplable to the power source, the driver circuit configured to output a modulated signal with energy from the power source, wherein the modulated signal has a duty cycle;
a sender-side tuned circuit magnetically couplable across a space to a receiver-side tuned circuit of a portable handheld electronic device, wherein the sender-side tuned circuit is configured to have a resonant frequency near or equal to the receiver-side tuned circuit;
a sender-side sensor configured to sense a parameter of the sender-side tuned circuit; and
a controller coupled to the driver circuit and to the sender-side sensor, wherein the controller is configured to;
cause the driver circuit to output a modulated signal at a first duty cycle and at a frequency near or equal to the resonance frequency of at least one of the sender-side tuned circuit and the receiver-side tuned circuit, andmodify the first duty cycle of the modulated signal based on the sensed parameter of the sender-side tuned circuit.
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Accused Products
Abstract
A battery charger and methods for magnetically transferring power from a power source to a battery is disclosed. A driver circuit outputs a modulated signal having a duty cycle from the power source to a sender-side circuit and across a space to a receiver-side tuned circuit. A sender-side sensor is configured to sense a parameter of the sender-side tuned circuit. The controller modifies the first duty cycle of the modulated signal based on the sensed parameter. A receiver-side circuit capable of determining charge status of the receiver side is also disclosed.
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Citations
22 Claims
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1. A battery charger for magnetically transferring power from a power source to a battery, the battery charger comprising:
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a driver circuit couplable to the power source, the driver circuit configured to output a modulated signal with energy from the power source, wherein the modulated signal has a duty cycle; a sender-side tuned circuit magnetically couplable across a space to a receiver-side tuned circuit of a portable handheld electronic device, wherein the sender-side tuned circuit is configured to have a resonant frequency near or equal to the receiver-side tuned circuit; a sender-side sensor configured to sense a parameter of the sender-side tuned circuit; and a controller coupled to the driver circuit and to the sender-side sensor, wherein the controller is configured to; cause the driver circuit to output a modulated signal at a first duty cycle and at a frequency near or equal to the resonance frequency of at least one of the sender-side tuned circuit and the receiver-side tuned circuit, and modify the first duty cycle of the modulated signal based on the sensed parameter of the sender-side tuned circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of transferring power from a sender-side circuit to a receiver-side circuit to charge a battery on the receiver-side, the method comprising:
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starting an energizing cycle by modulating a voltage provided by a power source through an inductor of the sender-side circuit, wherein the modulated voltage has a constant predetermined frequency and a first duty cycle; determining a voltage level variable corresponding to a voltage sensed by a voltage sensor at a high-side of the sender-side inductor; comparing the determined voltage level variable to a predetermined threshold voltage level; and modifying the duty cycle of the modulated voltage based on the comparison of the determined voltage level variable to the predetermined threshold voltage level. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A receiver-side charging circuit coupled to a portable device, the receiver-side circuit capable of determining charge status, the receiver-side charging circuit comprising:
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a tuned circuit having a resonance frequency; and a receiver-side sensor coupled to an input of a controller and configured to sense a parameter of the tuned circuit, wherein the tuned circuit is couplable to a battery and inductively couplable across a space to a sender-side circuit having substantially similar resonance frequency, and wherein the controller is configured to cause an indication that charging is not occurring if the sensed parameter is below a threshold level. - View Dependent Claims (22)
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Specification