Wireless charging systems, devices, and methods
First Claim
1. A power receiving device comprising:
- a receiving coil configured to produce an input alternating waveform from a received alternating magnetic field emanating from a source external to the power receiving device;
a rectifier coupled to the receiving coil and configured to rectify the input alternating waveform in order to deliver, at an output of the rectifier, power having a rectified voltage;
a loading circuit configured to be selectively coupled to the receiving coil, wherein the power receiving device presents a first load impedance when the loading circuit is uncoupled from the receiving coil, and the power receiving device presents a different, second load impedance when the loading circuit is coupled to the receiving coil; and
a modulation circuit coupled to the output of the rectifier, wherein the modulation circuit produces a modulation signal at a single pre-determined modulation rate as long as the rectified voltage and a first threshold voltage have a first inequality relationship, and the modulation circuit refrains from producing the modulation signal as long as the rectified voltage and the first threshold voltage do not have the first inequality relationship, and wherein the modulation circuit is configured to cause, based on the modulation signal, the loading circuit to be coupled to and uncoupled from the receiving coil at the single pre-determined modulation rate as long as the rectified voltage and the first threshold voltage have the first inequality relationship.
22 Assignments
0 Petitions
Accused Products
Abstract
A wireless charging system includes a power transmitting device and a power receiving device. In the transmitting device, a transmitting coil converts a drive signal from a drive signal circuit into an alternating magnetic field. In the receiving device, a receiving coil produces an alternating waveform from the magnetic field, and a rectifier rectifies the alternating waveform to deliver power having a rectified voltage. A modulation circuit causes a loading circuit to be coupled to and uncoupled from the receiving coil at a pre-determined modulation rate when, for example, the rectified voltage is greater than a threshold voltage. Back in the transmitting device, a modulation detector circuit detects modulation of the load impedance, and when the load impedance is modulating at the pre-determined modulation rate, causes the drive signal circuit to adjust a characteristic of the drive signal, resulting in an adjustment in an intensity of the magnetic field.
32 Citations
24 Claims
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1. A power receiving device comprising:
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a receiving coil configured to produce an input alternating waveform from a received alternating magnetic field emanating from a source external to the power receiving device; a rectifier coupled to the receiving coil and configured to rectify the input alternating waveform in order to deliver, at an output of the rectifier, power having a rectified voltage; a loading circuit configured to be selectively coupled to the receiving coil, wherein the power receiving device presents a first load impedance when the loading circuit is uncoupled from the receiving coil, and the power receiving device presents a different, second load impedance when the loading circuit is coupled to the receiving coil; and a modulation circuit coupled to the output of the rectifier, wherein the modulation circuit produces a modulation signal at a single pre-determined modulation rate as long as the rectified voltage and a first threshold voltage have a first inequality relationship, and the modulation circuit refrains from producing the modulation signal as long as the rectified voltage and the first threshold voltage do not have the first inequality relationship, and wherein the modulation circuit is configured to cause, based on the modulation signal, the loading circuit to be coupled to and uncoupled from the receiving coil at the single pre-determined modulation rate as long as the rectified voltage and the first threshold voltage have the first inequality relationship. - View Dependent Claims (2, 3, 4, 9, 10)
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5. A power receiving device comprising:
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a receiving coil configured to produce an input alternating waveform from a received alternating magnetic field emanating from a source external to the power receiving device; a rectifier coupled to the receiving coil and configured to rectify the input alternating waveform in order to deliver, at an output of the rectifier, power having a rectified voltage; a loading circuit configured to be selectively coupled to the receiving coil, wherein the power receiving device presents a first load impedance when the loading circuit is uncoupled from the receiving coil, and the power receiving device presents a different, second load impedance when the loading circuit is coupled to the receiving coil; and a modulation circuit coupled to the output of the rectifier, wherein the modulation circuit is configured to cause the loading circuit to be coupled to and uncoupled from the receiving coil at a single pre-determined modulation rate as long as the rectified voltage and a first threshold voltage have a first inequality relationship, wherein a reference voltage equal to the first threshold voltage is provided to the modulation circuit, and wherein the modulation circuit comprises; a comparator configured to compare the rectified voltage with the first threshold voltage, and to produce a modulation enable signal having a state that reflects whether the rectified voltage is greater than or less than the first threshold voltage, and a modulator configured to produce a modulation signal that oscillates between first and second signal levels at the pre-determined modulation rate when the modulation enable signal indicates that the rectified voltage is greater than the first reference voltage, and to refrain from producing the modulation signal when the modulation enable signal indicates that the rectified voltage is less than the first reference voltage, wherein the loading circuit is coupled to the receiving coil when the modulation signal has the first signal level, and the loading circuit is not coupled to the receiving coil when the modulation signal has the second signal level. - View Dependent Claims (6, 7, 8)
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11. A power transmitting device comprising:
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a drive signal circuit configured to produce a time-varying drive signal; a transmitting coil coupled to the drive signal circuit, and configured to receive the time-varying drive signal and to convert the time-varying drive signal into an alternating magnetic field that emanates from the power transmitting device; and a modulation detector circuit coupled to the transmitting coil and to the drive signal circuit, wherein the modulation detector circuit is configured to detect modulation of a load impedance that is magnetically coupled with the transmitting coil, to determine whether the load impedance is modulating at a single pre-determined modulation rate, and as long as the load impedance is modulating at the pre-determined modulation rate, to cause the drive signal circuit to adjust a characteristic of the time-varying drive signal, which results in an adjustment in an intensity of the magnetic field emanating from the power transmitting device, and wherein, when the load impedance is modulating at the pre-determined modulation rate, the modulation detector circuit is configured to cause the drive signal circuit to adjust the characteristic in a manner that causes a decrease the intensity of the magnetic field emanating from the power transmitting device. - View Dependent Claims (12, 13, 14)
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15. A system comprising:
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a power transmitting device, which includes a drive signal circuit configured to produce a time-varying drive signal, a transmitting coil coupled to the drive signal circuit, and configured to receive the time-varying drive signal and to convert the time-varying drive signal into an alternating magnetic field that emanates from the power transmitting device, and a modulation detector circuit coupled to the transmitting coil and to the drive signal circuit, wherein the modulation detector circuit is configured to detect modulation of a load impedance that is magnetically coupled with the transmitting coil, to determine whether the load impedance is modulating at a single pre-determined modulation rate, and as long as the load impedance is modulating at the pre-determined modulation rate, to cause the drive signal circuit to adjust a characteristic of the time-varying drive signal, which results in an adjustment in an intensity of the magnetic field emanating from the power transmitting device; and a power receiving device, which includes a receiving coil configured to produce an input alternating waveform from the alternating magnetic field emanating from the power transmitting device, a rectifier coupled to the receiving coil and configured to rectify the input alternating waveform in order to deliver power at an output of the rectifier, a loading circuit configured to be selectively coupled to the receiving coil, wherein the power receiving device presents a first load impedance when the loading circuit is uncoupled from the receiving coil, and the power receiving device presents a different, second load impedance when the loading circuit is coupled to the receiving coil, and a modulation circuit coupled to the output of the rectifier, wherein the modulation circuit produces a modulation signal at a single pre-determined modulation rate as long as the rectified voltage and a first threshold voltage have a first inequality relationship, and the modulation circuit refrains from producing the modulation signal as long as the rectified voltage and the first threshold voltage do not have the first inequality relationship, and wherein the modulation circuit is configured to cause, based on the modulation signal, the loading circuit to be coupled to and uncoupled from the receiving coil at the single pre-determined modulation rate as long as the rectified voltage and a first threshold voltage have the first inequality relationship.
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16. A wireless charging method performed by a power receiving device, the method comprising:
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producing, by a receiving coil, an input alternating waveform from a received alternating magnetic field emanating from a source external to the power receiving device; rectifying the input alternating waveform in order to deliver power having a rectified voltage; comparing the rectified voltage with a first threshold voltage; producing a modulation signal that oscillates between first and second signal levels at a single pre-determined modulation rate as long as the rectified voltage and a first threshold voltage have a first inequality relationship; refraining from producing the modulation signal as long as the rectified voltage and the first threshold voltage do not have the first inequality relationship; and causing, based on the modulation signal, a loading circuit to be coupled to and uncoupled from the receiving coil at the single pre-determined modulation rate as long as the rectified voltage and the first threshold voltage have the first inequality relationship, wherein the power receiving device presents a first load impedance when the loading circuit is uncoupled from the receiving coil, and the power receiving device presents a different, second load impedance when the loading circuit is coupled to the receiving coil. - View Dependent Claims (17, 18, 19, 20)
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21. A wireless charging method performed by a power transmitting device, the method comprising:
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providing a time-varying drive signal to a transmitting coil; converting, by the transmitting coil, the time-varying drive signal into an alternating magnetic field that emanates from the power transmitting device; detecting modulation of a load impedance that is magnetically coupled with the transmitting coil; determining whether the load impedance is modulating at a single pre-determined modulation rate; and as long as the load impedance is modulating at the single pre-determined modulation rate, adjusting a characteristic of the time-varying drive signal that results in an adjustment in an intensity of the magnetic field that emanates from the power transmitting device, wherein, when the load impedance is modulating at the pre-determined modulation rate, adjusting the characteristic of the time-varying drive signal comprises adjusting the characteristic in a manner that causes a decrease in the intensity of the magnetic field emanating from the power transmitting device. - View Dependent Claims (22, 23, 24)
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Specification