Wireless power receiver and/or foreign object detection by a wireless power transmitter
First Claim
Patent Images
1. A wireless power transmitter, comprising:
- a power train comprising at least one transistor coupled to an LC tank circuit;
an analog-to-digital converter (ADC) coupled to receive and convert an analog signal associated with the power train to digital values;
a controller coupled to the tank circuit and being configured to;
cause pulses generated by the controller to be applied to the at least one transistor of the power train to thereby cause the LC tank circuit of the power train to begin ringing;
receive digital values from the ADC acquired while the power train is ringing and after the pulses are completed; and
based on an analysis of the digital values of the ringing of the power train, to determine whether a wireless power receiver is present on or near the wireless power transmitter or whether a foreign object is present on or near the wireless power transmitter.
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Abstract
A wireless power transmitter includes an analog-to-digital converter (ADC) and a controller. The ADC is configured to convert an analog signal associated with a power train to digital values. The controller is configured to cause pulses to be applied to the power train to thereby cause the power train to ring, receive digital values from the ADC acquired while the power train is ringing and after the pulses complete, and, based on an analysis of the digital values of the ringing of the power train, to determine whether a wireless power receiver is present on or near the wireless power transmitter or whether a foreign object is present on the transmitter.
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Citations
22 Claims
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1. A wireless power transmitter, comprising:
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a power train comprising at least one transistor coupled to an LC tank circuit; an analog-to-digital converter (ADC) coupled to receive and convert an analog signal associated with the power train to digital values; a controller coupled to the tank circuit and being configured to; cause pulses generated by the controller to be applied to the at least one transistor of the power train to thereby cause the LC tank circuit of the power train to begin ringing; receive digital values from the ADC acquired while the power train is ringing and after the pulses are completed; and based on an analysis of the digital values of the ringing of the power train, to determine whether a wireless power receiver is present on or near the wireless power transmitter or whether a foreign object is present on or near the wireless power transmitter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A wireless power transmitter, comprising:
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a power train comprising at least one transistor coupled to an LC tank circuit; an analog-to-digital converter (ADC) coupled to receive and convert an analog signal associated with the power train to digital values; a controller coupled to the tank circuit and being configured to cause pulses generated by the controller to be applied to the at least one transistor of the power train to thereby cause the LC tank circuit of the power train to ring at a resonant frequency, to receive digital values from the ADC acquired while the power train is ringing, the digital values indicative of the ringing, to compute a value indicative of a duration of the ringing, a decay rate of the ringing and a peak amplitude at a beginning of a ringing period, and to; determine that no wireless power receiver nor foreign object is present on or near the wireless power transmitter if the value indicative of the duration of the ringing is greater than an empty wireless power transmitter duration threshold; determine that a foreign object is present on or near the wireless power transmitter if the value indicative of the duration is less than the empty wireless power transmitter duration threshold, the decay rate is greater than a decay rate threshold, and the peak amplitude is greater than a peak amplitude threshold; and determine that a wireless power receiver is present on or near the wireless power transmitter with no foreign object if the value indicative of the duration is less than the empty wireless power transmitter duration threshold, and at least one of the decay rate is less than the decay rate threshold or the peak amplitude is less than the peak amplitude threshold. - View Dependent Claims (12, 13)
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14. A method, comprising:
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pinging a wireless charging power train comprising at least one transistor and an LC tank circuit with a plurality of pulses to thereby cause the LC tank circuit of the power train to ring; and determining whether a wireless power receiver is present on or near a wireless power transmitter or whether a foreign object is present on the wireless power transmitter based on values computed from the power train ringing. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. A wireless power transmitter, comprising:
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a power train comprising at least one transistor coupled to an LC tank circuit; an analog-to-digital converter (ADC) coupled to receive and convert an analog signal associated with the power train to digital values; a pulse generator coupled to the tank circuit and being configured to; cause pulses generated by the pulse generator to be applied to the at least one transistor of the power train to thereby cause the LC tank circuit of the power train to begin ringing; receive digital values from the ADC acquired while the LC tank circuit of the power train is ringing and after the pulses are completed; and based on an analysis of the digital values of the ringing of the power train, to determine whether a wireless power receiver is present on or near the wireless power transmitter or whether a foreign object is present on or near the wireless power transmitter.
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22. A wireless power transmitter, comprising:
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a power train comprising at least one transistor coupled to an LC tank circuit; an analog-to-digital converter (ADC) coupled to receive and convert an analog signal associated with the power train to digital values; a pulse generator coupled to the tank circuit and being configured to cause pulses generated by the pulse generator to be applied to the at least one transistor of the power train to thereby cause the LC tank circuit of the power train to ring at a resonant frequency, to receive digital values from the ADC acquired while the power train is ringing, the digital values indicative of the ringing, to compute a value indicative of a duration of the ringing, a decay rate of the ringing and a peak amplitude at a beginning of a ringing period, and to; determine that no wireless power receiver nor foreign object is present on or near the wireless power transmitter if the value indicative of the duration of the ringing is greater than an empty wireless power transmitter duration threshold; determine that a foreign object is present on or near the wireless power transmitter if the value indicative of the duration is less than the empty wireless power transmitter duration threshold, the decay rate is greater than a decay rate threshold, and the peak amplitude is greater than a peak amplitude threshold; and determine that a wireless power receiver is present on or near the wireless power transmitter with no foreign object if the value indicative of the duration is less than the empty wireless power transmitter duration threshold, and at least one of the decay rate is less than the decay rate threshold or the peak amplitude is less than the peak amplitude threshold.
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Specification