SELF-TUNING DRIVE SOURCE EMPLOYING INPUT IMPEDANCE PHASE DETECTION
First Claim
1. A source device configured to cooperate with an untethered device comprising a resonant circuit, the source device comprising:
- a driver circuit configured to generate a varying magnetic field and comprising a drive coil circuit;
a phase detector coupled to the driver circuit and configured to detect a phase of an input impedance of the driver circuit in response to the source device inductively coupling with the resonant circuit of the untethered device; and
a controller coupled to the phase detector and the driver circuit, the controller configured to adjust a frequency of a source voltage applied to the driver circuit in response to an output signal of the phase detector, the controller adjusting the source voltage frequency so that the phase of the input impedance as indicated by the output signal of the phase detector is substantially zero.
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Accused Products
Abstract
An untethered device is configured to inductively couple to a source device. The source device includes a driver circuit configured to generate a varying magnetic field and comprising a drive coil circuit. A phase detector is coupled to the driver circuit and configured to detect a phase of an input impedance of the driver circuit in response to the source device inductively coupling with the resonant circuit of the untethered device. A controller is coupled to the phase detector and the driver circuit, and is configured to adjust a frequency of a source voltage applied to the driver circuit in response to an output signal of the phase detector. The controller adjusts the source voltage frequency so that the phase of the input impedance as indicated by the output signal of the phase detector is substantially zero.
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Citations
20 Claims
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1. A source device configured to cooperate with an untethered device comprising a resonant circuit, the source device comprising:
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a driver circuit configured to generate a varying magnetic field and comprising a drive coil circuit; a phase detector coupled to the driver circuit and configured to detect a phase of an input impedance of the driver circuit in response to the source device inductively coupling with the resonant circuit of the untethered device; and a controller coupled to the phase detector and the driver circuit, the controller configured to adjust a frequency of a source voltage applied to the driver circuit in response to an output signal of the phase detector, the controller adjusting the source voltage frequency so that the phase of the input impedance as indicated by the output signal of the phase detector is substantially zero. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A system, comprising:
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an untethered device comprising a resonant circuit; and a source device configured to inductively couple to the untethered device, the source device comprising; a driver circuit configured to generate a varying magnetic field and comprising a drive coil circuit; a phase detector coupled to the driver circuit and configured to detect a phase of an input impedance of the driver circuit in response to inductively coupling the source device and the untethered device; and a controller coupled to the phase detector and the driver circuit, the controller configured to adjust a frequency of a source voltage applied to the driver circuit in response to an output signal of the phase detector, the controller adjusting the source voltage frequency so that the phase of the input impedance as indicated by the output signal of the phase detector is substantially zero. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A method implemented in a source device configured to inductively couple to an untethered device having a resonant circuit, the method comprising:
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driving a drive coil circuit of the source device with a source voltage having an adjustable frequency, the drive coil circuit generating a varying magnetic field; detecting a phase of an input impedance of the drive coil circuit in response to inductively coupling the source device and the untethered device; and adjusting the source voltage frequency so that the phase of the input impedance of the drive coil circuit is substantially zero. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification