Sweep frequency for multiple magnetic resonant power transmission using alternating frequencies
First Claim
1. A power transmission pad for wireless power transmission comprising:
- a. a coil;
b. a power transmitter having a sweep frequency generator coupled to the coil to provide a frequency varying signal through the coil, thereby generating a variable magnetic field; and
c. a controller coupled to the coil and to the sweep frequency generator, wherein when multiple portable electronic devices to be charged are positioned within the variable magnetic field, the power transmission pad is configured to determine resonant frequencies for the multiple portable electronic devices each corresponding to a maximum energy transfer from the power transmission pad to a corresponding one of the multiple portable electronic devices, and to cycle a frequency of a power transmission signal through the determined resonant frequencies of the multiple portable electronic devices, wherein the resonant frequencies are determined by sweeping transmission frequencies of the frequency varying signal across a sweep frequency spectrum, monitoring a characteristic of the pad or of the multiple portable electronic devices in response to the variable magnetic field, and selecting specific frequencies according to the monitored characteristic.
1 Assignment
0 Petitions
Accused Products
Abstract
A power transmission pad is configured to provide wireless power transmission to multiple portable electronic devices where each device is orientation-free relative to the pad. The power transmission pad is also configured to be power adaptive by changing the power transmission level depending on the number of devices being concurrently charged. Each device, is placed within the magnetic field for the purpose of charging the device battery. The power transmission pad includes a sweep frequency generator for generating power transmissions across a frequency spectrum. The number of devices to be charged is determined as well as an optimal frequency for maximum energy transfer to each device. The sweep frequency generator is set to cycle through the optimal frequencies determined for each device.
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Citations
32 Claims
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1. A power transmission pad for wireless power transmission comprising:
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a. a coil; b. a power transmitter having a sweep frequency generator coupled to the coil to provide a frequency varying signal through the coil, thereby generating a variable magnetic field; and c. a controller coupled to the coil and to the sweep frequency generator, wherein when multiple portable electronic devices to be charged are positioned within the variable magnetic field, the power transmission pad is configured to determine resonant frequencies for the multiple portable electronic devices each corresponding to a maximum energy transfer from the power transmission pad to a corresponding one of the multiple portable electronic devices, and to cycle a frequency of a power transmission signal through the determined resonant frequencies of the multiple portable electronic devices, wherein the resonant frequencies are determined by sweeping transmission frequencies of the frequency varying signal across a sweep frequency spectrum, monitoring a characteristic of the pad or of the multiple portable electronic devices in response to the variable magnetic field, and selecting specific frequencies according to the monitored characteristic. - View Dependent Claims (2)
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3. A system for wireless power transmission comprising:
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a. multiple portable electronic devices to be charged; and b. a power transmission pad configured to generate a variable magnetic field, wherein when the multiple portable electronic devices are positioned within the variable magnetic field, the power transmission pad is configured to determine resonant frequencies for the multiple portable electronic devices each corresponding to a maximum energy transfer from the power transmission pad to a corresponding one of the multiple portable electronic devices, and to cycle a frequency of a power transmission signal through the determined resonant frequencies of the multiple portable electronic devices, wherein the resonant frequencies are determined by sweeping transmission frequencies of the variable magnetic field across a sweep frequency spectrum, monitoring a system characteristic in response to the variable magnetic field, and selecting the resonant frequencies corresponding to greatest changes in values of the system characteristic, highest values of the system characteristic among monitored values of the system characteristic, or values of the system characteristic exceeding corresponding threshold value levels. - View Dependent Claims (4)
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5. A system for wireless power transmission comprising:
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a. a power transmission pad comprising; i. a first coil; ii. a power transmitter having a sweep frequency generator coupled to the first coil to provide a frequency varying signal through the first coil, thereby generating a variable magnetic field; and iii. a controller coupled to the first coil and to the sweep frequency generator; and b. one or more portable electronic devices to be charged, each portable electronic device comprising; i. a second coil; and ii. a power receiver coupled to the second coil and configured to receive energy transferred from the power transmission pad via the second coil, wherein when the one or more portable electronic devices are positioned within the variable magnetic field generated by the power transmission pad, the controller is configured to determine a numeric total of portable electronic devices positioned within the variable magnetic field, to adjust a power transmission level of a power transmission signal according to the determined numeric total, to determine a resonant frequency for each of the one or more portable electronic devices each corresponding to a maximum energy transfer from the power transmission pad to a corresponding one of the one or more portable electronic devices, and to cycle a frequency of the power transmission signal through the determined resonant frequencies of the one or more portable electronic devices, wherein when one of the one or more portable electronic devices becomes fully charged, is removed from the variable magnetic field, or a new portable electronic device is positioned within the variable magnetic field, the power transmission pad is configured to re-calibrate the power transmission level by determining an updated numeric total of portable electronic devices to be charged, and to adjust the power transmission level according to the determined updated numeric total. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of wireless power transmission between a power transmission pad and multiple portable electronic devices to be charged, the method comprising:
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a. configuring the power transmission pad with a first coil and a sweep frequency generator, and each of the multiple portable electronic devices with a corresponding second coil; b. generating a variable magnetic field by applying the sweep frequency generator to the first coil; c. measuring one or more system characteristics in response to the variable magnetic field; d. determining a resonant frequency of each of the multiple portable electronic devices according to the measured one or more system characteristics; e. cycling a frequency of a power transmission signal through the determined resonant frequencies of the multiple portable electronic devices; and f. transmitting the power transmission signal from the power transmission pad to the multiple portable electronic devices. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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Specification