Impedance matching for inductive power transfer systems
First Claim
Patent Images
1. An electromagnetic induction power transfer apparatus comprising:
- an inductive power transmitter, comprising;
a power supply with an active state and an inactive state, configured to switch between the active state and the inactive state at a selectable duty cycle; and
a power-transmitting inductor coupled to the power supply; and
an inductive power receiver, comprising;
a power-receiving inductor, positioned inductively proximate the power-transmitting inductor;
a programmable load; and
an impedance controller coupled to the power receiving inductor and configured to increase or decrease an electrical impedance of the inductive power receiver in response to a change in a power requirement of the programmable load, the impedance controller comprising a synchronous bridge rectifier comprising;
an oscillator having a controllable duty cycle; and
a plurality of switches, each switchable at least in part in response a voltage polarity of the power-receiving inductor and a voltage magnitude of the oscillator.
2 Assignments
0 Petitions
Accused Products
Abstract
Methods and apparatuses for improved efficiency of power transfer across an inductive charging interface by adaptively changing the impedance of the receive coil in response to changes in load conditions during inductive power transfer are disclosed.
-
Citations
9 Claims
-
1. An electromagnetic induction power transfer apparatus comprising:
-
an inductive power transmitter, comprising; a power supply with an active state and an inactive state, configured to switch between the active state and the inactive state at a selectable duty cycle; and a power-transmitting inductor coupled to the power supply; and an inductive power receiver, comprising; a power-receiving inductor, positioned inductively proximate the power-transmitting inductor; a programmable load; and an impedance controller coupled to the power receiving inductor and configured to increase or decrease an electrical impedance of the inductive power receiver in response to a change in a power requirement of the programmable load, the impedance controller comprising a synchronous bridge rectifier comprising; an oscillator having a controllable duty cycle; and a plurality of switches, each switchable at least in part in response a voltage polarity of the power-receiving inductor and a voltage magnitude of the oscillator.
-
-
2. An electromagnetic induction power receiving apparatus comprising:
-
a power-receiving inductor; a programmable load; and an impedance controller coupled to the power-receiving inductor and configured to increase or decrease an electrical impedance of the power-receiving inductor in response to a change in a power requirement of the programmable load, the impedance controller comprising a synchronous bridge rectifier comprising; an oscillator having a controllable duty cycle; and a plurality of switches, each switchable at least in part in response a voltage polarity of the power-receiving inductor and a voltage magnitude of the oscillator.
-
-
3. A method of operating an inductive power receiver associated with a portable electronic device, the method comprising:
-
determining a load condition of the portable electronic device; receiving inductive power from an inductive power transmitter; and adjusting the input impedance of the inductive power receiver with respect to the inductive power transmitter in response to the determined load condition by modifying an operation of a synchronous bridge rectifier configured to rectify the received inductive power, the synchronous bridge rectifier comprising; an oscillator having a controllable duty cycle; and a plurality of switches, each switchable at least in part in response a voltage polarity of the received power and a voltage magnitude of the oscillator. - View Dependent Claims (4, 5, 6, 7, 8, 9)
-
Specification