Tunable synchronous rectifier
View Patent ↗A system for power transfer is provided. In one exemplary embodiment, the system includes an inductive power device, such as a device that transmits or receives power over an inductive coupling. For example, an adjustable impedance is coupled to the inductive power device, where the adjustable impedance is used for dynamically controlling the power gain in the inductive power device, such as by damping power generated by circuit impedances, such as inductances, capacitances or resistances, and combinations thereof.
1. A system for power transfer comprising:
an inductive power device;
an adjustable impedance coupled to the inductive power device, the adjustable impedance for dynamically controlling the gain in the inductive power device; and
an impedance controller for setting an impedance value of the adjustable impedance, wherein the impedance controller is configured to periodically determine whether optimized power is present in a received power signal and to adjust the impedance value of the adjustable impedance to reduce attenuation of the received power signal.
2. The system of claim 1 further comprising a receiver coupled to the inductive power device, wherein the receiver is configured to receive a power signal and generate a control signal for the adjustable impedance in response to the power signal.
3. The system of claim 2 wherein the receiver further comprises a power monitor for determining whether optimized power is present in the load.
4. The system of claim 3 wherein the power monitor further comprises a current and voltage monitor.
5. The system of claim 1 further comprising a transmitter coupled to the inductive power device, wherein the transmitter is configured to transmit a power signal and receive a control signal for the adjustable impedance in response to the power signal.
6. The system of claim 1 wherein the impedance controller is configured to vary the adjustable impedance based on an algorithm so as to optimize the impedance value of the adjustable impedance to reduce ringing without excessive attenuation of a received signal.
7. The system of claim 1 wherein the impedance controller is configured to periodically determine whether ringing is present in a received power signal and to adjust the impedance value of the adjustable impedance to reduce the ringing if ringing is present.
8. The system of claim 1 wherein the inductive power device comprises one of a cellular telephone, a computer device, a meter reading data, a computer peripheral, a camera, a portable storage device, a calculator or a telemetry device.
9. A system for power transfer comprising:
an inductive power device, the inductive power device including a plurality of coupling inductances and a plurality of capacitances;
an adjustable impedance coupled to the inductive power device, the adjustable impedance for controlling power gain in the inductive power device, wherein optimized power to a load is generated by one or more of the plurality of coupling inductances and the plurality of capacitances;
a receiver coupled to the inductive power device, wherein the receiver is configured to receive a power signal and generate a control signal for the adjustable impedance in response to the power signal;
a power monitor for determining whether optimized power is present at the load; and
an impedance controller for setting an impedance value of the adjustable impedance, wherein the impedance controller comprises means for varying the adjustable impedance to optimize the impedance value of the adjustable impedance to reduce ringing without excessive attenuation of a received signal.
10. A method for receiving power comprising:
receiving a power signal at an inductive power device;
dynamically adjusting an impedance value of an adjustable impedance circuit coupled to the inductive power device to control power gain in the inductive power device;
generating a control signal for adjusting the adjustable impedance in response to the power signal;
determining whether ringing is present in the power signal after adjusting the adjustable impedance; and
modifying the control signal if ringing is present in the power signal.
11. The method of claim 10 wherein determining whether ringing is present in the power signal comprises determining whether an optimized power is present in the power signal.
12. The method of claim 10 wherein dynamically adjusting the impedance value comprises adjusting the adjustable impedance circuit coupled to the inductive power device to control tuning in the inductive power device.
13. A method for receiving power comprising:
receiving a power signal at an inductive power device;
dynamically adjusting an impedance value of an adjustable impedance circuit coupled to the inductive power device to control power gain in the inductive power device; and
decreasing the adjustable impedance to reduce ringing.
14. A method for receiving power comprising:
receiving a power signal at an inductive power device;
dynamically adjusting an impedance value of an adjustable impedance circuit coupled to the inductive power device to control power gain in the inductive power device; and
increasing the adjustable impedance to reduce attenuation of the power signal.
15. A method for receiving power comprising:
receiving a power signal at an inductive power device;
dynamically adjusting an impedance value of an adjustable impedance circuit coupled to the inductive power device to control power gain in the inductive power device;
periodically determining whether optimized power is present in the power signal; and
adjusting the impedance value of the adjustable impedance to optimize power to the load.
16. A method for receiving power comprising:
receiving a power signal at an inductive power device;
dynamically adjusting an impedance value of an adjustable impedance circuit coupled to the inductive power device to control power gain in the inductive power device;
periodically determining whether ringing is present in the received power signal; and
adjusting the impedance value of the adjustable impedance to reduce attenuation of the received power signal if ringing is not present.
17. A system for power transfer comprising:
an inductive power device;
an adjustable impedance coupled to the inductive power device, the adjustable impedance for dynamically controlling the gain in the inductive power device; and
an impedance controller for setting an impedance value of the adjustable impedance, wherein the impedance controller is configured to periodically determine whether ringing is present in a received power signal and to adjust the impedance value of the adjustable impedance to reduce the ringing if ringing is present.
18. The system of claim 17 further comprising a receiver coupled to the inductive power device, wherein the receiver is configured to receive a power signal and generate a control signal for the adjustable impedance in response to the power signal.
19. The system of claim 18 wherein the receiver further comprises a power monitor for determining whether optimized power is present in the load.