INDUCTIVE POWER RECEIVER

• US 20180159378A1
• Filed: 05/19/2016
• Published: 06/07/2018
• Est. Priority Date: 05/19/2015
• Status: Abandoned Application

• Current Assignee: Apple Inc.
• Original Assignee: PowerbyProxi (Apple Inc.)
• Inventors: Chen, Liang, Kumar, Arunim, Qin, Aijun
• Application Number:
  US15/575,319
• Publication Number:
  US 20180159378A1
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02M 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

An inductive power receiver comprising: a power receiving coil; a power regulation stage, configured to connect in parallel with the power receiving coil, and a tuning capacitance configured to connect in series between the power receiving coil and a rectification stage and/or a load, wherein the power regulator is configured with a short circuit control strategy.

Claims

1. An inductive power receiver comprising:

a power receiving coil;

a power regulation stage, configured to connect in parallel with the power receiving coil, and

a tuning capacitance configured to connect in series between the power receiving coil and a rectification stage and/or a load, wherein the power regulator is configured with a short circuit control strategy.

2. The inductive power receiver in claim 1 wherein the power regulation stage is configured to connect between the coil and the series tuning capacitance.

3. The inductive power receiver in claim 1 wherein the power regulation stage comprises an AC switch.

4. The inductive power receiver as claimed in claim 1 wherein the AC switch includes back to back MOSFETs with a common gate and a common source.

5. The inductive power receiver in claim 2 wherein the AC switch is configured for zero voltage switch on and zero voltage switch off.

6. The inductive power receiver in claim 1 wherein the series tuning capacitance comprises two capacitors, each configured to connect between the power regulation stage and respective input terminals of a power rectification stage.

7. The inductive power receiver claim 3 wherein the shunt regulation strategy relates to determining the on time of the AC switch for each cycle at an inductive power transfer signal frequency, based on a load requirement.

8. The inductive power receiver in claim 1 further comprising a further tuning capacitor configured to connect in parallel with the power receiving coil.

9. The inductive power receiver in claim 8 wherein the parallel tuning capacitor is configured to provide a resonant frequency for a communications signal, and the series tuning capacitance is configured to provide a resonant frequency for an inductive power transfer signal.

10. An inductive power receiver comprising:

a power receiving coil and a tuning capacitance forming a resonant circuit;

a rectifier receiving an AC input from the resonant circuit and providing a DC output at its output terminals; and

a power regulation stage, configured to selectively connect the resonant circuit to an output terminal of the rectifier to achieve power flow control.

11. The inductive power receiver as claimed in claim 10 wherein the power regulation stage is connected directly to a terminal of the power receiving coil.

12. The inductive power receiver in claim 11 wherein, when switched in, the power regulation stage connects the power receiving coil to a negative output of the rectifier.

13. The inductive power receiver as claimed in claim 10 wherein the power regulation stage comprises a diode and a semiconductor switch in series.

14. The inductive power receiver as claimed in claim 10 including a controller which switches the power regulation stage based upon the DC output voltage of the receiver.

15. The inductive power receiver as claimed in claim 14 wherein the controller switches synchronously with the resonant frequency of the resonant circuit.

16. The inductive power receiver as claimed in claim 14 wherein the controller is a PID controller.

17. The inductive power receiver as claimed claim 10 wherein the resonant circuit is a series resonant circuit.

18. The inductive power receiver as claimed in claim 10 wherein the resonant circuit is a parallel resonant circuit.