Wireless Charging System with Auto-Detection

• US 20150115883A1
• Filed: 10/29/2014
• Published: 04/30/2015
• Est. Priority Date: 10/29/2013
• Status: Active Grant

• Current Assignee: GZ Electronic Company Limited
• Original Assignee: Knowmax Technology Ltd.
• Inventors: Huang, Kuo-Chan, Li, Che-Ying
• Granted Patent: US 9,716,400 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

A wireless charging system with auto-detection with an inductive loop for detecting an induced electric field resulted from the approach of an electrical receiver device to determine whether the electrical receiver device is close enough and thus adjust the output to the inductive loop from the power loop.

Claims

1. A wireless charging system with auto-detection, comprising:

an inductive loop including a induction coil and a capacitor, wherein said induction coil and said capacitor are connected in series;

a power loop including a power source, wherein said power loop is connected to said inductive loop; and

a control loop including;

a processor;

a detection circuit, coupled to said processor and a detection point of said inductive loop so that said processor can detect a variation of an induced electric field of said inductive loop due to an electric receiver device approaching to said inductive loop, wherein a first current or a first voltage of said inductive loop is created by said induced electric field as an induced waveform over time; and

a control line, coupled to said processor and said power loop so that said process can control a power supply of said power loop outputted to said inductive loop;

wherein said processor determines whether said electrical receiver device is close enough to said inductive loop or not based on said variation of said induced electric field to adjust said power supply of said power loop outputted to said inductive loop.

2. The system of claim 1, wherein said detection circuit of said control loop includes a filter, an input terminal of said filter is connected to said inductive loop, and an output terminal of said filter is connected to said processor.

3. The system of claim 2, wherein said induced waveform is changed from a sawtooth waveform to a curve waveform by said filter.

4. The system of claim 1, wherein said detection circuit of said control loop includes a detector located in said inductive loop.

5. The system of claim 4, wherein said detector is connected to said induction coil and said capacitor in series.

6. The system of claim 1, wherein said control line of said control loop is connected to said power source of said power loop so that said processor can control said power supply by controlling an output of said power source.

7. The system of claim 1, wherein said power loop includes a driving circuit, wherein an input terminal of said driving circuit is connected to said power source, and two output terminals of said driving circuit are connected to said capacitor and said induction coil respectively.

8. The system of claim 7, wherein said control loop includes an auxiliary control line, wherein said processor is connected to said auxiliary control line and said driving circuit so that said processor can control a phase or a frequency of said driving circuit to control said power supply.

9. The system of claim 8, wherein said driving circuit is a full-bridge driving circuit.

10. The system of claim 8, wherein said driving circuit is a half-bridge driving circuit.

11. The system of claim 8, wherein said processor can adjust said induced waveform by controlling said phase or said frequency of said driving circuit.

12. The system of claim 8, wherein said detection point is located between said driving circuit and said capacitor.

13. The system of claim 8, wherein said detection point is located between said driving circuit and said induction coil.

14. The system of claim 8, wherein said detection point is located between said capacitor and said induction coil.

15. The system of claim 8, wherein said power supply is increased as said induced waveform is changed.

16. The system of claim 8, wherein said power supply is increased as a maximum peak value or an average peak value of said induced waveform is over a pre-determined peak value.

17. The system of claim 8, wherein said power supply is increased as an area of said induced waveform is over a pre-determined value of area.

18. The system of claim 8, wherein a variation of said frequency of said induction wave is over a pre-determined value of frequency.

19. The system of claim 1, wherein said control loop includes an auxiliary control line coupled to said control loop to detect said induced electric field such that a current or a voltage of said power loop is created as an auxiliary induced waveform.

20. The system of claim 19, wherein as said processor determines that said induced waveform is not applicable, said induced waveform is replaced by said auxiliary induced waveform.