Inductive power supply system and intruding metal detection method thereof

• US 20130187476A1
• Filed: 03/08/2013
• Published: 07/25/2013
• Est. Priority Date: 05/31/2010
• Status: Active Grant

• Current Assignee: Fu Da Tong Technology Co., Ltd.
• Original Assignee: Fu Da Tong Technology Co., Ltd.
• Inventors: Tsai, Ming-Chiu, Chan, Chi-Che
• Granted Patent: US 9,413,197 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings

Abstract

The inductive power supply system comprises an input power module for receiving a stable voltage source, a storage module for storing a predetermined information, a processing module for generating a control signal according to the predetermined information and a feedback signal, a driving module for transforming the stable voltage source into a driving voltage according to the control signal, an inductive coil for electrically transmitting the driving voltage to process an inductive power transmission operation, and a feedback module for generating the feedback signal according to the driving voltage received by the inductive coil, where the predetermined information represents an initial state of the inductive power supply system comprising a sinusoidal amplitude corresponding to the driving voltage, and an intruding metal can affect another sinusoidal amplitude of the feedback signal to make the processing module correspondingly generate the control signal during the inductive power transmission operation.

Claims

1. An inductive power supply system, utilized for processing an inductive power transmission operation and detecting whether an intruding metal exists inside the inductive power supply system, comprising:

an input power module for receiving a stable voltage source;

a storage module for storing a predetermined information;

a processing module coupled to the input power module and the storage module for generating a control signal according to the predetermined information and a feedback signal;

a driving module coupled to the input power module and the processing module for transforming the stable voltage source into a driving voltage according to the control signal;

an inductive coil coupled to the driving module for electrically transmitting the driving voltage to a receipt power device, so as to process the inductive power transmission operation; and

a feedback module coupled to the inductive coil for generating the feedback signal according to the driving voltage received by the inductive coil;

wherein the predetermined information represents an initial state of the inductive power supply system comprising a sinusoidal amplitude corresponding to the driving voltage, and the intruding metal can affect another sinusoidal amplitude of the feedback signal to make the processing module correspondingly generate the control signal during the inductive power transmission operation.

2. The inductive power supply system of claim 1, wherein the inductive coil is further coupled to a capacitor to render an effective capacitance and an effective inductance, and the initial state forms an amplitude curve on a two dimensional coordinate system comprising a plurality of operational frequencies as an X-axis and a plurality of sinusoidal amplitudes as a Y-axis according to the effective capacitance and the effective inductance.

3. The inductive power supply system of claim 2, wherein when the driving voltage increases, the amplitude curve shifts upward along the Y-axis within the two dimensional coordinate system and a maximum sinusoidal amplitude of the amplitude curve increases as well.

4. The inductive power supply system of claim 2, wherein when the effective capacitance and the effective inductance increase, a sinusoidal amplitude of the amplitude curve with a fixed operational frequency decreases, and when the effective capacitance and the effective inductance decrease, the sinusoidal amplitude of the amplitude curve with the fixed operational frequency increases.

5. The inductive power supply system of claim 2, wherein when the intruding metal is onto a projective plane of the inductive coil, the sinusoidal amplitude of the feedback signal increases at each of the operational frequencies.

6. The inductive power supply system of claim 5, wherein the storage module further comprises a programming code for determining whether a sinusoidal amplitude difference between the feedback signal and the predetermined information exceeds an error range.

7. The inductive power supply system of claim 6, wherein the storage module stores a look-up table comprising the plurality of operational frequencies, the plurality of sinusoidal amplitudes and a plurality of error ranges, wherein each of the plurality of error ranges corresponds to one of the plurality of operational frequencies and one of the plurality of sinusoidal amplitudes.

8. The inductive power supply system of claim 6, wherein when the sinusoidal amplitude difference between the feedback signal and the predetermined information exceeds the error range, the processing module generates a first terminal signal to make the inductive power supply system stop the inductive power transmission operation.

9. The inductive power supply system of claim 6, further comprising an indication module which generates an indication signal when the sinusoidal amplitude difference between the feedback signal and the predetermined information exceeds the error range.

10. The inductive power supply system of claim 1, further comprising a switch module for generating a switch signal to switch the processing module between a setting operation and the inductive power transmission operation.

11. The inductive power supply system of claim 10, wherein the storage module further comprises a programming code for comparing an operational voltage of the feedback signal and another operational voltage of the predetermined information.

12. The inductive power supply system of claim 11, wherein when the operational voltage of the feedback signal is larger than the operational voltage of the predetermined information, the processing module generates a second terminal signal to stop the setting operation.

13. The inductive power supply system of claim 1, wherein the storage module further comprises a non-volatile memory (NVRAM) to store the predetermined information and another programming code, which controls the processing module to obtain the initial state of the inductive power supply system via a frequency modulation process.

14. The inductive power supply system of claim 1, wherein the feedback module detects a sinusoidal amplitude difference to make the processing module process the inductive power transmission operation whether or not the inductive coil is electrically coupled to the receipt power device.

15. A method for an inductive power supply system, which comprises a processing module, an inductive coil and a predetermined information for processing an inductive power transmission operation and detecting whether an intruding metal exists inside the inductive power supply system, comprising:

switching the inductive power supply system between a setting operation or the inductive power transmission operation according to a control signal; and

when the inductive power supply system processes the setting operation, the processing module processes a first operation process, and when the inductive power supply system processes the inductive power transmission operation, the processing module processes a second operation process;

wherein the predetermined information is an initial state of the inductive power supply system to be formed as a initial look-up table, the first operation process modifies the initial look-up table of the inductive power supply system to be formed as an adjusted look-up table, and the second operation process detects whether the intruding metal exists in the inductive power supply system according to the adjusted look-up table.

16. The method of claim 15, wherein the first operation process further comprises:

processing a voltage division operation for a stable voltage source to generate a first division voltage value;

predetermining the first division voltage value as an information header added into the initial look-up table as the adjusted look-up table;

setting an operational frequency of the processing module as a maximum operational frequency of the inductive power supply system according to the first division voltage value;

transmitting the operational frequency to a driving module such that the driving module correspondingly generates a driving voltage to the inductive coil, and a feedback module transforms a voltage signal of the inductive coil into a feedback signal; and

determining whether the voltage signal of the inductive coil exceeds a maximum operational frequency of the feedback module, and lowering the current operational frequency set by the processing module to obtain a plurality of information headers at different stable voltage sources if the voltage signal of the inductive coil does not exceed the maximum operational frequency of the feedback module so as to form the adjusted look-up table.

17. The method of claim 16, wherein the second operation process further comprises:

processing the voltage division operation for the stable voltage source to generate a second division voltage value; and

determining whether the second division voltage value matches one of the information headers in the adjusted look-up table so as to determine whether the second operation process is processed or finished.

18. The method of claim 17, wherein the second operation process further comprises:

when the second operation process is processed, the driving module generates the driving voltage according to the current operational frequency of the processing module, and accordingly, the feedback module transforms the current voltage signal of the inductive coil into the feedback signal to the processing module;

retrieving a sinusoidal amplitude corresponding to the operational frequency of the processing module from the adjusted look-up table; and

determining whether a sinusoidal amplitude difference between the feedback signal and the operational frequency exceeds an error range, and when the sinusoidal amplitude difference exceeds the error range, the processing module determines that the intruding metal is inside the inductive power supply system so as to stop the inductive power transmission operation.

19. The method of claim 18, further comprising utilizing an indication module for generating an indication signal when the sinusoidal amplitude difference exceeds the error range.

20. The method of claim 15, further comprising utilizing a switch module for generating a switch signal so as to switch the inductive power supply system between the setting operation and the inductive power transmission operation.

21. The method of claim 15, wherein the first operation process and the second operation process are compiled to be a programming code stored in a storage module, and the processing module operates the programming code to process the first operation process and the second operation process.

22. The method of claim 21, wherein the storage module further comprises a non-volatile memory (NVRAM) for storing the programming code, the initial look-up table and the adjusted look-up table.

23. The method of claim 15, wherein the processing module further operates another programming code to obtain the initial state of the inductive power supply system via a frequency modulation process so as to form the initial look-up table.

24. The method of claim 15, wherein the feedback module detects a sinusoidal amplitude difference to make the processing module process the inductive power transmission operation whether on not the inductive coil is electrically coupled to the receipt power device.