DYNAMIC CURRENT LIMITING CHARGING CIRCUIT

• US 20110151942A1
• Filed: 12/17/2009
• Published: 06/23/2011
• Est. Priority Date: 12/17/2009
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Anderson, Wayne, Hanley, Michael
• Granted Patent: US 8,427,102 B2
• Time in Patent Office: Days
• US Class Current: 455/573
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

An apparatus is provided for an electronic device. The apparatus includes a dynamic electrical load, a secondary power coil receiver module that inductively receives a current from a primary coil of an power conversion system, a means for monitoring a current in the secondary receiver module being delivered to the dynamic load, a means for transmitting a power control signal to the power conversion system through the secondary charging coil, a current monitoring circuit that measures a current delivered to the dynamic load and a current limiter circuit that limits the current to the dynamic load based upon the measured charging current.

Claims

1. An apparatus comprising:

a dynamic electrical load;

a secondary power coil receiver module that inductively receives a current from a primary coil of a power conversion system;

a means for monitoring a current in the secondary receiver module being delivered to the dynamic load;

a means for transmitting a power control signal to the power conversion system through the secondary charging coil;

a current monitoring circuit that measures a current delivered to the dynamic load; and

a current limiter circuit that limits the current to the dynamic load based upon the measured charging current.

2. The apparatus as in claim 1 wherein the current limiter further comprises a current processor that calculates a current limit threshold value from the average current.

3. The apparatus as in claim 2 wherein the threshold value further comprises the average current plus a predetermined incremental value.

4. The apparatus as in claim 1 wherein the dynamic load further comprises a cellular telephone.

5. The apparatus as in claim 4 wherein the dynamic load further comprises a time division multiplexed cellular telephone.

6. The apparatus as in claim 4 wherein the dynamic load further comprises a GSM cellular telephone.

7. The apparatus as in claim 1 further comprising a battery.

8. The apparatus as in claim 1 further comprising a secondary power control processor that controls the current through the secondary power coil receiver module via charge control packets inductively coupled to the power conversion system.

9. An apparatus comprising:

a secondary charging coil receiver module that inductively receives a current for charging a battery and for powering a cellular transceiver from a primary coil of a power conversion system;

a secondary power control processor that modulates a load to transmit charge control packets to a power control processor of a power conversion system;

a current processor that measures an average current delivered through the secondary charging coil to the battery and associated electronics powered by the battery; and

a current limiter that limits the current to the battery and transceiver based upon the average current.

10. The apparatus as in claim 9 further comprising a cellular telephone.

11. The apparatus as in claim 10 wherein the cellular telephone further comprises a GSM cellular telephone.

12. The apparatus as in claim 9 wherein the average current further comprises an average of charging current and peak transmitter current.

13. An apparatus comprising:

a cellular transceiver that periodically transceives a communicated signal through a local cellular base station;

a battery that powers the transceiver;

a secondary coil receiver module that inductively receives a current from a primary charging coil of a power conversion device;

a secondary power control processor that measures a power required to charge the battery and transmits a charge control packet to the power conversion device through the secondary charging coil;

means for measuring an average current through the secondary charging coil; and

means for limiting the current to the battery and transceiver based upon the average current.

14. The apparatus as in claim 13 further comprising the means for measuring located within the secondary power control processor.

15. The apparatus as in claim 13 further comprising the means for limiting located in the secondary power control processor.

16. The apparatus as in claim 13 wherein the means for limiting, further comprises a current processor that calculates a current limit threshold value from the average current.

17. The apparatus as in claim 16 wherein the threshold value further comprises the average current plus a predetermined incremental value.

18. The apparatus as in claim 13 further comprising a cellular telephone.

19. The apparatus as in claim 13 further comprising a time division multiplexed cellular telephone.

20. The apparatus as in claim 13 further comprising a GSM cellular telephone.