SYSTEM, METHOD AND APPARATUS FOR CONTACT-LESS BATTERY CHARGING WITH DYNAMIC CONTROL

• US 20030214821A1
• Filed: 05/16/2002
• Published: 11/20/2003
• Est. Priority Date: 05/16/2002
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Giannopoulos, Demetri, Lee, Nai-Chi, Li, Qiong M.
• Granted Patent: US 6,844,702 B2
• Time in Patent Office: Days
• US Class Current: 363/21.02
• 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 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

A system, method and apparatus for contact-less charging of battery operated devices is presented. There is a host charger with a power converter and resonant tank circuit and a portable device where the battery is located, with a battery charging control IC. The method obviates the need for a voltage controller in each of both the host and the portable stages, thus decreasing complexity and increasing efficiency. The charging of the battery in the portable device is controlled by a charging controller therein, which is in continual electric communication with the host, whose output power the control IC dynamically monitors and controls. Two embodiments for the charging circuitry in the portable device are presented. In one embodiment component count is minimized but battery charging is not optimized when the battery voltage is very low. In the other embodiment charging efficiency is maximized regardless of the output voltage of the battery, but additional components are utilized.

Claims

1. A method of contact-less charging of a portable device'"'"'s battery from an external host, comprising:

generating power in the host via a power converter;

electrically coupling the host to the portable device in a contact-less manner; and

dynamically controlling power generation in the host from the portable device.

2. The method of claim 1, where the dynamic control of power generation is effected via digital signals.

3. The method of claim 2, where the controlling of power generation is accomplished via a charging controller in the portable device.

4. The method of claim 3, where the power converter is inductively coupled to battery charging circuitry in the portable device.

5. The method of claim 4, where switches of the power converter are capacitively coupled to the charging controller.

6. The method of claim 5, where the power converter is a half-bridge converter.

7. The method of claim 5, where the power converter is a full-bridge converter.

8. A method of contact-less battery charging, comprising:

driving a resonant tank circuit with a power converter; and

transferring energy from the resonant tank circuit to a battery charging circuit connected to a battery via a transformer,

where during charging;

the resonant tank circuit and the battery charging circuit are brought into proximity but need not be physically connected, and

where the power converter is continually in electronic communication with, and under the dynamic control of, a charging controller located in the portable device.

9. The method of claim 8 where the charging controller utilizes digital control signals.

10. The method of claim 9, further comprising:

sensing an output voltage of the battery prior to charging; and

if the output voltage is too low, diverting power from the charging circuit to power the charging controller.

11. Apparatus for a contact-less battery charger, comprising:

a resonant tank circuit;

a power converter;

a spiral wound conductor; and

two conducting plates, where in operation the power converter is controlled by a voltage appearing across the two conducting plates.

12. The apparatus of claim 11, where the power converter is a half-bridge power converter.

13. The apparatus of claim 12, where the voltage appearing across the two conducting plates is a logic signal.

14. The apparatus of claim 13, further comprising a resistance connected across the two conducting plates, such that the logic signal is converted to a positive pulse for the duration of a rising transition and a negative pulse for the duration of a falling transition.

15. The apparatus of claim 14, further comprising a resistor in series with one of the half-bridge power converter switches.

16. Apparatus for a contact-less chargeable battery-operated device, comprising:

a spiral wound conductor;

a battery charging controller;

a full bridge rectifier; and

two conducting plates.

17. The apparatus of claim 16, where the battery charging controller is arranged to digitally control charging of a battery by signaling an external host charging device.

18. The apparatus of claim 17, where the battery charging controller signals the external host through the two conducting plates.

19. The apparatus of claim 18, where power is received from the external host via the spiral wound conductor.

20. System for contact-less charging of battery operated portable devices, comprising:

a charger, comprising;

a resonant tank circuit;

a power converter;

a first spiral wound conductor; and

a first set of two conducting plates,

where the power converter is controlled by a voltage appearing across the two conducting plates; and

a portable battery-operated device, comprising;

a second spiral wound conductor;

a battery charging controller;

a full bridge rectifier; and

a second set of two conducting plates;

where, when the charger and the portable device are brought into proximity the first and second spiral wound conductors form a transformer, and the first and second set of conducting plates form two capacitors.

21. The system of claim 20, where the battery charging controller controls a charging of a battery via signals sent to the power converter.

22. The system of claim 21, where the signals sent to the power converter are digital.

23. The system of claim 22, where power to charge a battery is transferred from the charger to the portable device via the transformer.

24. The system of claim 23 , where the digital signals from the battery charging controller are sent to the power converter via the two capacitors.