CHARGEABLE ELECTRIC DEVICE

• US 20100327804A1
• Filed: 06/21/2010
• Published: 12/30/2010
• Est. Priority Date: 06/25/2009
• Status: Abandoned Application

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Inventors: Takahashi, Atsushi, Asakawa, Koji, Yamashita, Mikihiro, Katsura, Yoshinori
• Application Number:
  US12/819,724
• Publication Number:
  US 20100327804A1
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection

Abstract

A chargeable electric device includes a rechargeable battery. A secondary coil is arranged to be coupled by electromagnetic induction to a primary coil of a non-contact charger when charging the rechargeable battery. A resonance capacitor is connected to the secondary coil. A rectification unit is connected to the secondary coil. A charging current control unit arranged between the rectification unit and the rechargeable battery control charging current supplied from the rectification unit to the rechargeable battery. A resonance obstruction element obstructs normal resonance produced by the secondary coil and the resonance capacitor in synchronism with the control performed by the charging current control unit to suppress the charging current.

Claims

1. A chargeable electric device comprising:

a rechargeable battery;

a secondary coil arranged to be coupled by electromagnetic induction to a primary coil of a non-contact charger when charging the rechargeable battery;

a resonance capacitor connected to the secondary coil;

a rectification unit connected to the secondary coil;

a charging current control unit arranged between the rectification unit and the rechargeable battery to control charging current supplied from the rectification unit to the rechargeable battery; and

a resonance obstruction element which obstructs normal resonance produced by the secondary coil and the resonance capacitor in synchronism with the control performed by the charging current control unit to suppress the charging current.

2. The chargeable electric device according to claim 1, wherein the resonance obstruction element is a switching element that short-circuits the two terminals of the secondary coil.

3. The chargeable electric device according to claim 2, wherein the switching element is arranged toward the charging current control unit from the rectification unit.

4. The chargeable electric device according to claim 3, wherein the switching element allows for current to flow in only one direction.

5. The chargeable electric device according to claim 2, wherein the switching element is arranged toward the secondary coil from the rectification unit and allows for a bidirectional flow of current.

6. The chargeable electric device according to claim 1, wherein the resonance obstruction element is a switching element that opens the connection between the secondary coil and the resonance capacitor.

7. The chargeable electric device according to claim 1, further comprising:

a charge detection unit that detects whether or not the non-contact charger is located in the vicinity of the chargeable electric device from the voltage at the secondary coil;

wherein the resonance obstruction element does not obstruct resonance during a predetermined detection timing of the charge detection unit regardless of the control performed by the charging current control unit to suppress the charging current.

8. The chargeable electric device according to claim 1, further comprising:

a controller connected to the rechargeable battery to provide the charging current control unit and the resonance obstruction element with a control signal, wherein the controller monitors whether the rechargeable battery is in a state in which the supply of the charging current is unnecessary or in a state in which only a small amount of the charging current small is necessary and synchronously operates the charging current control unit and the resonance obstruction element.

9. The chargeable electric device according to claim 8, wherein the controller synchronously operates the charging current control unit and the resonance obstruction element in a complementary manner when the rechargeable battery is in a state in which the supply of the charging current is unnecessary or in a state in which only a small amount of the charging current is necessary to suppress or stop the supply of charging current to the rechargeable battery.

10. The chargeable electric device according to claim 9, wherein the resonance obstruction element includes a switching element connected to a first node between one terminal of the secondary coil and the charging current control unit and a second node between the other terminal of the secondary coil and the rechargeable battery;

and

the controller deactivates the charging current control unit and activates the resonance obstruction element when the rechargeable battery is in a state in which the supply of the charging current is unnecessary or in a state in which only a small amount of the charging current is necessary.

11. The chargeable electric device according to claim 8, wherein the resonance obstruction element includes a switching element connected between the secondary coil and the resonance capacitor;

and

the controller deactivates the charging current control unit and the resonance obstruction element and opens the connection of the secondary coil and the resonance capacitor when the rechargeable battery is in a state in which the supply of the charging current is unnecessary or in a state in which only a small amount of the charging current is necessary.