Contactless battery charger

• US 6,683,438 B2
• Filed: 01/04/2002
• Issued: 01/27/2004
• Est. Priority Date: 01/05/2001
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Sang-Kyu, Park, Seo-Young, Park, Mae-Jin
• Primary Examiner(s): Tibbits, Pia
• Application Number:
  US10/037,615
• Publication Number:
  US 20020089305A1
• Time in Patent Office: 753 Days
• Field of Search: 320/108, 320/113, 320/114, 320/115, 320/112, 323/237, 323/242, 323/246, 363/18, 363/19, 363/97, 363/131
• US Class Current: 320/108
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

Disclosed is a contactless battery charger that avoids contact failure between a battery pack and the battery charger including a converter and a charging unit. A converter includes a primary side of a printed circuit board (PCB) transformer. The converter converts a commercial electric power to a high-frequency square wave, applies the converted high-frequency square wave to the primary side of the PCB transformer, and controls generation of a charge current depending on charge state information provided. A charging unit includes a secondary side of the PCB transformer. The charging unit converts to a DC voltage an electromotive force induced at the secondary side of the PCB transformer by a magnetic field generated by the square wave applied to the primary side of the PCB transformer, charges a rechargeable battery with the DC voltage, and provides the charge state information to the converter.

Claims

1. A contactless battery charger for use in a communication terminal, comprising:

a converter including a primary side of a printed circuit board (PCB) transformer, the converter converting a commercial electric power to a high-frequency square wave, applying the converted high-frequency square wave to the primary side of the PCB transformer, and controlling generation of a charge current depending on charge state information provided; and

a charging unit including a secondary side of the PCB transformer, the charging unit converting an electromotive force induced at the secondary side of the PCB transformer by a magnetic field generated by the square wave applied to the primary side of the PCB transformer to a DC (Direct Current) voltage, charging a rechargeable battery with the DC voltage, and providing the charge state information to the converter.

2. The contactless battery charger as claimed in claim 1, wherein the charging unit is mounted in a battery pack.

3. The contactless battery charger as claimed in claim 2, wherein the secondary side of the PCB transformer is mounted below a surface of the battery pack.

4. The contactless battery charger as claimed in claim 1, wherein the converter comprises:

a rectifying circuit for converting the commercial electric power to a DC voltage;

an inverter for converting the DC voltage to the high-frequency square wave and providing the converted high-frequency square wave to the primary side of the PCB transformer;

a photo-coupler receiver for converting a received light beam to an electric signal;

a controller for recognizing a specification and a charged state of the rechargeable battery based on the electric signal provided from the photo-coupler receiver, and generating charge control data according to the recognized results; and

an inverter controller for controlling a charge current by controlling a frequency of the square wave output from the inverter based on the charge control data provided from the controller.

5. The contactless battery charger as claimed in claim 4, wherein the rectifying circuit comprises:

rectifying diodes connected to the commercial electric power; and

an output capacitor connected in parallel between the rectifying diodes and the inverter.

6. The contactless battery charger as claimed in claim 1, wherein the charging unit comprises:

a monitoring circuit for detecting a voltage level of the rechargeable battery while the rechargeable battery is charged; and

a photo-coupler transmitter for radiating a light beam according to the detected results.

7. The contactless battery charger as claimed in claim 1, wherein the charging unit comprises:

a rectifying circuit for converting the electromotive force induced at the secondary side of the PCB transformer by the magnetic field generated at the primary side of the PCB transformer to the DC voltage; and

a monitoring circuit and photo-coupler transmitter connected to the rectifying circuit and the rechargeable battery, for detecting a voltage level of the rechargeable battery while the rechargeable battery is charged, and radiating a light beam according to the detected results.

8. The contactless battery charger as claimed in claim 7, wherein the rectifying circuit comprises:

rectifying diodes connected to the secondary side of the PCB transformer; and

an output capacitor connected in parallel between the rectifying diodes and the inverter.

9. The contactless battery charger as claimed in claim 2, wherein the battery pack is mounted on a mobile phone and provides the charged voltage to the mobile phone as an operating voltage.

10. The contactless battery charger as claimed in claim 4, wherein the controller is a microprocessor unit.

11. A contactless battery charger comprising:

a converter including;

a primary side of a PCB transformer;

a rectifying circuit for converting a commercial electric power to a DC voltage;

an inverter for converting the DC voltage to a high-frequency square wave and providing the converted high-frequency square wave to the primary side of the PCB transformer;

a photo-coupler receiver for converting a received light beam to an electric signal;

a controller for recognizing a specification and a charged state of a rechargeable battery based on the electric signal provided from the photo-coupler receiver, and generating charge control data according to the recognized results;

an inverter controller for controlling a charge current by controlling a frequency of the square wave output from the inverter based on the charge control data from the controller;

a charging unit including;

a rectifying circuit for converting an electromotive force induced at a secondary side of the PCB transformer by a magnetic field generated at the primary side of the PCB transformer to a DC voltage; and

a monitoring circuit and photo-coupler transmitter connected to the rectifying circuit and the rechargeable battery, for detecting a voltage level of the rechargeable battery while the rechargeable battery is charged, and radiating a light beam according to the detected results.