WIRELESS POWER TRANSMITTER AND WIRELESS CHARGING METHOD

• US 20180183267A1
• Filed: 02/28/2017
• Published: 06/28/2018
• Est. Priority Date: 12/27/2016
• Status: Abandoned Application

• Current Assignee: Foxconn Technology Co., Ltd.
• Original Assignee: Foxconn Technology Co., Ltd.
• Inventors: LIN, Yung-Ping
• Application Number:
  US15/444,495
• Publication Number:
  US 20180183267A1
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• 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 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

Abstract

A wireless power transmitter with protection against damage to Near Field Communication (NFC) devices within range includes a DC/DC converter, a power transmitting controller, an MCU, a switch having two switching ports, a matching unit having two capacitors connected in parallel, and a coil. The DC/DC converter converts a supplied direct current to another level and outputs the direct current before the wireless power transmitter is activated. The converted DC causes one switch port to be conductive, thereby the first capacitor and the coil cooperatively generate a first resonant frequency equal to NFC operating frequency. The power transmitting controller transmits a control signal to the coil which can determine the presence of an NFC device within the wireless charging field. The power transmitting controller is turned off if an NFC device is within the field.

Claims

1. A wireless power transmitter comprising:

a DC/DC converter configured to convert a direct current from an original level and output the direct current at another level when the wireless power transmitter being powered on and a power source of the wireless power transmitter output the direct current;

a power transmitting controller configured to maintain in an off state when the DC/DC converter output the direct current;

a switch having a first switching port and a second switching port;

a matching unit having a first capacitor and a second capacitor connected in parallel; and

a coil; and

a microcontroller unit (MCU) configured to control the first switch port to be conductive such that the first capacitor being electrically connected to the coil when the DC/DC converter output the direct current, thereby the first capacitor and the coil cooperatively generate a first resonant frequency;

wherein the first resonant frequency is equal to an operating frequency of NFC;

wherein the MCU is further configured to turn on the power transmitting controller and control the power transmitting controller to transmit a control signal to the coil;

wherein the coil is configured, to scan within a wireless charging field of the wireless power transmitter at the first resonant frequency in response to the control signal to determine whether at least one NFC device is within the wireless charging field;

wherein the MCU is further configured to turn off the power transmitting controller to disable a function of wireless charging of the wireless power transmitter when at least one NFC device is within the wireless charging field.

2. The wireless power transmitter of claim 1, further comprising a BLUETOOTH module, wherein the MCU is further configured to control the second switch port to be conductive such that the second capacitor is electrically connected to the coil when no NFC device is within the wireless charging field, thereby the second capacitor and the coil cooperatively generate a second resonant frequency different from the first resonant frequency, the second resonant frequency is equal to an operating frequency of the wireless power transmitter performing wireless charging;

wherein the MCU is further configured to control the power transmitting controller to transmit a shortwave electrical power to the coil such that the coil transmits the shortwave electrical power by magnetic resonance to a wireless power receiver, thereby allowing a power source of the wireless power receiver to be activated;

wherein the BLUETOOTH module is configured to broadcast an authentication signal within the wireless charging field at a preset time point after the power transmitting controller transmits the shortwave electrical power to the coil, thereby informing the wireless power receiver remained in the wireless charging field to transmits a feedback signal to the BLUETOOTH module;

wherein the MCU is further configured to control the power transmitting controller to continuously transmit electrical power to the wireless power receiver when the BLUETOOTH module receives the feedback signal, thereby performing wireless charging.

3. The wireless power transmitter of claim 2, wherein the BLUETOOTH module is further configured to communicate with the wireless power receiver to authenticate, protect over-current, detect foreign-object, or any combination thereof when the MCU controls the power transmitting controller to continuously transmit electrical power to the wireless power receiver.

4. The wireless power transmitter of claim 2, wherein the MCU is further configured to determine whether charging of the wireless power receiver is complete, the MCU is further configured to turn off the power transmitting controller and control the wireless power transmitter to enter a standby state when the charging of the wireless power receiver is complete.

5. The wireless power transmitter of claim 1, further comprising at least one indication lamp, wherein the MCU is further configured to control the indication lamp to emit light when at least one NFC device is within the wireless charging field.

6. The wireless power transmitter of claim 5, wherein the MCU is configured to control the indication lamp to emit red light.

7. A wireless charging method applied in a wireless power transmitter, the wireless power transmitter comprising a DC/DC converter, a power transmitting controller, a microcontroller unit (MCU), a switch having a first switching port and a second switching port, a matching unit having a first capacitor and a second capacitor connected in parallel, and a coil, the wireless charging method comprising:

converting, by the DC/DC converter, a direct current from an original level and outputting the direct current at another level when the wireless power transmitter being powered on and a power source of the wireless power transmitter output the direct current;

wherein the power transmitting controller maintains in an off state when the DC/DC converter outputs the direct current;

controlling, by the MCU, the first switch port to be conductive such that the first capacitor being electrically connected to the coil when the DC/DC converter output the direct current, thereby the first capacitor and the coil cooperatively generate a first resonant frequency, the first resonant frequency being equal to an operating frequency of NFC;

turning, by the MCU, on the power transmitting controller and controlling the power transmitting controller to transmit a control signal to the coil;

scanning, by the coil, within a wireless charging field of the wireless power transmitter at the first resonant frequency in response to the control signal to determine whether at least one NFC device being within the wireless charging field; and

turning, by the MCU, off the power transmitting controller to disable a function of wireless charging of the wireless power transmitter when at least one NFC device being within the wireless charging field.

8. The wireless charging method of claim 7, further comprising:

controlling, by the MCU, the second switch port to be conductive such that the second capacitor is electrically connected to the coil when no NFC device is within the wireless charging field, thereby the second capacitor and the coil cooperatively generate a second resonant frequency different from the first resonant frequency, the second resonant frequency is equal to an operating frequency of the wireless power transmitter performing wireless charging;

controlling, by the MCU, the power transmitting controller to transmit a shortwave electrical power to the coil such that the coil transmits the shortwave electrical power by magnetic resonance to a wireless power receiver, thereby allowing a power source of the wireless power receiver to be activated;

broadcasting, by a BLUETOOTH module, an authentication signal within the wireless charging field at a preset time point after the power transmitting controller transmits the shortwave electrical power to the coil, thereby informing the wireless power receiver remained in the wireless charging field to transmits a feedback signal to the BLUETOOTH module; and

controlling, by the MCU, the power transmitting controller to continuously transmit electrical power to the wireless power receiver when the BLUETOOTH module receives the feedback signal, thereby performing wireless charging.

9. The wireless charging method of claim 8, further comprising:

communicating, by the BLUETOOTH module, with the wireless power receiver to authenticate, protect over-current, detect foreign-object, or any combination thereof when the MCU controls the power transmitting controller to continuously transmit electrical power to the wireless power receiver.

10. The wireless charging method of claim 8, further comprising:

determining, by the MCU, whether charging of the wireless power receiver is complete; and

turning off, by the MCU, the power transmitting controller and controlling the wireless power transmitter to enter a standby state when the charging of the wireless power receiver is complete.

11. The wireless charging method of claim 7, further comprising:

controlling, by the MCU, at least one indication lamp to emit light when at least one NFC device is within the wireless charging field.