Charging system, charging method, and power adapter

Patent metadata

Field	Value
Publication number	US-10910852-B2
Application number	US-201715657572-A
Country	US
Kind code	B2
Filing date	Jul 24, 2017
Priority date	Jul 26, 2016
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

The present disclosure discloses a charging system, a charging method and a power adapter. The system includes a power adapter and a terminal. The power adapter includes a first rectifier, a switch unit, a transformer, a second rectifier, a sampling unit, and a control unit. The control unit outputs a control signal to the switch unit, and adjusts a duty ratio of the control signal according to coupled sampling performed by the sampling unit at an auxiliary winding, such that a third voltage outputted by the second rectifier meets a charging requirement. The terminal includes a battery. When the power adapter is coupled to the terminal, the third voltage is applied to the battery.

First claim

What is claimed is:

1. A power adapter, comprising:
a first rectifier, configured to rectify an input alternating current and output a first voltage with a first ripple waveform;
a switch unit, configured to modulate the first voltage according to a control signal and output a modulated first voltage;
a transformer, having a primary winding, a secondary winding and an auxiliary winding, wherein a first end of the primary winding is coupled to a first output end of the first rectifier, and a second end of the primary winding is coupled to the switch unit and the transformer is configured to output a second voltage with a second ripple waveform according to the modulated first voltage;
a second rectifier, coupled to the secondary winding, and configured to rectify the second voltage to output a third voltage with a third ripple waveform, wherein the third voltage is configured to be introduced into a terminal to charge a battery in the terminal when the power adapter is coupled to the terminal;
a sampling unit, configured to sample voltage and/or current at the auxiliary winding to obtain a voltage sampling value and/or a current sampling value;
a control unit, coupled to the sampling unit and the switch unit respectively, and configured to output the control signal to the switch unit, and to change an output of the second rectifier by adjusting a duty ratio of the control signal according to the current sampling value and/or the voltage sampling value, such that the third voltage meets a charging requirement of the battery of the terminal when the power adapter is coupled to the terminal; and
a first charging interface, wherein the control unit is configured to communicate with the terminal via the first charging interface to determine a charging mode, in which the charging mode comprises a second charging mode and a first charging mode, and the second charging mode is different from the first charging mode,
wherein during a process that the power adapter charges the terminal in the second charging mode, the control unit is configured to send an instruction to the terminal, in which the instruction is configured to query a current voltage of the battery in the terminal;
the control unit is configured to receive a reply instruction sent by the terminal, in which the reply instruction is configured to indicate the current voltage of the battery in the terminal; and
the control unit is configured to adjust the charging current by controlling the switch unit according to the current voltage of the battery,
wherein, during the process that the power adapter charges the terminal in the second charging mode, the control unit is further configured to determine whether there is a poor contact between the first charging interface and the second charging interface by performing bidirectional communication with the terminal via a data wire of the first charging interface,
wherein, when determining that there is the poor contact between the first charging interface and the second charging interface, the control unit is configured to control the power adapter to quit the second charging mode,
wherein, before determining whether there is the poor contact between the first charging interface and the second charging interface, the control unit is further configured to receive information indicating a path impedance of the terminal from the terminal, wherein
the control unit is configured to send an instruction to the terminal, in which the instruction is configured to query a current voltage of the battery in the terminal;
the control unit is configured to receive a reply instruction sent by the terminal, in which the reply instruction is configured to indicate the current voltage of the battery in the terminal;
the control unit is configured to determine a path impedance from the power adapter to the battery according to an output voltage of the power adapter and the current voltage of the battery; and
the control unit is configured to determine whether there is the poor contact between the first charging interface and the second charging interface according to the path impedance from the power adapter to the battery, the path impedance of the terminal, and a path impedance of a charging wire between the power adapter and the terminal.

2. The power adapter according to claim 1 , wherein the control unit is further configured to adjust a frequency of the control signal according to the voltage sampling value and/or the current sampling value.

3. The power adapter according to claim 1 , wherein the control unit is further configured to communicate with the terminal so as to obtain status information of the terminal when the power adapter is coupled to the terminal.

4. The power adapter according to claim 3 , wherein the control unit is further configured to adjust the duty ratio of the control signal according to the voltage sampling value and/or the current sampling value and the status information of the terminal.

5. The power adapter according to claim 1 , further comprising:
a driving unit, coupled between the switch unit and the control unit, and configured to drive the switch unit to switch on or off according to the control signal; and an isolation unit, coupled between the driving unit and the control unit.

6. The power adapter according to claim 5 , further comprising:
a power supply unit, coupled to the auxiliary winding, wherein the auxiliary winding is configured to generate a fourth voltage with a fourth ripple waveform according to the modulated first voltage, and the power supply unit is configured to convert the fourth voltage and output a direct current, so as to supply power to the driving unit and/or the control unit respectively.

7. The power adapter according to claim 6 , wherein the sampling unit is configured to sample voltage and/or current of the fourth voltage to obtain the voltage sampling value and/or the current sampling value.

8. The power adapter according to claim 1 , wherein a working frequency of the transformer ranges from 50 KHz to 2 MHz.

9. The power adapter according to claim 7 , wherein the sampling unit comprises:
a first current sampling circuit, configured to sample the current at the auxiliary winding so as to obtain the current sampling value; and
a first voltage sampling circuit, configured to sample the voltage at the auxiliary winding so as to obtain the voltage sampling value.

10. The power adapter according to claim 1 , wherein a waveform of the modulated first voltage keeps synchronous with the third ripple waveform.

11. The power adapter according to claim 1 , further comprising:
a voltage sampling circuit, configured to sample the first voltage, and coupled to the control unit, wherein the control unit is configured to control the switch unit to switch on for a first predetermined time period for discharging when a voltage value sampled by the voltage sampling circuit is greater than a first predetermined voltage value.

12. The power adapter according to claim 1 , wherein the first charging interface comprises:
a power wire, configured to charge the battery; and
a data wire, configured to communicate with the terminal when the power adapter is coupled to the terminal via the first charging interface.

13. The power adapter according to claim 12 , further comprising:
a controllable switch and a filtering unit coupled in series, coupled to a first output end of the second rectifier, wherein the control unit is further configured to control the controllable switch to switch on when determining the charging mode as the first charging mode so as to introduce the filtering unit to perform a filtering functio

Assignees

• Guangdong Oppo Mobile Telecommunications Corp Ltd

Inventors

• Zhang Jialiang
• Tian Chen
• Zhang Jun
• Chen Shebiao
• Wan Shiming
• Li Jiada

Classifications

• H02J7/42

  with electronic devices having internal batteries, e.g. mobile phones · CPC title

• H02J7/731

  specially adapted for holding portable devices containing batteries (H02J7/751 takes precedence) · CPC title

• H02J7/02 Primary

  for charging batteries from AC mains by converters · CPC title

• H02J2207/20

  Charging or discharging characterised by the power electronics converter · CPC title

• H02M3/33523

  with galvanic isolation between input and output of both the power stage and the feedback loop · CPC title