Charging system and method, and power adapter

Patent metadata

Field	Value
Publication number	US-10320217-B2
Application number	US-201715657377-A
Country	US
Kind code	B2
Filing date	Jul 24, 2017
Priority date	Feb 5, 2016
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

The present disclosure discloses a charging system and 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 compositing unit, 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 a current sampling value and/or a voltage sampling value, such that a second alternating current outputted by the compositing unit meets a charging requirement. The terminal includes a battery.

First claim

What is claimed is:

1. A power adapter, comprising:
a first rectifier, configured to rectify an input first 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 plurality of secondary windings, and an auxiliary winding, wherein the transformer is configured to output a plurality of voltages with ripple waveforms via the plurality of secondary windings according to the modulated first voltage, and to couple the modulated first voltage via the auxiliary winding;
a compositing unit, configured to composite the plurality of voltages to output a second alternating current, wherein for each cycle of the second alternating current, an absolute value of a peak voltage of a positive half of the second alternating current is greater than that of a trough voltage of a negative half of the second alternating current, wherein the second alternating current is configured to be introduced into a terminal to charge a battery of 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; and
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 adjust a duty ratio of the control signal according to the current sampling value and/or the voltage sampling value, such that the second alternating current meets a charging requirement of the terminal.

2. The power adapter according to claim 1 , wherein the plurality of secondary windings comprises a first secondary winding and a second secondary winding, a first end of the primary winding is coupled to a first output end of the first rectifier, a second end of the primary winding is coupled to the switch unit, the first secondary winding and the second secondary winding are coupled to the compositing unit respectively, and the transformer is configured to output a second voltage with a second ripple waveform via the first secondary winding according to the modulated first voltage, and to output a third voltage with a third ripple waveform via the second secondary winding according to the modulated first voltage, and the compositing unit is configured to composite the second voltage and the third voltage to output the second alternating current.

3. 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.

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

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/or
an isolation unit, coupled between the driving unit and the control unit; and/or
a power supply unit, coupled to the auxiliary winding, wherein the auxiliary winding is configured to output a fourth voltage with a fourth ripple waveform, and the power supply unit is configured to convert the fourth voltage and to output a first direct current, so as to supply power to the driving unit and/or the control unit respectively.

6. The power adapter according to claim 1 , 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.

7. The power adapter according to claim 1 , further comprising:
a second 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 second voltage sampling circuit is greater than a first predetermined voltage value.

8. The power adapter according to claim 1 , further comprising:
a first charging interface, wherein the first charging interface comprises: a power wire, configured to charge the battery; and a data wire, configured to communicate with the terminal;
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 first charging mode and a second charging mode.

9. The power adapter according to claim 8 , further comprising:
a rectifying and filtering unit, configured to perform a rectifying and filtering on one of the plurality of voltages to output a second direct current; and
a controllable switch, configured to control an operation of the rectifying and filtering unit;
wherein the control unit is further configured to control the rectifying and filtering unit to work and control the compositing unit to stop working by controlling the controllable switch when determining the charging mode is the first charging mode, such that the rectifying and filtering unit outputs the second direct current to charge the battery; and to control the rectifying and filtering unit to stop working and control the compositing unit to work by controlling the controllable switch when determining the charging mode as the second charging mode, such that the second alternating current is applied to the battery.

10. The power adapter according to claim 8 , wherein the control unit is further configured to obtain a charging current and/or a charging voltage corresponding to the second charging mode according to status information of the terminal and to adjust the duty ratio of the control signal according to the charging current and/or the charging voltage corresponding to the second charging mode, when determining the charging mode as the second charging mode.

11. The power adapter according to claim 10 , wherein the status information of the terminal comprises a temperature of the battery, wherein when the temperature of the battery is greater than a first predetermined temperature threshold or the temperature of the battery is less than a second predetermined temperature threshold, the second charging mode is switched to the first charging mode when a current charging mode is the second charging mode, in which the first predetermined temperature threshold is greater than the second predetermined temperature threshold.

12. The power adapter according to claim 11 , wherein the control unit is further configured to control the switch unit to switch off when the temperature of the battery is greater than a predetermined high temperature protection threshold, or
the control unit is further configured to control the switch unit to switch off when the voltage sampling value is greater than a second predetermined voltage value, or
the control unit is further configured to control the switch unit to switch off when the current sampling value is greater than a predetermined current value.

13. The power adapter according to claim 8 , wherein when performing the bidirec

Assignees

• Guangdong Oppo Mobile Telecommunications Corp Ltd

Inventors

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

Classifications

• H02J7/825

  Detection of fully charged condition · CPC title

• H02J7/94

  in response to battery current · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/42

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

• H02J7/975

  in response to temperature · CPC title