Charging system and charging method, and power adapter

Patent metadata

Field	Value
Publication number	US-10340727-B2
Application number	US-201615563867-A
Country	US
Kind code	B2
Filing date	Jul 26, 2016
Priority date	Feb 5, 2016
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

The present disclosure discloses a charging system, a charging method, and a power adapter. The charging system includes a battery, 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 a current sampling value and/or voltage sampling value sampled by the sampling unit, such that a third voltage with a third ripple waveform outputted by the second rectifier meets a charging requirement of the battery.

First claim

What is claimed is:

1. A charging system, comprising:
a battery;
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, configured to output a second voltage with a second ripple waveform according to the modulated first voltage;
a second rectifier, configured to rectify the second voltage to output a third voltage with a third ripple waveform, and the third voltage being configured to be applied to the battery charge the battery;
a sampling unit, configured to sample a voltage and/or current outputted by the second rectifier 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 third voltage meets a charging requirement of the battery.

2. 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, configured to output a second voltage with a second ripple waveform according to the modulated first voltage;
a second rectifier, configured to rectify the second voltage to output a third voltage with a third ripple waveform;
a sampling unit, configured to sample a voltage and/or current outputted by the second rectifier 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 third voltage meets a charging requirement of the terminal when the power adapter is coupled to the terminal.

3. The power adapter according to claim 2 , 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 2 , 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;
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 2 , 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 switch 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:
an auxiliary winding, configured to generate a fourth voltage with a fourth ripple waveform according to the modulated first voltage; and
a power supply unit, coupled to the auxiliary winding, and configured to convert the fourth voltage to 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 , further comprising:
a first voltage detecting unit, coupled to the auxiliary winding and the control unit respectively, and configured to detect the fourth voltage to generate a voltage detecting value, wherein the control unit is further configured to adjust the duty ratio of the control signal according to the voltage detecting value.

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

9. The power adapter according to claim 2 , wherein the sampling unit comprises:
a first current sampling circuit, configured to sample the current outputted by the second rectifier so as to obtain the current sampling value; and
a first voltage sampling circuit, configured to sample the voltage outputted by the second rectifier so as to obtain the voltage sampling value.

10. The power adapter according to claim 9 , wherein the first voltage sampling circuit comprises:
a peak voltage sampling and holding unit, configured to sample and hold a peak voltage of the third voltage;
a cross-zero sampling unit, configured to sample a zero crossing point of the third voltage;
a leakage unit, configured to perform a leakage on the peak voltage sampling and holding unit at the zero crossing point; and
an AD sampling unit, configured to sample the peak voltage in the peak voltage sampling and holding unit so as to obtain the voltage sampling value.

11. The power adapter according to claim 2 , wherein a waveform of the modulated first voltage is synchronized with the third ripple waveform.

12. The power adapter according to claim 2 , 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.

13. The power adapter according to claim 2 , wherein the power adapter comprises a first charging interface, 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;
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.

14. The power adapter according to claim 13 , 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 that the charging mode is the first charging mode, and to control the controllable switch to switch off when determining that the charging mode is the second charging mode.

15. The power adapter according to claim 2 , wherein the control unit s further configured to obtain a charging current and/or a charging voltage corresponding to the second charging mode according to the status information of the terminal when the power adapter is coupled to 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 that the charging mode is the second charging mode.

16. The power adapter according to claim 15 , 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

Assignees

• Guangdong Oppo Mobile Telecommunications Corp Ltd

Inventors

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

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