Charging system and charging method, and power adapter

Patent metadata

Field	Value
Publication number	US-10181745-B2
Application number	US-201715657984-A
Country	US
Kind code	B2
Filing date	Jul 24, 2017
Priority date	Feb 5, 2016
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

The present disclosure discloses a charging system, a charging method and a power adapter. The system includes a battery, 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 voltage sampling value and/or a current sampling value obtained by primary sampling of the sampling unit, such that a second alternating current outputted by the compositing unit meets a charging requirement. The second alternating current is applied to the battery.

First claim

What is claimed is:

1. A power adapter, comprising:
a first rectifier, configured to rectify a first alternating current and output a first voltage with a first ripple waveform;
a switch circuit, configured to modulate the first voltage according to a control signal and output a modulated first voltage;
a transformer, configured to output a plurality of voltages with ripple waveforms according to the modulated first voltage;
a compositing circuit, configured to composite the plurality of voltages to output a second alternating current, wherein, for each cycle of the second alternating current, a peak voltage of a positive half is greater than an absolute value of a valley voltage of a negative half, and the second alternating current 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 circuit, configured to sample voltage and/or current at a primary winding of the transformer to obtain a voltage sampling value and/or a current sampling value;
a control circuit, coupled to the sampling circuit and the switch circuit respectively, and configured to output the control signal to the switch circuit, 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 when the power adapter is coupled to the terminal.

2. The power adapter according to claim 1 , wherein the transformer comprises the primary winding, 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 circuit, the first secondary winding and the second secondary winding both are coupled to the compositing circuit, 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;
wherein the compositing circuit 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 circuit 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 circuit 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 circuit 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 circuit, coupled between the switch circuit and the control circuit, and configured to drive the switch circuit to switch on or off according to the control signal; and
an isolation circuit, coupled between the driving circuit and the control circuit.

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 circuit, coupled to the auxiliary winding, and configured to convert the fourth voltage and output a first direct current, so as to supply power to the driving circuit and/or the control circuit respectively.

7. The power adapter according to claim 6 , further comprising:
a first voltage detecting circuit, coupled to the auxiliary winding and the control circuit respectively, and configured to detect the fourth voltage to generate a voltage detecting value, wherein the control circuit 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 1 , wherein a working frequency of the transformer ranges from 50 KHz to 2 MHz.

9. The power adapter according to claim 1 , wherein the sampling circuit comprises:
a first current sampling circuit, configured to sample the current at the primary winding so as to obtain the current sampling value; and
a first voltage sampling circuit, configured to sample the voltage at the primary winding 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 circuit, configured to sample and hold a peak voltage of the modulated first voltage;
a cross-zero sampling circuit, configured to sample a zero crossing point of the modulated first voltage;
a discharging circuit, configured to perform a discharge on surge voltage; and
an AD sampling circuit, configured to sample the peak voltage in the peak voltage sampling and holding circuit so as to obtain the voltage sampling value.

11. 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 circuit, wherein the control circuit is configured to control the switch circuit 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.

12. The power adapter according to claim 1 , 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 circuit 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.

13. The power adapter according to claim 12 , further comprising:
a rectifying and filtering circuit, configured to rectify and filter one of the plurality of voltages and output a second direct current,
and a controllable switch, configured to control an operation of the rectifying and filtering circuit; wherein,
the control circuit is further configured to, when determining the charging mode as the first charging mode, control the rectifying and filtering circuit to work by controlling the controllable switch and control the compositing circuit to stop working, such that the rectifying and filtering circuit outputs the second direct current to charge the battery when the power adapter is coupled to the terminal; when determining the charging mode as the second charging mode, control the rectifying and filtering circuit to stop working by controlling the controllable switch and control the compositing circuit to work, such that the second alternating current is applied to the battery.

14. The power adapter according to claim 12 , wherein the control circuit 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 volt

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