Charging system and charging method, and power adapter and switching-mode power supply

Patent metadata

Field	Value
Publication number	US-10651677-B2
Application number	US-201715576236-A
Country	US
Kind code	B2
Filing date	Jan 7, 2017
Priority date	Feb 5, 2016
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A charging system and charging method for a terminal (2), and a power adapter (1) and a switch power source. The switch power source comprises a first rectification unit (101), a switch unit (102), a transformer (103), a second rectification unit (104), a sampling unit (106) and a control unit (107), wherein the control unit (107) outputs a control signal to the switch unit (102) and adjusts a voltage of a first pulse waveform according to a voltage sampling value and/or a current sampling value sampled by the sampling unit (106) to obtain a primary sampling voltage, and adjusts a duty ratio of the control signal according to the primary sampling voltage, the voltage sampling value and/or the current sampling value, so that a voltage of a third pulse waveform satisfies a charging requirement. The switch power source can make an output voltage and current waveform change along with an input voltage and current waveform, so that a good power factor can be obtained. Moreover, when the switch power source is applied to the power adapter (1), a voltage of an output pulse waveform can be directly loaded to a battery of the terminal (2), so that miniaturization and low costs of the power adapter (1) can be realized.

First claim

What is claimed is:

1. A switching-mode power supply, comprising:
a first rectification unit, configured to rectify an input alternating current and to output a voltage with a first pulsating waveform;
a switch unit, configured to modulate the voltage with the first pulsating waveform according to a control signal;
a transformer, configured to output a voltage with a second pulsating waveform according to the modulated voltage with the first pulsating waveform;
a second rectification unit, configured to rectify the voltage with the second pulsating waveform to output a voltage with a third pulsating waveform, and to apply the voltage with the third pulsating waveform on a battery of a terminal to charge the battery intermittently;
a sampling unit, configured to sample a voltage and/or a current output by the second rectification unit to acquire 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, to adjust the voltage with the first pulsating waveform according to the voltage sampling value and/or the current sampling value to acquire a primary sampling voltage, and to adjust a duty ratio of the control signal according to the primary sampling voltage, the current sampling value and/or the voltage sampling value, such that the voltage with the third pulsating waveform meets a charging requirement;
wherein the control unit comprises:
a first control module coupled to the sampling unit, and configured to acquire the voltage sampling value and/or the current sampling value, to judge whether the voltage sampling value and/or the current sampling value satisfy a preset requirement, and to output an adjusting signal when the voltage sampling value and/or the current sampling value fail to satisfy the preset requirement;
an adjusting module coupled to the first control module, and configured to adjust the voltage with the first pulsating waveform according to the adjusting signal so as to output the primary sampling voltage;
a second control module, wherein a feedback end of the second control module is configured to receive the voltage sampling value and/or the current sampling value, a primary sampling end of the second control module is coupled to an output end of the adjusting module to receive the primary sampling voltage, a driving output end of the second control module is coupled to the switch unit, and the second control module is configured to adjust the duty ratio of the control signal output to the switch unit according to the primary sampling voltage, the voltage sampling value and/or the current sampling value.

2. The switching-mode power supply according to claim 1 , wherein the adjusting module comprises:
an operational amplifier, wherein an output end of the operational amplifier is coupled to the primary sampling end of the second control module, an inverting input end of the operational amplifier is grounded via a first resistor, a non-inverting input end of the operational amplifier is coupled to a positive input end of the first rectification unit via a second resistor;
a third resistor, wherein a first end of the third resistor is coupled to the non-inverting input end of the operational amplifier and a second end of the third resistor is grounded; and
a digital potentiometer, wherein an adjusting end of the digital potentiometer is coupled to a first control module, the digital potentiometer is coupled between the inverting input end of the operational amplifier and the input end of the operational amplifier, and a resistance of the digital potentiometer is adjustable.

3. The switching-mode power supply according to claim 2 , wherein the first control module comprises:
a first control chip set on a secondary side and coupled to the sampling unit, wherein the first control chip is configured to judge whether the voltage sampling value and/or the current sampling value satisfy the preset requirement, and to generate an adjusting instruction when the voltage sampling value and/or the current sampling value fail to satisfy the preset requirement;
a second control chip set on a primary side, wherein the second control chip is configured to receive the adjusting instruction, and to output the adjusting signal to the digital potentiometer according to the adjusting instruction so as to adjust the resistance of the digital potentiometer, thereby changing an amplification factor of the operation amplifier; and
an isolating communicator set between the first control chip and the second control chip.

4. The switching-mode power supply according to claim 3 , wherein, when the voltage sampling value and/or the current sampling value are smaller, the second control chip is configured to adjust the resistance of the digital potentiometer to enlarge the amplification factor of the operation amplifier, the primary sampling voltage becomes bigger and varies with the voltage with the first pulsating waveform, and the duty ratio of the control signal output by the second control module becomes bigger, thereby enlarging the voltage and/or the current output by the second rectification unit.

5. The switching-mode power supply according to claim 3 , wherein, when the voltage sampling value and/or the current sampling value are bigger, the second control chip is configured to adjust the resistance of the digital potentiometer to reduce the amplification factor of the operation amplifier, the primary sampling voltage becomes smaller and varies with the voltage with the first pulsating waveform, and the duty ratio of the control signal output by the second control module becomes smaller, thereby reducing the voltage and/or the current output by the second rectification unit.

6. The switching-mode power supply according to claim 1 , wherein the feedback end of the second control module is coupled to a feedback module, the feedback module is configured to feedback the voltage with the third pulsating waveform to output a secondary feedback voltage to the second control module, such that the second control module adjusts the duty ratio of the control signal output to the switching-mode power supply according to the primary sampling voltage and the secondary feedback voltage.

7. The switching-mode power supply according to claim 6 , wherein the feedback module comprises a second digital potentiometer coupled to the first control module, the first control module is configured to adjust the second digital potentiometer when the voltage sampling value and/or the current sampling value fail to satisfy the preset requirement, so as to change a reference voltage of the feedback module to adjust the secondary feedback voltage.

8. The charging system according to claim 1 , wherein the sampling unit comprises:
a first current sampling circuit, configured to sample the current output by the second rectification unit so as to obtain the current sampling value; and
a first voltage sampling circuit, configured to sample the voltage output by the second rectification unit so as to obtain the voltage sampling value.

9. A power adapter, comprising:
a first rectification unit, configured to rectify an input alternating current and to output a voltage with a first pulsating waveform;
a switch unit, configured to modulate the voltage with the first pulsating waveform according to a control signal;
a transformer, configured to output a voltage with a second pulsating waveform according to the modulated voltage with the first pulsating waveform;
a second rectification unit, configured to rectify the voltage with the second pulsating waveform to output a voltage with a third pulsating waveform, and to apply the

Assignees

• Guangdong Oppo Mobile Telecommunications Corp Ltd

Inventors

• Chen Shebiao
• Zhang Jialiang

Classifications

• H02M7/06

  using discharge tubes without control electrode or semiconductor devices without control electrode · CPC title

• H02M3/33592

  having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer · CPC title

• H02J2207/10

  Control circuit supply, e.g. means for supplying power to the control circuit · CPC title

• H02M7/217

  using semiconductor devices only · CPC title

• H02M3/335

  using semiconductor devices only · CPC title