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

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 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;
• and
• a first charging interface coupled to the second rectification unit, wherein the first charging interface is configured to apply the voltage with the third pulsating waveform on a battery of a terminal;
• 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.

A charging system for a terminal, comprising:

• a battery;
• 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 to the battery, 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.