Charging system and charging circuit thereof

A charging system, comprising a circuit of a charging apparatus and a circuit of a wireless portable electronic device capable of recognizing an electric connection relation with the charging apparatus, wherein

• the circuit of the wireless portable electronic device comprises a second detection control module, a current source, a second switch, a resistor, and a charging input terminal;
• the charging input terminal is configured to be in contact with and electrically connected to a charging output terminal of the charging apparatus;
• and the current source is grounded through the charging input terminal and the resistor;
• the circuit of the charging apparatus comprises the charging output terminal, a first switch and a power source;
• the charging output terminal is grounded through the first switch;
• the first switch is controlled to be on when the power source is undervoltage, and controlled to be off when the power source is not undervoltage;
• the second detection control module is configured to enable, by controlling the second switch when a switch flag is ON, the current source to output a second current that passes through the resistor, and enable, by controlling the second switch when the switch flag is OFF, the current source to stop working;
• and
• the second detection control module is further configured to determine an electric connection relation between the wireless portable electronic device and the charging apparatus according to a detected level of the charging input terminal and the switch flag.

A circuit of a charging system, comprising a circuit of a charging apparatus capable of recognizing an electric connection relation with a wireless portable electronic device and a circuit of the wireless portable electronic device, wherein

• the circuit of the charging apparatus comprises:
• a power source, a DC-DC module, a first detection control module, and a charging output terminal;
• an output terminal of the DC-DC module is connected to the charging output terminal;
• the first detection control module is configured to set a mode flag to a constant current mode when a current outputted by the DC-DC module is equal to zero, and the DC-DC module is configured to work in the constant current mode according to the mode flag, so as to output a first current;
• the circuit of the wireless portable electronic device comprises:
• a resistor and a charging input terminal;
• the charging input terminal is grounded through the resistor;
• the charging output terminal is configured to be in contact with and electrically connected to the charging input terminal;
• and
• the first detection control module is configured to determine that an electric connection is formed between the charging apparatus and the wireless portable electronic device when it is detected that a voltage of the charging output terminal jumps from a high level to a low level and the mode flag is the constant current mode, set the mode flag to a voltage mode, and control the DC-DC module to output a first voltage according to the voltage mode.

A charging system, comprising a circuit of a charging apparatus capable of recognizing an electric connection relation with a wireless portable electronic device and a circuit of the wireless portable electronic device, wherein

• the circuit of the charging apparatus comprises:
• a power source, a DC-DC module, a first detection control module, and a charging output terminal;
• an output terminal of the DC-DC module is connected to the charging output terminal;
• the first detection control module is configured to set a mode flag to a constant current mode when a current outputted by the DC-DC module is equal to zero, and the DC-DC module is configured to work in the constant current mode according to the mode flag, so as to output a first current;
• the circuit of the wireless portable electronic device comprises:
• a resistor and a charging input terminal;
• the charging input terminal is grounded through the resistor;
• the charging output terminal is configured to be in contact with and electrically connected to the charging input terminal;
• and
• the first detection control module is configured to determine that an electric connection is formed between the charging apparatus and the wireless portable electronic device when it is detected that a voltage of the charging output terminal jumps from a high level to a low level and the mode flag is the constant current mode, set the mode flag to a voltage mode, and control the DC-DC module to output a first voltage according to the voltage mode.