CN209419249U

CN209419249U - The wireless headset and charging unit and the circuit of the two, charging system and circuit of recognizable connection relationship

Info

Publication number: CN209419249U
Application number: CN201822104556.1U
Authority: CN
Inventors: 翁建城; 黄海涛
Original assignee: Zhuhai Jieli Technology Co Ltd
Current assignee: Zhuhai Jieli Technology Co Ltd
Priority date: 2018-12-14
Filing date: 2018-12-14
Publication date: 2019-09-20
Anticipated expiration: 2028-12-14

Abstract

The utility model provides wireless headset, charging unit and system, and wireless headset includes the second detection control module, current source, second switch, resistance, charging input end；The charging input end with the charging output end of charging unit for connecting；The current source is via the charging input end and resistance eutral grounding；The second detection control module is used to make the current source export the second electric current by controlling the second switch when switch sign is conducting, so that the current source is stopped working by controlling the second switch when switch sign is to disconnect；The second detection control module is also used to determine according to the level and the switch sign that detect the charging input end electrical connection of the wireless headset Yu the charging unit.Wireless headset can level based on charging input end and switch sign determine the electrical connection of itself and the wireless headset.

Description

Wireless earphone capable of identifying connection relation, charging device, circuit of wireless earphone and charging device, charging system and circuit of wireless earphone and charging device

Technical Field

The utility model relates to a field of charging especially relates to wireless earphone and charging device of distinguishable relation of connection and circuit, charging system and circuit at the two.

Background

In recent years, various portable electronic products have been developed rapidly, and TWS (True Wireless headset) is one of the portable electronic products having a great representative today. For a wireless earphone which is not required to be connected with external equipment through a wire, a lithium battery in the wireless earphone is required to supply power, and the charging box is special equipment for charging the wireless earphone.

During wireless earphone and the box cooperation that charges were used, the initial box that charges was in standby state, put into the box that charges when wireless earphone, the box that charges detects the earphone and inserts, just opens the output that steps up and charges for wireless earphone. When the charging box detects that the earphone is taken out, the charging box enters the standby state again to reduce the power consumption of the charging box. At present, the detection technology of a plurality of charging boxes mainly depends on two modes, namely an active mode and a passive mode: 1. detect the switch lid action of box of charging through the box switch detection circuitry that charges and control the earphone in the box that charges, open the back through detecting the lid that charges promptly, awaken the box that charges and boost to wireless earphone and charge, when detecting the lid that charges closed back, turn off the box that charges and boost to reduce self consumption. 2. Through adding mechanical switch or shell fragment at the box that charges, put into and take out the box that charges at wireless earphone and have different hardware connection, change into the signal of telecommunication and transmit and do awaken up and close the module that steps up for the box chip that charges. For the active mode, since the switch detection circuit is always on, the charging box battery energy is consumed regardless of whether the charging box is in an open or closed state. For the passive mode, because of the mechanical switch or the elastic sheet, on one hand, the cost is increased, and on the other hand, the wireless earphone is put in and taken out for a plurality of times for a long time, and the problems of loss and reliability are inevitable. Especially, for the two modes, certain matching requirements are required to be made on the appearance sizes of the charging box and the wireless earphone.

In addition, with the development of portable electronic products towards the direction of further improving user experience and endurance, when the wireless earphone is taken out of the charging box, the mobile phone is automatically connected back, and if the song is played before the wireless earphone is placed in the charging box, the song is further played through wireless communication (for example, bluetooth communication), and the user does not need to manually press an on-off key. As long as the wireless earphone is still in the charging box, no matter the wireless earphone is being charged or is fully charged, especially under-voltage protection of the charging box or low-voltage protection of a battery of the charging box, the wireless earphone is required not to be connected back and enter a low-power-consumption mode under the condition that the output of the charging box is zero. In other words, even if the charging box has no output, the wireless headset needs to recognize whether it is inside the charging box. In the prior art, a Hall sensor is added in a charging box, and the action of putting in and taking out the wireless earphone from the charging box is identified by dividing a magnetic field of the Hall sensor to generate level change. But adding a hall sensor means increasing the cost.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the charging device is prevented from adopting the mechanical switch, the elastic sheet and the Hall sensor, and the wireless earphone is used for detecting the electric connection relation between the wireless earphone and the charging device, the utility model provides a circuit (such as a chip) of the wireless earphone, which can identify the electric connection relation between the wireless earphone and the charging device, and comprises a second detection control module, a current source, a second switch, a resistor and a charging input end; the charging input end is used for being in contact and electric connection with the charging output end of the charging device; the current source is grounded via the charging input terminal and the resistor; the second detection control module is used for controlling the second switch to enable the current source to output a second current to flow through the resistor when the switch mark is on, and controlling the second switch to enable the current source to stop working when the switch mark is off; the second detection control module is further used for judging the electric connection relation between the wireless earphone and the charging device according to the detected level of the charging input end and the switch mark.

In some embodiments, the second detection control module is further configured to determine, according to the detected level of the charging input terminal and the switch flag, that the electrical connection relationship between the wireless headset and the charging device is specifically: the second detection control module is further configured to determine that the wireless headset is electrically connected to the charging device when the second detection control module detects that the voltage at the charging input terminal is at a high level and the switch flag is off.

In some embodiments, the second detection control module is further configured to determine, according to the detected level of the charging input terminal and the switch flag, that the electrical connection relationship between the wireless headset and the charging device is specifically: the second detection control module is further configured to set the switch flag to be turned on when it is detected that the voltage at the charging input terminal jumps from a high level to a low level, and control the second switch to be turned on according to the switch flag; and if the charging input end is at a high level, the second detection control module judges that the wireless earphone is electrically disconnected with the charging device.

In some embodiments, the second detection control module is further configured to determine, according to the detected level of the charging input terminal and the switch flag, that the electrical connection relationship between the wireless headset and the charging device is specifically: the second detection control module is further configured to set the switch flag to be turned on when it is detected that the voltage at the charging input terminal jumps from a high level to a low level, and control the second switch to be turned on according to the switch flag; and if the charging input end is at a low level, the second detection control module judges that the wireless earphone is electrically connected with the charging device.

In some embodiments, the second detection control module is further configured to determine, according to the detected level of the charging input terminal and the switch flag, that the electrical connection relationship between the wireless headset and the charging device is specifically: after the second detection control module detects that the level of the charging input end jumps from a high level to a low level, the second detection control module is used for executing the following steps at a set frequency: modifying the switch flag to be conductive to control the second switch to be conductive; the second detection control module detects the level of the charging input end again, and if the level of the charging input end is a high level, the wireless earphone is judged to be electrically disconnected with the charging device; and if the level of the charging input end is low level, judging that the wireless earphone is electrically connected with the charging device.

In some embodiments, the second detection control module comprises a second control module and a second comparison module; the first input end of the second comparison module is connected with the charging input end, the second input end of the second comparison module is connected with a second reference voltage, and the output end of the second comparison module is connected with the second control module; the second control module is used for controlling the second switch to enable the current source to output a second current when the switch mark is on, controlling the second switch to enable the current source to stop working when the switch mark is off, and detecting the level of the charging input end according to the level output by the second comparison module; wherein a product of the second current and the resistance is greater than the second reference voltage.

In some embodiments, the circuit of the wireless headset further includes a reverse conduction prevention module and a charging module, and the reverse conduction prevention module is configured to prevent a voltage of the charging module from flowing backwards to the charging input terminal.

In order to overcome the defects of the prior art, the charging device is prevented from adopting the mechanical switch, the elastic sheet and the Hall sensor, and the wireless earphone is used for detecting the electric connection relation between the charging device and the wireless earphone; the circuit of the wireless earphone comprises a second detection control module, a current source, a second switch, a resistor and a charging input end; the charging input end is used for being electrically connected with a charging output end contact of a circuit of the charging device; the current source is grounded via the charging input terminal and the resistor; the circuit of the charging device comprises a charging output end and a first switch, wherein the charging output end is grounded through the first switch; the first switch is used for being controlled to be switched on when the power supply is undervoltage and being controlled to be switched off when the power supply is not undervoltage; the second detection control module is used for controlling the second switch to enable the current source to output a second current to flow through the resistor when the switch mark is on, and controlling the second switch to enable the current source to stop working when the switch mark is off; the second detection control module is further used for judging the electric connection relation between the wireless earphone and the charging device according to the detected level of the charging input end and the switch mark.

In some embodiments, the first switch is an enhancement P-channel MOS switch transistor, and the first detection control module outputs a zero voltage to a gate of the enhancement P-channel MOS switch transistor when the power supply is under-voltage.

In some embodiments, the second detection control module is further configured to determine, according to the detected level of the charging input terminal and the switch flag, that the electrical connection relationship between the wireless headset and the charging device is specifically: the second detection control module is further used for judging that the wireless earphone is electrically connected with the charging device when the voltage of the charging input end is detected to be high level and the switch mark is disconnected; or the second detection control module is further configured to set the switch flag to be turned on when it is detected that the voltage at the charging input terminal jumps from a high level to a low level, and control the second switch to be turned on according to the switch flag; if the charging input end is at a high level, the second detection control module judges that the wireless earphone is electrically connected with the charging device, and if the charging input end is at a low level, the second detection control module judges that the wireless earphone is electrically connected with the charging device; or, after the second detection control module detects that the level of the charging input end jumps from a high level to a low level, the second detection control module is configured to perform, at a set frequency: modifying the switch flag to be conductive to control the second switch to be conductive; the second detection control module detects the level of the charging input end again, and if the level of the charging input end is a high level, the wireless earphone is judged to be electrically disconnected with the charging device; and if the level of the charging input end is low level, judging that the wireless earphone is electrically connected with the charging device.

In order to overcome the defects of the prior art, the charging device is prevented from adopting the mechanical switch, the elastic sheet and the Hall sensor, and the wireless earphone is used for detecting the electric connection relation between the wireless earphone and the charging device, the utility model provides a circuit of the wireless earphone, which can identify the electric connection relation between the wireless earphone and the charging device, and comprises a second control module, a second comparison module, a current source, a second switch, a resistor, a charging input end and an anti-reverse conduction module; the charging input end is used for being in contact and electric connection with the charging output end of the charging device; the current source is grounded via the charging input terminal and the resistor; the first input end of the second comparison module is connected with the charging input end, the second input end of the second comparison module is connected with a second reference voltage, and the output end of the second comparison module is connected with the second control module; the second control module is used for controlling the second switch to enable the current source to output a second current to flow through the resistor when the switch mark is on, and controlling the second switch to enable the current source to stop working when the switch mark is off; the second control module is further configured to detect a level of the charging input terminal according to the level output by the second comparison module, and determine an electrical connection relationship between the wireless headset and the charging device according to the detected level of the charging input terminal and the switch flag.

In order to overcome prior art's not enough, avoid charging device to adopt above-mentioned mechanical switch, shell fragment and hall sensor to realize wireless earphone to its detection with the charging device electricity relation of connection, the utility model also provides a wireless earphone of distinguishable and charging device electricity relation of connection, including arbitrary wireless earphone's circuit.

In order to overcome prior art's not enough, avoid charging device to adopt above-mentioned mechanical switch, shell fragment and hall sensor to realize wireless earphone to its detection with the charging device electricity relation of connection, the utility model also provides a charging system, including arbitrary charging system's circuit.

In order to overcome prior art's not enough, avoid charging device to adopt above-mentioned mechanical switch, shell fragment and hall sensor in order to realize charging device to the detection with wireless earphone's electric connection relation, the utility model provides a distinguishable charging device's with wireless earphone electric connection relation circuit (for example chip), include: the charging device comprises a DC-DC module, a first detection control module and a charging output end; the output end of the DC-DC module is connected with the charging output end, and the charging output end is used for being in contact and electric connection with the charging input end of the wireless earphone; the first detection control module is used for setting a mode flag to be in a constant current mode when the current output by the DC-DC module is equal to zero, and the DC-DC module is used for working in the constant current mode according to the mode flag; the first detection control module is used for detecting that the voltage of the charging output end jumps from a high level to a low level, judging that the charging device is electrically connected with the wireless earphone when the mode flag is in a constant current mode, setting the mode flag bit to be in a voltage mode, and controlling the DC-DC module to output a first voltage according to the voltage mode.

In order to overcome prior art's not enough, avoid charging device to adopt above-mentioned mechanical switch, shell fragment and hall sensor in order to realize charging device to the detection with wireless headset's electric connection relation, the utility model provides a charging system's circuit, including distinguishable charging device's circuit and wireless headset's circuit with wireless headset electric connection relation, charging device's circuit includes: the charging device comprises a DC-DC module, a first detection control module and a charging output end; the output end of the DC-DC module is connected with the charging output end; the first detection control module is used for setting a mode flag to be in a constant current mode when the current output by the DC-DC module is equal to zero, and the DC-DC module is used for working in the constant current mode according to the mode flag to output a first current; the circuitry of the wireless headset comprises: a resistor, a charging input terminal; the charging input end is grounded through the resistor; the charging output end is used for being electrically connected with the charging input end in a contact way; the first detection control module is used for detecting that the voltage of the charging output end jumps from a high level to a low level, judging that the charging device is electrically connected with the wireless earphone when the mode flag is in a constant current mode, setting the mode flag bit to be in a voltage mode, and controlling the DC-DC module to output a first voltage according to the voltage mode.

In some embodiments, the first detection control module comprises a first control module and a first comparison module; the first input end of the first comparison module is connected with the charging output end, the second input end of the first comparison module is connected with the first reference voltage, and the output end of the first comparison module is connected with the first control module; the product of the first current, the resistance and the voltage division coefficient is smaller than the first reference voltage; the first control module is used for detecting the level of the charging input end according to the level output by the first comparison module.

In some embodiments, the circuitry of the wireless headset further comprises a second detection control module; the second detection control module comprises a second control module and a second comparison module; the first input end of the second comparison module is connected with the charging input end, the second input end of the second comparison module is connected with a second reference voltage, and the output end of the second comparison module is connected with the second control module; the product of the first current and the resistance is greater than the second reference voltage, and the product of the second current and the resistance is greater than the second reference voltage; the second control module is used for detecting the level of the charging input end according to the level output by the second comparison module so as to judge the electrical connection relation between the wireless earphone and the charging device.

In some embodiments, the circuit of the charging device further comprises a first switch, and the charging output terminal is grounded through the first switch; the first switch is used for being controlled to be switched on when the power supply is undervoltage and being controlled to be switched off when the power supply is not undervoltage; the circuitry of the wireless headset further comprises: the second detection control module, the current source and the second switch; the current source is grounded via the charging input terminal and the resistor; the second detection control module is used for controlling the second switch to enable the current source to output a second current when the switch mark is on and controlling the second switch to enable the current source to stop working when the switch mark is off; the second detection control module is further used for judging the electric connection relation between the wireless earphone and the charging device according to the detected level of the charging input end and the switch mark.

In some embodiments, the second detection control module comprises a second control module and a second comparison module; the first input end of the second comparison module is connected with the charging input end, the second input end of the second comparison module is connected with a second reference voltage, and the output end of the second comparison module is connected with the second control module; the product of the first current and the resistance is greater than the second reference voltage, and the product of the second current and the resistance is greater than the second reference voltage; the second detection control module is further configured to determine, according to the detected level of the charging input terminal and the switch flag, that the electrical connection relationship between the wireless headset and the charging device is specifically: the second control module is used for detecting the level of the charging input end and the switch mark according to the level output by the second comparison module so as to judge the electric connection relation between the wireless earphone and the charging device.

In order to overcome prior art's not enough, avoid charging device to adopt above-mentioned mechanical switch, shell fragment and hall sensor in order to realize charging device to the detection with wireless headset's electric connection relation, the utility model provides a charging system's circuit, including distinguishable charging device's circuit and wireless headset's circuit with wireless headset electric connection relation, charging device's circuit includes: the charging device comprises a DC-DC module, a first comparison module, a first control module, a first switch, a charging output end and a power supply; the circuit of the wireless earphone comprises a second comparison module, a second control module, a current source, a second switch, a resistor and a charging input end; the charging output end is used for being electrically connected with the charging input end in a contact way; the input end of the DC-DC module is connected with the power supply, the output end of the DC-DC module is connected with the charging output end, and the charging output end is grounded through a first switch; the first input end of the first comparison module is connected with the charging output end, the second input end of the first comparison module is connected with the first reference voltage, and the output end of the first comparison module is connected with the first control module; the first switch is used for being controlled to be conducted when the power supply is under-voltage; the current source is grounded through the charging input end and the resistor, the first input end of the second comparison module is connected with the charging input end, the second input end of the second comparison module is connected with a second reference voltage, and the output end of the second comparison module is connected with the second control module; the second control module is used for controlling the second switch to enable the current source to output a second current when the switch mark is on and controlling the second switch to enable the current source to stop working when the switch mark is off; the first control module is used for judging that the charging device is electrically disconnected with the wireless earphone when the current output by the DC-DC module is equal to zero, and setting a mode flag to be a constant current mode, and the DC-DC module is used for working in the constant current mode according to the mode flag to output a first current; the first control module is used for judging that the voltage of the charging output end jumps from a high level to a low level by detecting a signal output by the first comparison module, and when the mode flag is in a constant current mode, the first control module judges that the charging device is electrically connected with the wireless earphone, sets the mode flag bit to be in a voltage mode, and controls the DC-DC module to output a first voltage according to the voltage mode; the second control module is further used for judging the electrical connection relation between the wireless earphone and the charging device according to the detected level of the charging input end and the switch mark; wherein a product of the first current, the resistance and the voltage division coefficient is smaller than the first reference voltage, a product of the first current and the resistance is larger than the second reference voltage, and a product of the second current and the resistance is larger than the second reference voltage.

In order to overcome prior art's not enough, avoid charging device to adopt above-mentioned mechanical switch, shell fragment and hall sensor in order to realize charging device to the detection with wireless earphone's electric connection relation, the utility model provides a distinguishable charging device's with wireless earphone electric connection relation circuit (for example chip), include: the charging device comprises a DC-DC module, a first comparison module, a first control module, a first switch, a charging output end and a power supply; the input end of the DC-DC module is connected with the power supply, the output end of the DC-DC module is connected with the charging output end, and the charging output end is grounded through a first switch; the first input end of the first comparison module is connected with the charging output end, the second input end of the first comparison module is connected with the first reference voltage, and the output end of the first comparison module is connected with the first control module; the first switch is used for being controlled to be conducted when the power supply is under-voltage; the charging output end is used for being in contact and electric connection with the charging input end of the wireless earphone; the first control module is used for judging that the charging device is electrically disconnected with the wireless earphone when the current output by the DC-DC module is equal to zero, and setting a mode flag to be a constant current mode, and the DC-DC module is used for working in the constant current mode according to the mode flag; the first control module is used for judging that the voltage of the charging output end jumps from a high level to a low level by detecting the signal output by the first comparison module, and when the mode flag is in a constant current mode, the first control module judges that the charging device is electrically connected with the wireless earphone, sets the mode flag bit to be in a voltage mode, and controls the DC-DC module to output a first voltage according to the voltage mode.

In order to overcome prior art's not enough, avoid charging device to adopt above-mentioned mechanical switch, shell fragment and hall sensor in order to realize charging device to the detection with wireless headset's electric connection relation, the utility model also provides a charging device of distinguishable and wireless headset electric connection relation, including arbitrary charging device circuit of distinguishable and wireless headset electric connection relation.

In order to overcome prior art's not enough, avoid charging device to adopt above-mentioned mechanical switch, shell fragment and hall sensor in order to realize charging device to the detection with wireless earphone's electric connection relation, the utility model also provides a charging system, including arbitrary charging system's circuit.

Has the advantages that:

for the wireless earphone and the system comprising the wireless earphone, the scheme can prevent the charging device from being additionally provided with elements such as a mechanical switch, an elastic sheet or a Hall sensor and the like so that the wireless earphone can detect the electrical connection relation between the wireless earphone and the charging device. As a further effect, the charging device and the housing of the wireless headset do not need to be specially designed based on the above-mentioned mechanical switch, spring plate or hall sensor, thereby reducing the cost and improving the reliability.

For the charging device and the system comprising the same, by adopting the charging device, the wireless earphone, the charging system or the method, the charging device can be prevented from being additionally provided with elements such as a mechanical switch, an elastic sheet or a Hall sensor and the like so as to detect the electrical connection relation between the charging device and the wireless earphone. As a further effect, the charging device and the housing of the wireless headset do not need to be specially designed based on the above-mentioned mechanical switch, spring plate or hall sensor, thereby reducing the cost and improving the reliability.

Drawings

The invention will be further explained with reference to the drawings and examples, wherein:

fig. 1 is a schematic diagram of an embodiment of a charging system composed of a charging box and a wireless headset according to the present invention;

FIG. 2 is a schematic diagram of one embodiment of a voltage waveform diagram of a charging output of the charging box of FIG. 1 compared to a charging input of a wireless headset;

fig. 3 is a schematic diagram of another embodiment of the charging output of the charging box of fig. 1 compared to a voltage waveform diagram of the charging input of the wireless headset.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of a charging system composed of a charging box and a wireless headset according to an embodiment of the present invention, wherein the charging system can identify an electrical connection relationship between the charging box and the wireless headset. The charging box 10 includes a DC-DC module 11, a first detection control module, a first switch S1, a power source 12, a charging output terminal POWEROUT, and a first ground terminal GND1, wherein the DC-DC module 11 includes a current detection module 111, and in one embodiment, the first detection control module includes a first comparison module C1 and a first control module 13. The wireless headset 20 includes a charging module 21, a second detection control module, a current source 24, a second switch S2, a resistor R, an anti-reverse conduction module 23, a charging input terminal powerrin, a rechargeable battery VBAT, and a second ground terminal GND2, and in one embodiment, the second detection control module includes a second comparing module C2 and a second control module 22.

In the charging box 10, the input terminal of the DC-DC module 11 is connected to the power supply 12, the output terminal thereof is connected to the charging output terminal POWEROUT, and the charging output terminal POWEROUT is grounded through the first switch S1. A non-inverting input end of the first comparing module C1 is connected to the charging output end POWEROUT, an inverting input end is connected to the first reference voltage VR1, and an output end is connected to an input end of the first control module 13; the first ground terminal GND1 is connected to ground. The current detecting unit 111 is used for detecting the current output by the DC-DC module 11, and it is understood that the current detecting unit 111 may be disposed outside the DC-DC module 11. The first control module 13 manages a mode flag (the mode flag may be stored in a register) of the DC-DC module 11, the mode flag having two values: a constant current mode and a voltage mode (e.g., a boost mode), the first control module 13 may set the value of the mode flag to switch between the constant current mode and the voltage mode, and the initial value of the mode flag may be set to the constant current mode. The first control module 13 controls the working mode of the DC-DC module 11 according to the value of the mode flag, and when the value of the mode flag is the voltage mode, the first control module 13 controls the DC-DC module 11 to output a first voltage for charging the wireless headset 20 according to the mode flag; when the value of the mode flag is the constant current mode, the first control module 13 controls the DC-DC module 11 to output a constant current (first current) according to the mode flag. In one embodiment, the first voltage is a voltage (charging voltage) obtained by boosting the voltage of the power supply 12 when the DC-DC module 11 operates in the boost mode, such as 5V. The first control module 13 may be a logic circuit and the first comparison module C1 may be a comparator.

In the wireless earphone 20, the charging input terminal POWERIN is connected with the rechargeable battery VBAT via the reverse conduction preventing module 23 and the charging module 21, the non-inverting input terminal of the second comparing module C2 is connected with the charging input terminal POWERIN, the inverting input terminal thereof is connected with the second reference voltage VR2, and the output terminal thereof is connected with the input terminal of the second control module 22, the second comparing module C2 is configured to compare the voltage of the charging input terminal POWERIN with the second reference voltage VR 2; the second control module 22 manages switch flags (which may be stored in registers), the values of which include: the second control module 22 is used for controlling the second switch S2 to be switched on and off according to the value of the switch flag, when the value of the switch flag is switched on, the second control module 22 controls the second switch S2 to be switched on according to the value (on) of the switch flag, and when the value of the switch flag is switched off, the second control module 22 controls the second switch S2 to be switched off according to the value (off) of the switch flag; the charging battery VBAT is connected to the charging input terminal powerrin via the second switch S2 and the current source 24, and the charging input terminal powerrin is grounded via the resistor R; the second ground GND2 is connected to ground. The rechargeable battery VBAT supplies power to the current source 24 via the second switch S2, the current source 24 stops operating, i.e., outputs zero current, when the second switch S2 is turned off, and the current source 24 outputs a second current to flow through the resistor R when the second switch S2 is turned on. The second control module 22 may be a logic circuit and the second comparison module C2 may be a comparator. The reverse conduction preventing module 23 is configured to prevent the voltage of the charging module 21 and/or the battery VBAT (via the charging module 21) from flowing backward to the charging input terminal powerrin, so as to prevent the level detected by the second detection control module from being incorrect, and further prevent the determined electrical connection relationship from being incorrect. In one embodiment, the reverse conduction preventing module 23 may be a diode, an anode of the diode is connected to the charging input terminal powerrin, and a cathode of the diode is connected to the charging module 21; the reverse conduction preventing module 23 may also be a one-way conduction switch or the like. It will be appreciated that the reverse conduction prevention module 23 may also be integrated in the charging module 21.

At an initial stage (for example, after the charging box 10 is powered on), the charging earphone 20 is not yet in contact with the charging box 10 to form an electrical connection (for example, the charging box 10 is put into the charging box to form an electrical connection), at one side of the charging box 10, the first control module 13 sets the mode flag of the DC-DC module 11 to be in the constant current mode, and the first control module 13 controls the DC-DC module 11 to operate in the constant current mode according to the mode flag and controls the first switch S1 to be turned off; on the wireless headset 20 side, the second switch S2 is open. Specifically, as shown in fig. 2, in the charging box 10, since the first switch S1 is turned off at this time, the DC-DC module 11 is unloaded, the current actually output by the DC-DC module 11 is zero, the voltage at the charging output terminal POWEROUT is pulled to the second voltage U2 (in one embodiment, the second voltage U2 is the power supply voltage of the charging box 10), that is, the voltage at the non-inverting input terminal of the first comparing module C1 is the second voltage U2, the voltage at the inverting input terminal is the first reference voltage VR1, and since the second voltage U2 is greater than the first reference voltage VR1, the first comparing module C1 outputs a high level to the first control module 13. Based on this, when the first control module 13 detects that the first comparison module C1 outputs a high level and the mode flag is in the constant current mode, it is determined that the charging box 10 is not electrically connected to the wireless headset 20 at this time (or, when it is detected that the current output from the DC-DC module is 0, it is determined that the charging box 10 is not electrically connected to the wireless headset 20 at this time), so the value of the mode flag is maintained in the constant current mode, and the first switch S1 is maintained to be turned off. As shown in fig. 2, in the wireless headset 20, since the second switch S2 is turned off, the current outputted by the current source 24 is zero, the voltage at the charging input terminal POWERIN is zero, i.e., the voltage at the non-inverting input terminal of the second comparing module C2 is zero, and the voltage at the inverting input terminal of the second comparing module C2 is the second reference voltage VR2, the second comparing module C2 outputs a low level to the second control module 22. Based on this, when the second control module 22 detects that the second comparing module C2 outputs a low level and the switch flag is off, it is determined that the wireless headset 20 is not electrically connected to the charging box 10, thereby maintaining the switch flag unchanged.

When the wireless headset 20 needs to be electrically connected to the charging box 10 for charging (for example, the wireless headset 20 is put into the charging box 10 for charging), the charging output terminal POWEROUT is electrically contacted to the charging input terminal POWERIN, and the electric power of the charging box 10 is transmitted to the wireless headset 20 through the charging output terminal POWEROUT and the charging input terminal POWERIN. The first ground GND1 is connected to the second ground GND2, but the first ground GND1 may not be connected to the second ground GND 2. As shown in fig. 2, since the mode flag is the constant current mode, once the charging output terminal POWEROUT is electrically contacted to the charging input terminal POWERIN, the DC-DC module 11 outputs a constant first current, the first current is sent to the ground through the charging output terminal POWEROUT, the charging input terminal POWERIN and the resistor, and the voltage of the charging output terminal POWEROUT and the charging input terminal POWERIN is I1 × R2 (as shown in fig. 2, at time t1, the voltage of the charging output terminal POWEROUT is decreased to U3), that is, the voltage of the non-inverting input terminal of the first comparing module C1 is I1 × R2. Since I1 × R2 is smaller than the first reference voltage VR1, the first comparing module C1 outputs a low level to the first control module 13. Based on this, when the first control module 13 detects that the level output by the first comparing module C1 jumps from a high level to a low level (i.e., it is determined that the voltage of the charging output terminal POWEROUT jumps from a high level to a low level), and the value of the mode flag is the constant current mode, it is determined that the wireless headset 20 has been electrically connected to the charging box 10, and the mode flag is modified to the voltage mode, the first control module 13 switches the DC-DC module 11 from the constant current mode to the voltage mode (e.g., the step-up mode) that outputs the first voltage according to the mode flag (voltage mode). Thereafter, the voltage of the charging output terminal POWEROUT is maintained at the first voltage (as shown in fig. 2, the voltage of the charging output terminal POWEROUT is pulled up to U1 at time t 2), and since the first voltage is greater than the first reference voltage VR1, the first comparing module C1 outputs a high level. Based on this, when the first control module 13 detects that the first comparing module C1 outputs a high level and the value of the mode flag is the voltage mode, it is determined that the charging box 10 is still electrically connected to the wireless headset 20 and the charging box 10 is charging the wireless headset 20. For the wireless headset 20, at the moment when the wireless headset 20 is inserted into the charging box 10, the voltage of the charging input terminal POWERIN is I1 × R2 (i.e., the voltage of the non-inverting input terminal of the second comparing module C2 is I1 × R2, as shown in fig. 2, the voltage of the charging input terminal POWERIN is pulled up to U3 at time t 1), and since I1 × R2 is greater than the second reference voltage VR2, the second comparing module C2 outputs a high level to the second control module 22. Based on this, when the second control module 22 detects that the output level of the second comparing module C2 jumps from low level to high level (i.e. the voltage of the charging input terminal POWERIN jumps from low level to high level), and the value of the switch flag is off, it is determined that the wireless headset 20 is electrically connected to the charging box 10, and the charging module 21 is controlled to be turned on; thereafter, the charging input terminal powerrin is maintained at the first voltage (as shown in fig. 2, the voltage is further pulled up to U1 at time t 2), and the second comparing module C2 continues to output a high level since the first voltage is greater than the second reference voltage VR 2. The first voltage output from the charging box 10 charges the rechargeable battery VBAT through the charging input terminal powerrin, the reverse conduction preventing module 23, and the charging module 21. Based on this, when the second control module 22 detects that the second comparing module C2 outputs a high level (i.e. the voltage at the charging input terminal powerrin is a high level) and the value of the switch flag is off, it is determined that the wireless headset 20 is electrically connected to the charging box 10, and the charging module 21 continues to be controlled to be turned on.

As the charge amount of the rechargeable battery VBAT of the wireless headset 20 approaches full charge, the charging current flowing into the charging module 21 gradually decreases, and thus the charging current output by the DC-DC module 11 gradually decreases. On one hand, after the current detection unit 111 of the charging box 10 detects that the charging current is smaller than the set current threshold (in one embodiment, the current threshold is slightly larger than the current value obtained by dividing the first voltage by the resistor), a corresponding signal is output to the first control module 13, the first control module 13 modifies the value of the mode flag from the voltage mode to the constant current mode according to the signal, and the first control module 13 controls the DC-DC module 11 to operate in the constant current mode according to the mode flag (constant current mode), that is, outputs the first current; at this time, the charging box 10 no longer supplies power to the charging module 21, and this state of the charging box 10 may be referred to as a standby state. On the other hand, the wireless headset 20 may also perform the following operations: when the current detection unit 111 of the wireless headset 20 detects that the charging current flowing into the charging module 21 is less than a certain threshold, the second control module 22 controls the charging module 21 to turn off. When the DC-DC module 11 outputs the first current, the voltage of the charging output terminal POWEROUT and the charging input terminal powerrin is I1 × R2. For the charging box 10, the voltage I1 × R2 at the non-inverting input of the first comparing module C1 (the voltage drops to U3 at time t3 as shown in fig. 2) is less than the voltage at the inverting input (i.e., the first reference voltage VR1), so the first comparing module C1 outputs a low level. Based on this, when the first control module 13 detects that the level output by the first comparing module C1 jumps from the high level to the low level (i.e. the level of the charging output terminal POWEROUT jumps from the high level to the low level), and the value of the mode flag is the constant current mode, the first control module 13 determines that the wireless headset 20 is electrically connected to the charging box 10. For the wireless headset 20, the voltage I1 × R2 (shown in fig. 2, the voltage drops to U3 at time t 3) of the non-inverting input terminal of the second comparing module C2 is greater than the voltage of the inverting input terminal (i.e., the second reference voltage VR2), so the second comparing module C2 outputs a high level. Based on this, when the second control module 22 detects that the second comparing module C2 outputs a high level and the switch flag is off, the second control module 22 determines that the wireless headset 20 is still electrically connected to the charging box 10.

When the electrical connection between the wireless headset 20 and the charging box 10 is disconnected (e.g., the user takes the wireless headset 20 out of the charging box 10), the following situations are included: 1. the electrical connection with the wireless headset 20 is disconnected while the charging box 10 is charging the wireless headset 20 (at this time, the value of the mode flag is the voltage mode); 2. the electrical connection to the charging box 10 is disconnected when the wireless headset 20 has been fully charged (when the value of the mode flag is in the constant current mode). In case 1, for the charging box 10, since the voltage of the non-inverting input terminal (first voltage) of the first comparing module C1 is greater than the voltage of the inverting input terminal (first reference voltage VR1) at this time, the first comparing module C1 outputs a high level; the current detected by the current detection unit 111 of the charging box 10 is 0. Based on this, when the first control module 13 detects that the first comparing module C1 outputs a high level and the current detected by the current detecting unit 111 is 0, the first control module 13 determines that the electrical connection between the charging box 10 and the wireless headset 20 is disconnected at this time and modifies the mode flag from the voltage mode to the constant current mode. The first control module 13 controls the DC-DC module 11 to be modified from the voltage mode to the constant current mode according to a mode flag (constant current mode). In case 2, for the charging box 10, since the voltage of the non-inverting input terminal of the first comparing module C1 (the second voltage U2, as shown in fig. 2, the voltage is pulled up to U2 at time t 4) is greater than the voltage of the inverting input terminal (the first reference voltage VR1) at this time, the first comparing module C1 outputs a high level. Based on this, when the first control module 13 detects that the first comparing module C1 outputs a high level and the value of the mode flag is (constant current mode), the first control module 13 determines that the electrical connection between the charging box 10 and the wireless headset 20 is disconnected at this time (or, when the current output by the DC-DC module is detected to be 0, determines that the charging box 10 is not electrically connected to the wireless headset 20 at this time). For the wireless headset 20, in case 1 and 2, before the wireless headset 20 is unplugged, the voltage of the non-inverting input terminal of the second comparing module C2 (the first voltage in case 1, and the I1R 2 in case 2) is greater than the voltage of the inverting input terminal (the second reference voltage VR2), so the second comparing module C2 outputs high level; after the wireless headset 20 is unplugged, the voltages of the non-inverting input terminals (which are 0, and the voltage drops to 0 at the time point t4 as shown in fig. 2) of the second comparing modules C2 are all smaller than the voltage of the inverting input terminal (the second reference voltage VR2), so that the second comparing modules C2 all output a low level. That is, the level output from the second comparison module C2 transits from high level to low level in this process. Based on this, when the second control module 22 detects that the level output by the second comparing module C2 jumps from the high level to the low level, and the switch flag is off, the second control module 22 determines that the wireless headset 20 is electrically disconnected from the charging box 10 (e.g., the wireless headset 20 is pulled out from the charging box 10).

In one embodiment, in order to protect the charging box 10, the output of the DC-DC module 11 needs to be turned off when the voltage of the power source 12 of the charging box 10 is lower than a threshold value (which may be the case that 1, when the voltage of the power source 12 is lower than a first voltage threshold value, only the output of the DC-DC module 11 is turned off, but the power source 12 still supplies power to the first control module 13, so that the first control module 13 can still control the turning on and off of the first switch S1 by a high level or a low level in this case; 2, when the voltage of the power source 12 is lower than a second voltage threshold value (smaller than the first voltage threshold value), not only the output of the DC-DC module 11 is turned off while the power source 12 stops supplying power to the rest of the circuits, and the first switch S1 is controlled to be turned on, in order to enable the wireless headset 20 to more accurately detect the electrical connection between the wireless headset 20 and, when the second control module 22 detects that the level output by the second comparing module C2 jumps from a high level to a low level, the second control module 22 modifies the value of the switch flag to be on, then controls the second switch S2 to be closed according to the value of the switch flag (which is on at this time), and then detects the output level of the second comparing module C2, and the second control module 22 determines the electrical contact relationship between the wireless headset 20 and the charging box 10 at this time according to the output level of the second comparing module C2 and the switch flag.

In the case of the charging box 10 having under-voltage protection, there are several cases: 1. the electrical connection with the wireless headset 20 is disconnected while the charging box 10 is charging the wireless headset 20 (at this time, the value of the mode flag is the voltage mode); 2. the electrical connection with the charging box 10 is disconnected when the wireless headset 20 has been fully charged (at this time, the value of the mode flag is in the constant current mode); 3. an under-voltage (full or not full of the wireless headset 20) occurs before the electrical connection of the wireless headset 20 to the charging box 10 is disconnected. For the wireless headset 20, in case 1 and 2, before the wireless headset 20 is unplugged, the voltage of the non-inverting input terminal of the second comparing module C2 (the first voltage in case 1, and the I1R 2 in case 2) is greater than the voltage of the inverting input terminal (the second reference voltage VR2), so the second comparing module C2 outputs high level; after the wireless headset 20 is unplugged, the voltages (0) of the non-inverting input terminals of the second comparing module C2 are all smaller than the voltage (the second reference voltage VR2) of the inverting input terminal, so that the second comparing module C2 outputs a low level. That is, the level output from the second comparison module C2 transits from high level to low level in this process. Next, if the second switch S2 is turned on, the voltage at the non-inverting input terminal (I2 × R2) of the second comparing module C2 is greater than the voltage at the inverting input terminal (the second reference voltage VR2), so the second comparing module C2 outputs a high level. Based on this, when the second control module 22 detects that the level output by the second comparing module C2 jumps from high level to low level and the switch flag is off, the second control module 22 modifies the value of the switch flag to on, then controls the second switch S2 to be on according to the value of the switch flag (which is on at this time), the second control module 22 then detects the output level of the second comparing module C2, then the second control module 22 detects the output level, and if the output level is high, the second control module 22 determines that the wireless headset 20 is electrically disconnected from the charging box 10 (e.g., the wireless headset 20 is pulled out from the charging box 10). In case 3, before the charging box 10 is under-voltage, the voltage of the non-inverting input terminal of the second comparing module C2 (which is the first voltage or I1R 2) is greater than the voltage of the inverting input terminal (the second reference voltage VR 2); when the charging box 10 is under-voltage, the first control module 13 controls the DC-DC module 11 to stop outputting the voltage, and controls the first switch S1 to be turned on, and at this time, the voltage at the non-inverting input terminal of the second comparing module C2 (i.e. the voltage at the charging output terminal POWEROUT, is 0) is smaller than the voltage at the inverting input terminal (the second reference voltage VR2), so that the second comparing module C2 outputs a low level, as shown in fig. 3, and the voltages at the charging output terminal POWEROUT and the charging input terminal POWERIN drop from U1 to 0 at time t 3; if the second switch S2 is turned on at the time t4 immediately after t3, the voltage at the non-inverting input terminal of the second comparing module C2 (which is 0, as shown in fig. 3, and the voltage is still 0 at the time t 4) is still less than the voltage at the inverting input terminal (the second reference voltage VR2), so the second comparing module C2 outputs a low level. Based on this, when the second control module 22 detects that the level output by the second comparing module C2 jumps from a high level to a low level and the switch flag is off, the second control module 22 modifies the value of the switch flag to on, then controls the second switch S2 to be on according to the value of the switch flag (on at this time), the second control module 22 then detects the output level of the second comparing module C2, then the second control module 22 detects the output level, and if the output level is low, the second control module 22 determines that the wireless headset 20 is electrically connected to the charging box 10 and the charging box 10 is in an under-voltage state; if the output level is a high level, the second control module 22 determines that the wireless headset 20 is electrically disconnected from the charging box 10.

In order to more accurately determine the electrical connection relationship between the wireless headset 20 and the charging box 10 and to take the power consumption of the wireless headset 20 into account, in addition to controlling the second switch S2 to be turned on when the output level of the second comparing module C2 jumps from a high level to a low level, the switch flag may be modified at a certain frequency to control the second switch S2 to be turned on at a certain frequency (e.g., turned on every 1ms or 2 ms), and then the second controlling module 22 detects the output level of the second comparing module C2 and determines the electrical connection relationship between the wireless headset 20 and the charging box 10 according to the output level and the switch flag at that time. For example, for the above-mentioned case 3, when the second control module 22 detects that the level output by the second comparing module C2 jumps from high level to low level and the switch flag is off, the second control module 22 modifies the value of the switch flag to on, then controls the second switch S2 to be on according to the value of the switch flag (which is on at this time), the second control module 22 then detects the output level of the second comparing module C2, then the second control module 22 detects the output level, and if the output level is low level, the second control module 22 determines that the wireless headset 20 is electrically connected to the charging box 10 and the charging box 10 is in an under-voltage state. If the wireless headset 20 is pulled out of the charging box 10 by the user after a certain period of time, when the wireless headset 20 is pulled out of the charging box 10, the voltage (0) of the non-inverting input terminal of the second comparing module C2 is less than the voltage (the second reference voltage VR2) of the inverting input terminal, so that the second comparing module C2 outputs a low level; when the second switch S2 is closed, the voltage at the non-inverting input terminal of the second comparing module C2 (I2 × R2, as shown in fig. 3, the voltage at the charging input terminal POWERIN is pulled up to U5 at time t 5) is greater than the voltage at the inverting input terminal (the second reference voltage VR2), so the second comparing module C2 outputs a high level. In view of this, the second control module 22 modifies the switch flag to be on at a certain frequency, then controls the second switch S2 to be on according to the switch flag, then detects the level output by the second comparison module C2, determines that the wireless headset 20 is electrically disconnected from the charging box 10 if the second comparison module C2 outputs a low level before the second switch S2 is on and the second comparison module C2 outputs a high level when the second switch S2 is on, then modifies the switch flag to be off again, and controls the second switch S2 to be off according to the switch flag; if the second comparing module C2 outputs a low level before the second switch S2 is turned on and the second comparing module C2 still outputs a low level when the second switch S2 is turned on, it is determined that the wireless headset 20 is still electrically connected to the charging box 10 and the charging box 10 is under-voltage, and then the switch flag is modified to be off again and the second switch S2 is controlled to be off according to the switch flag.

In one embodiment, in order to cooperate with the wireless headset 20 to detect the electrical connection relationship between the charging box 10 and the wireless headset 20 when the charging box 10 is under-voltage, and further improve the under-voltage protection of the charging box 10, the first switch S1 employs an enhanced P-channel MOS switch, and the first control module 13 outputs a gate control signal to the gate of the enhanced P-channel MOS switch to control the on/off of the enhanced P-channel MOS switch. When the charging box 10 is under-voltage, all the circuits including the DC-DC module 11, the first control module 13, etc. can be turned off, so that the gate control signal of the enhanced P-channel MOS switch is at low level (0), and the enhanced P-channel MOS switch is turned on. It can be seen that, at this time, the enhanced P-channel MOS switch is turned on without consuming power of the charging box 10, and meanwhile, a basis is provided for detection of the wireless headset 20. In one embodiment, the source is connected to the charging output terminal POWEROUT, and the drain is connected to ground, because of the conduction characteristic of the enhancement P-channel MOS switch, I2 × R2 is greater than the threshold voltage Vth (the minimum voltage difference between the source and the gate required for conducting the source and the drain) of the enhancement P-channel MOS switch, so that the enhancement P-channel MOS switch can be conducted only when the charging box 10 enters under-voltage protection and the second switch S2 is conducted. Thus, when the voltage of the power supply 12 is smaller than the first voltage threshold, the first control module 13 may actively apply a low level to the gate of the enhancement type P-channel MOS switch transistor to turn on the enhancement type P-channel MOS switch transistor; when the voltage of the voltage 12 is smaller than the second voltage threshold, the level output by the first control module 13 to the gate of the enhancement P-channel MOS switch is forced to be pulled to a low level, so that the enhancement P-channel MOS switch is also turned on.

In one embodiment, the first reference voltage VR1 is small, in order to ensure that the first comparing module C1 outputs a low level at the moment when the wireless headset 20 is electrically connected to the charging box 10, the voltage at the charging output terminal POWEROUT may be divided by a voltage dividing circuit and then input to the non-inverting input terminal of the first comparing module C1, and assuming that the voltage dividing coefficient is k (less than 1), the following relationships exist: VR1> k I1R 2; in some cases, the voltage division coefficient may be equal to 1. However, the voltage at the charging input terminal powerrin may not be divided by the voltage dividing circuit and then input to the non-inverting input terminal of the second comparing module C2.

It is understood that the signal terminals connected to the two input terminals of the first comparing module C1 may be interchanged: the non-inverting input terminal of the first comparing module C1 is connected to the first reference voltage VR1, and the inverting input terminal is connected to the charging output terminal POWEROUT, so that the control logic of the first control module 13 is just opposite to that of the previous embodiment (for example, when the first comparing module C1 outputs a high level, the first control module 13 determines that the charging box 10 is electrically connected to the wireless headset 20, and controls the DC-DC module 11 to operate in a voltage mode). Of course, an inverter may be added between the output of the first comparison module C1 and the first control module 13, so that the control logic of the first control module 13 is the same as the previous embodiment. Similarly, the signal terminals connected to the two input terminals of the second comparing module C2 can be interchanged with each other, and are not described herein again.

To enable control of the current source 24, the second switch S2 may be part of the current source 24, and the second control module 22 controls the current source 24 by controlling the second switch S2 to turn on and off.

In the above embodiments, the determination of the electrical connection relationship between the wireless headset 20 and the charging box 10 is realized, and the wireless headset 20 can further control more operations of the wireless headset 20 based on the determined electrical connection relationship, for example, when the wireless headset 20 is electrically connected to the charging box 10, the connection with the mobile phone is disconnected, the playing of songs is stopped, and the like; when it is determined that the wireless headset 20 is electrically disconnected from the charging box 10, the connection with the cellular phone is re-established, the song is re-played, etc. Also, when the wireless headset 20 is electrically connected and disconnected to the charging box 10, the charging box 10 may issue a corresponding prompt.

Although the above embodiments have been described in detail with the charging box 10 and the wireless headset 20 as examples, it is understood that the charging box 10 may be any other form of charging device.

It should be understood that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some technical features; and all such modifications and alterations should fall within the scope of the appended claims.

Claims

1. A circuit of a wireless earphone capable of identifying the electrical connection relation with a charging device is characterized by comprising a second detection control module, a current source, a second switch, a resistor and a charging input end; the charging input end is used for being in contact and electric connection with the charging output end of the charging device; the current source is grounded via the charging input terminal and the resistor;

the second detection control module is used for controlling the second switch to enable the current source to output a second current to flow through the resistor when the switch mark is on, and controlling the second switch to enable the current source to stop working when the switch mark is off;

the second detection control module is further used for judging the electric connection relation between the wireless earphone and the charging device according to the detected level of the charging input end and the switch mark.

2. The circuit of claim 1, wherein,

the second detection control module is further configured to determine, according to the detected level of the charging input terminal and the switch flag, that the electrical connection relationship between the wireless headset and the charging device is specifically:

the second detection control module is further configured to determine that the wireless headset is electrically connected to the charging device when the second detection control module detects that the voltage at the charging input terminal is at a high level and the switch flag is off.

3. The circuit of claim 1, wherein,

the second detection control module is further configured to set the switch flag to be turned on when it is detected that the voltage at the charging input terminal jumps from a high level to a low level, and control the second switch to be turned on according to the switch flag; and if the charging input end is at a high level, the second detection control module judges that the wireless earphone is electrically disconnected with the charging device.

4. The circuit of claim 1, wherein,

the second detection control module is further configured to set the switch flag to be turned on when it is detected that the voltage at the charging input terminal jumps from a high level to a low level, and control the second switch to be turned on according to the switch flag; and if the charging input end is at a low level, the second detection control module judges that the wireless earphone is electrically connected with the charging device.

5. The circuit of claim 1, wherein,

after the second detection control module detects that the level of the charging input end jumps from a high level to a low level, the second detection control module is used for executing the following steps at a set frequency: modifying the switch flag to be conductive to control the second switch to be conductive; the second detection control module detects the level of the charging input end again, and if the level of the charging input end is a high level, the wireless earphone is judged to be electrically disconnected with the charging device; and if the level of the charging input end is low level, judging that the wireless earphone is electrically connected with the charging device.

6. The circuit according to any of claims 1-5,

the second detection control module comprises a second control module and a second comparison module; the first input end of the second comparison module is connected with the charging input end, the second input end of the second comparison module is connected with a second reference voltage, and the output end of the second comparison module is connected with the second control module;

the second control module is used for controlling the second switch to enable the current source to output a second current when the switch mark is on, controlling the second switch to enable the current source to stop working when the switch mark is off, and detecting the level of the charging input end according to the level output by the second comparison module; wherein a product of the second current and the resistance is greater than the second reference voltage.

7. The circuit according to any of claims 1-5,

the circuit of the wireless earphone further comprises a reverse conduction prevention module and a charging module, wherein the reverse conduction prevention module is used for preventing the voltage of the charging module from flowing backwards to the charging input end.

8. A circuit of a charging system is characterized by comprising a circuit of a charging device and a circuit of a wireless earphone capable of identifying the electrical connection relation with the charging device;

the circuit of the wireless earphone comprises a second detection control module, a current source, a second switch, a resistor and a charging input end; the charging input end is used for being in contact and electric connection with the charging output end of the charging device; the current source is grounded via the charging input terminal and the resistor;

the circuit of the charging device comprises a charging output end and a first switch, wherein the charging output end is grounded through the first switch; the first switch is used for being controlled to be switched on when the power supply is undervoltage and being controlled to be switched off when the power supply is not undervoltage;

9. The circuit of claim 8, wherein the first switch is an enhancement P-channel MOS switch, and the first detection control module outputs zero voltage to a gate of the enhancement P-channel MOS switch when the power supply is under-voltage.

10. The circuit of claim 8, wherein,

the second detection control module is further used for judging that the wireless earphone is electrically connected with the charging device when the voltage of the charging input end is detected to be high level and the switch mark is disconnected; or,

the second detection control module is further configured to set the switch flag to be turned on when it is detected that the voltage at the charging input terminal jumps from a high level to a low level, and control the second switch to be turned on according to the switch flag; if the charging input end is at a high level, the second detection control module judges that the wireless earphone is electrically connected with the charging device, and if the charging input end is at a low level, the second detection control module judges that the wireless earphone is electrically connected with the charging device; or,

11. The circuit according to any of claims 8-10,

the second detection control module comprises a second control module and a second comparison module;

the first input end of the second comparison module is connected with the charging input end, the second input end of the second comparison module is connected with a second reference voltage, and the output end of the second comparison module is connected with the second control module;

12. The circuit according to any of claims 8-10,

13. A circuit of a wireless earphone capable of identifying the electrical connection relation with a charging device is characterized by comprising a second control module, a second comparison module, a current source, a second switch, a resistor, a charging input end and an anti-reverse conduction module; the charging input end is used for being in contact and electric connection with the charging output end of the charging device; the current source is grounded via the charging input terminal and the resistor;

the second control module is used for controlling the second switch to enable the current source to output a second current to flow through the resistor when the switch mark is on, and controlling the second switch to enable the current source to stop working when the switch mark is off;

the second control module is further configured to detect a level of the charging input terminal according to the level output by the second comparison module, and determine an electrical connection relationship between the wireless headset and the charging device according to the detected level of the charging input terminal and the switch flag.

14. A wireless headset for recognizing an electrical connection with a charging device, comprising a circuit according to any one of claims 1-7, 13.

15. A charging system comprising a circuit as claimed in any one of claims 8 to 12.

16. A circuit for identifying a charging device in electrical connection with a wireless headset, comprising: the charging device comprises a DC-DC module, a first detection control module and a charging output end;

the output end of the DC-DC module is connected with the charging output end, and the charging output end is used for being in contact and electric connection with the charging input end of the wireless earphone; the first detection control module is used for setting a mode flag to be in a constant current mode when the current output by the DC-DC module is equal to zero, and the DC-DC module is used for working in the constant current mode according to the mode flag;

the first detection control module is used for detecting that the voltage of the charging output end jumps from a high level to a low level, judging that the charging device is electrically connected with the wireless earphone when the mode flag is in a constant current mode, setting the mode flag bit to be in a voltage mode, and controlling the DC-DC module to output a first voltage according to the voltage mode.

17. The circuit of claim 16, further comprising a first switch, the charging output terminal being connected to ground through the first switch;

the first switch is used for being controlled to be switched on when the power supply is undervoltage and being controlled to be switched off when the power supply is not undervoltage.

18. The circuit of claim 17, wherein the first switch is an enhancement P-channel MOS switch, and wherein the first detection control module outputs zero voltage to a gate of the enhancement P-channel MOS switch when the power supply is under-voltage.

19. The circuit of claim 16, wherein,

the first detection control module comprises a first control module and a first comparison module; the first input end of the first comparison module is connected with the charging output end, the second input end of the first comparison module is connected with the first reference voltage, and the output end of the first comparison module is connected with the first control module; the first control module is used for detecting the level of the charging input end according to the level output by the first comparison module.

20. The circuit of claim 16, wherein,

the first detection control module is further used for judging that the charging device is electrically disconnected with the wireless earphone when the current output by the DC-DC module is equal to zero.

21. A circuit of a charging system comprises a circuit of a charging device capable of identifying the electric connection relation with a wireless earphone and a circuit of the wireless earphone,

the circuit of the charging device comprises: the charging device comprises a DC-DC module, a first detection control module and a charging output end; the output end of the DC-DC module is connected with the charging output end; the first detection control module is used for setting a mode flag to be in a constant current mode when the current output by the DC-DC module is equal to zero, and the DC-DC module is used for working in the constant current mode according to the mode flag to output a first current;

the circuitry of the wireless headset comprises: a resistor, a charging input terminal; the charging input end is grounded through the resistor; the charging output end is used for being electrically connected with the charging input end in a contact way;

22. The circuit of claim 21, wherein,

the first detection control module comprises a first control module and a first comparison module; the first input end of the first comparison module is connected with the charging output end, the second input end of the first comparison module is connected with the first reference voltage, and the output end of the first comparison module is connected with the first control module;

the product of the first current, the resistance and the voltage division coefficient is smaller than the first reference voltage;

the first control module is used for detecting the level of the charging input end according to the level output by the first comparison module.

23. The circuit of claim 22, wherein,

the circuit of the wireless earphone also comprises a second detection control module;

the product of the first current and the resistance is greater than the second reference voltage, and the product of the second current and the resistance is greater than the second reference voltage;

the second control module is used for detecting the level of the charging input end according to the level output by the second comparison module so as to judge the electrical connection relation between the wireless earphone and the charging device.

24. The circuit of claim 22, wherein,

the circuit of the charging device further comprises a first switch, and the charging output end is grounded through the first switch; the first switch is used for being controlled to be switched on when the power supply is undervoltage and being controlled to be switched off when the power supply is not undervoltage;

the circuitry of the wireless headset further comprises: the second detection control module, the current source and the second switch; the current source is grounded via the charging input terminal and the resistor; the second detection control module is used for controlling the second switch to enable the current source to output a second current when the switch mark is on and controlling the second switch to enable the current source to stop working when the switch mark is off;

25. The circuit of claim 24, wherein,

26. The circuit of claim 25, wherein,

the second control module is used for detecting the level of the charging input end and the switch mark according to the level output by the second comparison module so as to judge the electric connection relation between the wireless earphone and the charging device.

27. The circuit according to any of claims 21-26,

the circuit of the wireless earphone further comprises a reverse conduction prevention module, and the reverse conduction prevention module is used for preventing the voltage of the charging module from flowing backwards to the charging input end.

28. The circuit of claim 26, wherein,

the second control module is used for judging that the wireless earphone is electrically connected with the charging device when the voltage of the charging input end is detected to be high level and the switch mark is disconnected; or,

the second control module is configured to set the switch flag to be on when the second control module detects that the voltage at the charging input end jumps from a high level to a low level, and control the second switch to be on according to the switch flag, if the charging input end is the high level, the second control module is configured to determine that the wireless headset is electrically disconnected from the charging device, and if the charging input end is the low level, the second control module is configured to determine that the wireless headset is electrically connected to the charging device; or,

after the second control module detects that the level of the charging input end jumps from a high level to a low level, the second detection control module is used for executing the following steps at a set frequency: modifying the switch flag to be conductive to control the second switch to be conductive; the second control module detects the level of the charging input end again, and if the level of the charging input end is a high level, the wireless earphone is judged to be electrically disconnected with the charging device; and if the level of the charging input end is low level, judging that the wireless earphone is electrically connected with the charging device.

29. The circuit according to any of claims 24, 25, 26, 28,

the first switch is an enhancement type P-channel MOS switch tube, and when the power supply is under-voltage, the first detection control module outputs zero voltage to a grid electrode of the enhancement type P-channel MOS switch tube.

30. The circuit according to any of claims 24, 25, 26, 28,

when the current output by the DC-DC module is equal to zero, the first detection control module judges that the charging device is disconnected from the wireless earphone.

31. A circuit of a charging system comprises a circuit of a charging device capable of identifying the electric connection relation with a wireless earphone and a circuit of the wireless earphone,

the circuit of the charging device comprises: the charging device comprises a DC-DC module, a first comparison module, a first control module, a first switch, a charging output end and a power supply; the circuit of the wireless earphone comprises a second comparison module, a second control module, a current source, a second switch, a resistor and a charging input end; the charging output end is used for being electrically connected with the charging input end in a contact way;

the input end of the DC-DC module is connected with the power supply, the output end of the DC-DC module is connected with the charging output end, and the charging output end is grounded through a first switch; the first input end of the first comparison module is connected with the charging output end, the second input end of the first comparison module is connected with the first reference voltage, and the output end of the first comparison module is connected with the first control module; the first switch is used for being controlled to be conducted when the power supply is under-voltage; the current source is grounded through the charging input end and the resistor, the first input end of the second comparison module is connected with the charging input end, the second input end of the second comparison module is connected with a second reference voltage, and the output end of the second comparison module is connected with the second control module; the second control module is used for controlling the second switch to enable the current source to output a second current when the switch mark is on and controlling the second switch to enable the current source to stop working when the switch mark is off;

the first control module is used for judging that the charging device is electrically disconnected with the wireless earphone when the current output by the DC-DC module is equal to zero, and setting a mode flag to be a constant current mode, and the DC-DC module is used for working in the constant current mode according to the mode flag to output a first current;

the first control module is used for judging that the voltage of the charging output end jumps from a high level to a low level by detecting a signal output by the first comparison module, and when the mode flag is in a constant current mode, the first control module judges that the charging device is electrically connected with the wireless earphone, sets the mode flag bit to be in a voltage mode, and controls the DC-DC module to output a first voltage according to the voltage mode;

the second control module is further used for judging the electrical connection relation between the wireless earphone and the charging device according to the detected level of the charging input end and the switch mark;

wherein a product of the first current, the resistance and the voltage division coefficient is smaller than the first reference voltage, a product of the first current and the resistance is larger than the second reference voltage, and a product of the second current and the resistance is larger than the second reference voltage.

32. A circuit for identifying a charging device in electrical connection with a wireless headset, comprising: the charging device comprises a DC-DC module, a first comparison module, a first control module, a first switch, a charging output end and a power supply;

the input end of the DC-DC module is connected with the power supply, the output end of the DC-DC module is connected with the charging output end, and the charging output end is grounded through a first switch; the first input end of the first comparison module is connected with the charging output end, the second input end of the first comparison module is connected with the first reference voltage, and the output end of the first comparison module is connected with the first control module; the first switch is used for being controlled to be conducted when the power supply is under-voltage; the charging output end is used for being in contact and electric connection with the charging input end of the wireless earphone;

the first control module is used for judging that the charging device is electrically disconnected with the wireless earphone when the current output by the DC-DC module is equal to zero, and setting a mode flag to be a constant current mode, and the DC-DC module is used for working in the constant current mode according to the mode flag;

the first control module is used for judging that the voltage of the charging output end jumps from a high level to a low level by detecting the signal output by the first comparison module, and when the mode flag is in a constant current mode, the first control module judges that the charging device is electrically connected with the wireless earphone, sets the mode flag bit to be in a voltage mode, and controls the DC-DC module to output a first voltage according to the voltage mode.

33. A charging device operable to identify an electrical connection to a wireless headset comprising a circuit as claimed in any one of claims 16 to 20 and 32.

34. A charging system comprising a circuit as claimed in any of claims 21 to 31.