CN220139259U

CN220139259U - Charge-discharge protection circuit of battery

Info

Publication number: CN220139259U
Application number: CN202321239324.1U
Authority: CN
Inventors: 陈志勇; 黄旭盛; 胡锡胜; 黄锐景; 李用
Original assignee: GAC Component Co Ltd
Current assignee: GAC Component Co Ltd
Priority date: 2023-05-22
Filing date: 2023-05-22
Publication date: 2023-12-05
Anticipated expiration: 2033-05-22

Abstract

The utility model discloses a charge and discharge protection circuit of a battery, which comprises a battery, a fuse, a voltage detection circuit, a battery discharge power control circuit, a current detection circuit, a load, a main control unit, a battery charge power control circuit, a battery charge voltage comparison circuit and a charge power supply, wherein the battery is connected with the load; the output end of the battery is connected with the input end of the voltage detection circuit; the fuse is arranged between the output end of the battery and the voltage detection circuit; the first output end of the voltage detection circuit is connected with the first input end of the battery discharge power control circuit; the first output end of the main control unit is connected with the second input end of the battery discharging power control circuit; the output end of the battery discharging power control circuit is connected with the input end of the current detection current; the first output of the current sense current is coupled to the load. The utility model ensures the normal operation of the battery by adding the circuit on the charge-discharge path of the battery.

Description

Charge-discharge protection circuit of battery

Technical Field

The utility model belongs to the field of battery charge and discharge control, and particularly relates to a battery charge and discharge protection circuit.

Background

In the event of emergency transport and abnormal power supply to the patient, a ventilator with a battery backup plays a key role. How to ensure the safety of the high-power battery in the use process, ensure the battery to be charged and discharged normally, avoid the overheat spontaneous combustion and explosion of the battery, and is a focus of attention of electronic design engineers.

The patent number is CN202122406023.0 discloses a battery charge-discharge protection circuit, a battery module and an electric vehicle, and solves the problem that potential safety hazards exist if the voltage of a charger is not matched with the voltage of the battery when the battery of the existing electric vehicle is charged. But such circuits still present safety concerns for the battery's charge and discharge paths.

Disclosure of Invention

The utility model aims to provide a charge and discharge protection circuit of a battery, which ensures the normal operation of the battery by adding a monitoring and switching-off circuit on a charge and discharge path of the battery, prevents accidents such as spontaneous combustion and the like caused by thermal runaway of the battery, and ensures the safety of products and users.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows:

a charge and discharge protection circuit of a battery comprises the battery, a fuse, a voltage detection circuit, a battery discharge power control circuit, a current detection circuit, a load, a main control unit, a battery charge power control circuit, a battery charge voltage comparison circuit and a charge power supply;

The output end of the battery is connected with the input end of the voltage detection circuit;

the fuse is arranged between the output end of the battery and the voltage detection circuit and is used for hard shutdown protection under the condition of battery overcurrent;

the first output end of the voltage detection circuit is connected with the first input end of the battery discharge power control circuit; the second output end of the voltage detection circuit is connected with the first input end of the main control unit and is used for detecting the voltage of the output path of the battery;

the first output end of the main control unit is connected with the second input end of the battery discharging power control circuit and is used for monitoring the output path of the battery;

the output end of the battery discharging power control circuit is connected with the input end of the current detection current;

the first output end of the current detection current is connected with the load; the second output end of the current detection current is connected with the second input end of the main control unit and is used for detecting the current of the output path of the battery;

the main control unit is communicated with the battery and used for collecting data of the battery;

the output end of the charging power supply is connected with the input end of the battery charging voltage comparison circuit, and the output end of the battery charging voltage comparison circuit is connected with the first input end of the battery charging power control circuit; the output end of the battery charging power control circuit is connected with the input end of the battery;

And the second output end of the main control unit is connected with the second input end of the battery charging power control circuit and is used for controlling the charging of the battery.

The battery is connected with the main control unit and is used for detecting information such as battery voltage, temperature and the like; the fuse is arranged on the output path of the battery, and hard turn-off protection is carried out under the condition of overcurrent; the voltage detection circuit and the current detection circuit are connected with the main control unit to detect the voltage and the current of the battery output path respectively; the battery discharging power control circuit is connected with the main control unit and is used for switching off output under the abnormal condition of the battery; the battery charging voltage comparison circuit is respectively connected with the charging power supply and the battery charging power control circuit, the battery charging power control circuit is respectively connected with the battery and the main control unit, and when the input charging voltage of the battery is overlarge, the battery charging power control circuit turns off the input of the charging power supply, so that the conditions of overcharge and the like of the battery are prevented.

Preferably, the voltage detection circuit comprises a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor, a first diode, a second diode and a first input voltage; the main control unit comprises a battery voltage acquisition port and a turn-off signal port; the output end of the battery is connected with one end of the fuse; the other end of the fuse comprises a first connecting end and a second connecting end; the first connecting end is connected with the battery voltage acquisition port and is sequentially connected with the first resistor and the second resistor in series; a first node is arranged between the first connecting end and the first resistor; the first node is connected with the ground wire and is connected with the first capacitor in series; a second node is arranged between the first resistor and the second resistor; the second node is connected with the ground wire and is connected with the third resistor in series; a third node is arranged between the second resistor and the battery voltage acquisition port; the third node is connected with the ground wire and is connected with the second capacitor in series; a fourth node is arranged between the third node and the battery voltage acquisition port; the anode of the first diode is connected with the fourth node, and the cathode of the first diode is connected with the first input voltage; the positive electrode of the second diode is connected with the ground wire, and the negative electrode of the second diode is connected with the fourth node.

Preferably, the battery discharge power control circuit comprises a first MOS tube, a second MOS tube, a third MOS tube, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a sampling resistor; the second connecting end is connected with the drain electrode of the first MOS tube and is connected with the fourth resistor in series; the turn-off signal port is connected with the grid electrode of the first MOS tube and is connected with the fifth resistor in series; the source electrode of the first MOS tube is grounded; a fifth node is arranged between the fourth resistor and the drain electrode of the first MOS tube; the fifth node is connected with the grid electrode of the second MOS tube and is connected with the sixth resistor in series; the source electrode of the second MOS tube is grounded; a sixth node is arranged between the fourth resistor and the second connecting end; the sixth node is connected with the drain electrode of the second MOS tube, and the seventh resistor and the eighth resistor are sequentially connected in series; a seventh node is arranged between the sixth node and the seventh resistor; the seventh node is connected with the source electrode of the third MOS tube and the source electrode of the fourth MOS tube; an eighth node is arranged between the seventh resistor and the eighth resistor; the eighth node is connected with the grid electrode of the third MOS tube and the grid electrode of the fourth MOS tube in series with the ninth resistor; the input end of the battery is connected with the drain electrode of the third MOS tube and the drain electrode of the fourth MOS tube in series with the sampling resistor.

Preferably, the current detection circuit includes a current sampling chip, a filter magnetic bead, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a tenth resistor, an eleventh resistor, a third diode, a fourth diode, a second input voltage, and a third input voltage; the current sampling chip comprises a first interface, a second interface, a third interface, a fourth interface, a fifth interface, a sixth interface, a seventh interface and an eighth interface; the seventh interface is idle; the main control unit also comprises a current acquisition port; a ninth node is arranged between the sampling resistor and a connection point of the drain electrode of the third MOS tube and the drain electrode of the fourth MOS tube; the first interface is connected with the ninth node; a tenth node is arranged between the sampling resistor and the input end of the battery; the second interface is connected with the tenth node; an eleventh node is arranged between the tenth node and the input end of the battery; the eighth interface is connected with the eleventh node;

the second input voltage is connected with the third interface and is connected with the filtering magnetic beads in series; a twelfth node is arranged between the filtering magnetic beads and the third interface; the twelfth node is connected with the ground wire and is connected with the third capacitor in series; a thirteenth node is arranged between the twelfth node and the third interface; the thirteenth node is connected with the ground wire and is connected with the fourth capacitor in series; a fourteenth node is arranged between the thirteenth node and the third interface; the fourteenth node is connected with the ground wire and is connected with the fifth capacitor in series; the fourth interface is grounded; the fifth interface is connected with the ground wire and is connected with the tenth resistor in series; the sixth interface is connected with the current acquisition port, and a fifteenth node is arranged between the sixth interface and the current acquisition port; the fifteenth node is connected with the ground wire and is connected with the eleventh resistor in series; a sixteenth node is arranged between the fifteenth node and the current acquisition port; the sixteenth node is connected with the ground wire and is connected with the sixth capacitor in series; a seventeenth node is arranged between the sixteenth node and the current collection port; the cathode of the third diode is connected with the third input voltage, and the anode of the third diode is connected with the seventeenth node; and the cathode of the fourth diode is connected with the seventeenth node, and the anode of the fourth diode is grounded.

Preferably, the battery charging voltage comparison circuit includes a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a voltage comparator, a fourth input voltage, and a fifth input voltage; the voltage comparator comprises a positive electrode input end, a negative electrode input end, a first wiring terminal, a second wiring terminal and a third wiring terminal; the output end of the charging power supply is connected with the positive electrode input end and the twelfth resistor is connected in series between the positive electrode input end and the output end of the charging power supply; the fourth input voltage is connected with the negative electrode input end, and the thirteenth resistor and the fourteenth resistor are sequentially connected in series; an eighteenth node is arranged between the thirteenth resistor and the fourteenth resistor; the eighteenth node is connected with the ground wire and is connected with the fifteenth resistor in series; a nineteenth node is arranged between the eighteenth node and the fourteenth resistor; the nineteenth node is connected with the ground wire and is connected with the seventh capacitor in series; the first wiring terminal is grounded; the second wiring terminal is connected with the ground wire and is connected with the eighth capacitor in series; a twentieth node is arranged between the second wiring terminal and the eighth capacitor; the twentieth node is connected to the fifth input voltage; the third terminal is connected with the ground wire and is connected with the ninth capacitor in series.

Preferably, the battery charging power control circuit includes a fifth diode, a sixth diode, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty first resistor, a twenty second resistor, a fifth MOS transistor, a sixth MOS transistor, a seventh MOS transistor, and an eighth MOS transistor; the main control unit also comprises a battery charging control port; a twenty-first node is arranged between the third wiring terminal and the ninth capacitor; the second eleventh node is connected with the positive electrode of the fifth diode; the negative electrode of the fifth diode is connected with the ground wire, and the sixteenth resistor and the seventeenth resistor are sequentially connected in series; a twenty-second node is arranged between the fifth diode and the sixteenth resistor; the cathode of the sixth diode is connected with the twenty-second node; the battery charge control port is connected with the anode of the sixth diode.

Preferably, a twenty-third node is arranged between the sixteenth resistor and the seventeenth resistor; the twenty-third node is connected with the grid electrode of the fifth MOS tube; the source electrode of the fifth MOS tube is grounded; the input end of the charging power supply is connected with the drain electrode of the fifth MOS tube, and the nineteenth resistor is connected in series between the input end of the charging power supply and the drain electrode of the fifth MOS tube; a twenty-fourth node is arranged between the drain electrode of the fifth MOS tube and the nineteenth resistor; the twenty-fourth node is connected with the grid electrode of the sixth MOS tube; the source electrode of the sixth MOS tube is grounded; a twenty-fifth node is arranged between the input end of the charging power supply and the nineteenth resistor; the twenty-fifth node is connected with the drain electrode of the sixth MOS tube, and the twentieth resistor and the twenty-first resistor are sequentially connected in series between the twenty-fifth node and the drain electrode of the sixth MOS tube; a twenty-sixth node is arranged between the twenty-fifth node and the twentieth resistor; the twenty-sixth node is connected with the source electrode of the seventh MOS tube and the source electrode of the eighth MOS tube; a twenty-seventh node is arranged between the twentieth resistor and the twenty-first resistor; the twenty-seventh node is connected with the grid electrode of the seventh MOS tube and the grid electrode of the eighth MOS tube in series with the twenty-second resistor; the output end of the charging power supply is also connected with the drain electrode of the seventh MOS tube and the drain electrode of the eighth MOS tube.

Preferably, the first MOS transistor, the second MOS transistor, the fifth MOS transistor, and the sixth MOS transistor are all N-MOS transistors; the third MOS tube, the fourth MOS tube, the seventh MOS tube and the eighth MOS tube are all P-MOS tubes.

The beneficial effects are that:

Drawings

Fig. 1 is a block diagram showing a charge-discharge protection circuit of a battery according to a first embodiment;

fig. 2 is a first circuit configuration diagram of a battery charge-discharge protection circuit according to the first embodiment;

Fig. 3 is a second circuit configuration diagram of a battery charge-discharge protection circuit according to the first embodiment;

fig. 4 is a first flowchart of a charge-discharge protection method of a charge-discharge protection circuit of a battery according to a second embodiment;

fig. 5 is a second flowchart of a charge-discharge protection method of a charge-discharge protection circuit of a battery according to the second embodiment.

Reference numerals

11. A first resistor; 12. a second resistor; 13. a third resistor; 14. a fourth resistor; 15. a fifth resistor; 16. a sixth resistor; 17. a seventh resistor; 18. an eighth resistor; 19. a ninth resistor; 21. a first capacitor; 22. a second capacitor; 23. a third capacitor; 24. a fourth capacitor; 25. a fifth capacitor; 26. a sixth capacitor; 27. a seventh capacitance; 28. an eighth capacitor; 29. a ninth capacitor; 31. a first diode; 32. a second diode; 33. a third diode; 34. a fourth diode; 35. a fifth diode; 36. a sixth diode; 40. a fuse; 50. sampling a resistor; 60. filtering the magnetic beads; 71. a tenth resistor; 72. an eleventh resistor; 81. a first MOS tube; 82. a second MOS tube; 83. a third MOS tube; 84. a fourth MOS transistor; 85. a fifth MOS transistor; 86. a sixth MOS transistor; 87. a seventh MOS transistor; 88. an eighth MOS transistor; 90. a twelfth resistor; 91. a thirteenth resistor; 92. a fourteenth resistor; 93. a fifteenth resistor; 94. a sixteenth resistor; 95. seventeenth resistance; 96. an eighteenth resistor; 97. nineteenth resistor; 98. a twentieth resistor; 99. a twenty-first resistor; 910. a twenty-second resistor; 101. an output terminal of the battery; 102. an input terminal of the battery; 201. a first input voltage; 202. a second input voltage; 203. a third input voltage; 204. a fourth input voltage; 205. a fifth input voltage; 301. a battery voltage acquisition port; 302. turning off the signal port; 303. a battery charge control port; 400. a current sampling chip; 500. a current collection port; 601. an output end of the charging power supply; 602. an input end of the charging power supply; 700. a voltage comparator.

Detailed Description

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following description will explain the specific embodiments of the present utility model with reference to the accompanying drawings. It is evident that the drawings in the following description are only examples of the utility model, from which other drawings and other embodiments can be obtained by a person skilled in the art without inventive effort.

The technical scheme of the utility model is described in detail in the following by specific embodiments.

Example 1

As shown in fig. 1 to 3, a battery charge-discharge protection circuit of the present embodiment includes a battery, a fuse 40, a voltage detection circuit, a battery discharge power control circuit, a current detection circuit, a load, a main control unit, a battery charge power control circuit, a battery charge voltage comparison circuit, and a charging power supply;

the output end 101 of the battery is connected with the input end of the voltage detection circuit;

the fuse 40 is arranged between the output end 101 of the battery and the voltage detection circuit, and is used for hard shutdown protection under the condition of overcurrent of the battery;

the output end 601 of the charging power supply is connected with the input end of the battery charging voltage comparison circuit, and the output end of the battery charging voltage comparison circuit is connected with the first input end of the battery charging power control circuit; the output end of the battery charging power control circuit is connected with the input end 102 of the battery;

the second output end of the main control unit is connected with the second input end of the battery charging power control circuit and is used for controlling the charging of the battery.

Preferably, the voltage detection circuit includes a first resistor 11, a second resistor 12, a third resistor 13, a first capacitor 21, a second capacitor 22, a first diode 31, a second diode 32, and a first input voltage 201; the main control unit comprises a battery voltage acquisition port 301 and a shutdown signal port 302; the output end 101 of the battery is connected with one end of the fuse 40; the other end of the fuse 40 includes a first connection end and a second connection end; the first connecting end is connected with the battery voltage acquisition port 301 and is sequentially connected with the first resistor 11 and the second resistor 12 in series; a first node is arranged between the first connection end and the first resistor 11; the first node is connected with the ground wire and is connected with a first capacitor 21 in series; a second node is arranged between the first resistor 11 and the second resistor 12; the second node is connected with the ground wire and is connected with a third resistor 13 in series; a third node is arranged between the second resistor 12 and the battery voltage acquisition port 301; the third node is connected with the ground line and is connected with a second capacitor 22 in series; a fourth node is arranged between the third node and the battery voltage acquisition port 301; the positive electrode of the first diode 31 is connected with the fourth node, and the negative electrode of the first diode 31 is connected with the first input voltage 201; the anode of the second diode 32 is connected to ground, and the cathode of the second diode 32 is connected to the fourth node.

Preferably, the battery discharge power control circuit includes a first MOS transistor 81, a second MOS transistor 82, a third MOS transistor 83, a fourth MOS transistor 84, a fourth resistor 14, a fifth resistor 15, a sixth resistor 16, a seventh resistor 17, an eighth resistor 18, a ninth resistor 19, and a sampling resistor 50; the second connection end is connected with the drain electrode of the first MOS tube 81 and is connected with a fourth resistor 14 in series; the turn-off signal port 302 is connected with the gate of the first MOS tube 81 and is connected in series with the fifth resistor 15; the source electrode of the first MOS tube 81 is grounded; a fifth node is arranged between the fourth resistor 14 and the drain electrode of the first MOS tube 81; the fifth node is connected with the grid electrode of the second MOS tube 82 and is connected with the sixth resistor 16 in series; the source electrode of the second MOS tube 82 is grounded; a sixth node is arranged between the fourth resistor 14 and the second connection terminal; the sixth node is connected with the drain electrode of the second MOS tube 82 and is sequentially connected with the seventh resistor 17 and the eighth resistor 18 in series; a seventh node is arranged between the sixth node and the seventh resistor 17; the seventh node is connected to the source of the third MOS transistor 83 and the source of the fourth MOS transistor 84; an eighth node is arranged between the seventh resistor 17 and the eighth resistor 18; the eighth node is connected with the grid electrode of the third MOS tube 83 and the grid electrode of the fourth MOS tube 84 in series with a ninth resistor 19; the input terminal 102 of the battery is connected to the drain of the third MOS transistor 83 and the drain of the fourth MOS transistor 84 and the sampling resistor 50 is connected in series between them.

Preferably, the current detection circuit includes a current sampling chip 400, a filter magnetic bead 60, a third capacitor 23, a fourth capacitor 24, a fifth capacitor 25, a sixth capacitor 26, a tenth resistor 71, an eleventh resistor 72, a third diode 33, a fourth diode 34, a second input voltage 202, and a third input voltage 203; the current sampling chip 400 includes a first interface, a second interface, a third interface, a fourth interface, a fifth interface, a sixth interface, a seventh interface, and an eighth interface; the seventh interface is idle; the main control unit also comprises a current acquisition port 500; a ninth node is arranged between the sampling resistor 50 and a connection point of the drain electrode of the third MOS tube 83 and the drain electrode of the fourth MOS tube 84; the first interface is connected with a ninth node; a tenth node is arranged between the sampling resistor 50 and the input terminal 102 of the battery; the second interface is connected with the tenth node; an eleventh node is disposed between the tenth node and the input 102 of the battery; the eighth interface is connected with the eleventh node;

the second input voltage 202 is connected with the third interface and the filter magnetic beads 60 are connected in series between the second input voltage and the third interface; a twelfth node is arranged between the filtering magnetic bead 60 and the third interface; the twelfth node is connected with the ground wire and is connected with a third capacitor 23 in series; a thirteenth node is arranged between the twelfth node and the third interface; the thirteenth node is connected to ground and a fourth capacitor 24 is connected in series between the thirteenth node and ground; a fourteenth node is arranged between the thirteenth node and the third interface; the fourteenth node is connected with the ground wire and is connected with a fifth capacitor 25 in series; the fourth interface is grounded; the fifth interface is connected with the ground wire and is connected with a tenth resistor 71 in series; the sixth interface is connected with the current acquisition port 500 and a fifteenth node is arranged between the sixth interface and the current acquisition port 500; the fifteenth node is connected to ground and has an eleventh resistor 72 in series between; a sixteenth node is disposed between the fifteenth node and the current collection port 500; the sixteenth node is connected with the ground line and is connected in series with a sixth capacitor 26; a seventeenth node is disposed between the sixteenth node and the current collection port 500; the cathode of the third diode 33 is connected to the third input voltage 203, and the anode of the third diode 33 is connected to the seventeenth node; the negative electrode of the fourth diode 34 is connected to the seventeenth node, and the positive electrode of the fourth diode 34 is grounded.

Preferably, the battery charging voltage comparison circuit includes a twelfth resistor 90, a thirteenth resistor 91, a fourteenth resistor 92, a fifteenth resistor 93, a seventh capacitor 27, an eighth capacitor 28, a ninth capacitor 29, a voltage comparator 700, a fourth input voltage 204, and a fifth input voltage 205; the voltage comparator 700 includes a positive input terminal, a negative input terminal, a first terminal, a second terminal, and a third terminal; the output end 601 of the charging power supply is connected with the positive electrode input end and is connected with the twelfth resistor 90 in series; the fourth input voltage 204 is connected with the negative input end and is sequentially connected with the thirteenth resistor 91 and the fourteenth resistor 92 in series; an eighteenth node is provided between the thirteenth resistor 91 and the fourteenth resistor 92; the eighteenth node is connected with the ground wire and is connected with a fifteenth resistor 93 in series; a nineteenth node is provided between the eighteenth node and the fourteenth resistor 92; the nineteenth node is connected to ground and has a seventh capacitor 27 connected in series between; the first wiring terminal is grounded; the second terminal is connected with the ground wire and is connected with an eighth capacitor 28 in series; a twentieth node is provided between the second terminal and the eighth capacitor 28; the twentieth node is connected to the fifth input voltage 205; the third terminal is connected to ground and a ninth capacitor 29 is connected in series between.

Preferably, the battery charging power control circuit includes a fifth diode 35, a sixth diode 36, a sixteenth resistor 94, a seventeenth resistor 95, an eighteenth resistor 96, a nineteenth resistor 97, a twentieth resistor 98, a twenty-first resistor 99, a twenty-second resistor 910, a fifth MOS transistor 85, a sixth MOS transistor 86, a seventh MOS transistor 87, and an eighth MOS transistor 88; the master control unit also includes a battery charge control port 303; a twenty-first node is provided between the third terminal and the ninth capacitor 29; the twenty-first node is connected to the anode of the fifth diode 35; the cathode of the fifth diode 35 is connected with the ground wire and a sixteenth resistor 94 and a seventeenth resistor 95 are sequentially connected in series between the cathode and the ground wire; a twenty-second node is provided between the fifth diode 35 and the sixteenth resistor 94; the cathode of the sixth diode 36 is connected to the twenty-second node; the battery charge control port 303 is connected to the anode of the sixth diode 36.

Preferably, a twenty-third node is disposed between the sixteenth resistor 94 and the seventeenth resistor 95; the twenty-third node is connected with the gate of the fifth MOS transistor 85; the source electrode of the fifth MOS tube 85 is grounded; the input end 602 of the charging power supply is connected with the drain electrode of the fifth MOS tube 85 and is connected with a nineteenth resistor 97 in series; a twenty-fourth node is arranged between the drain electrode of the fifth MOS tube 85 and the nineteenth resistor 97; the twenty-fourth node is connected to the gate of the sixth MOS transistor 86; the source electrode of the sixth MOS transistor 86 is grounded; a twenty-fifth node is arranged between the input end 602 of the charging power supply and the nineteenth resistor 97; the twenty-fifth node is connected with the drain electrode of the sixth MOS tube 86 and is sequentially connected with a twenty-first resistor 98 and a twenty-first resistor 99 in series; a twenty-sixth node is disposed between the twenty-fifth node and the twentieth resistor 98; the twenty-sixth node is connected to the source of the seventh MOS transistor 87 and the source of the eighth MOS transistor 88; a twenty-seventh node is disposed between the twentieth resistor 98 and the twenty-first resistor 99; the twenty-seventh node is connected with the gate of the seventh MOS tube 87 and the gate of the eighth MOS tube 88, and a twenty-second resistor 910 is connected in series between the twenty-seventh node and the gate of the seventh MOS tube 88; the output terminal 601 of the charging power supply is also connected to the drain of the seventh MOS transistor 87 and the drain of the eighth MOS transistor 88.

Preferably, the first MOS transistor 81, the second MOS transistor 82, the fifth MOS transistor 85, and the sixth MOS transistor 86 are all N-MOS transistors; the third MOS transistor 83, the fourth MOS transistor 84, the seventh MOS transistor 87, and the eighth MOS transistor 88 are all P-MOS transistors.

Specifically, the fuse 40 of the present embodiment is a primary protection of the output path of the battery, and when the output current of the battery is greater than the current of the fuse 40, the fuse 40 can perform self-turn-off protection; the voltage detection circuit of the present embodiment limits the voltage input to the battery voltage acquisition port 301 of the main control unit to between 0V and 3.3V; the discharging power control circuit of the embodiment is a secondary protection of the battery output path, and performs comprehensive judgment according to the information, the detection voltage and the current value of the battery collected by the main control unit, so as to perform controllable turn-off control protection of the battery output voltage.

Specifically, the charging voltage comparison circuit and the charging power control circuit of the embodiment form a battery charging path protection circuit, when the voltage of the charging power supply is lower than the charging cut-off voltage of the battery, the charging power supply can normally charge the battery, and when the voltage of the charging power supply is higher than the charging cut-off voltage of the battery, the charging power control circuit turns off the input of the charging power supply and stops the charging of the battery by the charging power supply. And meanwhile, when the main control unit detects the abnormality of the battery through the battery charging control port, the charging power supply can be turned off to prohibit the battery from being charged.

Specifically, the main control unit of the embodiment detects information such as voltage, temperature, etc. of the battery; the voltage detection circuit and the current detection circuit respectively detect the voltage and the current of the battery output path; the battery discharging power control circuit is used for turning off output under the abnormal condition of the battery; the battery charging power control circuit is used for switching off the input of the charging power supply when the input charging voltage of the battery is overlarge, so that the battery is prevented from being overcharged.

Specifically, the first resistor 11, the third resistor 13, the seventh resistor 17, the eighth resistor 18, the sixteenth resistor 94, the seventeenth resistor 95, the twentieth resistor 98, and the twenty-first resistor 99 of the present embodiment are voltage dividing resistors; the first capacitor 21, the second capacitor 22, the third capacitor 23, the fourth capacitor 24, the fifth capacitor 25 and the sixth capacitor 26 are filter capacitors; the first diode 31, the second diode 32, the third diode 33 and the fourth diode 34 are clamping diodes; the fifth diode 35 and the sixth diode 36 are anti-reflection diodes; the second resistor 12 is an input resistor; the fourth resistor 14 and the nineteenth resistor 97 are current limiting resistors; the fifth resistor 15, the sixth resistor 16 and the ninth resistor 19 are driving resistors; the tenth resistor 70 is a bias resistor; the eleventh resistor 71 is an acquisition resistor; the first input voltage 201, the second input voltage 202 and the third input voltage 203 are all 3.3V; the fourth input voltage 204 is 24V.

Specifically, the working principle of the battery discharge power control circuit of the present embodiment is: when the battery outputs normally, the voltage flows through the fourth resistor 14 and the sixth resistor 16, at this time, the second MOS transistor 81 is turned on and turned on, the seventh resistor 17 and the eighth resistor 18 form a voltage dividing circuit, the third MOS transistor 83 and the fourth MOS transistor 84 are turned on and turned on, and the battery outputs normally to the current detection circuit. When detecting that the battery output is abnormal, the main control unit turns off the signal to be high, at this time, the first MOS tube 81 is turned on and forms a loop with the fourth resistor 14, the sixth resistor 16 is pulled to about 0V, and the third MOS tube 83 and the fourth MOS tube 84 are turned off and output is forbidden.

Specifically, the third interface of the current sampling chip 400 is a power supply terminal, and the sixth interface is an output terminal. The filtering magnetic beads 60 and the third capacitor 23 mainly filter out high-frequency clutter interference at the power supply end of the current sampling chip 400, and the fourth capacitor 24 and the fifth capacitor 25 mainly filter out low-frequency clutter interference at the power supply end of the current sampling chip 400. The sixth capacitor 26 mainly filters clutter interference of the output voltage of the current sampling chip 400, and the third diode 33 and the fourth diode 34 mainly ensure the safety of the current collection port 500 of the main control unit, and ensure that the voltage input to the current collection port 500 of the main control unit is in the range of 0-3.3V.

Specifically, the battery charge comparing circuit compares the voltage of the charging power supply with the battery charge cutoff voltage through the voltage comparator 700, and outputs a high-level signal to the battery charge power control circuit when the voltage of the charging power supply is greater than the battery charge cutoff voltage, and the shutdown circuit prohibits battery charge, and the battery is normally charged when the voltage of the charging power supply is less than the battery charge cutoff voltage.

Specifically, twelfth resistor 90 is a non-inverting input resistor of voltage comparator 700; the fourteenth resistor 92 is the inverting input resistor of the voltage comparator 700; the thirteenth resistor 91 and the fifteenth resistor 93 are voltage dividing resistors; the seventh capacitor 27 is an inverting input filter capacitor; the eighth capacitor 28 is a filter capacitor of the fifth input voltage 205; the ninth capacitor 29 is a filter capacitor of the voltage comparator 700.

Specifically, the working principle of the battery charging voltage comparison circuit of the present embodiment is: the thirteenth resistor 91 and the fifteenth resistor 93 divide the fourth input voltage 204 to form a battery charging cut-off voltage, and the seventh capacitor 27 mainly filters noise interference of the standard charging voltage; the eighth capacitor 28 mainly filters clutter interference of the power supply of the voltage comparator 700; the ninth capacitor 29 mainly filters noise interference of the output voltage of the voltage comparator 700. When the voltage of the positive electrode input terminal of the voltage comparator 700 is greater than the battery charging cut-off voltage of the negative electrode input terminal, the voltage comparator 700 outputs a 24V high level; when the voltage of the positive input terminal of the voltage comparator 700 is less than the battery charge cutoff voltage of the negative input terminal, the voltage comparator 700 outputs a 0V low level.

Specifically, the working principle of the battery charging power control circuit of the present embodiment is: when the battery is normally charged, the voltage flows through the eighteenth resistor 96 and the nineteenth resistor 97, at this time, the sixth MOS transistor 86 is turned on and turned on, the twentieth resistor 98 and the twenty first resistor 99 form a voltage dividing circuit, the seventh MOS transistor 87 and the eighth MOS transistor 88 are turned on and turned on, and the battery charging voltage is output and the battery is normally charged. When the abnormality of the battery charging voltage is detected, the voltage comparator 700 outputs a 24V high level, and voltage division is performed through the fifth diode 35, the sixteenth resistor 94 and the seventeenth resistor 95, at this time, the fifth MOS transistor 85 is turned on and forms a loop with the nineteenth resistor 97, the pin voltage of the eighteenth resistor 96 is pulled to about 0V, the seventh MOS transistor 87 and the eighth MOS transistor 88 are turned off and the battery charging power supply output is disabled, and at this time, the battery stops charging. In the event of a failure or abnormality of the voltage comparison circuit, the battery charging voltage output is turned off through the battery charging control port 303 of the main control unit, stopping battery charging. The fifth diode 35 mainly prevents the output voltage from flowing backward to the voltage comparator 700, and the sixth diode 36 mainly prevents the 24V high-level backward battery charging control port 303 outputted from the voltage comparator 700 from causing a damage failure of the main control unit.

Example two

The charge and discharge protection method of a battery of the present embodiment includes a charge and discharge protection circuit of a battery of the first embodiment; as shown in fig. 4, the battery charge-discharge protection method further includes a battery discharge path protection method; the battery discharge path protection method comprises the following steps:

s1a, the output voltage of the battery enters a fuse, and the fuse judges whether the output voltage of the battery is normal or not; if yes, outputting voltage by the fuse and entering step S2a; if not, the fuse turns off automatically to inhibit the output voltage of the battery;

step S2a, the voltage output by the fuse enters a voltage detection circuit and a battery discharge power control circuit respectively, and the voltage detection circuit filters and divides the voltage output by the fuse and converts the voltage into acquired voltage to be output to a main control unit;

step S3a, the main control unit outputs the acquired voltage to a battery discharge power control circuit; the battery discharging power control circuit judges whether to output battery power voltage according to the voltage output by the fuse and the acquisition voltage; if yes, outputting the battery power voltage to a current detection circuit and entering step S4a; if not, prohibiting outputting the battery power voltage;

step S4a, the current detection circuit detects the power voltage of the battery and judges whether the battery has output voltage, if yes, the battery normally outputs the voltage to a load and enters step S5a; if not, the output of the power voltage of the battery is turned off through the main control unit;

And S5a, the load works normally.

As shown in fig. 5, the charge-discharge protection method of the battery further includes a battery charge path protection method; the battery charging path protection method comprises the following steps:

s1b, respectively inputting voltages to a battery charging voltage comparison circuit and a battery charging power control circuit by a charging power supply;

s2, a battery charging voltage comparison circuit judges whether the voltage input by a charging power supply is larger than a battery charging cut-off voltage or not; if yes, the battery charging power output is turned off to stop charging the battery; if not, opening the battery charging power output to charge the battery and entering step S3b;

s3b, the main control unit collects charging information of the battery and judges whether the battery is fully charged or not according to the collected charging information of the battery; if yes, the main control unit turns off the battery charging power output to stop battery charging; if not, the battery continues to charge.

The above description is made in detail on the embodiment of the charge-discharge protection circuit for a battery provided by the present utility model. The principles and embodiments of the present utility model have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the core concepts of the utility model. It should be noted that it will be apparent to those skilled in the art that the present utility model may be modified and adapted without departing from the principles of the present utility model, and that such modifications and adaptations are intended to be within the scope of the appended claims.

Claims

1. The battery charge and discharge protection circuit is characterized by comprising a battery, a fuse (40), a voltage detection circuit, a battery discharge power control circuit, a current detection circuit, a load, a main control unit, a battery charge power control circuit, a battery charge voltage comparison circuit and a charge power supply;

the output end (101) of the battery is connected with the input end of the voltage detection circuit;

the fuse (40) is arranged between the output end (101) of the battery and the voltage detection circuit and is used for hard shutdown protection under the condition of battery overcurrent;

the output end (601) of the charging power supply is connected with the input end of the battery charging voltage comparison circuit, and the output end of the battery charging voltage comparison circuit is connected with the first input end of the battery charging power control circuit; the output end of the battery charging power control circuit is connected with the input end (102) of the battery;

2. The battery charge-discharge protection circuit according to claim 1, wherein the voltage detection circuit comprises a first resistor (11), a second resistor (12), a third resistor (13), a first capacitor (21), a second capacitor (22), a first diode (31), a second diode (32), and a first input voltage (201); the main control unit comprises a battery voltage acquisition port (301) and a shutdown signal port (302); the output end (101) of the battery is connected with one end of the fuse (40); the other end of the fuse (40) comprises a first connecting end and a second connecting end; the first connecting end is connected with the battery voltage acquisition port (301) and is sequentially connected with the first resistor (11) and the second resistor (12) in series; a first node is arranged between the first connecting end and the first resistor (11); the first node is connected with the ground wire and is connected with the first capacitor (21) in series; a second node is arranged between the first resistor (11) and the second resistor (12); the second node is connected with the ground wire and is connected with the third resistor (13) in series; a third node is arranged between the second resistor (12) and the battery voltage acquisition port (301); the third node is connected with the ground wire and is connected with the second capacitor (22) in series; a fourth node is arranged between the third node and the battery voltage acquisition port (301); the positive electrode of the first diode (31) is connected with the fourth node, and the negative electrode of the first diode (31) is connected with the first input voltage (201); the positive electrode of the second diode (32) is connected with the ground wire, and the negative electrode of the second diode (32) is connected with the fourth node.

3. The battery charge-discharge protection circuit according to claim 2, wherein the battery discharge power control circuit comprises a first MOS transistor (81), a second MOS transistor (82), a third MOS transistor (83), a fourth MOS transistor (84), a fourth resistor (14), a fifth resistor (15), a sixth resistor (16), a seventh resistor (17), an eighth resistor (18), a ninth resistor (19), and a sampling resistor (50); the second connecting end is connected with the drain electrode of the first MOS tube (81) and is connected with the fourth resistor (14) in series; the turn-off signal port (302) is connected with the grid electrode of the first MOS tube (81) and is connected with the fifth resistor (15) in series; the source electrode of the first MOS tube (81) is grounded; a fifth node is arranged between the fourth resistor (14) and the drain electrode of the first MOS tube (81); the fifth node is connected with the grid electrode of the second MOS tube (82) and is connected with the sixth resistor (16) in series; the source electrode of the second MOS tube (82) is grounded; a sixth node is arranged between the fourth resistor (14) and the second connecting end; the sixth node is connected with the drain electrode of the second MOS tube (82) and is sequentially connected with the seventh resistor (17) and the eighth resistor (18) in series; a seventh node is arranged between the sixth node and the seventh resistor (17); the seventh node is connected with the source electrode of the third MOS tube (83) and the source electrode of the fourth MOS tube (84); an eighth node is arranged between the seventh resistor (17) and the eighth resistor (18); the eighth node is connected with the grid electrode of the third MOS tube (83) and the grid electrode of the fourth MOS tube (84) in series with the ninth resistor (19); the input end (102) of the battery is connected with the drain electrode of the third MOS tube (83) and the drain electrode of the fourth MOS tube (84) in series with the sampling resistor (50).

4. The battery charge-discharge protection circuit according to claim 3, wherein the current detection circuit comprises a current sampling chip (400), a filter magnetic bead (60), a third capacitor (23), a fourth capacitor (24), a fifth capacitor (25), a sixth capacitor (26), a tenth resistor (71), an eleventh resistor (72), a third diode (33), a fourth diode (34), a second input voltage (202), and a third input voltage (203); the current sampling chip (400) comprises a first interface, a second interface, a third interface, a fourth interface, a fifth interface, a sixth interface, a seventh interface and an eighth interface; the seventh interface is idle; the main control unit also comprises a current acquisition port (500); a ninth node is arranged between the sampling resistor (50) and a connection point of the drain electrode of the third MOS tube (83) and the drain electrode of the fourth MOS tube (84); the first interface is connected with the ninth node; a tenth node is arranged between the sampling resistor (50) and the input end (102) of the battery; the second interface is connected with the tenth node; an eleventh node is arranged between the tenth node and an input terminal (102) of the battery; the eighth interface is connected with the eleventh node;

The second input voltage (202) and the third interface are connected and the filtering magnetic beads (60) are connected in series; a twelfth node is arranged between the filtering magnetic beads (60) and the third interface; the twelfth node is connected with the ground wire and is connected with the third capacitor (23) in series; a thirteenth node is arranged between the twelfth node and the third interface; the thirteenth node is connected with the ground line and is connected with the fourth capacitor (24) in series; a fourteenth node is arranged between the thirteenth node and the third interface; the fourteenth node is connected with the ground wire and is connected with the fifth capacitor (25) in series; the fourth interface is grounded; the fifth interface is connected with the ground wire and is connected with the tenth resistor (71) in series; the sixth interface is connected with the current collection port (500) and a fifteenth node is arranged between the sixth interface and the current collection port; the fifteenth node is connected with the ground line and is connected with the eleventh resistor (72) in series; a sixteenth node is arranged between the fifteenth node and the current collection port (500); the sixteenth node is connected with the ground line and is connected with the sixth capacitor (26) in series; a seventeenth node is arranged between the sixteenth node and the current collection port (500); -a negative electrode of the third diode (33) is connected to the third input voltage (203), and a positive electrode of the third diode (33) is connected to the seventeenth node; the negative electrode of the fourth diode (34) is connected with the seventeenth node, and the positive electrode of the fourth diode (34) is grounded.

5. The battery charge-discharge protection circuit according to claim 4, wherein the battery charge voltage comparison circuit includes a twelfth resistor (90), a thirteenth resistor (91), a fourteenth resistor (92), a fifteenth resistor (93), a seventh capacitor (27), an eighth capacitor (28), a ninth capacitor (29), a voltage comparator (700), a fourth input voltage (204), and a fifth input voltage (205); the voltage comparator (700) comprises a positive input end, a negative input end, a first wiring terminal, a second wiring terminal and a third wiring terminal; the output end (601) of the charging power supply is connected with the positive electrode input end and is connected with the twelfth resistor (90) in series; the fourth input voltage (204) is connected with the negative electrode input end and is sequentially connected with the thirteenth resistor (91) and the fourteenth resistor (92) in series; an eighteenth node is arranged between the thirteenth resistor (91) and the fourteenth resistor (92); the eighteenth node is connected with the ground line and is connected with the fifteenth resistor (93) in series; a nineteenth node is disposed between the eighteenth node and the fourteenth resistor (92); the nineteenth node is connected with the ground line and is connected with the seventh capacitor (27) in series; the first wiring terminal is grounded; the second terminal is connected with the ground wire and is connected with the eighth capacitor (28) in series; a twentieth node is arranged between the second terminal and the eighth capacitor (28); -the twentieth node is connected to the fifth input voltage (205); the third terminal is connected with the ground line and is connected with the ninth capacitor (29) in series.

6. The battery charge-discharge protection circuit according to claim 5, wherein the battery charge power control circuit comprises a fifth diode (35), a sixth diode (36), a sixteenth resistor (94), a seventeenth resistor (95), an eighteenth resistor (96), a nineteenth resistor (97), a twentieth resistor (98), a twenty first resistor (99), a twenty second resistor (910), a fifth MOS transistor (85), a sixth MOS transistor (86), a seventh MOS transistor (87), and an eighth MOS transistor (88); the master control unit further comprises a battery charging control port (303); a twenty-first node is arranged between the third terminal and the ninth capacitor (29); -the twenty-first node is connected to the anode of the fifth diode (35); the negative electrode of the fifth diode (35) is connected with the ground wire, and the sixteenth resistor (94) and the seventeenth resistor (95) are sequentially connected in series; a twenty-second node is arranged between the fifth diode (35) and the sixteenth resistor (94); -a cathode of the sixth diode (36) is connected to the twenty-second node; the battery charge control port (303) is connected to the anode of the sixth diode (36).

7. The charge-discharge protection circuit of a battery according to claim 6, wherein a twenty-third node is provided between the sixteenth resistor (94) and the seventeenth resistor (95); the twenty-third node is connected with the grid electrode of the fifth MOS tube (85); the source electrode of the fifth MOS tube (85) is grounded; the input end (602) of the charging power supply is connected with the drain electrode of the fifth MOS tube (85) and the nineteenth resistor (97) is connected in series between the input end and the drain electrode of the fifth MOS tube; a twenty-fourth node is arranged between the drain electrode of the fifth MOS tube (85) and the nineteenth resistor (97); the twenty-fourth node is connected with the grid electrode of the sixth MOS tube (86); the source electrode of the sixth MOS tube (86) is grounded; a twenty-fifth node is arranged between the input end (602) of the charging power supply and the nineteenth resistor (97); the twenty-fifth node is connected with the drain electrode of the sixth MOS tube (86) and is sequentially connected with the twenty-first resistor (98) and the twenty-first resistor (99) in series; a twenty-sixth node is arranged between the twenty-fifth node and the twentieth resistor (98); the twenty-sixth node is connected with the source electrode of the seventh MOS tube (87) and the source electrode of the eighth MOS tube (88); a twenty-seventh node is arranged between the twentieth resistor (98) and the twenty-first resistor (99); the twenty-seventh node is connected with the grid electrode of the seventh MOS tube (87) and the grid electrode of the eighth MOS tube (88) in series with the twenty-second resistor (910); the output end (601) of the charging power supply is also connected with the drain electrode of the seventh MOS tube (87) and the drain electrode of the eighth MOS tube (88).

8. The battery charge-discharge protection circuit according to claim 7, wherein the first MOS transistor (81), the second MOS transistor (82), the fifth MOS transistor (85), and the sixth MOS transistor (86) are all N-MOS transistors; the third MOS tube (83), the fourth MOS tube (84), the seventh MOS tube (87) and the eighth MOS tube (88) are P-MOS tubes.