Double-battery-pack parameter detection circuit and electric equipment

Abstract

The utility model discloses a dual-battery pack parameter detection circuit and electric equipment, a dual-battery pack comprises a first battery pack and a second battery pack, the first battery pack comprises a thermistor and a first battery, and the second battery pack comprises a second battery. The double-battery-pack parameter detection circuit comprises a voltage dividing branch, a switch branch, a resistor branch and a controller. The controller outputs a first control signal and a second control signal. The switch branch is turned on in response to a first control signal to establish a connection between the first node and the resistive branch. The voltage dividing branch divides the voltage of the first node when the switch branch is switched on and then outputs the voltage to the controller, so that the controller determines the resistance value of the thermistor. The switch branch is turned off in response to a second control signal to disconnect the connection between the first node and the resistive branch. The voltage dividing branch divides the voltage of the first node when the switch branch is turned off and then outputs the divided voltage to the controller, so that the controller determines the voltage of the second battery. In this way, the purpose of reducing the cost can be achieved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of electronic circuits, and in particular, to a dual-battery-pack parameter detection circuit and an electric device. Background Art

[0002] Some electric devices that require lithium battery power supply in the market, such as lawn trimmers and lawn mowers, are usually configured to be powered by two battery packs connected in series. In order to ensure the normal operation of the battery packs and guarantee their performance and safety, corresponding detection circuits are usually required to detect the voltage and temperature of the battery packs.

[0003] However, the current detection method requires a corresponding detection circuit to be separately set for the voltage and temperature of each battery pack to detect the voltage and temperature of each battery pack, resulting in a high cost. Utility Model Content

[0004] The embodiments of the present application provide a dual-battery-pack parameter detection circuit and an electric device, which can achieve the purpose of reducing costs.

[0005] In a first aspect, the embodiments of the present application provide a dual-battery-pack parameter detection circuit. The dual-battery pack includes a first battery pack and a second battery pack. The first battery pack includes a thermistor and a first battery. The second battery pack includes a second battery. The first battery and the second battery are connected in series. The negative electrode of the first battery is connected to the positive electrode of the second battery and the first end of the thermistor respectively;

[0006] The dual-battery-pack parameter detection circuit includes a voltage division branch, a switch branch, a resistor branch, and a controller. The first end of the switch branch is connected to the controller. The second end of the switch branch is connected to the second end of the thermistor at a first node. The third end of the switch branch is connected to the resistor branch. The first node is connected to the first end of the voltage division branch. The second end of the voltage division branch is connected to the controller;

[0007] The controller is configured to output a first control signal to the switch branch;

[0008] The switch branch is configured to conduct in response to the first control signal to establish a connection between the first node and the resistor branch;

[0009] The voltage division branch is configured to divide the voltage of the first node and output a first voltage to the controller when the switch branch conducts, so that the controller determines the resistance value of the thermistor based on the first voltage;

[0010] The controller is further configured to output a second control signal to the switch branch;

[0011] The switch branch is further configured to turn off in response to the second control signal to disconnect the connection between the first node and the resistor branch;

[0012] The voltage dividing branch is configured to divide the voltage of the first node and output a second voltage to the controller when the switch branch is turned off, so that the controller determines the voltage of the second battery based on the second voltage.

[0013] In one or more embodiments, the dual-battery pack parameter detection circuit further includes a voltage follower branch;

[0014] The voltage follower branch is connected between the first node and the first end of the voltage dividing branch. The voltage follower branch is configured to output a voltage having the same amplitude as the voltage of the first node to the voltage dividing branch, wherein the input impedance of the voltage follower branch is greater than the output impedance.

[0015] In one or more embodiments, the dual-battery pack parameter detection circuit further includes a filtering branch;

[0016] The filtering branch is connected between the second end of the voltage dividing branch and the controller. The filtering branch is configured to filter the voltage output by the voltage dividing branch and then input it to the controller.

[0017] In one or more embodiments, the switch branch includes a first switch unit and a second switch unit;

[0018] The first end of the first switch unit is connected to the controller, the second end of the first switch unit is connected to the first end of the second switch unit, the second end of the second switch unit is connected to the first node, and the third end of the second switch unit is connected to the resistor branch;

[0019] The first switch unit is configured to turn on in response to the first control signal to output a first level signal to the second switch unit, and is configured to turn off in response to the second control signal to stop outputting the first level signal;

[0020] The second switch unit is configured to turn on when receiving the first level signal to establish the connection between the first node and the resistor branch, and is configured to turn off when not receiving the first level signal to disconnect the connection between the first node and the resistor branch.

[0021] In one or more embodiments, the first switch unit includes a first switch tube, a first resistor, and a second resistor;

[0022] The first resistor and the second resistor are connected in series between the controller and ground. The connection point between the first resistor and the second resistor is connected to the first end of the first switching transistor. The second end of the first switching transistor is grounded, and the third end of the first switching transistor is connected to the first end of the second switching unit.

[0023] In one or more embodiments, the second switching unit includes a second switching transistor, a third resistor, and a fourth resistor;

[0024] The third resistor and the fourth resistor are connected in series between the first node and the second end of the first switching unit. The connection point between the third resistor and the fourth resistor is connected to the first end of the second switching transistor. The second end of the second switching transistor is connected to the first node, and the third end of the second switching transistor is connected to the resistor branch.

[0025] In one or more embodiments, the voltage dividing branch includes a fifth resistor and a sixth resistor;

[0026] The fifth resistor and the sixth resistor are connected in series between the first node and ground. The connection point between the fifth resistor and the sixth resistor is connected to the controller.

[0027] In one or more embodiments, the voltage following branch includes an operational amplifier, a seventh resistor, and a zener diode;

[0028] The non-inverting input terminal of the operational amplifier is connected to the first node. The inverting input terminal of the operational amplifier is connected to the output terminal and is connected to the first end of the voltage dividing branch. The seventh resistor is connected between the positive electrode of the first battery and the power supply terminal of the operational amplifier. The anode of the zener diode and the ground terminal of the operational amplifier are both grounded, and the cathode of the zener diode is connected to the power supply terminal of the operational amplifier.

[0029] In one or more embodiments, the filtering branch includes an eighth resistor and a first capacitor;

[0030] The eighth resistor and the first capacitor are connected in series between the second end of the voltage dividing branch and ground. The connection point between the eighth resistor and the first capacitor is connected to the controller.

[0031] In a second aspect, an embodiment of the present application provides an electric device, including a first battery pack, a second battery pack, and the dual-battery-pack parameter detection circuit as described above;

[0032] The first battery pack includes a thermistor and a first battery, the second battery pack includes a second battery, the first battery and the second battery are connected in series, the negative electrode of the first battery is respectively connected to the positive electrode of the second battery and the first end of the thermistor, the negative electrode of the second battery is grounded, and the second end of the thermistor is connected to the dual-battery-pack parameter detection circuit.

[0033] The beneficial effects of this application are as follows: The dual-battery pack in the dual-battery-pack parameter detection circuit according to the embodiments of this application includes a first battery pack and a second battery pack. The first battery pack includes a thermistor and a first battery, the second battery pack includes a second battery, the first battery and the second battery are connected in series, and the negative electrode of the first battery is respectively connected to the positive electrode of the second battery and the first end of the thermistor. The dual-battery-pack parameter detection circuit includes a voltage division branch, a switch branch, a resistor branch, and a controller. The first end of the switch branch is connected to the controller, the second end of the switch branch is connected to the second end of the thermistor at a first node, the third end of the switch branch is connected to the resistor branch, the first node is connected to the first end of the voltage division branch, and the second end of the voltage division branch is connected to the controller. When it is necessary to detect the voltage of the second battery pack, the controller outputs a second control signal to the switch branch to turn off the switch branch. Subsequently, the connection between the first node and the resistor branch is disconnected, and the voltage output by the second battery pack acts on the first node through the thermistor. The voltage of the first node is then divided by the voltage division branch and a second voltage is output to the controller. The controller can, based on the second voltage and the voltage division ratio of the voltage division branch, conversely obtain the voltage of the first node, and further obtain the voltage of the second battery. When it is necessary to detect the temperature of the first battery pack, the controller outputs a first control signal to the switch branch to turn on the switch branch. The connection between the first node and the resistor branch is established, and the thermistor and the resistor branch divide the voltage output by the second battery, and the divided voltage acts on the first node. The voltage of the first node is then divided by the voltage division branch and a first voltage is output to the controller. The controller can, based on the first voltage and the voltage division ratio of the voltage division branch, conversely obtain the voltage of the first node, and by combining the voltage division ratio of the thermistor and the resistor branch and the voltage of the first node, can determine the magnitude of the thermistor, and further determine the temperature of the first battery pack. Through the above process, it is possible to use a single circuit structure to detect the temperature of the first battery pack and the voltage of the second battery pack. It can be seen that, compared with the related art in which corresponding detection circuits need to be separately set for the voltage and temperature of each battery pack, the cost of this application is lower, thus achieving the purpose of reducing costs. Description of the Drawings

[0034] One or more embodiments are illustrated by way of example in the accompanying drawings, which illustrations are not intended to limit the embodiments, and elements with the same reference numerals in the drawings are represented as similar elements.

[0035] Figure 1 is a schematic structural diagram of a dual battery pack parameter detection circuit provided by an embodiment of the present application Figure 1 ;

[0036] Figure 2 is a schematic structural diagram of a dual battery pack parameter detection circuit provided by an embodiment of the present application Figure 2 ;

[0037] Figure 3 is a schematic structural diagram of a dual battery pack parameter detection circuit provided by an embodiment of the present application Figure 3 ;

[0038] Figure 4 is a schematic structural diagram of a dual battery pack parameter detection circuit provided by an embodiment of the present application Figure 4 ;

[0039] Figure 5 is a schematic circuit diagram of a dual battery pack parameter detection circuit provided by an embodiment of the present application Figure 1 ;

[0040] Figure 6 is a schematic circuit diagram of a dual battery pack parameter detection circuit provided by an embodiment of the present application Figure 2 . Detailed implementation manners

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and detailedly described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0042] It should be noted that when an element is expressed as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween.

[0043] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0044] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a dual battery pack parameter detection circuit provided by an embodiment of the present application. As Figure 1As shown, the dual battery pack includes a first battery pack 200 and a second battery pack 300. The first battery pack 200 includes a thermistor RW1 and a first battery B1. The second battery pack 300 includes a second battery B2. The first battery B1 and the second battery B2 are connected in series. The negative electrode of the first battery B1 is connected to the positive electrode of the second battery B2 and the first end of the thermistor RW1 respectively.

[0045] The dual battery pack parameter detection circuit 100 includes a voltage division branch 10, a switch branch 20, a resistor branch 30 and a controller 40. Among them, the first end of the switch branch 20 is connected to the controller 40. The second end of the switch branch 20 and the second end of the thermistor RW1 are connected to a first node N1. The third end of the switch branch 20 is connected to the resistor branch 30. The first node N1 is connected to the first end of the voltage division branch 10. The second end of the voltage division branch 10 is connected to the controller 40.

[0046] Among them, the thermistor RW1 is a resistor made of a special material, and its resistance value changes with the change of temperature. The thermistor includes two types: positive temperature coefficient (PTC) and negative temperature coefficient (NTC). When the temperature rises, the resistance value of the positive temperature coefficient thermistor will increase; when the temperature drops, the resistance value of the positive temperature coefficient thermistor will decrease. When the temperature rises, the resistance value of the negative temperature coefficient thermistor will decrease; when the temperature drops, the resistance value of the negative temperature coefficient thermistor will increase.

[0047] The resistor branch 30 includes at least one resistor. When the resistor branch 30 includes more than two resistors, the resistors can be connected in series, in parallel, or in a form of series and parallel hybrid connection.

[0048] The controller 40 can adopt a microcontroller unit (MCU) or a digital signal processing (DSP) controller, etc.

[0049] Specifically, the controller 40 is configured to output a first control signal to the switching branch 20. The switching branch 20 is configured to conduct in response to the first control signal to establish a connection between the first node N1 and the resistor branch 30. The voltage dividing branch 10 is configured to divide the voltage of the first node N1 and output a first voltage to the controller 40 when the switching branch 20 is conducting, so that the controller 40 determines the resistance value of the thermistor RW1 based on the first voltage. The controller 40 is further configured to output a second control signal to the switching branch 20. The switching branch 20 is further configured to turn off in response to the second control signal to disconnect the connection between the first node N1 and the resistor branch 30. The voltage dividing branch 10 is configured to divide the voltage of the first node N1 and output a second voltage to the controller 40 when the switching branch 20 is off, so that the controller 40 determines the voltage of the second battery B2 based on the second voltage.

[0050] In practical applications, when it is necessary to detect the voltage of the second battery pack 300, the controller 40 outputs a second control signal to the switching branch 20 to turn off the switching branch 20. Subsequently, the connection between the first node N1 and the resistor branch 30 is disconnected, and the voltage output by the second battery B2 acts on the first node N1 through the thermistor RW1. The voltage of the first node N1 is divided by the voltage dividing branch 10 and a second voltage is output to the controller 40. The controller 40 can, based on the second voltage and the voltage division ratio of the voltage dividing branch 10, conversely obtain the voltage of the first node N1, and further obtain the voltage of the second battery B2. Assuming that the voltage division ratio of the voltage dividing branch 10 is K1, the second voltage is V2, and the voltage of the first node at this time is VN1 (which is also the voltage of the second battery B2), then at this time VN1 * K1 = V2, and it can be obtained that VN1 = V2 / K1, where V2 and K1 are determined values, so that the voltage of the second battery B2 can be obtained.

[0051] When it is necessary to detect the temperature of the first battery pack 200, the controller 40 outputs a first control signal to the switch branch 20 to turn on the switch branch 20. The connection between the first node N1 and the resistor branch 30 is established. The thermistor RW1 and the resistor branch 30 divide the voltage output by the second battery B2, and the divided voltage acts on the first node N1. The voltage of the first node N1 is further divided by the voltage dividing branch 10, and a first voltage is output to the controller 40. The controller 40 can, in turn, obtain the voltage of the first node N1 based on the first voltage and the voltage division ratio of the voltage dividing branch 10. By combining the voltage division ratio of the thermistor RW1 and the resistor branch 30, the voltage of the first node N1, and the voltage of the second battery B2, the size of the thermistor RW1 can be determined, and then the temperature of the first battery pack 200 can be determined. Assume that the resistance value of the thermistor RW1 is r1, the resistance value of the resistor branch 30 is r2, the voltage division ratio of the voltage dividing branch 10 is K1, the first voltage is V1, the voltage of the first node at this time is VN2, and the voltage of the second battery B2 is VN1. Then at this time, VN1*(r2 / (r1 + r2)) = VN2, VN2*K1 = V1, and it can be obtained that r1 = r2*VN1*K1 / V1 - r2. Among them, r2, VN1, K1, and V1 are all determined values, so the resistance value of the thermistor RW1 can be obtained. Then, based on the resistance value of the thermistor RW1, the temperature of the first battery pack 200 can be obtained.

[0052] Through the above process, it is possible to use a circuit structure to achieve the temperature detection of the first battery pack 200 and the voltage detection of the second battery pack 300. It can be seen that compared with the related art in which corresponding detection circuits need to be separately set for the voltage and temperature of each battery pack (the prior art needs to set 4 circuits to separately detect the voltage and temperature of two battery packs, while the present application only needs 2 circuits to detect the voltage and temperature of two battery packs), the cost of the present application is lower, thus achieving the purpose of reducing costs.

[0053] Secondly, in the related art, since corresponding detection circuits need to be separately set, at least 5 connection lines need to be led out from a total of two battery packs, 3 for voltage detection and 2 for temperature detection. In the embodiment of the present application, only 1 connection line (connected to the first node N1) needs to be led out for each circuit. It can be seen that compared with the related art, the present application can also reduce the number of connection lines required for the battery pack, which can also save costs and has higher stability.

[0054] In one embodiment, as Figure 2 shown, the dual-battery-pack parameter detection circuit 100 further includes a voltage follower branch 50.

[0055] Among them, the voltage follower branch 50 is connected between the first node N1 and the first end of the voltage dividing branch 10. The voltage follower branch 50 is used to output a voltage with the same voltage amplitude as that of the first node N1 to the voltage dividing branch 10. Among them, the input impedance of the voltage follower branch 50 is greater than the output impedance. The voltage follower branch 50 can achieve high-impedance matching isolation. Specifically, the voltage follower branch 50 can isolate its input voltage from the output voltage and keep the voltage amplitudes of its input voltage and output voltage the same. Thus, it can ensure that the collected temperature value is not affected by the battery pack voltage.

[0056] In one embodiment, as Figure 3 shown, the dual battery pack parameter detection circuit 100 further includes a filtering branch 60.

[0057] Among them, the filtering branch 60 is connected between the second end of the voltage dividing branch 10 and the controller 40. The filtering branch 60 is used to filter the voltage output by the voltage dividing branch 10 and then input it to the controller 40. In some specific embodiments, the filtering branch 60 is used to filter out the spike signals in the voltage output by the voltage dividing branch 10 to prevent the controller 40 from being damaged due to excessive input voltage.

[0058] In one embodiment, as Figure 4 shown, the switch branch 20 includes a first switch unit 21 and a second switch unit 22.

[0059] Among them, the first end of the first switch unit 21 is connected to the controller 40, the second end of the first switch unit 21 is connected to the first end of the second switch unit 22, the second end of the second switch unit 22 is connected to the first node N1, and the third end of the second switch unit 22 is connected to the resistor branch 30.

[0060] Specifically, the first switch unit 21 is used to conduct in response to the first control signal to output a first level signal to the second switch unit 22, and is used to turn off in response to the second control signal to stop outputting the first level signal. The second switch unit 22 is used to conduct when receiving the first level signal to establish a connection between the first node N1 and the resistor branch 30, and is used to turn off when not receiving the first level signal to disconnect the connection between the first node N1 and the resistor branch 30. Among them, the first level signal is a high level signal or a low level signal.

[0061] In practical applications, on the one hand, the switching branch 20 is controlled by the controller 40, so the switching branch 20 needs to be able to be driven by the controller 40; on the other hand, when the switching branch 20 is conducting, in order not to affect the voltage of the first node N1, the switching branch 20 needs to have a small on-resistance. In order to facilitate finding a device that can implement the function of the switching branch 20 in practical applications, the above two aspects can be implemented by different devices respectively, and then the switching branch 20 can be configured as a first switching unit 21 and a second switching unit 22. The first switching unit 21 only needs to satisfy being able to be driven by the controller 40, and the second switching unit 22 only needs to satisfy having a small on-resistance. This method can have high practicability.

[0062] Please refer to Figure 5 , Figure 5 which exemplarily shows a circuit structure of a dual battery pack parameter detection circuit. As Figure 5 shown, the voltage following branch 50 includes an operational amplifier U1, a seventh resistor R7, and a zener diode D1.

[0063] Among them, the non-inverting input terminal of the operational amplifier U1 is connected to the first node N1, the inverting input terminal and the output terminal of the operational amplifier U1 are connected and connected to the first end of the voltage dividing branch 10. The seventh resistor R7 is connected between the positive electrode of the first battery B1 and the power supply terminal of the operational amplifier U1. The anode of the zener diode D1 and the ground terminal of the operational amplifier U1 are both grounded to GND, and the cathode of the zener diode D1 is connected to the power supply terminal of the operational amplifier U1.

[0064] Specifically, by connecting the inverting input terminal and the output terminal of the operational amplifier U1, the voltage following function can be realized. The seventh resistor R7 and the zener diode D1 are used to generate a stable voltage based on the voltage of the first battery B1 to supply power to the operational amplifier U1.

[0065] In this embodiment, the voltage dividing branch 10 includes a fifth resistor R5 and a sixth resistor R6.

[0066] Among them, the fifth resistor R5 and the sixth resistor R6 are connected in series between the first node N1 and the ground GND, and the connection point between the fifth resistor R5 and the sixth resistor R6 is connected to the controller 40.

[0067] Specifically, the fifth resistor R5 and the sixth resistor R6 are used to divide the voltage output by the operational amplifier U1 (i.e., the voltage of the first node N1), and input the voltage division on the sixth resistor R6 (i.e., the first voltage or the second voltage) to the controller 40.

[0068] In this embodiment, the filtering branch 60 includes an eighth resistor R8 and a first capacitor C1.

[0069] Among them, the eighth resistor R8 and the first capacitor C1 are connected in series between the second end of the voltage dividing branch 10 and the ground GND, and the connection point between the eighth resistor R8 and the first capacitor C1 is connected to the controller 40. The eighth resistor R8 and the first capacitor C1 form an RC filter.

[0070] In this embodiment, the first switch unit 21 includes a first switching transistor Q1, a first resistor R1, and a second resistor R2.

[0071] Among them, the first resistor R1 and the second resistor R2 are connected in series between the controller 40 and the ground GND. The connection point between the first resistor R1 and the second resistor R2 is connected to the first end of the first switching transistor Q1. The second end of the first switching transistor Q1 is grounded to GND, and the third end of the first switching transistor Q1 is connected to the first end of the second switch unit 22.

[0072] Specifically, the first resistor R1 is used for current limiting. The first resistor R1 and the second resistor R2 are used for voltage division.

[0073] Among them, in this embodiment, taking the first switching transistor Q1 as an NPN type triode as an example. The base of the NPN type triode is the first end of the first switching transistor Q1, the emitter of the NPN type triode is the second end of the first switching transistor Q1, and the collector of the NPN type triode is the third end of the first switching transistor Q1.

[0074] In addition, the first switching transistor Q1 can be any controllable switch, for example, an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0075] In this embodiment, the second switch unit 22 includes a second switching transistor Q2, a third resistor R3, and a fourth resistor R4.

[0076] Among them, the third resistor R3 and the fourth resistor R4 are connected in series between the first node N1 and the second end of the first switch unit 21. The connection point between the third resistor R3 and the fourth resistor R4 is connected to the first end of the second switching transistor Q2. The second end of the second switching transistor Q2 is connected to the first node N1, and the third end of the second switching transistor Q2 is connected to the resistor branch 30.

[0077] Specifically, the third resistor R3 is used for current limiting. The third resistor R3 and the fourth resistor R4 are used for voltage division.

[0078] Among them, in this embodiment, the second switching transistor Q2 is taken as a PMOS transistor as an example. The gate of the PMOS transistor is the first end of the second switching transistor Q2, the source of the PMOS transistor is the second end of the second switching transistor Q2, and the drain of the PMOS transistor is the third end of the first switching transistor Q1.

[0079] In addition, the second switching transistor Q2 can be any controllable switch. For example, an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0080] In this embodiment, it is also taken that the resistor branch 30 includes a ninth resistor R9 as an example. The ninth resistor R9 is connected between the third end of the second switching transistor Q2 and the ground GND.

[0081] The following Figure 5 illustrates the principle of the circuit structure shown again.

[0082] When it is necessary to detect the voltage of the second battery pack 300, the controller 40 outputs a second control signal (which is a low-level signal at this time) to the first switching transistor Q1 to turn off the first switching transistor Q1. The connection between the second switching transistor Q2 and the ground GND is disconnected. Corresponding to the first switching transistor Q1 not outputting a first level signal (which is a low-level signal at this time), that is, corresponding to the second switching transistor Q2 not receiving the first level signal, and the second switching transistor Q2 is also turned off. Subsequently, the connection between the first node N1 and the ninth resistor R9 is disconnected, and the voltage output by the second battery B2 acts on the first node N1 through the thermistor RW1. The operational amplifier U1 outputs a voltage with the same amplitude as the voltage of the first node N1 to the fifth resistor R5 and is divided by the fifth resistor R5 and the sixth resistor R6. The voltage division on the sixth resistor R6 (i.e., the second voltage) is filtered by the eighth resistor R8 and the first capacitor C1 and then output to the controller 40. The controller 40 can, in turn, obtain the voltage of the first node N1 based on the second voltage and the resistance values of the fifth resistor R5 and the sixth resistor R6, and further obtain the voltage of the second battery B2.

[0083] When it is necessary to detect the temperature of the first battery pack 200, the controller 40 outputs a first control signal (which is a high-level signal at this time) to the first switching transistor Q1 to turn on the first switching transistor Q1. The second switching transistor Q2 is connected to the ground GND through the first switching transistor Q1, and a first level signal is output corresponding to the first switching transistor Q1, that is, the second switching transistor Q2 receives the first level signal and the second switching transistor Q2 turns on. The connection between the first node N1 and the ninth resistor R9 is established, and the thermistor RW1 and the ninth resistor R9 divide the voltage output by the second battery B2, and the divided voltage acts on the first node N1. The operational amplifier U1 outputs a voltage with the same voltage amplitude as that of the first node N1 to the fifth resistor R5, and is divided by the fifth resistor R5 and the sixth resistor R6. The voltage division on the sixth resistor R6 (i.e., the first voltage) is output to the controller 40 after being filtered by the eighth resistor R8 and the first capacitor C1. The controller 40 can, in turn, obtain the voltage of the first node N1 based on the first voltage, the resistance values of the fifth resistor R5 and the sixth resistor R6, and can determine the size of the thermistor RW1 by combining the thermistor RW1, the ninth resistor R9, the voltage of the first node N1, and the voltage of the second battery B2. Then, the temperature of the first battery pack 200 can be obtained according to the resistance value of the thermistor RW1.

[0084] It should be noted that, as Figure 5 shown, the hardware structure of the dual battery pack parameter detection circuit 100 is only an example, and moreover, the dual battery pack parameter detection circuit 100 may have more or fewer components than those shown in the figure, two or more components may be combined, or may have different component configurations. The various components shown in the figure can be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application specific integrated circuits.

[0085] For example, as Figure 6 shown, the voltage follower branch 50 can be replaced by a resistor with a relatively large resistance value (i.e., the tenth resistor R10), and the tenth resistor R10 is connected between the first node N1 and the fifth resistor R5. Figure 6 The process of implementing the temperature detection of the first battery pack 200 and the voltage detection of the second battery pack 300 in the circuit structure shown is similar to Figure 5 that, which is within the easy understanding range of those skilled in the art and will not be elaborated here.

[0086] The embodiment of the present application further provides an electric device, which includes a first battery pack 200, a second battery pack 300, and the dual battery pack parameter detection circuit 100 in any embodiment of the present application.

[0087] Among them, the first battery pack 200 includes a thermistor RW1 and a first battery B1, and the second battery pack 300 includes a second battery B2. The first battery B1 and the second battery B2 are connected in series. The negative electrode of the first battery B1 is connected to the positive electrode of the second battery B2 and the first end of the thermistor RW1 respectively. The negative electrode of the second battery B2 is grounded, and the second end of the thermistor RW1 is connected to the dual-battery-pack parameter detection circuit 200.

[0088] The above are only the embodiments of the present application, and thus do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present application.

[0089] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; under the idea of the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. Those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A dual battery pack parameter detection circuit, characterized in that: The dual battery pack includes a first battery pack and a second battery pack, the first battery pack includes a thermistor and a first battery, the second battery pack includes a second battery, the first battery and the second battery are connected in series, and the negative electrode of the first battery is connected to the positive electrode of the second battery and the first end of the thermistor respectively; The dual battery pack parameter detection circuit includes a voltage dividing branch, a switch branch, a resistance branch and a controller, wherein a first end of the switch branch is connected to the controller, a second end of the switch branch and a second end of the thermistor are connected to a first node, a third end of the switch branch is connected to the resistance branch, the first node is connected to a first end of the voltage dividing branch, and a second end of the voltage dividing branch is connected to the controller; The controller is used to output a first control signal to the switch branch; The switch branch is used to be turned on in response to the first control signal to establish a connection between the first node and the resistance branch; The voltage dividing branch is used to divide the voltage of the first node and output a first voltage to the controller when the switch branch is turned on, so that the controller determines the resistance value of the thermistor based on the first voltage; The controller is also used to output a second control signal to the switch branch; The switch branch is further configured to be turned off in response to the second control signal to disconnect the first node from the resistance branch; The voltage dividing branch is used for dividing the voltage of the first node and outputting a second voltage to the controller when the switch branch is turned off, so that the controller determines the voltage of the second battery based on the second voltage.

2. The dual battery pack parameter detection circuit according to claim 1, characterized in that: The dual battery pack parameter detection circuit also includes a voltage follower branch; The voltage follower branch is connected between the first node and the first end of the voltage divider branch, and is used to output a voltage with the same voltage amplitude as the first node to the voltage divider branch, wherein the input impedance of the voltage follower branch is greater than the output impedance.

3. The dual battery pack parameter detection circuit according to claim 1, characterized in that: The dual battery pack parameter detection circuit also includes a filter branch; The filter branch is connected between the second end of the voltage divider branch and the controller, and the filter branch is used to filter the voltage output by the voltage divider branch and then input it into the controller.

4. The dual battery pack parameter detection circuit according to claim 1, characterized in that: The switch branch includes a first switch unit and a second switch unit; The first end of the first switch unit is connected to the controller, the second end of the first switch unit is connected to the first end of the second switch unit, the second end of the second switch unit is connected to the first node, and the third end of the second switch unit is connected to the resistance branch; The first switch unit is used to be turned on in response to the first control signal to output the first level signal to the second switch unit, and is used to be turned off in response to the second control signal to stop outputting the first level signal; The second switch unit is used to be turned on when receiving the first level signal to establish a connection between the first node and the resistance branch, and is used to be turned off when not receiving the first level signal to disconnect the connection between the first node and the resistance branch.

5. The dual battery pack parameter detection circuit according to claim 4, characterized in that: The first switch unit includes a first switch tube, a first resistor and a second resistor; The first resistor and the second resistor are connected in series between the controller and the ground, the connection point between the first resistor and the second resistor is connected to the first end of the first switch tube, the second end of the first switch tube is grounded, and the third end of the first switch tube is connected to the first end of the second switch unit.

6. The dual battery pack parameter detection circuit according to claim 4, characterized in that: The second switch unit includes a second switch tube, a third resistor and a fourth resistor; The third resistor and the fourth resistor are connected in series between the first node and the second end of the first switch unit, the connection point between the third resistor and the fourth resistor is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the first node, and the third end of the second switch tube is connected to the resistance branch.

7. The dual battery pack parameter detection circuit according to claim 1, characterized in that: The voltage dividing branch includes a fifth resistor and a sixth resistor; The fifth resistor and the sixth resistor are connected in series between the first node and the ground, and a connection point between the fifth resistor and the sixth resistor is connected to the controller.

8. The dual battery pack parameter detection circuit according to claim 2, characterized in that: The voltage follower branch includes an operational amplifier, a seventh resistor and a voltage stabilizing diode; The non-inverting input terminal of the operational amplifier is connected to the first node, the inverting input terminal of the operational amplifier is connected to the output terminal and to the first end of the voltage divider branch, the seventh resistor is connected between the positive electrode of the first battery and the power supply terminal of the operational amplifier, the anode of the voltage regulator diode and the ground terminal of the operational amplifier are both grounded, and the cathode of the voltage regulator diode is connected to the power supply terminal of the operational amplifier.

9. The dual battery pack parameter detection circuit according to claim 3, characterized in that: The filtering branch includes an eighth resistor and a first capacitor; The eighth resistor and the first capacitor are connected in series between the second end of the voltage dividing branch and the ground, and a connection point between the eighth resistor and the first capacitor is connected to the controller.

10. An electric device, characterized in that: It comprises a first battery pack, a second battery pack and a dual battery pack parameter detection circuit as claimed in any one of claims 1 to 9; The first battery pack includes a thermistor and a first battery, the second battery pack includes a second battery, the first battery and the second battery are connected in series, the negative electrode of the first battery is respectively connected to the positive electrode of the second battery and the first end of the thermistor, the negative electrode of the second battery is grounded, and the second end of the thermistor is connected to the dual battery pack parameter detection circuit.

Images