Heating film control circuit, control device and battery pack

Abstract

The present application belongs to the field of circuit technology, and provides a heating film control circuit, a control device and a battery pack. The heating film control circuit includes: a main control circuit, a drive circuit and a protection circuit. The main control circuit is used to generate a heating drive signal, a heating stop signal and a heating protection signal. The drive circuit is used to turn on when receiving the heating drive signal to control the heating film to start working; it is cut off when receiving the heating stop signal to control the heating film to stop working. The protection circuit is used to turn on when receiving the heating protection signal to cut off the connection between the positive terminal and the heating film. By setting the drive circuit, the driving stability of the heating film in the battery pack can be guaranteed. By setting the protection circuit, when the drive circuit is not controlled and the continuous heating of the heating film may cause safety problems, the protection circuit can force the heating film to disconnect, thereby increasing the stability of the battery pack, improving the safety of the battery pack, and improving the user experience.

Description

Technical Field

[0001] The present application belongs to the field of circuit technology, and in particular relates to a heating film control circuit, a control device and a battery pack. Background Art

[0002] With the development of science and technology and the requirements of the social environment, household energy storage is increasingly valued by people, and an important component of household energy storage is the battery pack. In the cold winter in the north, the ambient temperature of the battery pack is very low, resulting in a low temperature for the battery pack itself. The battery pack works at a relatively low temperature, which will affect the life of the battery pack, especially when charging the battery. If the temperature of the battery pack is lower than the appropriate operating temperature, the life of the battery pack will be greatly reduced. At present, the battery pack is generally heated by heating film, PTC (Positive Temperature Coefficient) heater or liquid flow heating. However, the existing heating film control circuit may be out of control when working for a long time, resulting in the heating film being out of control and causing safety problems. Utility Model Content

[0003] The purpose of the present application is to provide a heating film control circuit, a control device and a battery pack, aiming to solve the problem that the existing heating film control circuit may lose control when working for a long time, resulting in the heating film being out of control and causing safety problems.

[0004] A first aspect of an embodiment of the present application provides a heating film control circuit, which is applied to a battery pack, wherein the battery pack comprises: a battery cell, a positive terminal, a negative output terminal, and a heating film, wherein the heating film is connected between the positive terminal and the negative output terminal, and the heating film is in contact with the battery cell; the heating film control circuit comprises:

[0005] A main control circuit, connected to the battery cell, for detecting the temperature of the battery cell, generating a temperature detection signal, and generating a heating drive signal when a voltage value of the temperature detection signal is less than a first preset temperature value, and generating a heating stop signal when a voltage value of the temperature detection signal is greater than a second preset temperature value;

[0006] A driving circuit is provided between the negative output terminal and the heating film and is connected to the main control circuit, and is used to receive the heating driving signal and the heating stop signal, and is turned on according to the heating driving signal to control the heating film to start working; and is turned off according to the heating stop signal to control the heating film to stop working;

[0007] The main control circuit is also used to generate a heating protection signal when the voltage value of the temperature detection signal is greater than a third temperature preset value;

[0008] The protection circuit is arranged between the positive terminal and the heating film and connected to the main control circuit, and is used for being turned on when receiving the heating protection signal to cut off the connection between the positive terminal and the heating film.

[0009] In one embodiment, the driving circuit comprises:

[0010] a first driving unit connected to the main control circuit, and configured to generate a first driving signal according to the heating driving signal when receiving the heating driving signal; and generate a first cutoff signal according to the heating stop signal when receiving the heating stop signal;

[0011] The first switch unit is arranged between the negative output terminal and the heating film and is connected to the first driving unit, and is used for being turned on when receiving the first driving signal to control the heating film to start working; and being turned off when receiving the first cut-off signal to control the heating film to stop working.

[0012] In one embodiment, the protection circuit comprises:

[0013] A second driving unit, connected to the main control circuit, for generating a second driving signal according to the heating protection signal when receiving the heating protection signal;

[0014] a second switch unit, connected to the second drive unit and the negative output terminal, and configured to be turned on when receiving the second drive signal to generate a temperature increase control signal;

[0015] a heating unit connected to the second switch unit, configured to receive the temperature increase control signal and generate a safety disconnection signal according to the temperature increase control signal;

[0016] The insurance unit is connected between the positive terminal and the heating film and is connected to the heating unit, and is used to receive the insurance disconnection signal and disconnect according to the insurance disconnection signal to cut off the connection between the positive terminal and the heating film.

[0017] In one embodiment, the first driving unit includes: a first driving chip, a first resistor, a first diode, a first capacitor, and a second capacitor; wherein,

[0018] The power supply end of the first driver chip is connected to the first power supply, the power supply end of the first driver chip is connected in series with the first capacitor and then grounded, the power supply end of the first driver chip is also connected in series with the first diode and then connected to the high suspension end of the first driver chip, the high suspension end of the first driver chip is connected in series with the second capacitor and then connected to the negative output end, the input end of the first driver chip is connected to the main control circuit, the input end of the first driver chip is also connected in series with the first resistor and then grounded, and the output end of the first driver chip is connected to the first switch unit.

[0019] In one embodiment, the first switch unit includes: a second resistor, a third resistor and a first switch tube; wherein,

[0020] The first end of the second resistor and the first end of the third resistor are connected to the output end of the first driving chip, the second end of the second resistor is connected to the negative output end, the second end of the third resistor is connected to the control end of the first switching tube, the first end of the first switching tube is connected to the negative output end, and the second end of the first switching tube is connected to the heating film.

[0021] In one embodiment, the second driving unit includes: a second driving chip, a fourth resistor, a second diode, a third capacitor, and a fourth capacitor; wherein,

[0022] The power supply end of the second driver chip is connected to the second power supply, the power supply end of the second driver chip is connected in series with the third capacitor and then grounded, the power supply end of the second driver chip is also connected in series with the second diode and then connected to the high suspension end of the second driver chip, the high suspension end of the second driver chip is connected in series with the fourth capacitor and then connected to the negative output end, the input end of the second driver chip is connected to the main control circuit, the input end of the second driver chip is also connected in series with the fourth resistor and then grounded, and the output end of the second driver chip is connected to the second switch unit.

[0023] In one embodiment, the second switch unit includes: a fifth resistor, a sixth resistor and a second switch tube; wherein,

[0024] The first end of the fifth resistor is connected to the output end of the second driving chip, the second end of the fifth resistor and the first end of the sixth resistor are commonly connected to the control end of the second switch tube, the first end of the second switch tube and the second end of the sixth resistor are commonly connected to the negative output end, and the second end of the second switch tube is connected to the heating unit.

[0025] In one embodiment, the fuse unit includes: a first fuse and a second fuse; wherein,

[0026] The first end of the first fuse is connected to the positive terminal, the second end of the first fuse and the first end of the second fuse are connected to the heating unit, and the second end of the second fuse is connected to the heating film.

[0027] A second aspect of the embodiments of the present application further provides a control device, which includes a heating film control circuit as described in any one of the above items.

[0028] A third aspect of the embodiment of the present application further provides a battery pack, comprising: a battery cell, a positive terminal, a negative output terminal, and a heating film, wherein the heating film is connected between the positive terminal and the negative output terminal, and the heating film is in contact with the battery cell;

[0029] It also includes a heating film control circuit as described in any one of the above items, and the heating film control circuit is used to control the working state of the heating film.

[0030] Compared with the prior art, the embodiments of the present application have the following beneficial effects: the embodiments of the present application provide a heating film control circuit, the heating film control circuit includes: a main control circuit, a driving circuit and a protection circuit, the main control circuit is used to generate a heating driving signal, a heating stop signal and a heating protection signal, the driving circuit is used to conduct when receiving a heating driving signal to control the heating film to start working; it is cut off when receiving a heating stop signal to control the heating film to stop working, and the protection circuit is used to conduct when receiving a heating protection signal to cut off the connection between the positive terminal and the heating film. By setting the driving circuit, the driving stability of the heating film in the battery pack can be guaranteed, and by setting the protection circuit, when the driving circuit is not controlled and the continuous heating of the heating film may cause safety problems, the protection circuit can force the heating film to disconnect, thereby increasing the stability of the battery pack, improving the safety of the battery pack, and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a heating film control circuit provided in one embodiment of the present application Figure 1 ;

[0032] Figure 2 A schematic diagram of a heating film control circuit provided in one embodiment of the present application Figure 2 ;

[0033] Figure 3 A schematic diagram of a heating film control circuit provided in one embodiment of the present application Figure 3 ;

[0034] Figure 4 A schematic diagram of a heating film control circuit provided in one embodiment of the present application Figure 4 ;

[0035] Figure 5 A specific circuit diagram of a heating film control circuit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. 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.

[0037] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0038] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0040] With the development of science and technology and the requirements of the social environment, household energy storage is increasingly valued by people, and an important component of household energy storage is the battery pack. In the cold winter in the north, the ambient temperature of the battery pack is very low, resulting in a low temperature for the battery pack itself. The battery pack works at a relatively low temperature, which will affect the life of the battery pack, especially when charging the battery. If the temperature of the battery pack is lower than the appropriate operating temperature, the life of the battery pack will be greatly reduced. At present, the battery pack is generally heated by heating film, PTC (Positive Temperature Coefficient) heater or liquid flow heating. However, the existing heating film control circuit may be out of control when working for a long time, resulting in the heating film being out of control and causing safety problems.

[0041] In order to solve the above technical problems, refer to Figure 1 As shown, an embodiment of the present application provides a heating film control circuit, which is applied to a battery pack. The battery pack includes: a battery cell 100, a positive terminal B+, a negative output terminal P- and a heating film 200, the heating film 200 is connected between the positive terminal B+ and the negative output terminal P-, and the heating film 200 is in contact with the battery cell 100; the heating film control circuit includes: a main control circuit 10, a drive circuit 20 and a protection circuit 30.

[0042] Specifically, the main control circuit 10 is connected to the battery cell 100. The main control circuit 10 is used to detect the temperature of the battery cell 100, generate a temperature detection signal, and generate a heating drive signal when the voltage value of the temperature detection signal is less than the first preset temperature value, and generate a heating stop signal when the voltage value of the temperature detection signal is greater than the second temperature preset value. The drive circuit 20 is arranged between the negative output terminal P- and the heating film 200, and is connected to the main control circuit 10. The drive circuit 20 is used to receive the heating drive signal and the heating stop signal, and is turned on according to the heating drive signal to control the heating film 200 to start working; and is turned off according to the heating stop signal to control the heating film 200 to stop working. The main control circuit 10 is also used to generate a heating protection signal when the heating stop signal is generated and the voltage value of the temperature detection signal is greater than the third temperature preset value. The protection circuit 30 is arranged between the positive terminal B+, the negative output terminal P- and the heating film 200, and is connected to the main control circuit 10. The protection circuit 30 is used to be turned on when receiving a heating protection signal to cut off the connection between the positive terminal B+ and the heating film 200.

[0043] In this embodiment, the battery pack includes a positive terminal B+, a negative terminal B-, a positive output terminal P+, and a negative output terminal P-, wherein the positive terminal B+ and the positive output terminal P+ are electrically connected by a wire, and the negative terminal B- and the negative output terminal P- are electrically connected by a wire, and the heating film 200 is connected between the positive terminal B+ and the negative output terminal P-, and the heating film 200 is in contact with the battery cell 100, and the heating film 200 is used to heat the battery cell 100 when the temperature of the battery cell 100 is too low, so that the temperature of the battery cell 100 is maintained within a preset temperature range.

[0044] In this embodiment, the main control circuit 10 is used to detect the temperature of the battery cell 100 in real time, generate a temperature detection signal, and generate a heating drive signal when the voltage value of the temperature detection signal is less than the first preset temperature value, and generate a heating stop signal when the voltage value of the temperature detection signal is greater than the second temperature preset value. For example, the main control circuit 10 can detect the temperature of the battery cell 100 by setting a PTC thermistor on the surface of the battery cell 100, and the main control circuit 10 compares the voltage value of the detected temperature detection signal with the first preset temperature value and the second preset temperature value (which can be achieved by a comparator), and outputs the corresponding heating drive signal and heating stop signal. It can be understood that when the heating drive signal is generated, it indicates that the temperature of the battery cell 100 is too low, and the battery cell 100 needs to be heated at this time. When the heating stop signal is generated, it indicates that the temperature of the battery cell 100 is within the preset temperature range at this time, and the battery cell 100 does not need to be heated. By setting the main control circuit 10, the heating of the battery cell 100 can be controlled by detecting the temperature of the battery cell 100, so that the temperature of the battery cell 100 is within a reasonable temperature range, and the service life of the battery cell 100 is extended.

[0045] In this embodiment, the driving circuit 20 is used to be turned on when receiving a heating driving signal to control the heating film 200 to start working; the driving circuit 20 is also used to be turned off when receiving a heating stop signal to control the heating film 200 to stop working. Specifically, since the driving circuit 20 is arranged between the negative output terminal P- and the heating film 200, when the driving circuit 20 is turned on, the heating film 200 is connected to the negative output terminal P-, and the power supply circuit of the heating film 200 is formed, and the heating film 200 starts working to heat the battery cell 100. When the driving circuit 20 is turned off, the heating film 200 is disconnected from the negative output terminal P-, and the power supply circuit of the heating film 200 is not turned on, and the heating film 200 stops working. By setting the driving circuit 20, the working state of the heating film 200 can be controlled, so that the temperature of the battery cell 100 is controlled, the battery cell temperature can be kept within a reasonable range, and the service life of the battery cell 100 can be improved.

[0046] In this embodiment, the main control circuit 10 is further used to generate a heating protection signal when the voltage value of the temperature detection signal is greater than the third temperature preset value, or the main control circuit 10 is further used to generate a heating protection signal when the heating stop signal is generated and the voltage value of the temperature detection signal is greater than the third temperature preset value. The protection circuit 30 is arranged between the positive terminal B+, the negative output terminal P- and the heating film 200, and is connected to the main control circuit 10. The protection circuit 30 is used to be turned on when receiving the heating protection signal to cut off the connection between the positive terminal B+ and the heating film 200.

[0047] In this embodiment, after the main control circuit 10 generates a heating stop signal, and the main control circuit 10 detects that the voltage value of the temperature detection signal is greater than the third temperature preset value, it indicates that the drive circuit 20 is no longer under control. Although the temperature of the battery cell is already within a reasonable range, the heating film 200 is still being heated. At this time, the main control circuit 10 needs to generate a heating protection signal. When the protection circuit 30 receives the heating protection signal, it is turned on to cut off the connection between the heating film 200 and the positive terminal B+, so that the heating film 200 is forced to be powered off and stop heating.

[0048] In this embodiment, when working in a relatively harsh environment, the drive circuit 20 often needs to be turned on or off, which may cause the drive circuit 20 to be damaged or out of control. When the drive circuit 20 needs to be turned off, the drive circuit 20 is not really turned off, but is continuously turned on, causing the temperature of the battery cell 100 to continue to rise, causing safety problems. By setting up a protection circuit 30, when the drive circuit 20 is out of control, the connection between the heating film 200 and the positive terminal B+ can be forcibly disconnected, so that the heating film 200 is forced to be powered off, thereby protecting the safety of the battery pack.

[0049] In one implementation, the main control circuit 10 may be implemented by a single chip microcomputer, and the specific model of the single chip microcomputer may be GD32F427VET6.

[0050] In one embodiment, the heating driving signal is a high level signal, the heating stopping signal is a low level signal, and the heating protection signal is a high level signal.

[0051] In one embodiment, reference Figure 2 As shown, the driving circuit 20 includes: a first driving unit 21 and a first switching unit 22 .

[0052] Specifically, the first driving unit 21 is connected to the main control circuit 10. The first driving unit 21 is used to generate a first driving signal according to the heating driving signal when receiving the heating driving signal; the first driving unit 21 is also used to generate a first cut-off signal according to the heating stop signal when receiving the heating stop signal. The first switch unit 22 is provided between the negative output terminal P- and the heating film 200 and is connected to the first driving unit 21. The first switch unit 22 is used to be turned on when receiving the first driving signal to control the heating film 200 to start working; the first switch unit 22 is also used to be turned off when receiving the first cut-off signal to control the heating film 200 to stop working.

[0053] In this embodiment, the first driving unit 21 is used to control the first switch unit 22 to be turned on when receiving the heating driving signal, so as to control the heating film 200 to start working; the first driving unit 21 is also used to control the first switch unit 22 to be turned off when receiving the heating stop signal, so as to control the heating film 200 to stop working. Specifically, since the first driving unit 21 and the first switch unit 22 are arranged between the negative output terminal P- and the heating film 200, when the first switch unit 22 is turned on, the heating film 200 is connected to the negative output terminal P-, and the power supply circuit of the heating film 200 is formed, and the heating film 200 starts working to heat the battery cell 100. When the first switch unit 22 is turned off, the heating film 200 is disconnected from the negative output terminal P-, and the power supply circuit of the heating film 200 is not turned on, and the heating film 200 stops working. By setting the first driving unit 21 and the first switch unit 22, the working state of the heating film 200 can be controlled, so that the temperature of the battery cell 100 is controlled, and the service life of the battery cell 100 can be improved.

[0054] In one implementation, reference Figure 3 As shown, the protection circuit 30 includes: a second driving unit 31 , a second switching unit 32 , a heating unit 33 and a fuse unit 34 .

[0055] Specifically, the second drive unit 31 is connected to the main control circuit 10, and the second drive unit 31 is used to generate a second drive signal according to the heating protection signal when receiving the heating protection signal. The second switch unit 32 is connected to the second drive unit 31 and the negative output terminal P-, and the second switch unit 32 is used to turn on when receiving the second drive signal to generate a temperature increase control signal. The heating unit 33 is connected to the second switch unit 32, and the heating unit 33 is used to receive the temperature increase control signal and generate a fuse disconnection signal according to the temperature increase control signal. The fuse unit 34 is connected between the positive terminal B+ and the heating film 200, and is connected to the heating unit 33. The fuse unit 34 is used to receive the fuse disconnection signal and disconnect according to the fuse disconnection signal to cut off the connection between the positive terminal B+ and the heating film 200.

[0056] In this embodiment, when the main control circuit 10 determines that the drive circuit 20 is not controlled, a heating protection signal is generated. When the second drive unit 31 receives the heating protection signal, it generates a corresponding second drive signal to control the second switch unit 32 to be turned on. The second switch unit 32 generates a temperature increase control signal according to the second drive signal. The heating unit 33 starts working according to the temperature increase control signal and generates a fuse disconnection signal according to the temperature increase control signal. When the fuse unit 34 receives the fuse disconnection signal, it indicates that the drive circuit 20 is no longer controlled and the heating film 200 should stop working, but the heating film 200 continues to work. At this time, the fuse unit 34 is disconnected according to the fuse disconnection signal to cut off the connection between the heating film 200 and the positive terminal B+, so that the heating film 200 is forced to be powered off. By setting the second drive unit 31, the second switch unit 32, the heating unit 33 and the fuse unit 34, when the drive circuit 20 is not controlled, the connection between the heating film 200 and the positive terminal B+ can be forcibly disconnected, so that the heating film 200 is forced to be powered off, thereby protecting the safety of the battery pack.

[0057] In one embodiment, reference Figure 5 As shown, the first driving unit 21 includes: a first driving chip U1, a first resistor R1, a first diode D1, a first capacitor C1, and a second capacitor C2.

[0058] Specifically, the power supply terminal VCC of the first driver chip U1 is connected to the first power supply, the power supply terminal VCC of the first driver chip U1 is connected in series with the first capacitor C1 and then grounded, the power supply terminal VCC of the first driver chip U1 is also connected in series with the first diode D1 and then connected to the high floating terminal VB of the first driver chip U1, the high floating terminal VB of the first driver chip U1 is connected in series with the second capacitor C2 and then connected to the negative output terminal P-, the input terminal HIN of the first driver chip U1 is connected to the main control circuit 10 through the port HEAT EN, the input terminal HIN of the first driver chip U1 is also connected in series with the first resistor R1 and then grounded, the output terminal HO of the first driver chip U1 is connected to the first switch unit 22, the high-end floating ground terminal VS of the first driver chip U1 is connected to the negative output terminal P-, and the low-channel logic signal input level terminal LIN and the ground terminal GND of the first driver chip U1 are both grounded.

[0059] In one embodiment, reference Figure 4 , Figure 5As shown, the first power supply can provide a 15V voltage, and a discharge switch tube 300 is generally provided between the negative terminal B- of the battery pack and the negative output terminal P-. The first capacitor C1 and the second capacitor C2 are both filter capacitors, the first resistor R1 is a pull-down resistor, and the first diode D1 has a unidirectional unidirectional conduction function. The first diode D1 has an isolation function. When the battery pack does not need to discharge and the discharge switch tube 300 of the battery pack is disconnected, at this time, P+ and P- are connected with a load. Then, when the charge and discharge switch tube 300 is disconnected, there will be a voltage at P+ at P- (generally, the voltage at P+ is 60V, so there will also be a large voltage at P- at this time). At this time, D2 is used to isolate the voltage at P- and the first power supply (12V) to prevent the voltage at P- from breaking through the first power supply and the single-chip microcomputer, thereby improving the stability of the circuit.

[0060] In one embodiment, reference Figure 5 As shown, the first switch unit 22 includes: a second resistor R2, a third resistor R3 and a first switch tube Q1.

[0061] Specifically, the first end of the second resistor R2 and the first end of the third resistor R3 are connected to the output terminal HO of the first driving chip U1, the second end of the second resistor R2 is connected to the negative output terminal P-, the second end of the third resistor R3 is connected to the control end of the first switch tube Q1, the first end of the first switch tube Q1 is connected to the negative output terminal P-, and the second end of the first switch tube Q1 is connected to the heating film 200.

[0062] In this embodiment, the first switch tube Q1 is used to control the connection state between the heating film 200 and the negative output terminal P-, and the second resistor R2 is a pull-down resistor. The second resistor R2 is a pull-down resistor. The function of the second resistor R2 is to increase the closing speed when the first switch tube Q1 is disconnected (closed), and when the first switch tube Q1 is not needed to be turned on, the driving signal of the first switch tube Q1 can be stably pulled down. By setting the second resistor R2, the third resistor R3 and the first switch tube Q1, the working state of the heating film 200 can be stably and safely controlled.

[0063] In one embodiment, the resistance of the second resistor R2 may range from 1K to 10K.

[0064] In one embodiment, reference Figure 5 As shown, the second driving unit 31 includes: a second driving chip U2, a fourth resistor R4, a second diode D2, a third capacitor C3, and a fourth capacitor C4.

[0065] Specifically, the power supply terminal VCC of the second driver chip U2 is connected to the second power supply, the power supply terminal VCC of the second driver chip U2 is connected in series with the third capacitor C3 and then grounded, the power supply terminal VCC of the second driver chip U2 is also connected in series with the second diode D2 and then connected to the high floating terminal VB of the second driver chip U2, the high floating terminal VB of the second driver chip U2 is connected in series with the fourth capacitor C4 and then connected to the negative output terminal P-, the input terminal HIN of the second driver chip U2 is connected to the main control circuit 10, the input terminal HIN of the second driver chip U2 is also connected in series with the fourth resistor R4 and then grounded, and the output terminal HO of the second driver chip U2 is connected to the second switch unit 32. In this embodiment, the functions of the various components in the second driver unit 31 are consistent with the functions of the various components in the first driver unit 21, and are not repeated here one by one.

[0066] In one embodiment, the model of the first driver chip U1 and the second driver chip U2 may be EG2132. By using the first driver chip U1 and the second driver chip U2, the driving capability and switching speed of the first switch tube Q1 and the second switch tube Q2 can be improved, making the system more stable.

[0067] In one embodiment, reference Figure 5 As shown, the second switch unit 32 includes: a fifth resistor R5, a sixth resistor R6 and a second switch tube Q2.

[0068] Specifically, the first end of the fifth resistor R5 is connected to the output end HO of the second driving chip U2, the second end of the fifth resistor R5 and the first end of the sixth resistor R6 are connected to the control end of the second switch tube Q2, the first end of the second switch tube Q2 and the second end of the sixth resistor R6 are connected to the negative output end P-, and the second end of the second switch tube Q2 is connected to the heating unit 33. In this embodiment, the fifth resistor R5 is a current limiting resistor, the sixth resistor R6 is a pull-down resistor, the second switch tube Q2 is used to control the conduction state between the heating unit 33 and the negative output end P-, the sixth resistor R6 can delay the conduction speed of the second switch tube Q2, the sixth resistor R6 can avoid the instantaneous second driving signal generated by false triggering, and can delay the opening of the second switch tube Q2 to avoid false triggering, thereby improving the stability of the circuit.

[0069] In one embodiment, reference Figure 5 As shown, the heating unit 33 includes: a first heating wire H1 and a second heating wire H2.

[0070] Specifically, the first end of the first heating wire H1 and the second end of the second heating wire H2 are connected to the second end of the second switch tube Q2, and the second end of the first heating wire H1 and the second end of the second heating wire H2 are connected to the second end of the first fuse. In this embodiment, the first heating wire H1 and the second heating wire H2 are used to start working when the second switch tube Q2 is turned on, and heat to melt the first fuse and the second fuse, so that the heating film 200 is powered off, thereby ensuring the safety of the battery pack.

[0071] In one embodiment, reference Figure 5 As shown, the fuse unit 34 includes a first fuse F1 and a second fuse F2.

[0072] Specifically, the first end of the first fuse F1 is connected to the positive terminal B+, the second end of the first fuse F1 and the first end of the second fuse F2 are connected to the heating unit 33, and the second end of the second fuse F2 is connected to the heating film 200. In this embodiment, the first fuse F1 and the second fuse F2 are used to fuse when the driving circuit 20 is not controlled to ensure the safety of the circuit.

[0073] In one embodiment, reference Figure 5 As shown, the heating film control circuit also includes: a third diode D3. Specifically, the first end of the third diode D3 is connected to the second end of the first switch tube Q1, and the second end of the third diode D3 is connected to the second end of the second fuse F2. The third diode D3 is used to release the residual voltage on the first diode D1 in time when the first switch tube Q1 is disconnected, so as to ensure the stability of the circuit.

[0074] An embodiment of the present application further provides a control device, which includes a heating film control circuit as described above.

[0075] In this embodiment, the above-mentioned heating film control circuit is integrated into the control device. Since the driving circuit 20 and the protection circuit 30 are provided in the heating film control circuit, the driving ability of the driving device can be guaranteed. When the driving circuit 20 is not controlled, the protection circuit 30 can force the heating film 200 to be disconnected, thereby increasing the stability of the driving device.

[0076] An embodiment of the present application also provides a battery pack, including: a battery cell 100, a positive terminal B+, a negative output terminal P- and a heating film 200, the heating film 200 is connected between the positive terminal B+ and the negative output terminal P-, and the heating film 200 is in contact with the battery cell 100; the battery pack also includes a heating film control circuit as any of the above items, and the heating film control circuit is used to control the working state of the heating film 200.

[0077] In this embodiment, the above-mentioned heating film control circuit is integrated into the battery pack. Since the driving circuit 20 and the protection circuit 30 are provided in the heating film control circuit, the driving stability of the heating film 200 in the battery pack can be ensured. When the driving circuit 20 is out of control and the continuous heating of the heating film 200 may cause safety problems, the protection circuit 30 can force the heating film 200 to be disconnected, thereby increasing the stability of the battery pack, improving the safety of the battery pack, and improving the user experience.

[0078] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0079] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0080] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0081] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A heating film control circuit, characterized in that: The heating film control circuit is applied to a battery pack, the battery pack comprising: a battery cell, a positive terminal, a negative output terminal and a heating film, the heating film is connected between the positive terminal and the negative output terminal, and the heating film is in contact with the battery cell; the heating film control circuit comprises: A main control circuit, connected to the battery cell, for detecting the temperature of the battery cell, generating a temperature detection signal, and generating a heating drive signal when a voltage value of the temperature detection signal is less than a first preset temperature value, and generating a heating stop signal when a voltage value of the temperature detection signal is greater than a second preset temperature value; A driving circuit is provided between the negative output terminal and the heating film and is connected to the main control circuit, and is used to receive the heating driving signal and the heating stop signal, and is turned on according to the heating driving signal to control the heating film to start working; and is turned off according to the heating stop signal to control the heating film to stop working; The main control circuit is also used to generate a heating protection signal when the voltage value of the temperature detection signal is greater than a third temperature preset value; The protection circuit is arranged between the positive terminal and the heating film and connected to the main control circuit, and is used for being turned on when receiving the heating protection signal to cut off the connection between the positive terminal and the heating film.

2. The heating film control circuit according to claim 1, characterized in that: The driving circuit comprises: a first driving unit connected to the main control circuit, and configured to generate a first driving signal according to the heating driving signal when receiving the heating driving signal; and generate a first cutoff signal according to the heating stop signal when receiving the heating stop signal; The first switch unit is arranged between the negative output terminal and the heating film and is connected to the first driving unit, and is used for being turned on when receiving the first driving signal to control the heating film to start working; and being turned off when receiving the first cut-off signal to control the heating film to stop working.

3. The heating film control circuit according to claim 1, characterized in that: The protection circuit comprises: A second driving unit, connected to the main control circuit, for generating a second driving signal according to the heating protection signal when receiving the heating protection signal; a second switch unit, connected to the second drive unit and the negative output terminal, and configured to be turned on when receiving the second drive signal to generate a temperature increase control signal; a heating unit connected to the second switch unit, configured to receive the temperature increase control signal and generate a safety disconnection signal according to the temperature increase control signal; The insurance unit is connected between the positive terminal and the heating film and is connected to the heating unit, and is used to receive the insurance disconnection signal and disconnect according to the insurance disconnection signal to cut off the connection between the positive terminal and the heating film.

4. The heating film control circuit according to claim 2, characterized in that: The first driving unit includes: a first driving chip, a first resistor, a first diode, a first capacitor, and a second capacitor; wherein, The power supply end of the first driver chip is connected to the first power supply, the power supply end of the first driver chip is connected in series with the first capacitor and then grounded, the power supply end of the first driver chip is also connected in series with the first diode and then connected to the high suspension end of the first driver chip, the high suspension end of the first driver chip is connected in series with the second capacitor and then connected to the negative output end, the input end of the first driver chip is connected to the main control circuit, the input end of the first driver chip is also connected in series with the first resistor and then grounded, and the output end of the first driver chip is connected to the first switch unit.

5. The heating film control circuit according to claim 4, characterized in that: The first switch unit includes: a second resistor, a third resistor and a first switch tube; wherein, The first end of the second resistor and the first end of the third resistor are connected to the output end of the first driving chip, the second end of the second resistor is connected to the negative output end, the second end of the third resistor is connected to the control end of the first switching tube, the first end of the first switching tube is connected to the negative output end, and the second end of the first switching tube is connected to the heating film.

6. The heating film control circuit according to claim 3, characterized in that: The second driving unit includes: a second driving chip, a fourth resistor, a second diode, a third capacitor, and a fourth capacitor; wherein, The power supply end of the second driver chip is connected to the second power supply, the power supply end of the second driver chip is connected in series with the third capacitor and then grounded, the power supply end of the second driver chip is also connected in series with the second diode and then connected to the high suspension end of the second driver chip, the high suspension end of the second driver chip is connected in series with the fourth capacitor and then connected to the negative output end, the input end of the second driver chip is connected to the main control circuit, the input end of the second driver chip is also connected in series with the fourth resistor and then grounded, and the output end of the second driver chip is connected to the second switch unit.

7. The heating film control circuit according to claim 6, characterized in that: The second switch unit includes: a fifth resistor, a sixth resistor and a second switch tube; wherein, The first end of the fifth resistor is connected to the output end of the second driving chip, the second end of the fifth resistor and the first end of the sixth resistor are commonly connected to the control end of the second switch tube, the first end of the second switch tube and the second end of the sixth resistor are commonly connected to the negative output end, and the second end of the second switch tube is connected to the heating unit.

8. The heating film control circuit according to claim 3, characterized in that: The insurance unit comprises: a first fuse and a second fuse; wherein, The first end of the first fuse is connected to the positive terminal, the second end of the first fuse and the first end of the second fuse are connected to the heating unit, and the second end of the second fuse is connected to the heating film.

9. A control device, characterized in that: The control device comprises a heating film control circuit as claimed in any one of claims 1 to 8.

10. A battery pack, characterized in that: include: A battery cell, a positive terminal, a negative output terminal, and a heating film, wherein the heating film is connected between the positive terminal and the negative output terminal, and the heating film is in contact with the battery cell; It also includes a heating film control circuit as described in any one of claims 1 to 8, wherein the heating film control circuit is used to control the working state of the heating film.

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