Heating protection circuit

Abstract

The embodiment of the invention provides a heating protection circuit. The circuit comprises at least two comparison modules, a circuit opening module corresponding to each comparison module, a first output module, a second output module and a fault marking module, the comparison module is connected with a corresponding circuit opening module, and the circuit opening module is further connected to a first node; the first end of the first output module is connected to the first node, and the second end of the first output module is connected to the fault marking module; the first end of the second output module is connected to the first node, and the second end of the second output module is connected to a first protection voltage end and a second protection voltage end. In the embodiment of the invention, one heating protection circuit is arranged for a plurality of seats, so that the circuit structure is simple, and the cost is reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of automobile technology, and in particular to a heating protection circuit. Background Art

[0002] With the advancement of automobile manufacturing technology, users have higher and higher requirements for automobile comfort. As an important part of the car, the seat is the main contact point between the driver and the passenger and the car. Seats with heating function can improve the driving and riding experience.

[0003] The main consideration for seat heating performance is the temperature of the seat. Too high or too low a seat temperature will affect the user's experience. In a seat heating system, the seat is usually heated by a seat heating circuit to control the seat temperature within the temperature range required by the user.

[0004] In the prior art, each seat needs to be provided with a set of heating protection circuits, so there are problems of complex circuit structure and high cost. Summary of the invention

[0005] In view of this, an embodiment of the present application provides a heating protection circuit, which is used to simplify the circuit structure and reduce the cost.

[0006] A first aspect provides a heating protection circuit, comprising: at least two comparison modules, a circuit opening module corresponding to each of the comparison modules, a first output module, a second output module and a fault marking module; the comparison module is connected to the corresponding circuit opening module, and the circuit opening module is also connected to a first node; a first end of the first output module is connected to the first node, and a second end of the first output module is connected to the fault marking module; a first end of the second output module is connected to the first node, and a second end of the second output module is connected to a first protection voltage terminal and a second protection voltage terminal;

[0007] The comparison module is used to output a comparison voltage to the circuit start module according to the received current sampling output voltage;

[0008] The circuit start-up module is used to start up according to the comparison voltage so that the voltage of the first node is the comparison voltage;

[0009] The first output module is used to output a first heating protection voltage to the first protection voltage terminal and output a second heating protection voltage to the second protection voltage terminal according to the comparison voltage;

[0010] The second output module is used to output an error marking voltage to the fault marking module according to the comparison voltage;

[0011] The fault marking module is used to output a fault acquisition signal to the integrated circuit chip under the control of the error marking voltage, so that the integrated circuit chip can determine whether a heating circuit fails according to the fault acquisition signal.

[0012] In a possible implementation, the heating protection circuit further includes: a power-on clearing module, the power-on clearing module being connected to the first node;

[0013] The power-on clearing module is used to receive the clearing voltage generated when the integrated circuit chip determines that the heating circuit fails, and pull down the voltage of the first node to a low level according to the clearing voltage.

[0014] In a possible implementation, the comparison module includes a comparator, a negative polarity end of the comparator is connected to a reference voltage generation module, a negative polarity end of the comparator is connected to a current sampling output end, and an output end of the comparator is connected to the circuit start module.

[0015] In a possible implementation, the comparison module further includes a first resistor, a second resistor and a first diode;

[0016] A first end of the first resistor is connected to a first voltage terminal, and a second end of the first resistor is connected to an output terminal of the comparator;

[0017] The anode of the first diode is connected to the output terminal of the comparator, and the cathode of the first diode is connected to the first terminal of the second resistor;

[0018] The second end of the second resistor is connected to the positive polarity terminal of the comparator.

[0019] In a possible implementation, the circuit start module includes a second diode;

[0020] An anode of the second diode is connected to an output terminal of the corresponding comparator, and a cathode of the second diode is connected to the first node.

[0021] In a possible implementation, the first output module includes a third resistor, and the second output module includes a fourth resistor;

[0022] A first end of the third resistor is connected to the first node, and a second end of the third resistor is connected to the fault marking module;

[0023] A first end of the fourth resistor is connected to the first node, and a second end of the fourth resistor is connected to the first protection voltage terminal and the second protection voltage terminal.

[0024] In a possible implementation, the fault marking module includes a first transistor, a fifth resistor, and a sixth resistor;

[0025] The base of the first transistor is connected to the second node, the collector of the first transistor is connected to the third node, and the emitter of the first transistor is connected to the low voltage terminal;

[0026] A first end of the fifth resistor is connected to the second voltage terminal, and a second end of the fifth resistor is connected to the third node;

[0027] A first end of the sixth resistor is connected to the third node, and a second end of the sixth resistor is connected to the integrated circuit chip.

[0028] In a possible implementation, the heating protection circuit further includes a seventh resistor;

[0029] A first end of the seventh resistor is connected to the second node, and a second end of the seventh resistor is connected to the low voltage end.

[0030] In a possible implementation, the power-on clearing module includes a second transistor, an eighth resistor and a ninth resistor;

[0031] The base of the second transistor is connected to the fourth node, the collector of the second transistor is connected to the first node, and the emitter of the second transistor is connected to the low voltage terminal;

[0032] A first end of the eighth resistor is connected to the fourth node, and a second end of the eighth resistor is connected to the integrated circuit chip;

[0033] A first end of the ninth resistor is connected to the fourth node, and a second end of the ninth resistor is connected to the low voltage terminal.

[0034] In the technical solution provided in the embodiment of the present application, the heating protection circuit includes at least two comparison modules, a circuit start module corresponding to each comparison module, a first output module, a second output module and a fault marking module. The comparison module samples the output voltage according to the received current, the circuit start module is turned on according to the comparison voltage so that the voltage of the first node is the comparison voltage, the first output module outputs a first heating protection voltage to the first protection voltage terminal and outputs a second heating protection voltage to the second protection voltage terminal according to the comparison voltage, the second output module outputs an error marking voltage to the fault marking module according to the comparison voltage, and the fault marking module outputs a fault collection signal to the integrated circuit chip under the control of the error marking voltage, so that the integrated circuit chip can determine whether the heating circuit fails according to the fault collection signal. In the embodiment of the present application, a heating protection circuit is set for multiple seats, so that the circuit structure is simple and the cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 A schematic diagram of the structure of a heating protection circuit provided in an embodiment of the present application;

[0037] Figure 2 for Figure 1 Schematic diagram of the specific structure of the heating protection circuit. DETAILED DESCRIPTION

[0038] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0039] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0040] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0041] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0042] Figure 1 A schematic diagram of a heating protection circuit provided in an embodiment of the present application is shown in FIG. Figure 1As shown, the heating protection circuit includes: at least two comparison modules, a circuit opening module corresponding to each comparison module, a first output module, a second output module and a fault marking module. The comparison module is connected to the corresponding circuit opening module, and the circuit opening module is also connected to the first node TP1; the first end of the first output module is connected to the first node TP1, and the second end of the first output module is connected to the fault marking module; the first end of the second output module is connected to the first node TP1, and the second end of the second output module is connected to the first protection voltage terminal and the second protection voltage terminal.

[0043] The comparison module is used to output a comparison voltage to the circuit start-up module according to the received current sampling output voltage; the circuit start-up module is used to start according to the comparison voltage so that the voltage of the first node TP1 is the comparison voltage; the first output module is used to output a first heating protection voltage to the first protection voltage terminal according to the comparison voltage, and output a second heating protection voltage to the second protection voltage terminal; the second output module is used to output an error mark voltage to the fault mark module according to the comparison voltage; the fault mark module is used to output a fault collection signal to the integrated circuit chip under the control of the error mark voltage, so that the integrated circuit chip can determine whether a heating circuit fails according to the fault collection signal.

[0044] In the embodiment of the present application, each comparison module may correspond to a heating circuit of a seat. If the car includes multiple seats with heating function, the heating protection circuit may include multiple comparison modules.

[0045] As an alternative, Figure 1 As shown, the heating protection circuit further includes: a power-on clearing module connected to the first node TP1. The power-on clearing module is used to receive a clearing voltage generated when the integrated circuit chip determines that the heating circuit fails, and pull the voltage of the first node TP1 down to a low level according to the clearing voltage.

[0046] Figure 2 for Figure 1 The specific structural diagram of the heating protection circuit is as follows: Figure 2As shown, in the embodiment of the present application, the number of comparison modules is two, and the heating protection circuit includes two comparison modules, and the two comparison modules include a first comparison module and a second comparison module. The first comparison module and the second comparison module have the same structure, and the first comparison module is described as an example. The first comparison module includes a comparator A, the negative polarity end of the comparator A is connected to the reference voltage generation module, the negative polarity end of the comparator A is connected to the current sampling output end, and the output end of the comparator A is connected to the circuit start module. The power supply end of the comparator A is connected to the fourth voltage end U4, and the ground end of the comparator A is connected to the low voltage end. In the embodiment of the present application, the automobile includes a first seat and a second seat, and the first seat and the second seat both have a heating function. The first comparison module corresponds to the heating circuit of the first seat, and the second comparison module corresponds to the heating circuit of the second seat.

[0047] like Figure 2 As shown, the comparison module also includes: a first resistor R1, a second resistor R2 and a first diode D1. The first end of the first resistor R1 is connected to the first voltage terminal U1, and the second end of the first resistor R1 is connected to the output end of the comparator A; the positive electrode of the first diode D1 is connected to the output end of the comparator A, and the negative electrode of the first diode D1 is connected to the first end of the second resistor R2; the second end of the second resistor R2 is connected to the positive polarity end of the comparator A. As an optional solution, the first voltage terminal U1, the second voltage terminal U2 and the third voltage terminal U3 can be the same voltage terminal, for example, the first voltage terminal U1, the second voltage terminal U2 and the third voltage terminal U3 can output the same voltage, for example, the output voltages are all 3.3V.

[0048] like Figure 2 As shown, the reference voltage generating module includes: a tenth resistor R10 and an eleventh resistor R11. The first end of the tenth resistor R10 is connected to the third voltage terminal U3, and the second end of the first resistor R10 is connected to the fifth node TP5; the first end of the eleventh resistor R11 is connected to the fifth node TP5, and the second end of the eleventh resistor R11 is connected to the low voltage terminal.

[0049] As an alternative, Figure 2 As shown, the comparison module further includes: a twelfth resistor R12 and a thirteenth resistor R13. A first end of the twelfth resistor R12 is connected to the fifth node TP5, and a second end of the twelfth resistor R12 is connected to the negative polarity end of the comparator; a first end of the thirteenth resistor R13 is connected to the current sampling output end, and a second end of the thirteenth resistor R13 is connected to the positive polarity end of the comparator.

[0050] As an alternative, Figure 2 As shown, the comparison module further includes: a first capacitor C1, a first end of the first capacitor C1 is connected to the fifth node TP5, and a second end of the first capacitor C1 is connected to the low voltage end.

[0051] like Figure 2 As shown, the circuit start module includes a second diode D2. The anode of the second diode D2 is connected to the output terminal of the corresponding comparator A, and the cathode of the second diode D2 is connected to the first node TP1.

[0052] like Figure 2 As shown, the first output module includes a third resistor R3, and the second output module includes a fourth resistor R4. A first end of the third resistor R3 is connected to the first node TP1, and a second end of the third resistor R3 is connected to the fault marking module; a first end of the fourth resistor R4 is connected to the first node TP1, and a second end of the fourth resistor R4 is connected to the first protection voltage terminal and the second protection voltage terminal.

[0053] like Figure 2 As shown, the fault marking module includes a first transistor Q1, a fifth resistor R5 and a sixth resistor R6. The base of the first transistor Q1 is connected to the second node TP2, the collector of the first transistor Q1 is connected to the third node TP3, and the emitter of the first transistor Q1 is connected to the low voltage terminal; the first end of the fifth resistor R5 is connected to the second voltage terminal U2, and the second end of the fifth resistor R5 is connected to the third node TP3; the first end of the sixth resistor R6 is connected to the third node TP3, and the second end of the sixth resistor is connected to the integrated circuit chip.

[0054] As an alternative, Figure 2 As shown, the fault marking module may further include: a second capacitor C2. A first end of the second capacitor C2 is connected to the second node TP2, and a second end of the second capacitor C2 is connected to the low voltage end.

[0055] As an alternative, Figure 2 As shown, the fault marking module may further include: a third capacitor C3. A first end of the third capacitor C3 is connected to the second end of the sixth resistor R6, and a second end of the third capacitor C3 is connected to the low voltage end.

[0056] like Figure 2 As shown, the heating protection circuit further includes a seventh resistor R7. A first end of the seventh resistor R7 is connected to the second node TP2, and a second end of the seventh resistor R7 is connected to the low voltage end.

[0057] like Figure 2As shown, the power-on clear module includes a second triode Q2, an eighth resistor R8 and a ninth resistor R9. The base of the second triode Q2 is connected to the fourth node TP4, the collector of the second triode Q2 is connected to the first node TP1, and the emitter of the second triode Q2 is connected to the low voltage end; the first end of the eighth resistor R8 is connected to the fourth node TP4, and the second end of the eighth resistor R8 is connected to the integrated circuit chip; the first end of the ninth resistor R9 is connected to the fourth node TP4, and the second end of the ninth resistor R9 is connected to the low voltage end.

[0058] As an alternative, Figure 2 As shown, the power-on clear module may further include: a fourth capacitor C4. A first end of the fourth capacitor C4 is connected to a fourth node TP4, and a second end of the fourth capacitor C4 is connected to a low voltage end.

[0059] In the embodiment of the present application, the low voltage end is the ground terminal GND, then the second end of the eleventh resistor R11 is connected to the ground terminal GND, the first capacitor C1 is connected to the ground terminal GND, the ground end of the comparator A is connected to the ground terminal GND, the emitter of the first transistor Q1 is connected to the ground terminal GND, the second end of the second capacitor C2 is connected to the ground terminal GND, the second end of the third capacitor C3 is connected to the ground terminal GND, the second end of the seventh resistor R7 is connected to the ground terminal GND, the emitter of the second transistor Q2 is connected to the ground terminal GND, the second end of the fourth capacitor C4 is connected to the ground terminal GND, and the second end of the ninth resistor R9 is connected to GND.

[0060] As an optional solution, the integrated circuit chip may include a microcontroller unit (MCU). In the embodiment of the present application, the integrated circuit chip is described as an MCU.

[0061] Combine the following Figure 2 , the working principle of the heating protection circuit provided in the embodiment of the present application is described in detail.

[0062] The third voltage terminal U3 inputs the third voltage to the first comparison module, and the tenth resistor R10 and the eleventh resistor R11 divide the input third voltage to generate a reference voltage at the fifth node TP5, and the fifth node TP5 can input the reference voltage to the negative polarity terminal of the comparator A. For example, the third voltage can be 3.3V. The heating circuit outputs the first current sampling output voltage (HEAT1_comparator) to the negative polarity terminal of the comparator A of the first comparison module through the current sampling output terminal, and the comparator A of the first comparison module compares the first current sampling output voltage (HEAT1_comparator) with the reference voltage; if the first current sampling output voltage (HEAT1_comparator) is less than the reference voltage, the comparison voltage outputted from the output terminal of the comparator A is a low level; if the first current sampling output voltage (HEAT1_comparator) is greater than the reference voltage, the comparison voltage outputted from the output terminal of the comparator A is a high level. The twelfth resistor R12 can limit the current of the voltage at the negative polarity end of the comparator A, and the thirteenth resistor R13 can limit the current of the voltage at the positive polarity end of the comparator A, thereby avoiding excessive current flowing into the comparator A due to excessive first current sampling output voltage (HEAT1_comparator) and reference voltage, thereby avoiding damage to the comparator A. In addition, in the first comparison module, the first capacitor C1 performs filtering on the reference voltage of the fifth node TP5.

[0063] The third voltage terminal U3 inputs the third voltage to the second comparison module, and the tenth resistor R10 and the eleventh resistor R11 divide the input third voltage to generate a reference voltage at the fifth node TP5, and the fifth node TP5 can input the reference voltage to the negative polarity terminal of the comparator A. For example, the third voltage can be 3.3V. The heating circuit outputs the second current sampling output voltage (HEAT2_comparator) to the negative polarity terminal of the comparator A of the second comparison module through the current sampling output terminal, and the comparator A of the second comparison module compares the second current sampling output voltage (HEAT2_comparator) with the reference voltage; if the second current sampling output voltage (HEAT2_comparator) is less than the reference voltage, the comparison voltage output by the output terminal of the comparator A is low level; if the second current sampling output voltage (HEAT2_comparator) is greater than the reference voltage, the comparison voltage output by the output terminal of the comparator A is high level. The twelfth resistor R12 can limit the voltage at the negative polarity end of the comparator A, and the thirteenth resistor R13 can limit the voltage at the positive polarity end of the comparator A, thereby avoiding excessive current flowing into the comparator A due to excessive second current sampling output voltage (HEAT2_comparator) and the reference voltage, thereby avoiding damage to the comparator A. In addition, in the second comparison module, the first capacitor C1 performs filtering on the reference voltage of the fifth node TP5.

[0064] In the first comparison module and the second comparison module, the first resistor R1 is a pull-up voltage. When the comparison voltage output by the comparator A is a high level, the first resistor R1 can pull up the comparison voltage to the first voltage under the action of the first voltage output by the first voltage terminal U1, so that the voltage at the positive polarity terminal of the comparator A is the first voltage, for example, the first voltage can be 3.3V. When the voltage at the positive polarity terminal of the comparator A is the first voltage, the voltage at the positive polarity terminal is greater than the voltage at the negative polarity terminal, so that the output terminal of the comparator A can maintain an output high level. When the comparison voltage output by the comparator A is a low level, the first resistor R1 will not pull up the comparison voltage.

[0065] In the first comparison module, the second resistor R2 plays a current limiting role and shares power for the first diode D1. The first diode D1 can cut off the first current sampling output voltage (HEAT1_comparator) to prevent the first current sampling output voltage (HEAT1_comparator) from affecting the output end of the comparator A, and at the same time, the first voltage output by the first voltage terminal U1 can act on the positive polarity end of the comparator A. When the heating circuit is heating, the first current sampling output voltage (HEAT1_comparator) increases as the heating current increases. When the first current sampling output voltage (HEAT1_comparator) has not reached the reference voltage, the voltage at the output end of the comparator A is low. The first diode D1 cuts off the first current sampling output voltage (HEAT1_comparator) and acts on the output end of the comparator A, so that the output end of the comparator A remains low. When the heating current is abnormal and becomes very large, the first current sampling output voltage (HEAT1_comparator) is also very large, and eventually exceeds the reference voltage and triggers the protection. After the protection is triggered, the output will be cut off, and the heating current disappears at this time, and the first current sampling output voltage (HEAT1_comparator) voltage also disappears. The first voltage output by the first voltage terminal U1 acts on the positive polarity end of the comparator A through the first diode D1, so that the voltage of the positive polarity end of the comparator A continues to be greater than the reference voltage, so that the comparator A continues to output a high level. Similarly, the role played by the first diode D1 and the second resistor R2 in the second comparison module is the same as the role played by the first diode D1 and the second resistor R2 in the first comparison module, and will not be repeated here.

[0066] If at least one of the first comparison module and the second comparison module outputs a high level to the corresponding second diode D2, the subsequent circuit can start to work. For example, the first comparison module outputs a high level to the corresponding second diode D2, and the second comparison module outputs a low level to the corresponding second diode D2. At this time, the second diode D2 corresponding to the second comparison module is turned off under the control of the low level, and the second diode D2 corresponding to the first comparison module is turned on under the control of the high level, so that the voltage of the first node TP1 is the comparison voltage, for example, the comparison voltage is 3.3V; the first comparison module outputs a low level to the corresponding second diode D2, and the second comparison module outputs a high level to the corresponding second diode D2. At this time, the second diode D2 corresponding to the first comparison module is turned off under the control of the low level, and the second diode D2 corresponding to the second comparison module is turned on under the control of the high level, so that the voltage of the first node TP1 is the comparison voltage, for example, the comparison voltage is 3.3V; the first comparison module outputs a high level to the corresponding second diode D2, and the second comparison module outputs a high level to the corresponding second diode D2. At this time, the second diode D2 corresponding to the first comparison module is turned on under the control of the high level, and the second diode D2 corresponding to the second comparison module is turned on under the control of the high level, so that the voltage of the first node TP1 is the comparison voltage, for example, the comparison voltage is 3.3V. Among them, the heating circuit has not failed, the comparator A of the first comparison module outputs a low level so that the second diode D2 corresponding to the first comparison module is not turned on, and the comparator A of the second comparison module outputs a low level so that the second diode D2 corresponding to the first comparison module is not turned on, and the subsequent circuit does not work at this time.

[0067] The first node TP1 outputs a first heating protection voltage (HEAT1_PROTECT) to the first protection voltage terminal through the fourth resistor R4, and outputs a second heating protection voltage (HEAT2_PROTECT) to the first protection voltage terminal through the fourth resistor R4. The first heating protection voltage can be used to stop heating the first seat, and the second heating protection voltage can be used to stop heating the second seat. For example, the heating circuit of the first seat reads the first heating protection voltage from the first protection voltage terminal, and stops heating the first seat according to the first heating protection voltage; the heating circuit of the second seat reads the second heating protection voltage from the second protection voltage terminal, and stops heating the second seat according to the second heating protection voltage.

[0068] The first node TP1 makes the voltage of the second node TP2 an error mark voltage (HEAT1,2_ERR_FLAG) through the third resistor R3, and the first transistor Q1 is turned on under the control of the error mark voltage to pull the voltage of the third node TP3 down to a low level, so that the fault acquisition signal output to the MCU is a low level. The seventh resistor R7 plays a role of voltage clamping, so that the voltage of the second node TP2 is an error mark voltage (HEAT1,2_ERR_FLAG). The second capacitor C2 can filter the error mark voltage (HEAT1,2_ERR_FLAG). The third capacitor C3 can filter the fault acquisition signal.

[0069] The fifth resistor R5 and the sixth resistor R6 can both play a role in current limiting. When the first transistor Q1 is not turned on, the second voltage of the second voltage terminal U2 acts on the MCU through the fifth resistor R5 and the sixth resistor R6, and the fifth resistor R5 and the sixth resistor R6 perform current limiting protection on the MCU. After the first transistor Q1 is turned on, the second voltage output by the second voltage terminal U2 is conducted to the ground through the fifth resistor R5 and the turned-on first transistor Q1. At this time, the fifth resistor R5 performs current limiting protection on the first transistor Q1, and the sixth resistor R6 can perform current limiting protection on the fault collection signal port of the MCU.

[0070] When the fault mark voltage is at a low level, the MCU can determine that the heating circuit has failed according to the fault mark voltage to generate a clear voltage (MCU_CLR), which is at a high level. The MCU outputs the clear voltage to the power-on clear module. The eighth resistor R8 and the ninth resistor R9 of the power-on clear module divide the clear voltage to generate a control voltage at the fourth node TP4, which is at a high level. The second transistor Q2 is turned on under the control of the control voltage, and the voltage of the first node TP1 is pulled down to a low level to achieve power-on clearing of the subsequent circuit, thereby resetting the circuit. The fourth capacitor C4 can filter the control voltage of the fourth node TP4.

[0071] When it is determined that the heating circuit fails and the heating circuit of the first seat stops heating the first seat and the heating circuit of the second seat stops heating the second seat, it can be further determined which seat has a heating circuit failure. Specifically, only the heating circuit of the first seat is turned on again, the negative polarity end of the comparator A of the first comparison module receives the first current sampling output voltage (HEAT1_comparator) output by the heating circuit of the first seat, and the first comparison module outputs a comparison voltage to the corresponding first diode D1 according to the first current sampling output voltage. If the comparison voltage is high, the first diode D1 is turned on, and the subsequent circuit starts to work at this time. The fault marking module outputs a fault acquisition signal to the MCU, and the fault acquisition signal is low. The MCU can determine that the heating circuit of the first seat fails according to the fault marking voltage, and generate a reset voltage (MCU_CLR), which is a high level, so that the power-on reset module pulls down the voltage of the first node to a low level according to the reset voltage to reset the subsequent circuit. Furthermore, it is also possible to determine whether the heating circuit of the second seat is faulty in the above manner, thereby achieving the purpose of troubleshooting the heating circuits of multiple seats.

[0072] In an embodiment of the present application, the heating protection circuit includes at least two comparison modules, a circuit start module corresponding to each comparison module, a first output module, a second output module and a fault marking module. The comparison module samples the output voltage according to the received current, the circuit start module is turned on according to the comparison voltage so that the voltage of the first node is the comparison voltage, the first output module outputs a first heating protection voltage to the first protection voltage terminal and outputs a second heating protection voltage to the second protection voltage terminal according to the comparison voltage, the second output module outputs an error marking voltage to the fault marking module according to the comparison voltage, and the fault marking module outputs a fault collection signal to the MCU under the control of the error marking voltage, so that the MCU can determine whether the heating circuit fails according to the fault collection signal. In an embodiment of the present application, a heating protection circuit is set for multiple seats, so that the circuit structure is simple and the cost is reduced.

[0073] In an embodiment of the present application, each comparison module is connected to a corresponding circuit start-up module, the circuit start-up module is also connected to a first node, the first end of the first output module is connected to the first node, the second end of the first output module is connected to a fault marking module, the first end of the second output module is connected to the first node, and the second end of the second output module is connected to a first protection voltage terminal and a second protection voltage terminal. The heating protection circuit of an embodiment of the present application does not need to set up a post-stage circuit for each comparison module, but multiple comparison modules share one post-stage circuit, saving at least one post-stage circuit, thereby reducing costs.

[0074] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A heating protection circuit, characterized in that: include: At least two comparison modules, a circuit opening module corresponding to each of the comparison modules, a first output module, a second output module and a fault marking module; the comparison module is connected to the corresponding circuit opening module, and the circuit opening module is also connected to a first node; a first end of the first output module is connected to the first node, and a second end of the first output module is connected to the fault marking module; a first end of the second output module is connected to the first node, and a second end of the second output module is connected to a first protection voltage terminal and a second protection voltage terminal; The comparison module is used to output a comparison voltage to the circuit start module according to the received current sampling output voltage; The circuit start-up module is used to start up according to the comparison voltage so that the voltage of the first node is the comparison voltage; The first output module is used to output a first heating protection voltage to the first protection voltage terminal and output a second heating protection voltage to the second protection voltage terminal according to the comparison voltage; The second output module is used to output an error marking voltage to the fault marking module according to the comparison voltage; The fault marking module is used to output a fault acquisition signal to the integrated circuit chip under the control of the error marking voltage, so that the integrated circuit chip can determine whether a heating circuit fails according to the fault acquisition signal.

2. The heating protection circuit according to claim 1, characterized in that: The heating protection circuit further includes: a power-on clearing module, the power-on clearing module is connected to the first node; The power-on clearing module is used to receive the clearing voltage generated when the integrated circuit chip determines that the heating circuit fails, and pull down the voltage of the first node to a low level according to the clearing voltage.

3. The heating protection circuit according to claim 1, characterized in that: The comparison module comprises a comparator, a negative polarity end of the comparator is connected to the reference voltage generation module, a negative polarity end of the comparator is connected to the current sampling output end, and an output end of the comparator is connected to the circuit start module.

4. The heating protection circuit according to claim 3, characterized in that: The comparison module also includes a first resistor, a second resistor and a first diode; A first end of the first resistor is connected to a first voltage terminal, and a second end of the first resistor is connected to an output terminal of the comparator; The anode of the first diode is connected to the output terminal of the comparator, and the cathode of the first diode is connected to the first terminal of the second resistor; The second end of the second resistor is connected to the positive polarity terminal of the comparator.

5. The heating protection circuit according to claim 1, characterized in that: The circuit opening module includes a second diode; An anode of the second diode is connected to an output terminal of the corresponding comparator, and a cathode of the second diode is connected to the first node.

6. The heating protection circuit according to claim 1, characterized in that: The first output module includes a third resistor, and the second output module includes a fourth resistor; A first end of the third resistor is connected to the first node, and a second end of the third resistor is connected to the fault marking module; A first end of the fourth resistor is connected to the first node, and a second end of the fourth resistor is connected to the first protection voltage terminal and the second protection voltage terminal.

7. The heating protection circuit according to claim 1, characterized in that: The fault marking module includes a first transistor, a fifth resistor and a sixth resistor; The base of the first transistor is connected to the second node, the collector of the first transistor is connected to the third node, and the emitter of the first transistor is connected to the low voltage terminal; A first end of the fifth resistor is connected to the second voltage terminal, and a second end of the fifth resistor is connected to the third node; A first end of the sixth resistor is connected to the third node, and a second end of the sixth resistor is connected to the integrated circuit chip.

8. The heating protection circuit according to claim 7, characterized in that: The heating protection circuit also includes a seventh resistor; A first end of the seventh resistor is connected to the second node, and a second end of the seventh resistor is connected to the low voltage end.

9. The heating protection circuit according to claim 1, characterized in that: The power-on clearing module includes a second triode, an eighth resistor and a ninth resistor; The base of the second transistor is connected to the fourth node, the collector of the second transistor is connected to the first node, and the emitter of the second transistor is connected to the low voltage terminal; A first end of the eighth resistor is connected to the fourth node, and a second end of the eighth resistor is connected to the integrated circuit chip; A first end of the ninth resistor is connected to the fourth node, and a second end of the ninth resistor is connected to the low voltage terminal.

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