A multifunctional seat heating drive circuit

Abstract

The present invention proposes a multifunctional seat heating drive circuit, comprising: an MCU circuit, a first diagnostic drive circuit, a second diagnostic drive circuit, a third diagnostic drive circuit, and a heating wire. The MCU circuit is bidirectionally connected to the first diagnostic drive circuit, the second diagnostic drive circuit, and the third diagnostic drive circuit. The output end of the first diagnostic drive circuit is connected to the input end of the second diagnostic drive circuit, and the output end of the second diagnostic drive circuit is connected to the input end of the third diagnostic drive circuit through the heating wire. The connection end of the heating wire and the second diagnostic drive circuit is a negative electrode, and the connection end of the heating wire and the third diagnostic drive circuit is a positive electrode. The first diagnostic drive circuit, the second diagnostic drive circuit, and the third diagnostic drive circuit can be efficiently and quickly shut down and feedback can be given to the cause of the fault in the circuit. At the same time, anti-static TVS diodes D2, D3, and D5 are arranged to provide overvoltage protection, saving PCB space.

Description

Technical Field

[0001] The present invention relates to the field of electricity, and more specifically, to a multifunctional seat heating drive circuit. Background Art

[0002] With the development of technology and the popularization of automobiles, consumers have higher and higher requirements for comfort and pay more and more attention to the functional configuration of seats. More car series are beginning to add functions such as seat heating.

[0003] Existing technical solutions:

[0004] 1. Most of the existing seat heating drive circuits control the positive electrode of the heating wire through PMOS.

[0005] 2. The negative pole of the existing heating wire is often grounded through the wiring harness.

[0006] 3. The fault types that can be identified by the existing diagnosis include heating wire overcurrent, overvoltage, heating wire positive short circuit to ground, and heating pad resistance out of range.

[0007] Disadvantages of existing technology:

[0008] 1. The existing seat heating drive circuit has a protection mechanism for circuit faults that needs to be implemented by adding external discrete components. The protection for a small number of fault types is large and the PCB occupies a large space.

[0009] 2. The existing negative electrode of the heating wire cannot be disconnected from the ground, and the only way to stop heating is to turn off the PMOS, which cannot protect the positive electrode of the heating wire from short circuit.

[0010] 3. Existing diagnosis can identify few fault types, and cannot identify chip overheating, heating wire positive short circuit to power supply, heating wire negative short circuit to power supply, heating wire negative short circuit to ground, heating wire open circuit.

[0011] 4. The existing heating drive circuit has a low functional safety level.

[0012] Therefore, how to safely and effectively shut down the heating mode when a seat heating failure occurs and accurately feedback the cause of the heating failure is an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0013] In view of this, the present invention provides a multifunctional seat heating drive circuit, which can shut down and feedback in time when a seat heating failure occurs, reduce the occurrence of safety accidents, and quickly lock the cause of the failure according to the feedback content, thereby improving maintenance efficiency.

[0014] A multifunctional seat heating drive circuit is characterized in that it includes: an MCU circuit, a first diagnostic drive circuit, a second diagnostic drive circuit, a third diagnostic drive circuit, and a heating wire. The MCU circuit is bidirectionally connected to the first diagnostic drive circuit, the second diagnostic drive circuit, and the third diagnostic drive circuit. The output end of the first diagnostic drive circuit is connected to the input end of the second diagnostic drive circuit. The output end of the second diagnostic drive circuit is connected to the input end of the third diagnostic drive circuit through the heating wire. The connection end of the heating wire and the second diagnostic drive circuit is a negative electrode, and the connection end of the heating wire and the third diagnostic drive circuit is a positive electrode.

[0015] In some embodiments, the first diagnostic drive circuit includes an NPN transistor Q5 and an anti-static TVS diode D2. Pin 1 of the MCU chip U1 is connected to the base of the NPN transistor Q5. The collector of the NPN transistor Q5 is respectively connected to the input end of the second diagnostic drive circuit and the anti-static TVS diode D2. The emitter of the NPN transistor Q5 is grounded. The anti-static TVS diode D2 is used to protect and prevent the MCU circuit from being broken down.

[0016] Furthermore, a resistor R1 is provided at the connection between the base of the NPN transistor Q5 and the input terminal of the second diagnostic drive circuit to play the role of voltage division and current limiting. A resistor R2 is also provided between the resistor R1 and the emitter of the NPN transistor Q5 to prevent accidental start-up.

[0017] In some embodiments, the second diagnostic drive circuit includes a K1 relay and an anti-static TVS diode D3. Pin 1 of the K1 relay is connected to the VBAT power pin of the peripheral device, and the VBAT power pin is used to provide an external power supply for the K1 relay. Pin 2 of the K1 relay is connected to the collector of the NPN transistor Q5. Pin 3 of the K1 relay is respectively connected to pin 3 of the MCU chip U1 and ground. Pin 4 of the K1 relay is respectively connected to the anti-static TVS diode D3 and the negative electrode of the heating wire. The anti-static TVS diode D3 plays a role in protecting and preventing the MCU circuit from being broken down.

[0018] Furthermore, capacitor C1, resistor R7, resistor R6, and capacitor C2 are sequentially connected between pin 3 of the K1 relay and pin 3 of the MCU chip U1, and capacitor C1, resistor R7, resistor R6, and capacitor C2 play a role in voltage stabilization.

[0019] In some embodiments, the third diagnostic drive circuit includes a high-side driver chip U6 and an anti-static TVS diode D5. Pin 1 of the high-side driver chip U6 is respectively connected to the VBAT power pin and ground of the peripheral device. Pins 2, 3, and 4 of the high-side driver chip U6 are connected to the positive electrode of the heating wire and the anti-static TVS diode D5. The anti-static TVS diode D5 plays a role in protecting and preventing the MCU circuit from being broken down. Pin 5 of the high-side driver chip U6 is connected to the VBAT power pin of the peripheral device, pin 6 of the high-side driver chip U6 is connected to pin 2 of the MCU chip U1, pin 7 of the high-side driver chip U6 is connected to pin 4 of the MCU chip U1, and pin 8 of the high-side driver chip U6 is connected to pin 5 of the MCU chip U1.

[0020] Furthermore, a resistor R8 is connected between pin 6 of the high-side driver chip U6 and pin 2 of the MCU chip U1, and a resistor R9 is connected between pin 7 of the high-side driver chip U6 and pin 4 of the MCU chip U1. Resistors R8 and R9 both play a current limiting role; pin 8 of the high-side driver chip U6 is also connected to capacitor C4, resistor R10, and resistor R11, respectively. Capacitor C4 plays a voltage stabilizing role, resistor R10 plays a current limiting role, and resistor R11 plays a current detecting role.

[0021] In some embodiments, the MCU circuit is composed of an MCU chip U1, pin 1 of the MCU chip U1 is the Heat2_Relay_CTL pin, pin 2 of the MCU chip U1 is the MCU_Heat2_CTL pin, pin 3 of the MCU chip U1 is the HEAT2_GND_DIG pin, pin 4 of the MCU chip is the MCU_DEN pin, and pin 5 of the MCU chip U1 is the Heat2_AD pin.

[0022] In some embodiments, the pin connecting the collector of the NPN transistor Q5 and the input end of the second diagnostic drive circuit is the HEAT2_Relay_CTL pin; pin 2 of the K1 relay is the HEAT2_Relay_CTL pin, the pin connecting pin 3 of the K1 relay and pin 3 of the MCU chip U1 is the HEAT2_GND_DIG pin, and the pin connecting pin 4 of the K1 relay and the negative pole of the heating wire is the HEAT2_GND pin.

[0023] Working principle of the present invention:

[0024] When the multifunctional seat heating drive circuit works normally: the MCU chip U1 in the MCU circuit sends a high-level signal to the base of the NPN transistor Q5. At this time, the NPN transistor Q5 is grounded and turned on, and the switch of the relay K1 is closed, so that the 3rd and 4th pins of the relay K1 are turned on, and the 4th pin is connected to the negative electrode of the heating wire;

[0025] Meanwhile, the 6th pin of the high-side drive chip U6 sends out a high-level signal or outputs PWM, and the 2nd, 3rd, and 4th pins of the high-side drive chip U6 are connected to the positive electrode of the heating wire.

[0026] When a fault occurs in the multi-functional seat heating drive circuit, the circuit enters the diagnostic mode:

[0027] The circuit enters Diagnostic Mode 1: Determine whether the heating wire is short-circuited to the positive electrode. Among them, when the default state of the multi-functional seat heating drive circuit is that the 1st, 2nd, and 3rd pins of the MCU chip U1 are at low level, if the 3rd pin of the MCU chip is at high level at this time, the heating wire is short-circuited to the power supply, that is, the positive electrode of the heating wire is short-circuited;

[0028] The circuit enters Diagnostic Mode 2: The 2nd pin of the MCU chip sends out a high-level signal. When working normally, the HEAT2_GND_DIG pin is at high level. If the HEAT2_GND_DIG pin is at low level, it is determined that the heating wire is short-circuited to the ground, that is, the negative electrode of the heating wire is short-circuited;

[0029] The circuit enters Diagnostic Mode 3: The 1st pin of the MCU chip sends out a high-level signal. When working normally, the HEAT2_GND_DIG pin is at low level, and the value of the Heat2_AD pin is the preset value.

[0030] If 1 > Heat2_AD value > the maximum value of the design value or 0 < Heat2_AD value < the minimum value of the design value, it is determined that the resistance of the heating pad is out of range;

[0031] If the Heat2_AD value > 1, it is determined that the heating wire is short-circuited to the ground, that is, the negative electrode of the heating wire is short-circuited;

[0032] If the Heat2_AD value = 0, it is determined that the heating wire is short-circuited to the power supply, that is, the positive electrode of the heating wire is short-circuited;

[0033] If the HEAT2_GND_DIG pin is at high level during a working fault, it is determined that the heating wire is open-circuited.

[0034] Beneficial effects of the present invention: The present invention proposes a multifunctional seat heating drive circuit, including: an MCU circuit, a first diagnostic drive circuit, a second diagnostic drive circuit, a third diagnostic drive circuit, and a heating wire. The MCU circuit is bidirectionally connected to the first diagnostic drive circuit, the second diagnostic drive circuit, and the third diagnostic drive circuit. The output end of the first diagnostic drive circuit is connected to the input end of the second diagnostic drive circuit, and the output end of the second diagnostic drive circuit is connected to the input end of the third diagnostic drive circuit through the heating wire. The connection end of the heating wire and the second diagnostic drive circuit is the negative pole, and the connection end of the heating wire and the third diagnostic drive circuit is the positive pole. The first diagnostic drive circuit, the second diagnostic drive circuit, and the third diagnostic drive circuit can be efficiently and quickly shut down and the cause of the fault in the circuit can be fed back. At the same time, anti-static TVS diodes D2, D3, and D5 are arranged to provide overvoltage protection, saving PCB space. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a circuit diagram of the first diagnostic drive circuit of the multifunctional seat heating drive circuit of the present application.

[0036] Figure 2 This is a circuit diagram of the MCU circuit of the multifunctional seat heating drive circuit of the present application.

[0037] Figure 3 This is a circuit diagram of the second diagnostic drive circuit, the third diagnostic drive circuit, and the heating wire of the multifunctional seat heating drive circuit of the present application.

[0038] The accompanying drawings will be described in detail below in conjunction with specific implementation cases. DETAILED DESCRIPTION

[0039] The following examples are described to assist the understanding of the present application, and the examples are not and should not be interpreted in any way as limiting the scope of protection of the present application.

[0040] In the following description, those skilled in the art will recognize that throughout this discussion, components may be described as separate functional units (which may include sub-units), but those skilled in the art will recognize that various components or portions thereof may be divided into separate components or may be integrated together (including within a single system or component).

[0041] At the same time, the connections between components or systems are not intended to be limited to direct connections, rather, the data between these components may be modified, reformatted, or otherwise changed by intermediate components. In addition, additional or fewer connections may be used. It should also be noted that the terms "coupled," "connected," or "input" should be understood to include direct connections, indirect connections through one or more intermediate devices, and wireless connections.

[0042] Embodiment 1:

[0043] A multifunctional seat heating drive circuit, such as Figure 1-Figure 3 As shown, it includes: an MCU circuit, a first diagnostic drive circuit, a second diagnostic drive circuit, a third diagnostic drive circuit, and a heating wire. The MCU circuit is bidirectionally connected to the first diagnostic drive circuit, the second diagnostic drive circuit, and the third diagnostic drive circuit. The output end of the first diagnostic drive circuit is connected to the input end of the second diagnostic drive circuit, and the output end of the second diagnostic drive circuit is connected to the input end of the third diagnostic drive circuit through the heating wire. The connection end of the heating wire and the second diagnostic drive circuit is the negative electrode, and the connection end of the heating wire and the third diagnostic drive circuit is the positive electrode.

[0044] The first diagnostic drive circuit includes an NPN transistor Q5 and an anti-static TVS diode D2. Pin 1 of the MCU chip U1 is connected to the base of the NPN transistor Q5. The collector of the NPN transistor Q5 is respectively connected to the input end of the second diagnostic drive circuit and the anti-static TVS diode D2. The emitter of the NPN transistor Q5 is grounded. The anti-static TVS diode D2 is used to protect and prevent the MCU circuit from being broken down.

[0045] A resistor R1 is also provided at the connection between the base of the NPN transistor Q5 and the input end of the second diagnostic drive circuit, which plays a role of voltage division and current limiting. One end of the resistor R1 is connected to the base of the NPN transistor Q5, and the other end of the resistor R1 is connected to pin 2 of the relay K1. A resistor R2 is also provided between the resistor R1 and the emitter of the NPN transistor Q5 to prevent accidental start-up. The resistor R2 is connected in parallel with the NPN transistor Q5 and then grounded.

[0046] The second diagnostic drive circuit includes a K1 relay and an anti-static TVS diode D3. Pin 1 of the K1 relay is connected to the VBAT power pin of the peripheral device. The VBAT power pin is used to provide an external power supply for the K1 relay. Pin 2 of the K1 relay is connected to the collector of the NPN transistor Q5. Pin 3 of the K1 relay is respectively connected to pin 3 of the MCU chip U1 and ground. Pin 4 of the K1 relay is respectively connected to the anti-static TVS diode D3 and the negative electrode of the heating wire. The anti-static TVS diode D3 plays a role in protecting and preventing the MCU circuit from being broken down.

[0047] Capacitor C1, resistor R7, resistor R6, and capacitor C2 are also connected in sequence between pin 3 of the K1 relay and pin 3 of the MCU chip U1. Capacitor C1, resistor R7, resistor R6, and capacitor C2 play a role in voltage stabilization. Capacitor C1, resistor R7, and resistor R6 are arranged in series, one end of capacitor C1 is connected to pin 3 of the K1 relay and then grounded, the other end of capacitor C1 is connected to one end of resistor R7, the other end of resistor R7 is connected to one end of resistor R6, the other end of resistor R6 is grounded, one end of capacitor C2 is connected to the connection between resistor R7 and resistor R6, and the other end of capacitor C2 is grounded.

[0048] The third diagnostic drive circuit includes a high-side driver chip U6 and an anti-static TVS diode D5. Pin 1 of the high-side driver chip U6 is respectively connected to the VBAT power pin and ground of the peripheral device. Pins 2, 3, and 4 of the high-side driver chip U6 are connected to the positive electrode of the heating wire and the anti-static TVS diode D5. The anti-static TVS diode D5 plays a role in protecting and preventing the MCU circuit from being broken down. Pin 5 of the high-side driver chip U6 is connected to the VBAT power pin of the peripheral device, pin 6 of the high-side driver chip U6 is connected to pin 2 of the MCU chip U1, pin 7 of the high-side driver chip U6 is connected to pin 4 of the MCU chip U1, and pin 8 of the high-side driver chip U6 is connected to pin 5 of the MCU chip U1.

[0049] A resistor R8 is also connected between pin 6 of the high-side driver chip U6 and pin 2 of the MCU chip U1, and a resistor R9 is also connected between pin 7 of the high-side driver chip U6 and pin 4 of the MCU chip U1. Both resistors R8 and R9 play a role in current limiting.

[0050] Pin 8 of the high-side driver chip U6 is also connected to capacitor C4, resistor R10, and resistor R11, respectively. Capacitor C4 plays a role of voltage stabilization, resistor R10 plays a role of current limiting, and resistor R11 plays a role of current detection. One end of resistor R10 is connected to pin 8 of the high-side driver chip U6, and the other end of resistor R10 is connected to pin 5 of the MCU chip U1. Capacitor C4 and resistor R11 are arranged in parallel, one end of capacitor C4 is connected to the connection between resistor R10 and pin 5 of the MCU chip U1, and the other end of capacitor C4 is grounded. One end of resistor R11 is connected to the connection between resistor R10 and pin 8 of the high-side driver chip U6, and the other end of resistor R11 is grounded.

[0051] The MCU circuit is composed of the MCU chip U1, the 1st pin of the MCU chip U1 is the Heat2_Relay_CTL pin, the 2nd pin of the MCU chip U1 is the MCU_Heat2_CTL pin, the 3rd pin of the MCU chip U1 is the HEAT2_GND_DIG pin, the 4th pin of the MCU chip is the MCU_DEN pin, and the 5th pin of the MCU chip U1 is the Heat2_AD pin. The collector of the NPN transistor Q5 and the pin of the second diagnostic drive circuit input end are the HEAT2_Relay_CTL pin; the 2nd pin of the K1 relay is the HEAT2_Relay_CTL pin, the 3rd pin of the K1 relay and the 3rd pin of the MCU chip U1 are connected to the HEAT2_GND_DIG pin, and the 4th pin of the K1 relay and the pin connected to the negative pole of the heating wire are the HEAT2_GND pin.

[0052] Working principle of the present invention:

[0053] When the multi-functional seat heating drive circuit is working properly: The 1st pin of the MCU chip U1 in the MCU circuit sends out a high-level signal and is connected to the base of the NPN transistor Q5. At this time, after the NPN transistor Q5 is grounded and conducts, the switch of the relay K1 is attracted, making the 3rd and 4th pins of the relay K1 conduct. The 4th pin is connected to the negative pole of the heating wire;

[0054] At the same time, the 6th pin of the high-side drive chip U6 sends out a high-level signal or outputs a PWM. The 2nd, 3rd, and 4th pins of the high-side drive chip U6 are connected to the positive pole of the heating wire.

[0055] When a fault occurs in the multi-functional seat heating drive circuit, the circuit enters the diagnostic mode:

[0056] The circuit enters Diagnostic Mode 1: Determine whether the heating wire is short-circuited to the positive pole. Among them, when the default state of the multi-functional seat heating drive circuit is that the 1st, 2nd, and 3rd pins of the MCU chip U1 are at low level. If the 3rd pin of the MCU chip is at high level at this time, the heating wire is short-circuited to the power supply, that is, the positive pole of the heating wire is short-circuited;

[0057] The circuit enters Diagnostic Mode 2: The 2nd pin of the MCU chip sends out a high-level signal. When it works properly, the HEAT2_GND_DIG pin is at high level. If the HEAT2_GND_DIG pin is at low level, it is determined that the heating wire is short-circuited to the ground, that is, the negative pole of the heating wire is short-circuited;

[0058] The circuit enters Diagnostic Mode 3: The 1st pin of the MCU chip sends out a high-level signal. When it works properly, the HEAT2_GND_DIG pin is at low level, and the value of the Heat2_AD pin is the preset value.

[0059] If 1 > Heat2_AD value > the maximum value of the design value or 0 < Heat2_AD value < the minimum value of the design value, it is determined that the resistance of the heating pad is out of range;

[0060] If the Heat2_AD value > 1, it is determined that the heating wire is short-circuited to the ground, that is, the negative pole of the heating wire is short-circuited;

[0061] If the Heat2_AD value = 0, it is determined that the heating wire is short-circuited to the power supply, that is, the positive pole of the heating wire is short-circuited;

[0062] If the HEAT2_GND_DIG pin is at high level during a working fault, it is determined that the heating wire is open-circuited.

[0063] Beneficial effects of the present invention: The present invention proposes a multifunctional seat heating drive circuit, including: an MCU circuit, a first diagnostic drive circuit, a second diagnostic drive circuit, a third diagnostic drive circuit, and a heating wire. The MCU circuit is bidirectionally connected to the first diagnostic drive circuit, the second diagnostic drive circuit, and the third diagnostic drive circuit. The output end of the first diagnostic drive circuit is connected to the input end of the second diagnostic drive circuit, and the output end of the second diagnostic drive circuit is connected to the input end of the third diagnostic drive circuit through the heating wire. The connection end of the heating wire and the second diagnostic drive circuit is the negative pole, and the connection end of the heating wire and the third diagnostic drive circuit is the positive pole. The first diagnostic drive circuit, the second diagnostic drive circuit, and the third diagnostic drive circuit can be efficiently and quickly shut down and the cause of the fault in the circuit can be fed back. At the same time, anti-static TVS diodes D2, D3, and D5 are arranged to provide overvoltage protection, saving PCB space.

[0064] Although the present application has disclosed multiple aspects and embodiments, other aspects and embodiments will be obvious to those skilled in the art, and several modifications and improvements may be made without departing from the concept of the present application, all of which belong to the protection scope of the present application. The multiple aspects and embodiments disclosed in the present application are only for illustration and are not intended to limit the present application. The actual protection scope of the present application shall be subject to the claims.

Claims

1. A multifunctional seat heating drive circuit, characterized in that: include: MCU circuit, first diagnostic drive circuit, second diagnostic drive circuit, third diagnostic drive circuit, heating wire, MCU circuit is bidirectionally connected with the first diagnostic drive circuit, the second diagnostic drive circuit, and the third diagnostic drive circuit, the output end of the first diagnostic drive circuit is connected with the input end of the second diagnostic drive circuit, the output end of the second diagnostic drive circuit is connected with the input end of the third diagnostic drive circuit through the heating wire, the connection end of the heating wire and the second diagnostic drive circuit is the negative pole, and the connection end of the heating wire and the third diagnostic drive circuit is the positive pole, the first diagnostic drive circuit includes NPN transistor Q5, anti-static TVS diode D2, pin 1 of MCU chip U1 is connected with the base of NPN transistor Q5, the collector of NPN transistor Q5 is respectively connected with the input end of the second diagnostic drive circuit and the anti-static TVS diode D2, the emitter of NPN transistor Q5 is grounded, the anti-static TVS diode D2 is used to protect and prevent the MCU circuit from being broken down, the second diagnostic drive circuit includes K1 relay, anti-static TVS diode D3, pin 1 of K1 relay is connected with the VBAT power pin of the peripheral, VB The AT power pin is used to provide an external power supply for the K1 relay. The 2nd pin of the K1 relay is connected to the collector of the NPN transistor Q5. The 3rd pin of the K1 relay is respectively connected to the 3rd pin of the MCU chip U1 and the ground. The 4th pin of the K1 relay is respectively connected to the anti-static TVS diode D3 and the negative electrode of the heating wire. The anti-static TVS diode D3 plays a role in protecting and preventing the MCU circuit from being broken down. The third diagnostic drive circuit includes a high-side drive chip U6 and an anti-static TVS diode D5. The 1st pin of the high-side drive chip U6 is respectively connected to the V The BAT power pin is connected to the ground. The 2nd, 3rd and 4th pins of the high-side driver chip U6 are connected to the positive electrode of the heater wire and the anti-static TVS diode D5. The anti-static TVS diode D5 protects and prevents the MCU circuit from being broken down. The 5th pin of the high-side driver chip U6 is connected to the VBAT power pin of the peripheral. The 6th pin of the high-side driver chip U6 is connected to the 2nd pin of the MCU chip U1. The 7th pin of the high-side driver chip U6 is connected to the 4th pin of the MCU chip U1. The 8th pin of the high-side driver chip U6 is connected to the 5th pin of the MCU chip U1.

2. The multifunctional seat heating driving circuit according to claim 1, characterized in that: A resistor R1 is provided at the connection between the base of the NPN transistor Q5 and the input terminal of the second diagnostic drive circuit to play the role of voltage division and current limiting. A resistor R2 is provided between the resistor R1 and the emitter of the NPN transistor Q5 to prevent accidental start-up.

3. The multifunctional seat heating driving circuit according to claim 1, characterized in that: A capacitor C1, a resistor R7, a resistor R6, and a capacitor C2 are connected in sequence between the 3rd pin of the K1 relay and the 3rd pin of the MCU chip U1. The capacitor C1, the resistor R7, the resistor R6, and the capacitor C2 play a role in voltage stabilization.

4. The multifunctional seat heating driving circuit according to claim 1, characterized in that: A resistor R8 is also connected between pin 6 of the high-side driver chip U6 and pin 2 of the MCU chip U1, and a resistor R9 is also connected between pin 7 of the high-side driver chip U6 and pin 4 of the MCU chip U1. Resistors R8 and R9 both play a current limiting role. Pin 8 of the high-side driver chip U6 is also connected to capacitor C4, resistor R10, and resistor R11, respectively. Capacitor C4 plays a voltage stabilizing role, resistor R10 plays a current limiting role, and resistor R11 plays a current detecting role.

5. The multifunctional seat heating driving circuit according to claim 1, characterized in that: The MCU circuit is composed of an MCU chip U1, wherein pin 1 of the MCU chip U1 is the Heat2_Relay_CTL pin, pin 2 of the MCU chip U1 is the MCU_Heat2_CTL pin, pin 3 of the MCU chip U1 is the HEAT2_GND_DIG pin, pin 4 of the MCU chip is the MCU_DEN pin, and pin 5 of the MCU chip U1 is the Heat2_AD pin.

6. The multifunctional seat heating driving circuit according to claim 1, characterized in that: The pin connecting the collector of NPN transistor Q5 and the input end of the second diagnostic drive circuit is HEAT2_Relay_CTL pin; pin 2 of K1 relay is HEAT2_Relay_CTL pin, the pin connecting pin 3 of K1 relay and pin 3 of MCU chip U1 is HEAT2_GND_DIG pin, and the pin connecting pin 4 of K1 relay and the negative pole of the heating wire is HEAT2_GND pin.

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