Reverse polarity protection circuit and windshield wiper system comprising reverse polarity protection circuit

Abstract

A reverse polarity protection circuit and a windshield wiper system comprising said reverse polarity protection circuit. The circuit comprises: a MOS circuit, which is configured to connect a first terminal and a second terminal when the voltage of the first terminal voltage of the MOS circuit is higher than the voltage of the second terminal, and to disconnect the first terminal and the second terminal when the voltage of the first terminal is lower than the voltage of the second terminal; a first diode, the anode of the first diode being connected to the first terminal of the MOS circuit; a second diode, the anode of the second diode being connected to the first terminal of a triode, and the cathode of the second diode being connected to the cathode of the first diode; said triode, the second terminal of the triode being connected to the second terminal of the MOS circuit; a first resistor, the first resistor being connected between the cathode of the first diode and ground; a second resistor, the second resistor being connected between the third terminal of the triode and ground; and a third resistor, the third resistor being connected between the third terminal of the MOS circuit and the third terminal of the triode. The reverse polarity protection circuit can protection the power supply from being damaged by reverse polarity voltage.

Description

Reverse polarity protection circuit and wiper system including the same Technical Field

[0001] The present invention relates to an electronic circuit, and in particular to a reverse polarity protection circuit and a wiper system comprising the reverse polarity protection circuit. Background Art

[0002] Currently, vehicles generally include windshield wipers (also known as windshield wipers or windshield wipers, etc.) for clearing rain, snow, ice, washer fluid, water, or debris from the windshield of the cab.

[0003] To accommodate different weather conditions or user needs, most wipers are configured to operate at different speeds, such as low and high, using a motor with multiple windings. However, operating one of the windings may induce voltage in the remaining windings. This induced voltage in the remaining windings may adversely affect the wiper's power supply circuit.

[0004] Summary of the Invention

[0005] The present disclosure provides a reverse polarity protection circuit, comprising: a MOS circuit, configured to conduct the first and second ends of the MOS circuit when the voltage of the first end of the MOS circuit is higher than the voltage of the second end of the MOS circuit, and to disconnect the first and second ends of the MOS circuit when the voltage of the first end of the MOS circuit is lower than the voltage of the second end of the MOS circuit; a first diode, wherein the anode of the first diode is connected to the first end of the MOS circuit; a second diode, wherein the anode of the second diode is connected to the first end of a transistor, and the cathode of the second diode is connected to the cathode of the first diode; a transistor, wherein the second end of the transistor is connected to the second end of the MOS circuit; a first resistor, wherein the first resistor is connected between the cathode of the first diode and ground; a second resistor, wherein the second resistor is connected between the third end of the transistor and ground; and a third resistor, wherein the third resistor is connected between the third end of the MOS circuit and the third end of the transistor.

[0006] The reverse polarity protection circuit according to the present disclosure further includes: a power supply connected to the first end of the MOS circuit, and a load connected to the second end of the MOS circuit.

[0007] According to the reverse polarity protection circuit disclosed herein, the MOS circuit includes a PMOS circuit, wherein the first end of the MOS circuit corresponds to the drain of the PMOS circuit, the second end of the MOS circuit corresponds to the source of the PMOS circuit, and the third end of the MOS circuit corresponds to the gate of the PMOS circuit.

[0008] According to the reverse polarity protection circuit disclosed herein, the transistor includes a PNP transistor, wherein the first end of the transistor corresponds to the base of the PNP transistor, the second end of the transistor corresponds to the emitter of the PNP transistor, and the third end of the transistor corresponds to the collector of the PNP transistor.

[0009] According to the reverse polarity protection circuit disclosed herein, the first resistor is at least used for current limiting and pulling down the cathode voltages of the first diode and the second diode, and the resistance of the first resistor is between 5000 and 15000 ohms.

[0010] According to the reverse polarity protection circuit disclosed herein, the second resistor is used at least for current limiting and pulling down the voltage of the third end of the MOS circuit when the voltage of the first end of the MOS circuit is higher than the voltage of the second end of the MOS circuit. The resistance value of the second resistor is between 5000 and 15000 ohms.

[0011] According to the reverse polarity protection circuit disclosed herein, the third resistor is used at least to provide a signal loop for the third end of the MOS circuit and to perform current limiting. The resistance value of the third resistor is at least partially determined based on the current limiting requirement of the MOS circuit.

[0012] The reverse polarity protection circuit according to the present disclosure further includes a voltage stabilizing diode, which is used to limit the voltage difference between the second terminal and the third terminal of the MOS circuit.

[0013] The reverse polarity protection circuit according to the present disclosure further includes an electrostatic discharge (ESD) protection circuit for protecting the reverse polarity protection circuit module and the power supply module to avoid device damage caused by electrostatic discharge pulses.

[0014] According to the reverse polarity protection circuit of the present disclosure, the electrostatic discharge (ESD) protection circuit is configured to reduce the voltage at the second end of the MOS circuit when the voltage at the first end of the MOS circuit is lower than the voltage at the second end of the MOS circuit.

[0015] The reverse polarity protection circuit according to the present disclosure further includes a micro control unit MCU configured to monitor a voltage outputted by the reverse polarity protection circuit.

[0016] The present disclosure provides a domain controller, including the reverse polarity protection circuit according to the present disclosure described above. Detailed descriptions can be found in the above description of the reverse polarity protection circuit, which will not be repeated here for the sake of brevity.

[0017] The present disclosure provides a wiper system, comprising: a wiper module, the wiper module comprising: a wiper motor, the motor comprising at least two windings, the motor being configured to use power from a power supply module to drive a wiper through the at least two windings, the wiper being operably connected to one of the at least two windings; a power supply module, the power supply module being configured to supply power to the wiper module; a reverse polarity protection circuit module, the reverse polarity protection circuit module comprising at least one reverse polarity protection circuit, the at least one reverse polarity protection circuit corresponding to one of the at least two windings, the at least one reverse polarity protection circuit being used to prevent a reverse polarity voltage generated by one of the at least two windings from acting on the power supply module, the at least one reverse polarity protection circuit comprising: a MOS circuit, configured to: when a voltage at a first end of the MOS circuit is higher than a voltage at a first end of the MOS circuit The first and second ends of the MOS circuit are connected when the voltage at the second end of the MOS circuit is lower than the voltage at the second end of the MOS circuit, and the first and second ends of the MOS circuit are disconnected when the voltage at the first end of the MOS circuit is lower than the voltage at the second end of the MOS circuit; a first diode, wherein the anode of the first diode is connected to the first end of the MOS circuit; a second diode, wherein the anode of the second diode is connected to the first end of the triode, and the cathode of the second diode is connected to the cathode of the first diode; a triode, wherein the second end of the triode is connected to the second end of the MOS circuit; a first resistor, wherein the first resistor is connected between the cathode of the first diode and ground; a second resistor, wherein the second resistor is connected between the third end of the triode and ground; and a third resistor, wherein the third resistor is connected between the third end of the MOS circuit and the third end of the triode.

[0018] The present disclosure provides a motor vehicle including the reverse polarity protection circuit and / or the wiper system described above. For details, please refer to the above description of the reverse polarity protection circuit and / or the domain controller and / or the wiper system, which will not be repeated here for the sake of brevity.

[0019] According to the reverse polarity protection circuit and wiper system disclosed herein, when the power supply is normally supplying power to the load, the power consumption generated by the reverse polarity protection circuit is minimal. When the load transmits a reverse polarity voltage to the power supply, the reverse polarity protection circuit reversely shuts down, thereby protecting the power supply. Furthermore, the reverse polarity protection circuit can adaptively turn on and off based on the power supply voltage and the reverse polarity voltage, without requiring additional control signals, thereby effectively reducing system complexity, control difficulty, and manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0021] Figure 1a is a windshield wiper system;

[0022] Figure 1b shows another wiper system;

[0023] FIG2 is a reverse polarity protection circuit according to an embodiment of the present disclosure;

[0024] FIG3 a is a schematic diagram of the reverse polarity protection circuit of FIG2 in a forward conduction state according to an embodiment of the present disclosure;

[0025] FIG3 b is a schematic diagram of the reverse polarity protection circuit of FIG2 in a reverse off-conduction state according to an embodiment of the present disclosure;

[0026] FIG4 is another reverse polarity protection circuit according to an embodiment of the present disclosure;

[0027] FIG5 is another reverse polarity protection circuit according to an embodiment of the present disclosure;

[0028] FIG6 is another reverse polarity protection circuit according to an embodiment of the present disclosure;

[0029] FIG7 is a wiper system according to an embodiment of the present disclosure;

[0030] FIG. 8 is a motor vehicle according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] Before proceeding with the following detailed description, it may be helpful to set forth definitions of certain words and phrases used throughout this disclosure. The terms "include" and "comprising" and their derivatives mean including, but not limited to, including. The phrase "at least one of," when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item from the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A, B, and C.

[0032] Definitions for other specific words and phrases are provided throughout this disclosure. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior and future uses of such defined words and phrases.

[0033] The various embodiments of the principles of the present disclosure in this patent document described below in conjunction with the accompanying drawings are intended only as illustrations and should not be construed in any way to limit the scope of the present disclosure. Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any appropriately arranged system or device. In some cases, the actions described in this disclosure can be performed in a different order and still achieve the desired result. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired result. In specific embodiments, multitasking and parallel processing may be advantageous.

[0034] The text and drawings are provided as examples only to aid understanding of the present disclosure. They should not be interpreted as limiting the scope of the claims appended hereto in any way. Throughout the drawings, the same reference numerals generally indicate the same elements. Although certain embodiments and examples have been provided, it will be clear to those skilled in the art based on the contents of this disclosure that the illustrated embodiments and examples may be modified without departing from the scope of this disclosure.

[0035] Figure 1a is a windshield wiper system.

[0036] The windshield wiper system shown in FIG1a can be installed in various vehicles. Vehicles include, but are not limited to, cars, tractors (with or without trailers), buses, recreational vehicles, minivans or sport utility vehicles (SUVs), construction equipment, agricultural equipment, aircraft, etc. As shown in FIG1 , the windshield wiper system may include a power supply 110 , a wiper motor 120 , and a wiper 130 .

[0037] The power source 110 may be configured to provide an input voltage to the wiper motor 120. The power source 110 may be a battery of the vehicle, such as a nickel-cadmium battery, a nickel-metal hydride battery, a lithium-ion battery, a polymer battery, a lead-acid battery, or the like.

[0038] The wiper motor 120 can be configured to receive an input voltage from a power source 110 and drive the wiper 130 in different speed modes by selecting different windings. The wiper motor 120 can include DC motors such as permanent magnet DC motors and electromagnetic DC motors, as well as AC motors such as synchronous AC motors and asynchronous AC motors. As shown in FIG1a , the wiper motor 120 can include a first winding 121 and a second winding 122. However, those skilled in the art will appreciate that the wiper motor 120 can include more windings. The first winding 121 and the second winding 122 can be used by the wiper motor 120 to drive the wiper 130 in different speed modes. In one embodiment, the first winding 121 can have a greater number of turns than the second winding 122. Therefore, the first winding 121 can correspond to a fast mode that drives the wiper 130 at a faster speed, while the second winding 122 can correspond to a slow mode that drives the wiper 130 at a slower speed. More windings with different numbers of turns can correspond to more speed modes.

[0039] The wipers 130 may include one or more of a bone wiper, a boneless wiper, and a composite wiper. The wipers 130 may be configured to be driven by the wiper motor 120 using windings to remove rain, snow, ice, washer fluid, water, or debris on the windshield.

[0040] In one embodiment, when a user chooses to drive the wiper 130 in high-speed mode, the power supply 110 supplies power to the first winding 121 of the wiper motor 120, thereby driving the wiper 130 at high speed. However, an induced voltage may be generated in the second winding that is not powered due to electromagnetic induction with the first winding 121. The induced voltage may be opposite to the input voltage provided by the power supply 110 to the wiper motor 120. In other words, the second winding 122 that is not powered may generate a reverse polarity voltage opposite to the input voltage due to electromagnetic induction with the first winding 121 that is powered. This reverse polarity voltage may act on the power supply 110, and when the reverse polarity voltage is large enough, it may cause damage to components of the power supply 110 and cause failure.

[0041] Figure 1b shows another windshield wiper system.

[0042] The parts in FIG1b that are the same as those in FIG1a will not be described again.

[0043] The wiper system in FIG1b further includes a diode 140. Due to the unidirectional conduction characteristic of diode 140, the reverse polarity voltage induced in the non-operated winding (e.g., the second winding) cannot be supplied to power supply 110, thereby protecting power supply 110 from damage caused by the reverse polarity voltage. However, if the operated winding (e.g., the first winding) is heavily loaded, diode 140 may generate high power consumption due to its own voltage drop and on-resistance.

[0044] FIG. 2 is a reverse polarity protection circuit 200 according to an embodiment of the present disclosure.

[0045] The input terminal of the reverse polarity protection circuit 200 shown in FIG. 2 may be connected to the power source 110 , and the output terminal may be connected to a load, such as a winding of a wiper motor 120 .

[0046] As shown in FIG. 2 , the reverse polarity protection circuit may include a MOS circuit 210 , a first diode 220 , a second diode 230 , a first resistor 240 , a second resistor 250 , a third resistor 260 , and a transistor 270 .

[0047] As shown in FIG2 , MOS circuit 210 may include a first terminal MOS1, a second terminal MOS2, and a third terminal MOS3. The first terminal MOS1 of MOS circuit 210 may be connected to the anode and input terminal of first diode 220. The second terminal MOS2 of MOS circuit 210 may be connected to the second terminal TR2 and output terminal of transistor 270. The third terminal MOS3 of MOS circuit 210 may be connected to third resistor 260. MOS circuit 210 is configured to conduct when the voltage at the first terminal MOS1 is higher than the voltage at the second terminal MOS2; and to disconnect when the voltage at the first terminal MOS1 is lower than the voltage at the second terminal MOS2.

[0048] The first diode 220 and the second diode 230 may include various diodes such as a silicon diode and a germanium diode. The anode of the first diode 220 may be connected to the first terminal MOS1 of the MOS circuit 210. The cathode of the first diode 220 may be connected to the cathode of the second diode 230. The anode of the second diode 230 may be connected to the third terminal TR1 of the transistor 270.

[0049] The first resistor 240 can be connected between the cathode of the first diode 220 and the ground. The ground shown in FIG2 can be a power ground. The second resistor 250 can be connected between the third terminal TR3 of the transistor 270 and the ground. The third resistor 250 can be connected between the third terminal MOS3 of the MOS circuit 210 and the third terminal TR3 of the transistor 270.

[0050] The transistor 270 may include a first terminal TR1, a second terminal TR2, and a third terminal TR3. The first terminal TR1 of the transistor 270 may be connected to the anode of the second diode 230. The second terminal TR2 of the transistor 270 may be connected to the second terminal MOS2 of the MOS circuit 210. The third terminal TR2 of the transistor 270 may be connected to one end of the second resistor 250 and one end of the third resistor 260.

[0051] In one embodiment, the MOS circuit 210 may include a PMOS circuit. For example, the first terminal MOS1 of the MOS circuit 210 corresponds to the drain of the PMOS circuit, the second terminal MOS2 of the MOS circuit 210 corresponds to the source of the PMOS circuit, and the third terminal MOS3 of the MOS circuit 210 corresponds to the gate of the PMOS circuit.

[0052] In one embodiment, the transistor 270 may include a PNP transistor. For example, the first terminal TR1 of the transistor 270 corresponds to the base of the PNP transistor, the second terminal TR2 of the transistor 270 corresponds to the emitter of the PNP transistor, and the third terminal TR3 of the transistor 270 corresponds to the collector of the PNP transistor.

[0053] FIG3 a is a schematic diagram of the reverse polarity protection circuit 200 of FIG2 in a forward conduction state according to an embodiment of the present disclosure.

[0054] By way of example only, first diode 220 and second diode 230 in FIG. 3 a may be germanium diodes, and their forward voltage drop Vdon may be equal to 0.3 V. The input terminal may be connected to ground via first diode 220 and first resistor 240. First resistor 240 may be used to limit current and pull down the cathode voltage of first diode 220 and second diode 220. The resistance of first resistor 240 may be between 5 kΩ and 15 kΩ. For example, the resistance of first resistor 240 may be 10 kΩ. As shown in FIG. 3 a , when the voltage Vin provided via the input terminal is 10 V, the voltage Vp1 at point P1 = Vin - Vdon = 9.7 V.

[0055] Assume that MOS circuit 210 is turned on and its conduction voltage drop, Vmos, is 0.1V. At this point, the voltage at the second terminal MOS2 of MOS circuit 210 is Vin - Vmos = 9.9V. Therefore, the voltage at the output terminal and the second terminal TR2 of transistor 270 can be determined to be 9.9V. When the voltage at the second terminal TR2 of the transistor is 9.9V, the voltage Vp1 at point P1, as described above, is equal to Vin - Vdon = 9.7V. The voltage difference between the second terminal TR2 of the transistor and the voltage Vp1 at point P1 is 0.2V. Due to the unidirectional conduction characteristics of second diode 230, when conducting, second diode 230 requires a conduction voltage drop of Vdon = 0.3V. Therefore, the voltage difference between the second terminal TR2 of the transistor and the voltage Vp1 at point P1 is insufficient to turn on second diode 230 and transistor 270, resulting in transistor 270 being in the off state.

[0056] Because transistor 270 is in the off state, the third terminal TR3 of transistor 270 cannot provide a voltage to second resistor 260 or third resistor 270. Therefore, the third terminal MOS3 of MOS circuit 210 can be connected to ground via third resistor 260 and second resistor 250. Second resistor 250 is used to at least limit current and pull down the voltage at the third terminal of the MOS circuit. The resistance of second resistor 250 is between 5 kΩ and 15 kΩ. For example, the resistance of second resistor 250 can be 10 kΩ. Therefore, the third terminal MOS3 of MOS circuit 210 is in a low level state, and MOS circuit 210 is turned on.

[0057] In the scenario shown in Figure 3a, the reverse polarity protection circuit shown in Figure 2 is in the forward conduction state. The input voltage Vin provided by the power supply is provided to the output terminal as Vout after losing the relatively small conduction voltage drop Vmos of the MOS circuit 210. The output terminal can be connected to a load such as a wiper motor to power the windings in the wiper motor to drive the wipers.

[0058] FIG3 b is a schematic diagram of the reverse polarity protection circuit 200 of FIG2 in a reverse-off conduction state according to an embodiment of the present disclosure.

[0059] FIG3b shows a scenario in which an inoperative winding in a wiper motor generates an induced voltage due to electromagnetic induction, resulting in a voltage of 12V at the output of the reverse polarity protection circuit. In FIG3b , the voltage Vin at the input terminal is 10V. As described with reference to FIG3a , the input terminal can be connected to the ground via the first diode 220 and the first resistor 240. The first resistor 240 can be used to limit the current and pull down the cathode voltage of the first diode 220 and the second diode 220. The resistance of the first resistor 240 is between 5kΩ and 15kΩ. For example, the resistance of the first resistor 240 can be 10kΩ. As shown in FIG3a , when the voltage Vin provided via the input terminal is 10V, the voltage Vp1 at point P1 is Vp1-Vdon=9.7V.

[0060] At this point, the voltage at the output terminal is Vout = 12V. Therefore, it can be determined that the voltage at the second terminal MOS2 of MOS circuit 210 and the second terminal TR2 of transistor 270 are both 12V. When the voltage at the second terminal TR2 of transistor 270 is 12V, due to the unidirectional conduction characteristics of second diode 230, it can be determined that the voltage VTR1 at the first terminal TR1 of transistor 270 is equal to the voltage at P1 plus the conduction voltage drop Vdon of second diode 230, that is, 10V. Therefore, the voltage difference between the second terminal TR2 of transistor 270 and the first terminal TR1 of transistor 270 can be equal to Vout - VTR1 = 2V. This voltage difference is sufficient to turn on transistor 270, and thus transistor 270 is in the on state. Considering that the conduction voltage drop of transistor 270 is 0.2V, the voltage at the third terminal TR3 of transistor 270 is 11.8V. At this point, it can be determined that the voltage at the third terminal MOS3 of MOS circuit 210 is equal to the voltage of 11.8V at the third terminal TR3 of transistor 270. Therefore, the third terminal MOS3 of the MOS circuit 210 is in a high level state, and the MOS circuit 210 is turned off. The third resistor 260 can be used to provide at least a signal loop for the third terminal MOS3 of the MOS circuit 210 and to limit current. The resistance value of the third resistor 260 can be determined at least in part based on the current limiting requirements of the MOS circuit 210.

[0061] In the scenario shown in Figure 3b, the reverse polarity protection circuit shown in Figure 2 is in the reverse-off state. The voltage Vout supplied by the load terminal cannot be transmitted to the input terminal or the power supply. Consequently, the reverse polarity voltage generated by electromagnetic induction between the unpowered winding and the powered winding cannot act on the power supply. Therefore, the reverse polarity protection circuit shown in Figure 2 protects power supply components from damage and failure.

[0062] As described in Figures 2, 3a and 3b, the reverse polarity protection circuit according to the embodiment of the present disclosure has at least the following advantages: when the reverse polarity protection circuit is forward-conducted, the power supply can supply power to the load, and the power consumption generated by the reverse polarity protection circuit is extremely small. When the reverse polarity protection circuit is reverse-turned off, the reverse polarity protection voltage induced in the unoperated winding cannot be transmitted to the power supply, so the power supply is protected. The reverse polarity protection circuit according to the embodiment of the present disclosure is adaptive. When connected to the wiper system, the reverse polarity protection circuit can be adaptively turned on and off according to the voltage at its input and output terminals without the need for additional control signals, thereby effectively reducing system complexity, control difficulty and manufacturing costs.

[0063] FIG. 4 shows another reverse polarity protection circuit 200 ′ according to an embodiment of the present disclosure.

[0064] Parts in FIG. 4 that are similar to the components of the reverse polarity protection circuit shown in FIG. 2 will not be described again.

[0065] The reverse polarity protection circuit of FIG. 4 according to an embodiment of the present disclosure further includes a Zener diode 280. The cathode of the Zener diode 280 is connected to the second terminal TR2 of the transistor 270, and the anode of the Zener diode 280 is connected to the third terminal TR3 of the transistor 270. In one embodiment, the Zener diode 280 can be used to provide voltage protection for the MOS circuit 210. For example, depending on the use requirements of the MOS circuit 210, the voltage difference between the second terminal MOS2 and the third terminal MOS3 of the MOS circuit 210 may not be allowed to exceed a certain threshold, otherwise the MOS circuit 210 may be damaged by the excessively high voltage difference. The Zener diode 280 can be selected based on this threshold. When the voltage difference between the second terminal MOS2 and the third terminal MOS3 of the MOS circuit 210 is too high to exceed the threshold, the Zener diode 280 can stabilize the voltage difference at or below the threshold, thereby protecting the MOS circuit 210 from damage.

[0066] FIG5 is another reverse polarity protection circuit 200 according to an embodiment of the present disclosure.

[0067] Parts in FIG. 5 that are similar to the components of the reverse polarity protection circuit shown in FIG. 2 will not be described again.

[0068] According to the reverse polarity protection circuit of Figure 5 of the embodiment of the present disclosure, it also includes an electrostatic discharge (ESD) protection circuit 290. The electrostatic discharge of the external load may cause a reverse electrostatic discharge pulse to flow to the power supply, which may cause sudden failure or potential failure of the power supply. The ESD protection circuit 290 may include one or more of a transient suppressor diode TVS tube, a multilayer varistor MLV, a metal oxide varistor MOV, a polymer ESD protection device, and a glass ceramic ESD protection device. When a reverse electrostatic discharge pulse flows to the power supply due to an external load or other components, the ESD protection circuit 290 can operate to discharge the electrostatic discharge pulse and thus protect the power supply. In one embodiment, when the unpowered winding generates a reverse polarity voltage opposite to the input voltage due to the electromagnetic induction between the unpowered winding and the powered winding, the ESD protection circuit 290 can reduce the reverse polarity voltage to a certain extent. Therefore, the ESD protection circuit 290 can also at least partially alleviate the adverse effects caused by the reverse polarity voltage.

[0069] FIG6 shows another reverse polarity protection circuit 200 ′″ according to an embodiment of the present disclosure.

[0070] Parts in FIG. 6 that are similar to the components of the reverse polarity protection circuit shown in FIG. 2 will not be described again.

[0071] According to the reverse polarity protection circuit of Figure 6 of the embodiment of the present disclosure, it also includes a micro-control unit (MCU) diagnostic circuit 290. Although not shown, a voltage detection component can be connected between the micro-control unit diagnostic circuit 290 and the output terminal. The voltage detection component can be configured to detect the voltage output by the output terminal. The micro-control unit MCU, also known as a single-chip microcomputer, is a microcomputer that integrates a central processing unit, memory, timer / counter, various input and output interfaces, etc. on an integrated circuit chip. The MCU diagnostic circuit 290 can monitor the voltage output by the reverse polarity protection circuit through the micro-control unit MCU. When the MCU diagnostic circuit 290 monitors that the voltage output by the reverse polarity protection circuit is abnormal, it can further diagnose the cause of the abnormality by itself or in other ways, for example, a power supply failure or a reverse polarity protection circuit failure, etc.

[0072] Although Figures 4 to 6 respectively show that the reverse polarity protection circuit includes a Zener diode 280, an ESD protection circuit 290, and an MCU diagnostic circuit 295, as those skilled in the art will understand, the reverse polarity protection circuit may include one or more of the Zener diode 280, the ESD protection circuit 290, and the MCU diagnostic circuit 295 at the same time.

[0073] A domain controller (or regional controller) is the core of each functional domain in a vehicle. It primarily consists of three components: a domain master processor, an operating system, and application software and algorithms. Leveraging its high-performance domain master processor, extensive hardware interface resources, and robust software features, the domain controller can integrate core functions that previously required multiple ECUs, significantly improving system integration. Furthermore, the standardized data exchange interface significantly reduces development and manufacturing costs. The reverse polarity protection circuit described in this article can be applied to domain controllers or regional controllers.

[0074] FIG. 7 illustrates a wiper system 700 according to an embodiment of the present disclosure.

[0075] The wiper system 700 shown in FIG. 7 may include a battery module 710 , a reverse polarity protection circuit module 720 , and a wiper module 730 .

[0076] The power module 710 may be configured to provide power to the wiper module 730. The power module 710 may include a battery of the vehicle, such as a nickel-cadmium battery, a nickel-metal hydride battery, a lithium-ion battery, a polymer battery, a lead-acid battery, and the like.

[0077] The reverse polarity protection circuits 722 and 724 included in the reverse polarity protection circuit module 720 can be the reverse polarity protection circuits described in Figures 2, 4-6, or a combination thereof. The reverse polarity protection circuits 722 and 724 included in the reverse polarity protection circuit module 720 can correspond to the windings 734 and 735 in the wiper module 730, respectively. The reverse polarity protection circuit in the reverse polarity protection circuit module 720 can conduct forward to maintain power delivery when the power module 710 is normally supplying power to the wiper module 730; and reversely shut down when the wiper module 730 sends a reverse polarity voltage to the power module 720, thereby protecting the power module 710 from damage caused by the reverse polarity voltage.

[0078] The wiper module 730 may include a wiper motor 732 and a wiper 733. The wiper motor 732 may be configured to drive the wiper 733 to move through the power from the power module 710 and through the windings. The wiper motor 732 may include a DC motor such as a permanent magnet DC motor and an electromagnetic DC motor, as well as an AC motor such as a synchronous AC motor and an asynchronous AC motor. Although two windings 734 and 745 are shown in FIG7 , those skilled in the art will understand that the wiper motor 732 may include more windings to correspond to more wiper operating modes. In one example, more windings may each correspond to a reverse polarity protection circuit. In another example, only windings with a number of turns exceeding a threshold may each correspond to a reverse polarity protection circuit or only the winding with the highest number of turns may correspond to a reverse polarity protection circuit.

[0079] The wipers 733 may include one or more of a boned wiper, a boneless wiper, or a composite wiper. The wipers 733 may be configured to be driven by a wiper motor 732 via a winding 734 or a winding 735 to remove rain, snow, ice, washer fluid, water, or debris from the windshield.

[0080] In the wiper system shown in Figure 7 , when power module 710 normally supplies power to wiper module 730, the power consumption of reverse polarity protection circuit module 720 is minimal. When wiper module 730 transmits a reverse polarity voltage to power module 710, reverse polarity protection circuit module 720 reversely shuts down, thereby protecting power module 710. Furthermore, the wiper system according to embodiments of the present disclosure can adaptively turn on and off based on the power supply voltage and reverse polarity voltage without requiring additional control signals, effectively reducing system complexity, control difficulty, and manufacturing costs.

[0081] FIG. 8 is a motor vehicle 800 according to an embodiment of the present disclosure.

[0082] As shown in FIG8 , the motor vehicle 800 includes the reverse polarity protection circuits 200, 200′, 200″, 200′″ and / or the wiper system 700 according to the present disclosure as described above. For details, please refer to the description of the reverse polarity protection circuit and / or the wiper system above, which will not be repeated here for the sake of brevity.

[0083] Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.

[0084] Any description in the present invention should not be construed as implying that any particular element, step, or function is essential to be included in the scope of the claims. The scope of the patented subject matter is limited only by the claims.

Claims

1. A reverse polarity protection circuit, comprising: a MOS circuit configured to conduct the first and second ends of the MOS circuit when the voltage of the first end of the MOS circuit is higher than the voltage of the second end of the MOS circuit, and to disconnect the first and second ends of the MOS circuit when the voltage of the first end of the MOS circuit is lower than the voltage of the second end of the MOS circuit; a first diode, wherein an anode of the first diode is connected to a first end of the MOS circuit; a second diode, wherein an anode of the second diode is connected to the first end of the triode, and a cathode of the second diode is connected to the cathode of the first diode; A triode, wherein a second end of the triode is connected to a second end of the MOS circuit; a first resistor, wherein the first resistor is connected between the cathode of the first diode and ground; a second resistor, wherein the second resistor is connected between the third terminal of the transistor and the ground; A third resistor, wherein the third resistor is connected between a third terminal of the MOS circuit and a third terminal of the transistor.

2. The reverse polarity protection circuit according to claim 1, further comprising: power supply, connected to the first terminal of the MOS circuit, A load is connected to the second terminal of the MOS circuit.

3. The reverse polarity protection circuit according to claim 1, wherein: The MOS circuit comprises a PMOS circuit, wherein: The first terminal of the MOS circuit corresponds to the drain of the PMOS circuit, The second end of the MOS circuit corresponds to the source of the PMOS circuit. The third terminal of the MOS circuit corresponds to the gate of the PMOS circuit.

4. The reverse polarity protection circuit according to claim 1, wherein: The transistor comprises a PNP transistor, wherein: The first end of the transistor corresponds to the base of the PNP transistor. The second end of the transistor corresponds to the emitter of the PNP transistor. The third end of the transistor corresponds to the collector of the PNP transistor.

5. The reverse polarity protection circuit according to claim 1, wherein: The first resistor is at least used for current limiting and pulling down the cathode voltages of the first diode and the second diode. The resistance of the first resistor is between 5000 and 15000 ohms.

6. The reverse polarity protection circuit according to claim 1, wherein: The second resistor is at least used for current limiting and pulling down the voltage of the third end of the MOS circuit when the voltage of the first end of the MOS circuit is higher than the voltage of the second end of the MOS circuit. The resistance of the second resistor is between 5000 and 15000 ohms.

7. The reverse polarity protection circuit according to claim 1, wherein: The third resistor is at least used to provide a signal loop for the third end of the MOS circuit and to perform current limiting. The resistance value of the third resistor is at least partially determined based on the current limiting requirement of the MOS circuit. 8 . The reverse polarity protection circuit according to claim 1 , further comprising a Zener diode, wherein the Zener diode is used to limit the voltage difference between the second terminal and the third terminal of the MOS circuit.

9. The reverse polarity protection circuit according to claim 1, further comprising an electrostatic discharge (ESD) protection circuit for protecting the reverse polarity protection circuit module and the power supply module to avoid device damage caused by an electrostatic discharge pulse.

10. The reverse polarity protection circuit according to claim 9, wherein the electrostatic discharge (ESD) protection circuit is configured to reduce a voltage at a second end of the MOS circuit when a voltage at a first end of the MOS circuit is lower than a voltage at a second end of the MOS circuit. 11 . The reverse polarity protection circuit according to claim 1 , further comprising a micro control unit (MCU) configured to monitor a voltage outputted via the reverse polarity protection circuit.

12. A domain controller comprising the reverse polarity protection circuit according to any one of claims 1 to 11.

13. A windshield wiper system, comprising: A windshield wiper module, the windshield wiper module comprising: A wiper motor, the motor comprising at least two windings, the motor being configured to use power from a power module to drive the wiper through the at least two windings, a wiper operatively connected to one of the at least two windings; a power module, wherein the power module is configured to supply power to the wiper module; A reverse polarity protection circuit module, the reverse polarity protection circuit module comprising at least one reverse polarity protection circuit, the at least one reverse polarity protection circuit corresponding to one of the at least two windings, the at least one reverse polarity protection circuit being used to prevent a reverse polarity voltage generated by one of the at least two windings from acting on a power supply module, the at least one reverse polarity protection circuit comprising: A MOS circuit configured to conduct the first and second ends of the MOS circuit when the voltage of the first end of the MOS circuit is higher than the voltage of the second end of the MOS circuit, and to disconnect the first and second ends of the MOS circuit when the voltage of the first end of the MOS circuit is lower than the voltage of the second end of the MOS circuit The second end; a first diode, wherein an anode of the first diode is connected to a first end of the MOS circuit; a second diode, wherein an anode of the second diode is connected to the first end of the triode, and a cathode of the second diode is connected to the cathode of the first diode; A triode, wherein a second end of the triode is connected to a second end of the MOS circuit; a first resistor, wherein the first resistor is connected between the cathode of the first diode and ground; a second resistor, wherein the second resistor is connected between the third terminal of the transistor and the ground; A third resistor, wherein the third resistor is connected between a third terminal of the MOS circuit and a third terminal of the transistor.

14. A motor vehicle comprising The reverse polarity protection circuit according to any one of claims 1 to 11; and / or The domain controller as claimed in claim 12; and / or The windshield wiper system according to claim 13.

Images