Multi-water-level single-output sensor and fuel filtering system

Abstract

The invention is suitable for the technical field of automotive electronics, and provides a multi-water-level single-output sensor and a fuel filtering system.The sensor comprises a reference probe, a first probe, a second probe, a first water level voltage comparison circuit, a second water level voltage comparison circuit and an ECU interface circuit; when the multi-water-level single-output sensor is used for detecting the water level, the multi-water-level single-output sensor determines the water level according to the output voltage of the output end of the multi-water-level single-output sensor. According to the invention, the problem of long drainage time is solved, and the output terminal and the wire harness are not additionally introduced.

Description

Technical Field

[0001] The present application belongs to the field of automotive electronics technology, and in particular relates to a multi-water level single-output sensor and a fuel filtration system. Background Art

[0002] The fuel filtration system of a diesel vehicle is responsible not only for removing impurities from the fuel but also for removing water from the fuel. This is because diesel fuel not only serves as fuel in the engine but also lubricates key components such as the fuel pump and injectors. Excessive water content in the diesel fuel can cause these components to malfunction and trigger alarms. Therefore, the oil-water separator is an essential component of the fuel filtration system. The oil-water separator is typically equipped with a water level sensor (WIF) installed at the bottom of the fuel filter (coarse filter). Due to the different densities of water and oil, oil floats on the water surface. When the water level reaches a certain level and touches the water level sensor's probe, the sensor's electrical potential changes, transmitting a corresponding electrical signal to the ECU, which then illuminates the fault warning light to remind the driver to drain the fuel.

[0003] Currently, water level sensors on the market are divided into single-level and dual-level types. Single-level sensors detect only a single water level, but their disadvantage is that they struggle to precisely control the duration of water draining. A prolonged draining time can cause fuel to be drained, resulting in energy waste and environmental pollution. A short draining time, on the other hand, can result in excessive residual water, shortening drain intervals and increasing drain frequency, making it inconvenient. Dual-level sensors, on the other hand, include two probes, high and low, that generate high and low water level alarm signals, respectively. When the high-level probe detects water, it issues a drain alarm, prompting the operator to immediately begin draining. When the low-level probe detects water, it issues a stop signal, prompting the operator to cease draining. Compared to single-level sensors, dual-level sensors offer more effective draining control, but their disadvantage is the need for two signal output terminals, which in turn requires an additional output terminal in the connector, resulting in multiple output terminals and wiring harnesses. Summary of the Invention

[0004] The embodiment of the present application provides a multi-water level single-output sensor and a fuel filtration system, which not only solves the problem of drainage time, but also does not introduce extra output terminals and wiring harnesses, thus saving costs, having higher compatibility and a wider range of application scenarios.

[0005] This application is achieved through the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a multi-water level single-output sensor, comprising: a reference probe, a first probe, a second probe, a first water level voltage comparison circuit, a second water level voltage comparison circuit, and an ECU interface circuit; the length of the second probe is greater than that of the first probe.

[0007] The reference probe and the first probe are respectively connected to the first input terminal and the second input terminal of the first water level voltage comparison circuit, the output terminal of the first water level voltage comparison circuit is connected to the output terminal of the ECU interface circuit, and the output terminal of the first water level voltage comparison circuit is connected to the output terminal of the multi-water level single output sensor.

[0008] The reference probe and the second probe are respectively connected to the first input terminal and the second input terminal of the second water level voltage comparison circuit, the output terminal of the second water level voltage comparison circuit is connected to the output terminal of the ECU interface circuit, and the output terminal of the second water level voltage comparison circuit is connected to the output terminal of the multi-water level single output sensor.

[0009] When the multiple water level single output sensor is used to detect the water level, the multiple water level single output sensor determines the water level according to an output voltage of an output terminal of the multiple water level single output sensor.

[0010] In combination with the first aspect, in some possible implementations, the first water level voltage comparison circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a first operational amplifier.

[0011] The first end of the first resistor is connected to the power supply VCC, the second end of the first resistor is connected to the second input end of the first water level voltage comparison circuit, the second end of the first resistor is also connected to the first end of the first capacitor, the second end of the first capacitor is connected to the first input end of the first water level voltage comparison circuit, the second end of the first capacitor is grounded, and the second end of the first resistor is also connected to the non-inverting input end of the first operational amplifier.

[0012] The first end of the second resistor is connected to the power supply VCC, the second end of the second resistor is connected to the inverting input terminal of the first operational amplifier, the second end of the second resistor is also connected to the first end of the third resistor, and the second end of the third resistor is grounded.

[0013] A power input terminal of the first operational amplifier is connected to a power source VCC, and a ground terminal of the first operational amplifier is grounded.

[0014] The output end of the first operational amplifier is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the output end of the first water level voltage comparison circuit, the first end of the second capacitor is connected to the output end of the first water level voltage comparison circuit, and the second end of the second capacitor is grounded.

[0015] In combination with the first aspect, in some possible implementations, the second water level voltage comparison circuit includes: a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a third capacitor, a fourth capacitor, and a second operational amplifier.

[0016] The first end of the fifth resistor is connected to the power supply VCC, the second end of the fifth resistor is connected to the second input end of the second water level voltage comparison circuit, the second end of the fifth resistor is also connected to the first end of the third capacitor, the second end of the third capacitor is connected to the first input end of the second water level voltage comparison circuit, the second end of the third capacitor is grounded, and the second end of the fifth resistor is also connected to the non-inverting input end of the second operational amplifier.

[0017] The first end of the sixth resistor is connected to the power supply VCC, the second end of the sixth resistor is connected to the inverting input terminal of the second operational amplifier, the second end of the sixth resistor is also connected to the first end of the seventh resistor, and the second end of the seventh resistor is grounded.

[0018] A power input terminal of the second operational amplifier is connected to the power supply VCC, and a ground terminal of the second operational amplifier is grounded.

[0019] The output end of the second operational amplifier is connected to the first end of the eighth resistor, the second end of the eighth resistor is connected to the output end of the second water level voltage comparison circuit, the first end of the fourth capacitor is connected to the output end of the second water level voltage comparison circuit, and the second end of the fourth capacitor is grounded.

[0020] In combination with the first aspect, in some possible implementations, the ECU interface circuit includes: a ninth resistor and a tenth resistor.

[0021] The first end of the ninth resistor is connected to the first regulated power supply, the second end of the ninth resistor is connected to the output end of the ECU interface circuit, the second end of the ninth resistor is also connected to the first end of the tenth resistor, and the second end of the tenth resistor is grounded.

[0022] In combination with the first aspect, in some possible implementations, the multi-water-level single-output sensor further includes: a voltage stabilizing circuit.

[0023] The voltage stabilizing circuit includes: an eleventh resistor, a seventh capacitor, an eighth capacitor, a first diode and a second diode.

[0024] The anode of the first diode is connected to the second regulated power supply, the cathode of the first diode is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is connected to the power supply VCC, the second end of the eleventh resistor is also connected to the cathode of the second diode, and the anode of the second diode is grounded.

[0025] A first end of the seventh capacitor is connected to the second regulated power supply, and a second end of the seventh capacitor is grounded.

[0026] A first end of the eighth capacitor is connected to the power supply VCC, and a second end of the eighth capacitor is grounded.

[0027] With reference to the first aspect, in some possible implementations, the second diode is a Zener diode.

[0028] In combination with the first aspect, in some possible implementations, the multi-water-level single-output sensor further includes a third probe and a third water-level voltage comparison circuit; and the length of the third probe is greater than that of the second probe.

[0029] The reference probe and the third probe are respectively connected to the first input terminal and the second input terminal of the third water level voltage comparison circuit, the output terminal of the third water level voltage comparison circuit is connected to the output terminal of the ECU interface circuit, and the output terminal of the third water level voltage comparison circuit is connected to the output terminal of the multi-water level single output sensor.

[0030] In combination with the first aspect, in some possible implementations, the third water level voltage comparison circuit includes: a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a fifth capacitor, a sixth capacitor, and a third operational amplifier.

[0031] The first end of the twelfth resistor is connected to the power supply VCC, the second end of the twelfth resistor is connected to the second input end of the third water level voltage comparison circuit, the second end of the twelfth resistor is also connected to the first end of the fifth capacitor, the second end of the fifth capacitor is connected to the first input end of the third water level voltage comparison circuit, the second end of the fifth capacitor is grounded, and the second end of the twelfth resistor is also connected to the non-inverting input end of the third operational amplifier.

[0032] A first end of the thirteenth resistor is connected to the power supply VCC, a second end of the thirteenth resistor is connected to the inverting input terminal of the third operational amplifier, a second end of the thirteenth resistor is also connected to the first end of the fourteenth resistor, and a second end of the fourteenth resistor is grounded.

[0033] A power input terminal of the third operational amplifier is connected to the power supply VCC, and a ground terminal of the third operational amplifier is grounded.

[0034] The output end of the third operational amplifier is connected to the first end of the fifteenth resistor, the second end of the fifteenth resistor is connected to the output end of the third water level voltage comparison circuit, the first end of the sixth capacitor is connected to the output end of the third water level voltage comparison circuit, and the second end of the sixth capacitor is grounded.

[0035] In combination with the first aspect, in some possible implementations, the first operational amplifier in the first water level voltage comparison circuit and the second operational amplifier in the second water level voltage comparison circuit have the same power supply interface, and the first operational amplifier in the first water level voltage comparison circuit and the second operational amplifier in the second water level voltage comparison circuit have the same ground interface.

[0036] In a second aspect, an embodiment of the present application provides a fuel filtration system, comprising: a multi-water-level single-output sensor as described in any one of the first aspects.

[0037] It can be understood that the beneficial effects of the second aspect mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0038] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0039] This application first connects the reference probe, the first probe, and the second probe to the corresponding water level voltage comparison circuit, and then connects the output ends of the first water level voltage comparison circuit, the second water level voltage comparison circuit, and the ECU interface circuit together to output voltage signals of different sizes. When the output end is connected to a light bulb, the corresponding water level detection result can be directly obtained according to the brightness of the light bulb. Finally, it is determined whether the drainage time has been reached based on the brightness of the light bulb. Compared with the traditional method of connecting multiple light bulbs to indicate the water level detection result and controlling the drainage time, this method solves the drainage time problem without introducing additional output terminals and wiring harnesses, saving costs and having higher compatibility.

[0040] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. 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 any creative work.

[0042] Figure 1 This is a schematic structural diagram of a multi-water-level single-output sensor provided in one embodiment of the present application;

[0043] Figure 2 This is a schematic diagram of the lengths of multiple probes provided in one embodiment of the present application;

[0044] Figure 3 This is a circuit diagram of a multi-water-level single-output sensor provided in one embodiment of the present application;

[0045] Figure 4 is a circuit diagram of a voltage stabilizing circuit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0046] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0047] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0048] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0049] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0050] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0051] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0052] The embodiment of the present application provides a multi-water level single output sensor, Figure 1 This is a schematic diagram of the structure of a multi-water level single output sensor provided in one embodiment of the present application, referring to Figure 1 , the details of the multi-water level single output sensor are as follows:

[0053] The multi-water-level single-output sensor includes: a reference probe 101 , a first probe 102 , a second probe 103 , a first water-level voltage comparison circuit 104 , a second water-level voltage comparison circuit 105 and an ECU interface circuit 106 .

[0054] The reference probe 101 and the first probe 102 are respectively connected to the first input terminal and the second input terminal of the first water level voltage comparison circuit 104, the output terminal of the first water level voltage comparison circuit 104 is connected to the output terminal of the ECU interface circuit 106, and the output terminal of the first water level voltage comparison circuit 104 is connected to the output terminal of the multi-water level single output sensor.

[0055] The reference probe 101 and the second probe 103 are respectively connected to the first input terminal and the second input terminal of the second water level voltage comparison circuit 105, the output terminal of the second water level voltage comparison circuit 105 is connected to the output terminal of the ECU interface circuit 106, and the output terminal of the second water level voltage comparison circuit 105 is connected to the output terminal of the multi-water level single output sensor.

[0056] When the multiple water level single output sensor is used to detect the water level, the multiple water level single output sensor determines the water level according to an output voltage of an output terminal of the multiple water level single output sensor.

[0057] For example, the reference probe 101 is Figure 2 The probe 1 in the embodiment of the present invention is the first probe 102. Figure 2 The probe 2 in the second probe 103 is Figure 2 The length of the reference probe is the same as that of the first probe, and the length of the second probe is greater than that of the first probe. In actual use, the length of the reference probe may also be less than that of the first probe.

[0058] For example, Figure 3 As shown, the first water level voltage comparison circuit 104 includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2 and a first operational amplifier U1.

[0059] The first end of the first resistor R1 is connected to the power supply VCC, the second end of the first resistor R1 is connected to the second input end of the first water level voltage comparison circuit 104, the second end of the first resistor R1 is also connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the first input end of the first water level voltage comparison circuit 104, the second end of the first capacitor C1 is grounded, and the second end of the first resistor R1 is also connected to the non-inverting input end of the first operational amplifier U1.

[0060] A first end of the second resistor R2 is connected to the power supply VCC, a second end of the second resistor R2 is connected to the inverting input terminal of the first operational amplifier U1, a second end of the second resistor R2 is also connected to a first end of the third resistor R3, and a second end of the third resistor R3 is grounded.

[0061] A power input terminal of the first operational amplifier U1 is connected to the power supply VCC, and a ground terminal of the first operational amplifier U1 is grounded.

[0062] The output end of the first operational amplifier U1 is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the output end of the first water level voltage comparison circuit 104, the first end of the second capacitor C2 is connected to the output end of the first water level voltage comparison circuit 104, and the second end of the second capacitor C2 is grounded.

[0063] For example, Figure 3 As shown, the second water level voltage comparison circuit 105 includes: a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a third capacitor C3, a fourth capacitor C4 and a second operational amplifier U2.

[0064] The first end of the fifth resistor R5 is connected to the power supply VCC, the second end of the fifth resistor R5 is connected to the second input end of the second water level voltage comparison circuit 105, the second end of the fifth resistor R5 is also connected to the first end of the third capacitor C3, the second end of the third capacitor C3 is connected to the first input end of the second water level voltage comparison circuit 105, the second end of the third capacitor C3 is grounded, and the second end of the fifth resistor R5 is also connected to the non-inverting input end of the second operational amplifier U2.

[0065] The first end of the sixth resistor R6 is connected to the power supply VCC, the second end of the sixth resistor R6 is connected to the inverting input terminal of the second operational amplifier U2, the second end of the sixth resistor R6 is also connected to the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is grounded.

[0066] A power input terminal of the second operational amplifier U2 is connected to the power supply VCC, and a ground terminal of the second operational amplifier U2 is grounded.

[0067] The output end of the second operational amplifier U2 is connected to the first end of the eighth resistor R8, the second end of the eighth resistor R8 is connected to the output end of the second water level voltage comparison circuit 105, the first end of the fourth capacitor C4 is connected to the output end of the second water level voltage comparison circuit 105, and the second end of the fourth capacitor C4 is grounded.

[0068] For example, Figure 3 As shown, the ECU interface circuit 106 includes a ninth resistor R9 and a tenth resistor R10.

[0069] The first end of the ninth resistor R9 is connected to the first regulated power supply, the second end of the ninth resistor R9 is connected to the output end of the ECU interface circuit 106, the second end of the ninth resistor R9 is also connected to the first end of the tenth resistor R10, and the second end of the tenth resistor R10 is grounded.

[0070] For example, Figure 4 As shown, the multi-water level single-output sensor also includes: a voltage stabilizing circuit.

[0071] The voltage stabilizing circuit includes: an eleventh resistor R11, a seventh capacitor C7, an eighth capacitor CC8, a first diode D1 and a second diode D2.

[0072] The anode of the first diode D1 is connected to the second regulated power supply, the cathode of the first diode D1 is connected to the first end of the eleventh resistor R11, the second end of the eleventh resistor R11 is connected to the power supply VCC, the second end of the eleventh resistor R11 is also connected to the cathode of the second diode D2, and the anode of the second diode D2 is grounded.

[0073] A first end of the seventh capacitor C7 is connected to the second regulated power supply, and a second end of the seventh capacitor C7 is grounded.

[0074] A first end of the eighth capacitor C8 is connected to the power supply VCC, and a second end of the eighth capacitor C8 is grounded.

[0075] For example, Figure 3 and Figure 4 As shown, the voltage values ​​of the first regulated power supply and the second regulated power supply are the same. In actual use, the first regulated power supply and the second regulated power supply can be considered to be the same regulated power supply. In addition, the voltage values ​​of the first regulated power supply and the second regulated power supply can be 12V and 24V in addition to 5V.

[0076] Exemplarily, the second diode D2 may be a Zener diode.

[0077] Exemplarily, the eleventh resistor R11 is used to provide a VCC power supply signal, the first diode D1 is used for reverse connection protection, the second diode D2 protects the circuit by limiting the input power supply voltage, the eleventh resistor R11 is used for current limiting, and the seventh capacitor C7 and the eighth capacitor CC8 are used to filter out interference signals.

[0078] Exemplarily, the multi-water-level single-output sensor further includes a third probe 107 and a third water-level voltage comparison circuit 108 .

[0079] The reference probe 101 and the third probe 107 are respectively connected to the first input terminal and the second input terminal of the third water level voltage comparison circuit 108, the output terminal of the third water level voltage comparison circuit 108 is connected to the output terminal of the ECU interface circuit 106, and the output terminal of the third water level voltage comparison circuit 108 is connected to the output terminal of the multi-water level single output sensor.

[0080] For example, the third probe 101 is Figure 2 In the probe 4 , the length of the third probe 107 is greater than the length of the second probe 103 .

[0081] For example, Figure 3 As shown, the third water level voltage comparison circuit 108 includes: a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a fifth capacitor C5, a sixth capacitor C6 and a third operational amplifier U3.

[0082] A first end of the twelfth resistor R12 is connected to the power supply VCC, a second end of the twelfth resistor R12 is connected to the second input end of the third water level voltage comparison circuit 108, a second end of the twelfth resistor R12 is also connected to the first end of the fifth capacitor C5, a second end of the fifth capacitor C5 is connected to the first input end of the third water level voltage comparison circuit 108, a second end of the fifth capacitor C5 is grounded, and a second end of the twelfth resistor R12 is also connected to the non-inverting input end of the third operational amplifier U3.

[0083] A first end of the thirteenth resistor R13 is connected to the power supply VCC, a second end of the thirteenth resistor R13 is connected to the inverting input terminal of the third operational amplifier U3, a second end of the thirteenth resistor R13 is also connected to a first end of the fourteenth resistor R14, and a second end of the fourteenth resistor R14 is grounded.

[0084] A power input terminal of the third operational amplifier U3 is connected to the power supply VCC, and a ground terminal of the third operational amplifier U3 is grounded.

[0085] The output end of the third operational amplifier U3 is connected to the first end of the fifteenth resistor R15, the second end of the fifteenth resistor R15 is connected to the output end of the third water level voltage comparison circuit 108, the first end of the sixth capacitor C6 is connected to the output end of the third water level voltage comparison circuit 108, and the second end of the sixth capacitor C6 is grounded.

[0086] Exemplarily, the first operational amplifier U1 and the second operational amplifier U2 have the same power supply interface, and the first operational amplifier U1 and the second operational amplifier U2 have the same ground interface.

[0087] For example, in actual production life, the first operational amplifier U1 and the second operational amplifier U2 can be two modules in an operational amplifier device, and the two modules share a set of ground wires and power supply wires. Figure 3 In the figure, the power input terminal of the second operational amplifier U2 is connected to the power supply VCC, and the ground terminal of the second operational amplifier U2 is grounded, which is not shown.

[0088] The multi-water-level single-output sensor first connects the reference probe, the first probe, and the second probe to the corresponding water-level voltage comparison circuit. The output terminals of the first and second water-level voltage comparison circuits and the ECU interface circuit are then connected together to output voltage signals of varying magnitudes. When the output terminal is connected to a light bulb, the corresponding water-level detection result can be directly obtained based on the bulb's brightness. Finally, the bulb's brightness is used to determine whether the drainage time has been reached. Compared to the traditional method of connecting multiple light bulbs to indicate water-level detection results and control drainage time, this method solves the drainage time issue without introducing additional output terminals and wiring harnesses, saving costs and offering greater compatibility.

[0089] For ease of understanding of this solution, the following are some examples:

[0090] In this article, we set R4 = 28KΩ, R8 = 14KΩ, and R15 = 4.7KΩ. The ECU-side integrated resistors R9 = 11.8KΩ and R10 = 11.5KΩ. The entire sensor operation can be described as follows:

[0091] (1) When probes 1, 2, 3, and 4 are not exposed to water, that is, when the water level is below the low water level probe position, the voltage at the non-inverting input terminal of the first operational amplifier U1 is higher than the voltage at the inverting input terminal of the first operational amplifier U1, and the first operational amplifier U1 outputs a high level. Similarly, the second operational amplifier U2 and the third operational amplifier U3 both output a high level. Figure 3 The 5V voltage pulled up by the ECU interface circuit passes directly through R9 and R10 to ground. R10 and R9 divide the voltage, and the output terminal Output is 4V.

[0092] (2) When probes 1 and 2 encounter water, but probes 3 and 4 do not encounter water, that is, when the water level is above the low water level probe and below the middle and high water level probes, the voltage at the inverting input terminal of the first operational amplifier U1 is higher than the voltage at the non-inverting input terminal of U1, and the first operational amplifier U1 outputs a low level; the voltage at the non-inverting input terminal of the second operational amplifier U2 is higher than the voltage at the inverting input terminal of U2, and the second operational amplifier U2 outputs a high level. Similarly, the third operational amplifier U3 also outputs a high level. Figure 3 The 5V voltage pulled up by the ECU interface circuit passes directly through R9 and R10 to ground. R10 and R9 divide the voltage, and the output terminal Output is 3V.

[0093] (3) When probes 1, 2, and 3 encounter water, but probe 4 does not encounter water, that is, when the water level is at the low and middle water level probe positions and below the high water level probe, the voltages at the non-inverting input terminals of the first operational amplifier U1 and the second operational amplifier U2 are both lower than the voltages at the inverting input terminals, and the first operational amplifier U1 and the second operational amplifier U2 both output a low level; the voltage at the non-inverting input terminal of the third operational amplifier U3 is higher than the voltage at the inverting input terminal of the third operational amplifier U3, and the third operational amplifier U3 outputs a high level; Figure 3 The 5V voltage pulled up by the ECU interface circuit passes directly through R9 and R10 to ground. R10 and R9 divide the voltage, and the output terminal Output is 2V.

[0094] (4) When probes 1, 2, 3, and 4 encounter water, that is, when the water level is above the low, medium, and high water level probe positions, the voltages at the inverting input terminals of the first operational amplifier U1, the second operational amplifier U2, and the third operational amplifier U3 are all higher than the voltages at the non-inverting input terminals, and the first operational amplifier U1, the second operational amplifier U2, and the third operational amplifier U3 all output low levels; Figure 3 The 5V voltage pulled up by the ECU interface circuit passes directly through R9 and R10 to ground. R10 and R9 divide the voltage, and the output terminal Output is 1V.

[0095] The above description can be summarized as shown in Table 1.

[0096] Table 1

[0097] Probe 1, 2, 3 water contact state Output terminal (V) Probes 1, 2, 3, and 4 are not exposed to water. 4 Probes 1 and 2 are exposed to water, but probes 3 and 4 are not exposed to water 3 Probes 1, 2, and 3 are exposed to water, but probe 4 is not. 2 Probes 1, 2, 3, and 4 come into contact with water 1

[0098] The above is the signal transmission process when the sensor is working, which is summarized in Table 1. It can be clearly seen that compared with ordinary sensors, the three-water-level sensor described in this example can output three water-level status signals using one output port, thus avoiding the limitations of traditional water-level sensors.

[0099] An embodiment of the present application further provides a fuel filtration system, comprising: the multi-water-level single-output sensor described in any one of the above items.

[0100] The fuel filtration system plays a vital role, removing impurities and water from the fuel to ensure fuel purity and protect the engine from potential damage. An efficient fuel filtration system can extend engine life, improve fuel efficiency, and reduce engine failures caused by fuel quality issues.

[0101] For example, the fuel filtration system is provided with a multi-water level single-output sensor in the scheme, so that the water level can be efficiently guaranteed, the service life of the engine can be extended, the fuel efficiency can be improved, and the engine failure caused by fuel quality problems can be reduced, thereby ultimately saving costs.

[0102] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

Claims

1. A multi-water level single output sensor, characterized in that: include: A reference probe, a first probe, a second probe, a first water level voltage comparison circuit, a second water level voltage comparison circuit and an ECU interface circuit; The length of the second probe is greater than the length of the first probe; The reference probe and the first probe are connected to the first input terminal and the second input terminal of the first water level voltage comparison circuit respectively, the output terminal of the first water level voltage comparison circuit is connected to the output terminal of the ECU interface circuit, and the output terminal of the first water level voltage comparison circuit is connected to the output terminal of the multi-water level single output sensor; The reference probe and the second probe are respectively connected to the first input terminal and the second input terminal of the second water level voltage comparison circuit, the output terminal of the second water level voltage comparison circuit is connected to the output terminal of the ECU interface circuit, and the output terminal of the second water level voltage comparison circuit is connected to the output terminal of the multi-water level single output sensor; When the multiple water level single output sensor is used to detect the water level, the multiple water level single output sensor determines the water level according to the output voltage of the output terminal of the multiple water level single output sensor.

2. The multi-water level single output sensor according to claim 1, characterized in that: The first water level voltage comparison circuit comprises: a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor and a first operational amplifier; The first end of the first resistor is connected to the power supply VCC, the second end of the first resistor is connected to the second input end of the first water level voltage comparison circuit, the second end of the first resistor is also connected to the first end of the first capacitor, the second end of the first capacitor is connected to the first input end of the first water level voltage comparison circuit, the second end of the first capacitor is grounded, and the second end of the first resistor is also connected to the non-inverting input end of the first operational amplifier; The first end of the second resistor is connected to the power supply VCC, the second end of the second resistor is connected to the inverting input terminal of the first operational amplifier, the second end of the second resistor is also connected to the first end of the third resistor, and the second end of the third resistor is grounded; The power input terminal of the first operational amplifier is connected to the power supply VCC, and the ground terminal of the first operational amplifier is grounded; The output end of the first operational amplifier is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the output end of the first water level voltage comparison circuit, the first end of the second capacitor is connected to the output end of the first water level voltage comparison circuit, and the second end of the second capacitor is grounded.

3. The multi-water level single output sensor according to claim 1, characterized in that: The second water level voltage comparison circuit includes: a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a third capacitor, a fourth capacitor and a second operational amplifier; The first end of the fifth resistor is connected to the power supply VCC, the second end of the fifth resistor is connected to the second input end of the second water level voltage comparison circuit, the second end of the fifth resistor is also connected to the first end of the third capacitor, the second end of the third capacitor is connected to the first input end of the second water level voltage comparison circuit, the second end of the third capacitor is grounded, and the second end of the fifth resistor is also connected to the non-inverting input end of the second operational amplifier; The first end of the sixth resistor is connected to the power supply VCC, the second end of the sixth resistor is connected to the inverting input end of the second operational amplifier, the second end of the sixth resistor is also connected to the first end of the seventh resistor, and the second end of the seventh resistor is grounded; The power input terminal of the second operational amplifier is connected to the power supply VCC, and the ground terminal of the second operational amplifier is grounded; The output end of the second operational amplifier is connected to the first end of the eighth resistor, the second end of the eighth resistor is connected to the output end of the second water level voltage comparison circuit, the first end of the fourth capacitor is connected to the output end of the second water level voltage comparison circuit, and the second end of the fourth capacitor is grounded.

4. The multiple water level single output sensor according to claim 1, characterized in that: The ECU interface circuit comprises: a ninth resistor and a tenth resistor; The first end of the ninth resistor is connected to the first regulated power supply, the second end of the ninth resistor is connected to the output end of the ECU interface circuit, the second end of the ninth resistor is also connected to the first end of the tenth resistor, and the second end of the tenth resistor is grounded.

5. The multiple water level single output sensor according to claim 4, characterized in that: The multi-water-level single-output sensor further includes: a voltage stabilizing circuit; The voltage stabilizing circuit comprises: an eleventh resistor, a seventh capacitor, an eighth capacitor, a first diode and a second diode; The anode of the first diode is connected to the second regulated power supply, the cathode of the first diode is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is connected to the power supply VCC, the second end of the eleventh resistor is also connected to the cathode of the second diode, and the anode of the second diode is grounded; The first end of the seventh capacitor is connected to the second regulated power supply, and the second end of the seventh capacitor is grounded; A first end of the eighth capacitor is connected to the power supply VCC, and a second end of the eighth capacitor is grounded.

6. The multiple water level single output sensor according to claim 1, characterized in that: The second diode is a voltage regulator diode.

7. The multiple water level single output sensor according to claim 1, characterized in that: The multi-water-level single-output sensor further includes a third probe and a third water-level voltage comparison circuit; the length of the third probe is greater than the length of the second probe; The reference probe and the third probe are respectively connected to the first input terminal and the second input terminal of the third water level voltage comparison circuit, the output terminal of the third water level voltage comparison circuit is connected to the output terminal of the ECU interface circuit, and the output terminal of the third water level voltage comparison circuit is connected to the output terminal of the multi-water level single output sensor.

8. The multiple water level single output sensor according to claim 7, characterized in that: The third water level voltage comparison circuit comprises: a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a fifth capacitor, a sixth capacitor and a third operational amplifier; The first end of the twelfth resistor is connected to the power supply VCC, the second end of the twelfth resistor is connected to the second input end of the third water level voltage comparison circuit, the second end of the twelfth resistor is also connected to the first end of the fifth capacitor, the second end of the fifth capacitor is connected to the first input end of the third water level voltage comparison circuit, the second end of the fifth capacitor is grounded, and the second end of the twelfth resistor is also connected to the non-inverting input end of the third operational amplifier; The first end of the thirteenth resistor is connected to the power supply VCC, the second end of the thirteenth resistor is connected to the inverting input terminal of the third operational amplifier, the second end of the thirteenth resistor is also connected to the first end of the fourteenth resistor, and the second end of the fourteenth resistor is grounded; The power input terminal of the third operational amplifier is connected to the power supply VCC, and the ground terminal of the third operational amplifier is grounded; The output end of the third operational amplifier is connected to the first end of the fifteenth resistor, the second end of the fifteenth resistor is connected to the output end of the third water level voltage comparison circuit, the first end of the sixth capacitor is connected to the output end of the third water level voltage comparison circuit, and the second end of the sixth capacitor is grounded.

9. The multiple water level single output sensor according to claim 1, characterized in that: The first operational amplifier in the first water level voltage comparison circuit and the second operational amplifier in the second water level voltage comparison circuit have the same power supply interface, and the first operational amplifier in the first water level voltage comparison circuit and the second operational amplifier in the second water level voltage comparison circuit have the same grounding interface.

10. A fuel filter system, characterized in that: include: A multiple water level single output sensor as claimed in any one of claims 1 to 9.

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