Multi-level single-output sensor and fuel filter system

Abstract

This application relates to the field of automotive electronics technology and provides a multi-level single-output sensor and a fuel filter system. The sensor includes: 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-level single-output sensor is used to detect the water level, it determines the water level based on the output voltage of its output terminal. This application solves the problem of long drainage time and avoids introducing additional output terminals and wiring harnesses.

Description

Technical Field

[0001] This application belongs to the field of automotive electronics technology, and in particular relates to a multi-level single-output sensor and a fuel filter system. Background Technology

[0002] The fuel filter system in diesel vehicles is responsible not only for removing impurities from the fuel but also for removing water. This is because diesel fuel is used not only as fuel in the engine but also for lubricating critical components such as the fuel pump and injectors. If the diesel fuel has too much water content, it will cause these components to malfunction and trigger alarms. Therefore, the water separator is an indispensable component of the fuel filter system. The water separator is usually equipped with a water level sensor (WIF) installed at the bottom of the fuel filter (coarse filter). Due to the difference in density between water and oil, oil floats on the surface. When the water level accumulates to a certain level and touches the probe of the water level sensor, the sensor's potential changes, and the corresponding electrical signal is transmitted to the ECU. The ECU then controls the malfunction warning light to illuminate, reminding the driver to drain the fuel.

[0003] Currently, water level sensors on the market are divided into two types: single-level and dual-level. Single-level sensors can only detect a single water level, and their disadvantage is that it's difficult to accurately control the water discharge time. Excessive discharge time may result in fuel being discharged along with the water, causing energy waste and environmental pollution; while insufficient discharge time may lead to excessive remaining water, thus shortening the discharge interval and increasing the discharge frequency, causing inconvenience. Dual-level sensors include two probes, one for high water level and one for low water level, which can emit alarm signals for high and low water levels respectively. When the high-level probe detects water, it emits a discharge alarm signal, and the driver immediately begins discharging water; when the low-level probe detects water, it emits a stop-discharge signal, and the driver immediately stops discharging water. Compared to single-level sensors, dual-level sensors can control the water discharge time more effectively, but their disadvantage is the introduction of two signal output terminals. Consequently, the connector also needs an additional output, introducing multiple sets of output terminals and wiring harnesses. Summary of the Invention

[0004] This application provides a multi-level single-output sensor and fuel filter system, which solves the problem of drainage time, avoids the introduction of additional output terminals and wiring harnesses, saves costs, has higher compatibility, and is applicable to a wider range of scenarios.

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

[0006] In a first aspect, embodiments of this application provide a multi-level single-output sensor, including: a reference probe, a first probe, a second probe, a first level voltage comparison circuit, a second level voltage comparison circuit, and an ECU interface circuit; the length of the second probe is greater than the length 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. 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. 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 a multi-level single-output sensor is used to detect water level, the multi-level single-output sensor determines the water level based on the output voltage at the output terminal of the multi-level single-output sensor.

[0010] In conjunction 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 terminal of the first water level voltage comparator 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 terminal of the first water level voltage comparator circuit. The second end of the first capacitor is grounded. The second end of the first resistor is also connected to the non-inverting input terminal 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 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] 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.

[0014] The output 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 of the first water level voltage comparator circuit, the first end of the second capacitor is connected to the output of the first water level voltage comparator circuit, and the second end of the second capacitor is grounded.

[0015] In conjunction 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 terminal of the second water level voltage comparator 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 terminal of the second water level voltage comparator circuit. The second end of the third capacitor is grounded. The second end of the fifth resistor is also connected to the non-inverting input terminal 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 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] 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.

[0019] The output 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 of the second water level voltage comparator circuit, the first end of the fourth capacitor is connected to the output of the second water level voltage comparator circuit, and the second end of the fourth capacitor is grounded.

[0020] In conjunction 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 conjunction with the first aspect, among some possible implementations, the multi-level single-output sensor also includes: a voltage stabilizing circuit.

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

[0024] The positive terminal of the first diode is connected to the second regulated power supply, the negative terminal 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 negative terminal of the second diode, and the positive terminal of the second diode is grounded.

[0025] The first terminal of the seventh capacitor is connected to the second regulated power supply, and the second terminal of the seventh capacitor is grounded.

[0026] The first terminal of the eighth capacitor is connected to the power supply VCC, and the second terminal of the eighth capacitor is grounded.

[0027] In conjunction with the first aspect, in some possible implementations, the second diode is a Zener diode.

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

[0029] The reference probe and the third probe are connected to the first and second input terminals of the third water level voltage comparison circuit, respectively. The output terminal of the third water level voltage comparison circuit is connected to the output terminal of the ECU interface circuit. 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 conjunction 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 terminal of the third water level voltage comparator 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 terminal of the third water level voltage comparator circuit. The second end of the fifth capacitor is grounded. The second end of the twelfth resistor is also connected to the non-inverting input terminal of the third operational amplifier.

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

[0033] 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.

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

[0035] In conjunction 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 grounding interface.

[0036] Secondly, embodiments of this application provide a fuel filtration system, including: a multi-level single-output sensor as described in any of the first aspects.

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

[0038] The beneficial effects of the embodiments in this application compared with the prior art are:

[0039] This application first connects a reference probe, a first probe, and a second probe to corresponding water level voltage comparison circuits. Then, it connects the outputs of the first and second water level voltage comparison circuits to the ECU interface circuit to output voltage signals of different magnitudes. When the output is connected to a light bulb, the water level detection result can be directly obtained based on the bulb's brightness. Finally, the brightness of the bulb determines whether the required drainage time has been reached. Compared to the traditional method of connecting multiple bulbs to indicate water level detection results, this method of controlling drainage time solves the drainage time problem without introducing additional output terminals and wiring harnesses, saving costs and offering higher compatibility.

[0040] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this specification. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the structure of a multi-level single-output sensor provided in an embodiment of this application;

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

[0044] Figure 3 This is a circuit diagram of a multi-level single-output sensor provided in an embodiment of this application;

[0045] Figure 4 This is a circuit diagram of a voltage regulator circuit provided in one embodiment of this application. Detailed Implementation

[0046] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

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

[0048] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0049] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0050] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0051] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of 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 "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0052] This application provides a multi-level single-output sensor. Figure 1 This is a schematic diagram of the structure of a multi-level single-output sensor provided in an embodiment of this application, with reference to... Figure 1 The following is a detailed description of the multi-level single-output sensor:

[0053] The aforementioned multi-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] Reference probe 101 and 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. 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] Reference probe 101 and 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. 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 a multi-level single-output sensor is used to detect water level, the multi-level single-output sensor determines the water level based on the output voltage at the output terminal of the multi-level single-output sensor.

[0057] For example, reference probe 101 is Figure 2 Probe 1 in the middle, the first probe 102 is Figure 2 Probe 2 in the middle, the second probe 103 is Figure 2 Probe 3 is used in the test. The reference probe has the same length as the first probe, and the second probe has a longer length than the first probe. In practical applications, the reference probe can also have a shorter length than the first probe.

[0058] For example, such as 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 terminal 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 terminal of the first water level voltage comparison circuit 104. The second end of the first capacitor C1 is grounded. The second end of the first resistor R1 is also connected to the non-inverting input terminal of the first operational amplifier U1.

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

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

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

[0063] For example, such as 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 terminal of the second water level voltage comparator 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 terminal of the second water level voltage comparator circuit 105. The second end of the third capacitor C3 is grounded. The second end of the fifth resistor R5 is also connected to the non-inverting input terminal 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 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] 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.

[0067] The output 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 of the second water level voltage comparator circuit 105, the first end of the fourth capacitor C4 is connected to the output of the second water level voltage comparator circuit 105, and the second end of the fourth capacitor C4 is grounded.

[0068] For example, such as 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, such as Figure 4 As shown, the multi-level single-output sensor also includes a voltage stabilizing circuit.

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

[0072] The positive terminal of the first diode D1 is connected to the second regulated power supply, the negative terminal 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 negative terminal of the second diode D2, and the positive terminal of the second diode D2 is grounded.

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

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

[0075] For example, such as Figure 3 and Figure 4 As shown, the first and second regulated power supplies have the same voltage value, and in practical use, they can be considered as the same regulated power supply. In addition to 5V, the voltage values ​​of the first and second regulated power supplies can also be 12V and 24V.

[0076] For example, the second diode D2 can be a Zener diode.

[0077] For example, the eleventh resistor R11 is used to provide the VCC power signal, the first diode D1 is used for reverse connection protection, the second diode D2 is used to limit the input power voltage protection circuit, 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] For example, the multi-level single-output sensor also includes a third probe 107 and a third level voltage comparison circuit 108.

[0079] Reference probe 101 and 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. 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, such as 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] The first end of the twelfth resistor R12 is connected to the power supply VCC. The second end of the twelfth resistor R12 is connected to the second input terminal of the third water level voltage comparator circuit 108. The second end of the twelfth resistor R12 is also connected to the first end of the fifth capacitor C5. The second end of the fifth capacitor C5 is connected to the first input terminal of the third water level voltage comparator circuit 108. The second end of the fifth capacitor C5 is grounded. The second end of the twelfth resistor R12 is also connected to the non-inverting input terminal of the third operational amplifier U3.

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

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

[0085] The output 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 of the third water level voltage comparator circuit 108, the first end of the sixth capacitor C6 is connected to the output of the third water level voltage comparator circuit 108, and the second end of the sixth capacitor C6 is grounded.

[0086] For example, the first operational amplifier U1 and the second operational amplifier U2 have the same power supply interface and the same grounding interface.

[0087] For example, in real-world applications, the first operational amplifier U1 and the second operational amplifier U2 can be two modules within a single operational amplifier device. These two modules share a common set of ground and power supply lines. Figure 3 In the diagram, 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 and is not shown.

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

[0089] For example, to facilitate understanding of this solution, specific embodiments are as follows:

[0090] This paper sets R4 = 28KΩ, R8 = 14KΩ, R15 = 4.7KΩ, and the integrated resistors at the ECU terminal are R9 = 11.8KΩ and R10 = 11.5KΩ. The entire working process of the sensor can be described as follows:

[0091] (1) When probes 1, 2, 3, and 4 are not in contact with water, i.e., 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 is directly grounded through R9 and R10. R10 and R9 divide the voltage, and the output terminal Output is 4V.

[0092] (2) When probes 1 and 2 encounter water, and probes 3 and 4 do not encounter water, i.e., when the water level is above the low water level probe position and below the medium and high water level probe positions, 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 is directly grounded through R9 and R10. R10 and R9 divide the voltage, and the output terminal outputs 3V.

[0093] (3) When probes 1, 2, and 3 encounter water, and probe 4 does not encounter water, that is, when the water level is at the low and medium water level probe positions and below the high water level probe, the non-inverting input voltage of the first operational amplifier U1 and the second operational amplifier U2 is lower than the inverting input voltage, and both the first operational amplifier U1 and the second operational amplifier U2 output a low level; the non-inverting input voltage of the third operational amplifier U3 is higher than the inverting input voltage 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 is directly grounded through R9 and R10. 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 voltage at the inverting input terminals of the first operational amplifier U1, the second operational amplifier U2, and the third operational amplifier U3 is higher than the voltage 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 a low level. Figure 3 The 5V voltage pulled up by the ECU interface circuit is directly grounded through R9 and R10. 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] Probes 1, 2, and 3 in water-contaminated state Output (V) Probes 1, 2, 3, and 4 do not come into contact with water. 4 Probes 1 and 2 come into contact with water, while probes 3 and 4 do not. 3 Probes 1, 2, and 3 come into contact with water, while probe 4 does not. 2 Probes 1, 2, 3, and 4 come into contact with water. 1

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

[0099] This application also provides a fuel filtration system, including: the multi-level single-output sensor described in any of the above claims.

[0100] The fuel filter system plays a crucial role, primarily responsible for removing impurities and moisture from the fuel, ensuring its purity and protecting the engine from potential damage. An efficient fuel filter system can extend engine life, improve fuel efficiency, and reduce engine malfunctions caused by fuel quality issues.

[0101] For example, the fuel filter system is equipped with the multi-level single-output sensor described in the solution, which can efficiently ensure the water level, extend the engine's service life, improve fuel efficiency, and reduce engine failures caused by fuel quality problems, ultimately saving costs.

[0102] It should be understood that the sequence number of each step in the above embodiments does not imply 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 multiple water level single output sensor, characterized by, The application relates to a multi-water-level single-output sensor. The reference probe, the first probe, the second probe, a first water level voltage comparison circuit, a second water level voltage comparison circuit and an ECU interface circuit are included. The length of the second probe is greater than that of the first probe. The reference probe and the first probe are connected with a first input end and a second input end of the first water level voltage comparison circuit respectively, an output end of the first water level voltage comparison circuit is connected with an output end of the ECU interface circuit, and the output end of the first water level voltage comparison circuit is connected with an output end of the multi-water-level single-output sensor. The reference probe and the second probe are connected with a first input end and a second input end of the second water level voltage comparison circuit respectively, an output end of the second water level voltage comparison circuit is connected with an output end of the ECU interface circuit, and the output end of the second water level voltage comparison circuit is connected with an output end of the multi-water-level single-output sensor. When the multi-water-level single-output sensor is used for detecting a water level, the multi-water-level single-output sensor determines the water level according to an output voltage of the output end of the multi-water-level single-output sensor. 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. A first end of the first resistor is connected with a power supply VCC, a second end of the first resistor is connected with the second input end of the first water level voltage comparison circuit, the second end of the first resistor is also connected with a first end of the first capacitor, a second end of the first capacitor is connected with 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 with a non-inverting input end of the first operational amplifier. A first end of the second resistor is connected with the power supply VCC, a second end of the second resistor is connected with an inverting input end of the first operational amplifier, and the second end of the second resistor is also connected with a first end of the third resistor. A power supply input end of the first operational amplifier is connected with the power supply VCC, and a grounding end of the first operational amplifier is grounded. An output end of the first operational amplifier is connected with a first end of the fourth resistor, a second end of the fourth resistor is connected with an output end of the first water level voltage comparison circuit, a first end of the second capacitor is connected with the output end of the first water level voltage comparison circuit, and a second end of the second capacitor is grounded. The second water level voltage comparison circuit comprises a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a third capacitor, a fourth capacitor and a second operational amplifier. A first end of the fifth resistor is connected with the power supply VCC, a second end of the fifth resistor is connected with a second input end of the second water level voltage comparison circuit, the second end of the fifth resistor is also connected with a first end of the third capacitor, a second end of the third capacitor is connected with a 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 with a non-inverting input end of the second operational amplifier. A first end of the sixth resistor is connected with the power supply VCC, a second end of the sixth resistor is connected with the inverting input end of the second operational amplifier, and the second end of the sixth resistor is also connected with a first end of the seventh resistor, and a second end of the seventh resistor is grounded; A power supply input end of the second operational amplifier is connected with the power supply VCC, and a grounding end of the second operational amplifier is grounded; An output end of the second operational amplifier is connected with a first end of the eighth resistor, a second end of the eighth resistor is connected with an output end of the second water level voltage comparison circuit, a first end of the fourth capacitor is connected with the output end of the second water level voltage comparison circuit, and a second end of the fourth capacitor is grounded; The ECU interface circuit comprises a ninth resistor and a tenth resistor; A first end of the ninth resistor is connected with a first voltage stabilizer, a second end of the ninth resistor is connected with an output end of the ECU interface circuit, and the second end of the ninth resistor is also connected with a first end of the tenth resistor, and a second end of the tenth resistor is grounded.

2. The multiple water level single output sensor of claim 1, wherein, The multi-water level single-output sensor further comprises 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; A positive electrode of the first diode is connected with a second voltage stabilizer, a negative electrode of the first diode is connected with a first end of the eleventh resistor, a second end of the eleventh resistor is connected with the power supply VCC, the second end of the eleventh resistor is also connected with a negative electrode of the second diode, and a positive electrode of the second diode is grounded; A first end of the seventh capacitor is connected with the second voltage stabilizer, and a second end of the seventh capacitor is grounded; A first end of the eighth capacitor is connected with the power supply VCC, and a second end of the eighth capacitor is grounded.

3. The multiple water level single output sensor of claim 1, wherein, The second diode is a voltage stabilizing diode.

4. The multiple water level single output sensor of claim 1, wherein, The multi-water level single-output sensor further comprises a third probe and a third water level voltage comparison circuit, and a length of the third probe is greater than a length of the second probe; The reference probe and the third probe are respectively connected with a first input end and a second input end of the third water level voltage comparison circuit, an output end of the third water level voltage comparison circuit is connected with an output end of the ECU interface circuit, and the output end of the third water level voltage comparison circuit is connected with an output end of the multi-water level single-output sensor.

5. The multiple water level single output sensor of claim 4, wherein, 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; A first end of the twelfth resistor is connected with the power supply VCC, a second end of the twelfth resistor is connected with a second input end of the third water level voltage comparison circuit, the second end of the twelfth resistor is also connected with a first end of the fifth capacitor, a second end of the fifth capacitor is connected with a 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 with a non-inverting input end of the third operational amplifier; A first end of the thirteenth resistor is connected with the power supply VCC, a second end of the thirteenth resistor is connected with the inverting input end of the third operational amplifier, and the second end of the thirteenth resistor is also connected with a first end of the fourteenth resistor, and a second end of the fourteenth resistor is grounded; A power supply input end of the third operational amplifier is connected with the power supply VCC, and a grounding end of the third operational amplifier is grounded; An output end of the third operational amplifier is connected with a first end of the fifteenth resistor, a second end of the fifteenth resistor is connected with an output end of the third water level voltage comparison circuit, a first end of the sixth capacitor is connected with the output end of the third water level voltage comparison circuit, and a second end of the sixth capacitor is grounded.

6. The multiple water level single output sensor of claim 1, wherein, 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.

7. A fuel filtration system characterized by, The application further discloses a multi-water level single-output sensor. The multi-water level single-output sensor according to any one of claims 1 to 6.

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