CN108627218B

CN108627218B - Liquid detection sensor generating output signal and sensor diagnostic device connected to liquid detection sensor

Info

Publication number: CN108627218B
Application number: CN201810228992.1A
Authority: CN
Inventors: 洪甲杓; 金荣云; 闵相东
Original assignee: Tyco Electronics AMP Korea Co Ltd
Current assignee: Tyco Electronics AMP Korea Co Ltd
Priority date: 2017-03-20
Filing date: 2018-03-20
Publication date: 2021-10-08
Anticipated expiration: 2038-03-20
Also published as: CN108627218A

Abstract

The present invention relates to a liquid detection sensor that generates an output signal based on the presence of liquid and a malfunction of the liquid detection sensor, and a sensor diagnostic apparatus connected to the liquid detection sensor. In particular, provided is a liquid detection sensor that can detect whether liquid is present between two different electrodes based on whether a detection signal is transmitted between the two electrodes. The liquid detection sensor may output a result of detecting whether the liquid is present by adjusting a level of the output signal. The liquid detection sensor may output information on whether the detection signal is detected (i.e., whether the liquid detection sensor malfunctions) by adjusting the level of the output signal based on whether the detection signal is detected. The sensor diagnostic device connected to the liquid detection sensor may identify a malfunction of the liquid detection sensor and the presence of liquid detected by the liquid detection sensor by measuring a level of the output signal.

Description

Liquid detection sensor generating output signal and sensor diagnostic device connected to liquid detection sensor

Cross Reference to Related Applications

The present application claims priority to korean patent application No. 10-2017-.

Background

1. Field of the invention

At least one example embodiment relates to a sensor for detecting a liquid.

2. Description of the related Art

A vehicle may include a coolant reservoir for supplying coolant (i.e., cooling water) to an engine. The coolant may be delivered from the coolant reservoir to the engine in response to operation of the engine. If the amount of coolant supplied to the vehicle engine becomes insufficient, the engine may be damaged due to overheating. Accordingly, many vehicles may include sensors configured to measure the amount of coolant stored in the coolant container.

Disclosure of Invention

At least one example embodiment provides a liquid detection sensor that can detect the presence of liquid and whether the sensor is malfunctioning.

In accordance with an aspect of at least one example embodiment, there is provided a liquid detection sensor, comprising: a pulse signal generator configured to generate a pulse signal; a pulse electrode configured to output the generated pulse signal; a receiving electrode configured to be separated from the pulse electrode; an output signal generator configured to generate an output signal, wherein the output signal has different levels (levels) based on whether the pulse signal is transmitted through the liquid between the pulse electrode and the receiving electrode and is input to the receiving electrode; and a pulse signal detector connected to the pulse electrode and configured to adjust a level of an output signal generated by the output signal generator based on whether the pulse signal is generated.

The output signal generator may include a plurality of resistors configured to receive a Direct Current (DC) signal and connected in series; and a switch configured to connect at least one of the plurality of resistances to the ground electrode in response to a pulse signal input to the receiving electrode.

The output signal of the output signal generator may be determined based on a distribution state of the DC signal with respect to the plurality of resistances.

The pulse signal detector may include a resistor connected in parallel to the plurality of resistors, configured to determine a level of the output signal, and connected in series; and a switch configured to adjust a level of the output signal based on whether the pulse signal is generated by connecting a resistance connected to the plurality of resistances in parallel to the ground electrode based on whether the pulse signal is input to the pulse electrode.

The liquid detection sensor may further include: a second receiving electrode configured to be separated from the pulse electrode and the receiving electrode; and a second output signal generator configured to generate a second output signal having a different level based on whether the pulse signal is transmitted through the liquid and input to the second receiving electrode.

The second output signal generator may include a switch configured to adjust a voltage of the resistance connected to the ground electrode by changing a number of resistances supplying current to the resistance connected to the ground electrode based on whether the pulse signal is input to the second receiving electrode, and the adjusted voltage may be used to adjust a level of the second output signal.

The output signal generator and the second output signal generator may be configured to generate output signals having different levels when the pulse signal is transmitted through the liquid and input to the receiving electrode and the second receiving electrode.

The sum of the levels of the output signals respectively output from the output signal generator and the second output signal generator may correspond to the level of the DC signal input to the liquid detection sensor.

In accordance with an aspect of at least one example embodiment, there is provided a liquid detection sensor, comprising: a detection electrode configured to output a detection signal; a receiving electrode configured to be separated from the detecting electrode; and an output electrode configured to output an output signal having a level selected from among a plurality of preset levels. The output signal may have a level selected based on whether a liquid is present between the detection electrode and the receiving electrode and whether the detection signal is output from the detection electrode.

The plurality of preset levels may include: a first level indicating that liquid is not present between the detection electrode and the receiving electrode; a second level indicating that liquid is present between the detection electrode and the reception electrode and different from the first level; and a third level indicating that the detection signal is not output from the detection electrode and is different from the first level and the second level.

The liquid detection sensor may further include: a second receiving electrode configured to be separated from the detecting electrode and the receiving electrode; and a second output electrode configured to output a second output signal having a level determined based on whether the detection signal is input to the second receiving electrode through the liquid.

The level of the second output signal may have a fourth level when the liquid is not present between the detection electrode and the second receiving electrode, and may have a fifth level when the liquid is present between the detection electrode and the second receiving electrode.

The fourth level may correspond to the second level.

The fifth level may correspond to the first level.

The sum of the fourth level and the fifth level may correspond to a level of a Direct Current (DC) signal input to the liquid detection sensor.

The sum of the first level and the second level may correspond to a level of a DC signal input to the liquid detection sensor.

The liquid detection sensor may further include: a plurality of resistors configured to receive a DC signal; and a switch configured to connect at least one of the plurality of resistances to the ground electrode based on whether the detection signal is input to the receiving electrode through the liquid.

The level of the output signal may be determined based on a voltage of a node (node) excluding a remaining resistance other than the resistance connected to the ground electrode through the switch from among the plurality of resistances.

The liquid detection sensor may further include: a plurality of resistors configured to receive a DC signal input to the liquid detection sensor and connected in series, one of the plurality of resistors being connected to a node determining a level of the output signal; a resistor connected in parallel to the plurality of resistors at a node; and a switch connected in parallel to the detection electrode and configured to switch a resistance connected in parallel to the plurality of resistances to the ground electrode in response to the detection signal.

The detection signal may be a pulse signal having a preset frequency.

According to an aspect of at least one example embodiment, there is provided a sensor diagnostic apparatus connected to a liquid detection sensor, the sensor diagnostic apparatus including a processor configured to obtain levels of output signals output from two output electrodes of the liquid detection sensor. The processor may be configured to determine that the liquid detection sensor is malfunctioning when the combination of the levels of the output signals does not correspond to (or equal to) the level of the DC signal input to the liquid detection sensor.

The processor may be configured to determine whether the liquid detection sensor detects liquid based on a level of the output signal when the combination of the levels of the output signals corresponds to a level of the DC signal input to the liquid detection sensor.

The level of the output signal may include one of a first level, a second level corresponding to a value obtained by subtracting the first level from the level of the DC signal, and a third level different from the first level and the second level.

The processor may be configured to determine that the liquid detection sensor is malfunctioning when a level of one of the output signals corresponds to a third level.

The processor may be configured to obtain a liquid detection result of the liquid detection sensor based on whether a level of each of the output signals output from the two output electrodes corresponds to the first level or the second level.

According to some example embodiments, a liquid detection sensor may determine whether liquid is present and whether the sensor is malfunctioning.

Drawings

These and/or other aspects, features and advantages of the present disclosure will be apparent and more readily appreciated from the following description of example embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 shows a liquid detection sensor and a sensor diagnostic device according to an example embodiment.

Fig. 2 shows an appearance of a liquid detection sensor according to an example embodiment.

Fig. 3 shows a structure of a sensor diagnostic device according to an example embodiment.

FIG. 4 shows a circuit diagram of a liquid detection sensor according to an example embodiment.

Fig. 5 is a table used to describe an operation of adjusting the level of the output electrode of the liquid detection sensor based on whether liquid is present and whether the liquid detection sensor malfunctions.

Detailed Description

Hereinafter, some example embodiments will be described in detail with reference to the accompanying drawings. With regard to the reference numerals assigned to the elements in the figures, it should be noted that, whenever possible, the same elements will be denoted by the same reference numerals even though they are shown in different figures. In addition, in the description of the embodiments, a detailed description of well-known related structures or functions will be omitted when it is considered that such description may cause an ambiguous explanation of the present disclosure.

The following detailed structural and functional descriptions of example embodiments are provided only as examples and various changes and modifications may be made to example embodiments. Accordingly, the example embodiments should not be construed as limiting the present disclosure but should be construed to include all variations, equivalents, and alternatives falling within the technical scope of the present disclosure.

Terms such as "first," "second," and the like may be used herein to describe components. Each of these terms is not intended to define the nature, order, or sequence of the corresponding elements, but rather is merely intended to distinguish the respective elements from other element(s). For example, a first member can be referred to as a second member, and similarly, a second member can also be referred to as a first member.

It should be noted that if one component is described as being "connected," "coupled," or "joined" to another component, although a first component may be directly connected, coupled, or joined to a second component, a third component may also be "connected," "coupled," and "joined" between the first and second components. Conversely, it should be noted that if one component is described as being "directly connected," "directly coupled," or "directly linked" to another component, there may be no third component. Expressions describing the relationship between components, such as "between … …", "directly between … …" or "directly adjacent", etc., should be considered to have the same meaning.

The singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes/including," and/or "including/having," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Hereinafter, example embodiments are described with reference to the drawings. Herein, the same reference numerals refer to the same elements throughout and repeated descriptions related thereto are omitted herein.

FIG. 1 shows a liquid detection sensor 120 and a sensor diagnostic device 130 according to an example embodiment.

The liquid detection sensor 120 may detect the liquid 111 stored in the container 110. For example, the liquid 111 may be a coolant supplied to an engine of a vehicle. Referring to fig. 1, the liquid detection sensor 120 may include three electrodes provided in the container 110 or provided to an inner wall of the container 110.

When the liquid 111 is present in the container 110, an electrical signal output from one of the electrodes may be transmitted to the remaining electrodes. In contrast, when the liquid 111 is not present in the container 110, the electric signal output from one of the electrodes may not be transmitted to the remaining electrodes. The liquid detection sensor 120 may detect the liquid 111 stored in the container 110 based on whether an electrical signal is transmitted between the electrodes. The electrode provided in the container 110 or provided to the inner wall of the container 110 may include: an output electrode configured to output a detection signal, which is an electric signal for detecting the liquid 111; and two receiving electrodes configured to receive a detection signal transmitted through the liquid 111. The detection signal may be a pulse signal in which a preset waveform of the electric signal is repeated based on a preset frequency.

Referring to fig. 1, the liquid detection sensor 120 may include at least two electrodes each configured to output a result of detecting the liquid 111 stored in the container 110. An electrode configured to output a result of detecting the liquid 111 (also referred to as a liquid detection result) may be provided outside the container 110. In addition, an electrode configured to output a liquid detection result may be connected to the sensor diagnosis device 130. The sensor diagnostic device 130 may recognize the liquid diagnostic result of the liquid detection sensor 120 or may determine whether the liquid detection sensor 120 malfunctions based on the output signal of the liquid detection sensor 120 received from the connected electrodes. When it is determined that the liquid detection sensor 120 is malfunctioning, the liquid detection sensor 120 may not output a detection signal or may not process a detection signal received via the receiving electrode.

In detail, the sensor diagnostic device 130 may compare levels of output signals respectively received from at least two electrodes connected to the liquid detection sensor 120, and may identify a liquid detection result of the liquid detection sensor 120. Alternatively, the sensor diagnosis device 130 may compare the level of the output signal with a preset reference value and may determine whether the liquid detection sensor 120 malfunctions.

Fig. 2 shows the appearance of a liquid detection sensor 210 according to an example embodiment. It is provided only as an example and the appearance of the liquid detection sensor 210 may be provided in different shapes based on the structure of a container using the liquid detection sensor 210 and the intention of a designer.

Referring to fig. 2, the liquid detection sensor 210 may include

electrodes

220, 230, and 240 provided in a space in which liquid is stored, for example, in a container. One of the

electrodes

220, 230, and 240 may be a detection electrode configured to output a detection signal. The remaining electrodes excluding the detection electrodes from among the

electrodes

220, 230, and 240 may be receiving electrodes each configured to receive a detection signal.

Referring to fig. 2, the liquid detection sensor 210 may include

electrodes

250, 260, 270, and 280, each of which is configured to output an output signal including a liquid detection result obtained using the

electrodes

220, 230, and 240 or to be supplied with power for generating a detection signal. For example, the electrodes 250 may be connected to a battery pack and may receive electrical energy (e.g., a Direct Current (DC) signal having a desired voltage) for use by the liquid detection sensor 210. Electrode 280 may be connected to a ground electrode. Each of the

electrodes

260 and 270 may transmit an output signal to the outside. The output signal may be an electrical signal having a voltage of a preset level or magnitude.

The level of the output signal may be determined to be one of a plurality of levels based on whether the detection signal reaches the

electrodes

230 and 240. The level of the output signal may be determined to be one of a plurality of levels based on whether the detection signal is output from the detection electrode. Accordingly, a device (e.g., the sensor diagnostic device 130 of fig. 1) connected to the

electrodes

260 and 270 may determine whether liquid is present and whether the liquid detection sensor 210 is malfunctioning based on the output signals.

Referring to fig. 3, the sensor diagnostic device may be connected to at least one liquid detection sensor, for example, a liquid detection sensor 1310 and a liquid detection sensor 2320. The sensor diagnostic device may include a plurality of input ports respectively corresponding to the plurality of liquid detection sensors. Since a single liquid detection sensor outputs an output signal using a plurality of electrodes (e.g.,

electrodes

260 and 270 of fig. 2), each of the plurality of input ports may include a circuit connected to each of the plurality of electrodes of the liquid detection sensor.

The sensor diagnostic device may include a Main Control Unit (MCU) 330 configured to determine whether the detection sensor detects liquid and whether the liquid detection sensor malfunctions based on an output signal of the connected liquid detection sensor. The sensor diagnosis device may include a capacitor for reducing resistance or noise and an amplifier for impedance matching in a circuit connecting the liquid detection sensor and the MCU 330.

When a plurality of liquid detection sensors are connected to the sensor diagnostic apparatus, the MCU 330 may independently determine whether the corresponding liquid detection sensor detects liquid (i.e., whether liquid is present) and whether the liquid detection sensor is malfunctioning, with respect to each of the plurality of liquid detection sensors.

For example, the sensor diagnostic apparatus may determine the meaning of the corresponding output signal and the operation state of the liquid detection sensor based on the voltages (output #1 and output # 2) of the two electrodes outputting the output signal in the liquid detection sensor, as shown in table 1 below.

[ Table 1]

Referring to table 1, the sensor diagnosis means may compare the voltages of the respective electrodes with a preset voltage range and may determine the meaning of the corresponding output signal and the operation state of the liquid detection sensor. In table 1, the voltage range used by the sensor diagnostic apparatus may include, in descending order of magnitude, (1) a first range, which is a range of 4.5V or more, indicating that the liquid detection sensor is malfunctioning, that is, in a failure state, specifically, indicating that the liquid detection sensor is short-circuited on the electrode supply power, (2) a second range, which is a range between 3V and 4V, indicating that the liquid detection sensor is in a normal state and for determining whether or not the liquid is detected, (3) a third range, which is a range between 1V and 2V, indicating that the liquid detection sensor is in a normal state and for determining whether or not the liquid is detected, (4) a fourth range, which is a range between 0.5V and 1V, indicating that the liquid detection sensor is malfunctioning, specifically, indicating that the detection signal of the liquid detection sensor is not generated, and (5) a fifth range, as a range between 0V and 0.5V, it indicates that the liquid detection sensor is out of order and the liquid detection sensor is short-circuited to the ground electrode supply power source.

That is, the sensor diagnostic apparatus may determine a range in which the plurality of electrodes of the liquid detection sensor are included among a plurality of preset voltage ranges, and may determine whether or not the liquid is present and whether or not the liquid detection sensor malfunctions. In addition, when the liquid detection sensor malfunctions, the sensor diagnostic device can identify the cause of the malfunction of the liquid detection sensor, that is, the cause of the failure. For example, referring to table 1, the sensor diagnostic device may determine, as the cause of failure, one of erroneously shorting across the voltage Vcc input to the liquid detection sensor in the liquid detection sensor, not generating a detection signal at the liquid detection sensor, and erroneously shorting between a ground electrode being connected to the liquid detection sensor and the liquid detection sensor.

Referring to table 1, when the liquid detection sensor operates normally, that is, in a normal state, the voltages of the respective electrodes may be included in different voltage ranges. The sensor diagnostic device may recognize the presence of the liquid detected by the liquid detection sensor based on a voltage range in which the voltage of each electrode is included. For example, when the voltage output #1 of the electrode connected to the liquid detection sensor 1310 is included in the second range (i.e., the range between 3V and 4V) and when the voltage output #2 of the electrode is included in the third range (i.e., the range between 1V and 2V), the sensor diagnostic apparatus may determine that there is no (or no) liquid through the liquid detection sensor 1310. Alternatively, the sensor diagnostic device may determine that liquid is detected (i.e., present) when the voltage output #1 of the electrode is included in the third range (i.e., the range between 1V and 2V) and the voltage output #2 of the electrode is included in the second range (i.e., the range between 3V and 4V).

As described above, the liquid detection sensor may output signals to the plurality of electrodes, each of the output signals having voltages included in different voltage ranges based on whether or not liquid is present and whether or not the liquid detection sensor is malfunctioning. That is, the output signal of the liquid detection sensor can be generated by considering whether or not the liquid is present and also whether or not the liquid detection sensor malfunctions.

Fig. 4 is a circuit diagram showing a liquid detection sensor according to an example embodiment.

Referring to fig. 4, the liquid detection sensor may receive power required for the liquid detection sensor to operate through the power electrode 411. The power electrode 411 may be connected to a device (e.g., a battery pack of a vehicle, an ECU, or a sensor diagnostic device) that is capable of supplying electrical energy to the liquid detection sensor.

The liquid detection sensor may include a power unit 420 as a circuit configured to generate a DC signal necessary to operate the circuit included in the liquid detection sensor using the electric power received from the power electrode 411. The DC signal generated by the power unit 420 may be transmitted to the circuit of the liquid detection sensor as a signal having a preset DC voltage.

The liquid detection sensor may include a detection signal generator 430 configured to generate a detection signal, which is an electrical signal for detecting the presence of liquid from the DC signal of the power unit 420. The detection signal may be a pulse signal in which the magnitude of the current or voltage repeatedly changes based on a preset frequency. For example, the detection signal may be a pulse signal in which a sine wave, a triangular wave, a pulse wave, a rectangular wave, or other preset wave is repeated. In this case, the detection signal generator 430 may function as a pulse signal generator that generates a pulse signal.

The liquid detection sensor may include a detection electrode 471 configured to output a generated detection signal. When the detection signal generator 430 functions as a pulse signal generator that generates a pulse signal, the detection electrode 471 may function as a pulse electrode that outputs the pulse signal. The detection electrode 471 may be provided in a space in which a liquid is stored. In addition, the liquid detection sensor may include a detection signal detector 440 connected to the detection signal generator 430 and the detection electrode 471 in parallel. The detection signal detector 440 may determine whether the detection signal is generated by the detection signal generator 430 by receiving the detection signal output from the detection signal generator 430.

The liquid detection sensor may include a plurality of receiving electrodes, such as a receiving electrode 1472 and a receiving electrode 2473, which are configured to be separated from the detection electrode 471. The receiving electrodes 1472 and 2473 may be provided in a space in which liquid is stored together with the detection electrode 471. When there is no liquid in the space, the detection signal output from the detection electrode 471 may not be transmitted to the receiving electrode 1472 and the receiving electrode 2473. When liquid is present in the space, a detection signal output from the detection electrode 471 can be transmitted through the liquid and can be transmitted to the receiving electrode 1472 and the receiving electrode 2473.

The liquid detection sensor may include a plurality of output signal generators, for example, an output signal generator 1450 connected to the receiving electrode 1472 and an output signal generator 2460 connected to the receiving electrode 2473, which are respectively connected to the plurality of receiving electrodes and are each configured to generate output signals having different levels (for example, levels of voltage or current) based on whether the detection signal is input to the connected receiving electrode. The level of the output signal generated by the output signal generator may be determined based on a plurality of preset levels or ranges (e.g., the voltage ranges of table 1).

The level of the output signal generated by each output signal generator may be determined based on whether the liquid is present and whether the detection signal is generated. Referring to fig. 4, in response to the connection between the output signal generator 1450 and the detection signal detector 440, the level of the output signal generated by the output signal generator 1450 may be adjusted based on (1) whether the detection signal is input to the receiving electrode 1472 and (2) whether the detection signal is transferred to the detection electrode 471. That is, the detection signal detector 440 may adjust the level of the output signal generator 1450 based on whether the detection signal is generated. The output signal generator 2460 is not connected to the signal detector 440, and thus the level of the output signal generated by the output signal generator 2460 may be adjusted based on whether the detection signal is input to the receiving electrode 2473.

The liquid detection sensor may include a plurality of output electrodes, for example, an output electrode 1412 connected to the output signal generator 1450 and an output electrode 2413 connected to the output signal generator 2460, which are respectively connected to the output signal generator and respectively configured to output the output signal generated by the output signal generator to the outside.

Referring to fig. 4, the circuits of the respective output signal generators may be different based on whether the level of the output signal is adjusted based on the presence or absence of liquid and whether the level of the output signal is adjusted based on the output of the detection signal. That is, the circuits of the respective output signal generators may have different structures based on whether the corresponding circuits are connected to the signal detector 440.

Hereinafter, an operation of adjusting the level of the output signal generated by the output signal generator 1450 based on (1) whether the detection signal is input to the receiving electrode 1472 and (2) whether the detection signal is transferred to the detection electrode 471 will be further described.

The output signal generator 1450 may include a switch 451 configured to operate in response to a detection signal input to the receiving electrode 1472. The switch 451 may be a transistor. The output signal generator 1450 may include a plurality of resistors 452 configured to receive the DC signal generated by the power unit 420 and connected in series. Referring to fig. 4, three resistors R1, R2, and R3 may receive the DC signal. Accordingly, the sum of the voltages of the resistors R1, R2, and R3 may correspond to the voltage of the DC signal, e.g., 5V. According to ohm's law, the voltages of the resistors R1, R2, and R3 may be determined based on values obtained by dividing the voltage of the DC signal based on the ratio of the resistors R1, R2, and R3. That is, the voltages of the resistors R1, R2, and R3 may have values as represented by formula 1.

[ equation 1]

V(R1):V(R2):V(R3)=R1:R2:R3

V (R1) + V (R2) + V (R3) = (voltage of DC signal)

In the example of fig. 4, since the voltage of the DC signal input to the plurality of resistors 452 is 5V, V (R1) + V (R2) + V (R3) = 5V.

The switch 451 may connect one of nodes between the plurality of resistors 452 to the ground electrode in response to a detection signal input to the receiving electrode 1472. The switch 451 may connect the node a of the connection resistances R2 and R3 to the ground electrode in response to the detection signal input to the reception electrode 1472. Resistor R3 does not receive a DC signal once node a is connected to the ground electrode. That is, the switch 451 may connect at least one of the plurality of resistors 452 (e.g., resistor R3) to the ground electrode, or may alter the DC signal flow such that at least one of the plurality of resistors 452 (e.g., resistor R3) may not receive a DC signal. The DC signal delivered to the plurality of resistors 452 may be sequentially transmitted through resistors R1 and R2 and then flow to a ground electrode connected by switch 451. Since the resistor R3 does not receive the DC signal, V (R1) and V (R2) may have values as represented by equation 2.

[ formula 2]

V(R1):V(R2)=R1:R2

V (R1) + V (R2) = (voltage of DC signal)

In the example of fig. 4, since the voltage of the DC signal input to the plurality of resistors 452 is 5V, V (R1) + V (R2) = 5V.

The level of the output signal generated by the output signal generator 1450 may be determined based on the voltage of one of nodes except for the node a connected to the switch 451, among nodes existing between the plurality of resistors 452. Referring to fig. 4, the level of the output signal generated by the output signal generator 1450 may be determined based on the voltage of the node b, which is different from the node a. The node b may be connected to the output electrode 1412 through an impedance matcher 453. Each of the

impedance matchers

453 and 464 may be a circuit provided between two different circuits and configured to match impedance between the two circuits. Accordingly, the voltage of the output electrode 1412 may correspond to the voltage of the node b.

Referring to the above-described operation of the switch 451, when the detection signal is not input to the receiving electrode 1472 (i.e., when there is no liquid), the voltage of the node b may be determined as the voltage of the node b according to equation 1

。

In contrast, when the detection signal is input to the receiving electrode 1472 (i.e., when the liquid is present), the voltage of the node b may be determined according to equation 2 as

。

That is, the voltage of output electrode 1412 may be selected based on the presence or absence of liquid as

And

one of them. The voltage of the output electrode 1412 (i.e., the output signal of the output signal generator 1450) may be determined based on the distribution of the DC signal with respect to the plurality of resistances 452.

As described above, the level of the output signal generated by the output signal generator 1450 may be adjusted by considering whether the detection signal is input to the receiving electrode 1472 and also whether the detection signal is transmitted to the detection electrode 471. Referring to fig. 4, a node b for determining the level of the output signal existing in a node between the plurality of resistors 452 may be connected to the resistor R4 of the detection signal detector 440.

The detection signal detector 440 may be connected to the detection electrode 471 and may receive a detection signal input to the detection electrode 471. When the detection signal generator 430 does not generate the detection signal, the detection signal detector 440 may not receive the detection signal. Detection signal detector 440 may include a switch 441 configured to connect resistor R4 to the ground electrode based on whether a detection signal is received. Switch 441 may be connected to switch 442, which is configured to operate based on the voltage of detection electrode 471. The

switches

442, 441 may be transistors.

The gate electrode of the switch 441 may be connected to the ground electrode in response to the operation of the switch 442 (i.e., in response to the detection signal input to the detection electrode 471 and the detection signal generator 440). Thus, switch 441 may not connect resistor R4 to the ground electrode. In this case, the resistor R4 is not connected to the ground electrode. Therefore, although the resistor R4 is connected to the node b, the current flowing in the node b may not flow into the resistor R4. That is, the magnitude of the current flowing in the resistor R4 may be zero. That is, the resistor R4 may be in an open state and may not operate as if the resistor R4 were separate from the plurality of resistors 452.

When the switch 442 is not operated (that is, when the detection signal is not input to the detection electrode 471 and the detection signal detector 440), the voltage of the gate electrode of the switch 441 may be the voltage of a DC signal, for example, 5V. Thus, switch 441 may connect resistor R4 to the ground electrode. With resistor R4 connected to the ground electrode, current flowing in node b may pass through resistor R4 and may flow into the ground electrode. That is, the resistor R4 may operate as if the resistor R4 is connected to the plurality of resistors 452, unlike the case where the detection signal is input to the detection signal detector 440.

When the detection signal is not generated (i.e., when the detection signal is not input to the detection electrode 471 and the detection signal detector 440), the resistor R4 may receive a current from the plurality of resistors 452 (e.g., the node b between the plurality of resistors 452).

When the detection signal is not input to the detection electrode 471 and the detection signal detector 440, the detection signal may not be transmitted to the reception electrode 1472. Since the detection signal is not transmitted to the receiving electrode 1472, the switch 451 may not connect the node a to the ground electrode. Accordingly, the DC signal input to the plurality of resistors 452 may be transmitted through the resistor R1 and then may be transmitted to the respective resistors R4 and R2 at the node b. The DC signal delivered to resistor R4 may be delivered to the ground electrode via switch 441, and the DC signal delivered to resistor R2 may be delivered to resistor R3. The DC signal transmitted through the resistor R1 is distributed to the resistor R4 and the resistor R2 at the node b. Therefore, V (R1) to V (R4) can be represented by formula 3.

[ formula 3]

V (R1) + V (R2) + V (R3) = (voltage of DC signal)

V (R1) + V (R4) = (voltage of DC signal)

The voltage of the output electrode 1412 corresponds to the voltage of the node b. Therefore, when the detection signal is not generated, the voltage of the node b may beV (R4) (or V (R2) + V (R3)) satisfying formula 3. That is, the voltage of the output electrode 1412 may be determined as (1) V (R4) satisfying equation 3 if the detection signal is not generated, (2) V if the detection signal is generated and liquid is present

And (3) if the detection signal is generated and there is no liquid is

。

Hereinafter, an operation of adjusting the level of the output signal generated by the output signal generator 2460 based on whether the detection signal is input to the receiving electrode 2473 will be further described.

Referring to fig. 4, the output signal generator 2460 may include a plurality of resistors 463 configured to receive the DC signal generated by the power unit 420 and connected in series. For example, two resistors (i.e., resistor R5 and resistor R6) may receive the DC signal. Accordingly, the sum of the voltages of the resistor R5 and the resistor R6 may correspond to the voltage of the DC signal, e.g., 5V.

The level of the output signal generated by the output signal generator 2460 may be determined based on the voltage of the node c existing between the plurality of resistors 463. Node c may be connected to the output electrode 2413 through an impedance matcher 464. Accordingly, the voltage of the output electrode 2413 may correspond to the voltage of the node c.

The output signal generator 2460 may include a switch 461 configured to operate in response to a detection signal input to the receiving electrode 2473. The output signal generator 2460 can include a switch 462 configured to route a DC signal to at least one of the plurality of resistors 463 through the switch 461. Switch 462 may be connected to a resistor R7 that is connected in parallel to a plurality of resistors 463 at node c. Switch 462 may supply a DC signal to resistor R7 based on switch 461. The

switches

461, 462 may be transistors.

When a detection signal is input to the receiving electrode 2473 (i.e., when liquid is present), the switch 461 may connect the gate electrode of the switch 462 to the ground electrode. In this case, the switch 462 may not supply the DC signal to the resistor R7. Accordingly, resistor R7 may enter the off state and may not receive current from the plurality of resistors 463. The resistor R5 may only receive the DC signal transmitted through the resistor R6. The voltages of the resistors R5 and R6, that is, V (R5) and V (R6), may have values represented by formula 4.

[ formula 4]

V(R5):V(R6)=R5:R6

V (R5) + V (R6) = (voltage of DC signal)

In the example of fig. 4, since the voltage of the DC signal input to the plurality of resistors 463 is 5V, V (R5) + V (R6) = 5V. The voltage of the output electrode 2413 corresponds to the voltage of the node c. Accordingly, when the detection signal is input to the receiving electrode 2473, the voltage of the output electrode 2413 may be determined as

。

When the detection signal is not input to the receiving electrode 2473 (i.e., when there is no liquid), the switch 461 may be operated and thus the voltage of the gate electrode of the switch 462 may be the voltage of the DC signal, for example, 5V. In this case, the switch 462 may supply the DC signal to the resistor R7. Accordingly, the resistor R5 may receive both the full DC signal transmitted through the resistor R6 and the DC signal transmitted through the resistor R7. That is, the number of resistances supplying current to the resistance R5 may vary based on whether the detection signal is input to the receiving electrode 2473. The voltage of the resistor R5 or the voltage of the node c may vary according to the change in the number of resistors supplying current to the resistor R5. The voltages V (R5) to V (R7) of the resistors R5 to R7 may have values as represented by formula 5.

[ formula 5]

V (R5) + V (R6) = (voltage of DC signal)

V (R5) + V (R7) = (voltage of DC signal)

The voltage of the output electrode 2413 corresponds to the voltage of the node c. Therefore, when the detection signal is not input to the receiving electrode 2473, the voltage of the output electrode 2413 may be determined as V (R5) satisfying equation 5.

The voltage of the output electrode 2413 of the liquid detection sensor may be determined to be one of different levels based on whether liquid is present. The voltage of the output electrode 1412 may be determined to be one of the different levels by considering whether liquid is present and also whether the liquid detection sensor is malfunctioning.

Fig. 5 is a table 500 used to describe an operation of adjusting the level of the output electrode of the liquid detection sensor based on whether liquid is present and whether the liquid detection sensor malfunctions. The level of the output electrode adjusted based on whether the liquid is present and whether the liquid detection sensor is malfunctioning may be used when the sensor diagnosis device connected to the liquid detection sensor recognizes the malfunction of the liquid detection sensor.

The level of the output electrode may be selected to be one of a plurality of levels. For example, the plurality of levels selectable as the level of the output electrode 1 may include a first level and a second level for detecting the presence or absence of liquid, and a third level indicating that the liquid detection sensor is malfunctioning (e.g., does not generate a detection signal). The first level, the second level, and the third level may be different from each other.

In this instance, the plurality of levels selectable as the level of the output electrode 2 may include a fourth level and a fifth level for detecting the presence or absence of liquid. The plurality of levels of the output electrode 2 may be determined as a plurality of levels corresponding to the output electrode 1. For example, when the fifth level is greater than the fourth level, the fourth level may correspond to the second level and the fifth level may correspond to the first level.

Referring to the table of fig. 5, the first level and the second level may be determined to be 3.5V and 1.5V, respectively, and the third level may be determined to be 0.5V. The resistance of the element configured to adjust the level of the output electrode in the liquid detection sensor (e.g., the plurality of

resistances

452 and 463 of fig. 4) may be determined based on the determined plurality of levels. The combination of the first level and the second level may correspond to the level of the DC signal, e.g., 5V in the example embodiment of fig. 4. In this case, the sensor diagnostic apparatus may determine whether the liquid detection sensor is malfunctioning by comparing the combination of the levels of the output electrodes with the level of the DC signal. For example, when the combination of the levels of the output electrodes does not match (or is equal to) the level of the DC signal, then the sensor diagnostic device may determine that the liquid detection sensor is malfunctioning.

In contrast, if the combination of the levels of the output electrodes matches (or is equal to) the level of the DC signal, the sensor diagnostic device may determine that the liquid detection sensor is operating normally, that is, in a normal state. In this case, the level of the output electrode of the liquid detection sensor may vary based on the presence or absence of liquid. For example, when the liquid detection sensor detects the presence of liquid, the level of the output electrode 1 may be 1.5V and the level of the output electrode 2 may be 3.5V. When the liquid detection sensor does not detect liquid, the level of the output electrode 1 may be 3.5V and the level of the output electrode 2 may be 1.5V.

As described above, the level of at least one of the output electrodes may be adjusted based on whether the detection signal is generated. The sensor diagnostic device may determine that the liquid detection sensor is malfunctioning when the combination of the levels of the output electrodes does not match the level of the DC signal. Referring to the table of fig. 5, when the level of at least one of the output electrodes corresponds to the third level, the sensor diagnostic device may determine that the liquid detection sensor is malfunctioning.

According to example embodiments, the liquid detection sensor may detect the presence or absence of liquid between two different electrodes based on whether a detection signal is transmitted between the two different electrodes. The liquid detection sensor may output the liquid detection result by adjusting a level of the output signal. In addition, the liquid detection sensor may output information about whether the detection signal is generated (i.e., whether the liquid detection sensor malfunctions) by adjusting the level of the output signal based on whether the detection signal is generated. The sensor diagnostic device connected to the liquid detection sensor may identify a malfunction of the liquid detection sensor and the presence of liquid detected by the liquid detection sensor by measuring a level of the output signal.

The example embodiments described herein may be implemented using hardware components, software components, and/or combinations thereof. For example, the processing devices and components described herein may be implemented using one or more general purpose or special purpose computers, such as, for example, processors, controllers, and Arithmetic Logic Units (ALUs), digital signal processors, microcomputers, Field Programmable Gate Arrays (FPGAs), Programmable Logic Units (PLUs), microprocessors, or any other device that is capable of responding to and executing instructions in a defined manner. The processing device may run an Operating System (OS) and one or more software applications running on the OS. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For simplicity, the description of the processing means is taken as singular; however, one skilled in the art will recognize that the processing device may include multiple processing elements and/or multiple types of processing elements. For example, the processing device may include a plurality of processors, or a processor and a controller. Also, different processing configurations are possible, such as parallel processors.

The software may include computer programs, code segments, instructions, or a combination thereof, that independently or collectively direct or configure the processing device to operate as desired. Software and data may be embodied permanently or temporarily in any type of machine, component, physical or virtual device, computer storage medium or apparatus, or in a propagated signal wave capable of providing instructions or data to or for interpretation by a processing apparatus. The software may also be distributed over network coupled computer systems so that the software is stored and executed in a distributed fashion. The software and data may be stored by one or more non-transitory computer-readable recording media.

The method according to the example embodiments described above may be recorded in a non-transitory computer-readable medium, including program instructions to implement various operations of the example embodiments described above. The media may also include, alone or in combination, program instructions, data files, data structures, and the like. The program instructions recorded on the medium may be those specially designed and constructed for the purposes of the example embodiments, or they may be of the kind well known and available to those having skill in the computer software arts. Examples of non-transitory computer readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROM disks, DVDs, and/or Blu-ray disks; magneto-optical media, such as optical disks; and hardware devices that are specially constructed to store and execute program instructions, such as Read Only Memory (ROM), Random Access Memory (RAM), flash memory (e.g., USB flash drives, memory cards, memory sticks, etc.), and so forth. Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The apparatus described above may be configured to act as one or more software modules in order to perform the operations of the example embodiments described above, or vice versa.

A number of example embodiments have been described above. Nevertheless, it will be understood that various modifications may be made to the example embodiments. For example, suitable results may be achieved if the techniques were performed in a different order and/or if components in a described system, architecture, device, or circuit were combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims.

Claims

1. A liquid detection sensor, comprising:

a pulse signal generator configured to generate a pulse signal;

a pulse electrode configured to output the generated pulse signal;

a receiving electrode configured to be separated from the pulse electrode;

an output signal generator configured to generate output signals having different levels based on whether the pulse signal is transmitted through the liquid between the pulse electrode and the receiving electrode and is input to the receiving electrode; and

a pulse signal detector connected to the pulse electrode and configured to adjust a level of an output signal generated by the output signal generator based on whether the pulse signal is generated,

the pulse signal detector includes:

a resistor connected in parallel to the plurality of resistors, configured to determine a level of the output signal, and connected in series; and

a switch configured to adjust a level of the output signal based on whether the pulse signal is generated by connecting a resistance connected in parallel to the plurality of resistances to a ground electrode based on whether the pulse signal is input to the pulse electrode.

2. The liquid detection sensor according to claim 1, wherein the output signal generator includes:

a plurality of resistors configured to receive a Direct Current (DC) signal and connected in series; and

a switch configured to connect at least one of the plurality of resistances to a ground electrode in response to the pulse signal being input to the receiving electrode.

3. The liquid detection sensor according to claim 2, wherein the output signal of the output signal generator is determined based on a distribution state of the DC signal with respect to the plurality of resistances.

4. The liquid detection sensor according to claim 1, further comprising:

a second receiving electrode configured to be separated from the pulse electrode and the receiving electrode; and

a second output signal generator configured to generate a second output signal having a different level based on whether the pulse signal is transmitted through the liquid and input to the second receiving electrode.

5. The liquid detection sensor according to claim 4, wherein the second output signal generator includes:

a switch configured to adjust a voltage of a resistance connected to the ground electrode by changing a number of resistances supplying current to the resistance connected to the ground electrode based on whether the pulse signal is input to the second receiving electrode; and

the regulated voltage is used to regulate the level of the second output signal.

6. The liquid detection sensor according to claim 4, wherein the output signal generator and the second output signal generator are configured to generate output signals having different levels when the pulse signal is transmitted through the liquid and input to the receiving electrode and the second receiving electrode.

7. The liquid detection sensor according to claim 6, wherein a sum of levels of the output signals respectively output from the output signal generator and the second output signal generator corresponds to a level of a DC signal input to the liquid detection sensor.

8. A liquid detection sensor, comprising:

a detection electrode configured to output a detection signal;

a receiving electrode configured to be separated from the detecting electrode; and

an output electrode configured to output an output signal having a level selected from among a plurality of preset levels,

wherein the output signal has a level selected based on whether liquid is present between the detection electrode and the reception electrode and whether the detection signal is output from the detection electrode,

the liquid detection sensor further includes:

a plurality of resistors configured to receive a DC signal input to the liquid detection sensor and connected in series, one of the plurality of resistors being connected to a node that determines a level of the output signal;

a resistor connected in parallel to the plurality of resistors at the node; and

a switch connected in parallel to the detection electrode and configured to switch a resistance connected in parallel to the plurality of resistances to a ground electrode in response to the detection signal.

9. The liquid detection sensor of claim 8, wherein the plurality of preset levels comprises:

a first level representing no liquid between the detection electrode and the receiving electrode;

a second level indicating that the liquid is present between the detection electrode and the reception electrode and different from the first level; and

a third level indicating that the detection signal is not output from the detection electrode and is different from the first level and the second level.

10. The liquid detection sensor of claim 9, further comprising:

a second receiving electrode configured to be separated from the detecting electrode and the receiving electrode; and

a second output electrode configured to output a second output signal having a level determined based on whether the detection signal is input to the second receiving electrode through the liquid.

11. The liquid detection sensor according to claim 10, wherein a level of the second output signal has a fourth level when no liquid is present between the detection electrode and the second receiving electrode, and has a fifth level when the liquid is present between the detection electrode and the second receiving electrode.

12. The liquid detection sensor according to claim 11, wherein the fourth level corresponds to the second level.

13. The liquid detection sensor of claim 11, wherein the fifth level corresponds to the first level.

14. The liquid detection sensor according to claim 11, wherein a sum of the fourth level and the fifth level corresponds to a level of a Direct Current (DC) signal input to the liquid detection sensor.

15. The liquid detection sensor according to claim 9, wherein a sum of the first level and the second level corresponds to a level of a DC signal input to the liquid detection sensor.

16. The liquid detection sensor of claim 8, further comprising:

a plurality of resistors configured to receive a DC signal; and

a switch configured to connect at least one of the plurality of resistances to a ground electrode based on whether the detection signal is input to the receiving electrode through the liquid.

17. The liquid detection sensor according to claim 16, wherein the level of the output signal is determined based on a voltage of a node excluding a remaining resistance other than the resistance connected to the ground electrode through the switch from the plurality of resistances.

18. The liquid detection sensor according to claim 8, wherein the detection signal is a pulse signal having a preset frequency.