Temperature measurement device

Abstract

A temperature measuring device according to an embodiment of the present invention comprises: a power input unit; a thermistor electrically connected to the power input unit; a first resistor connected in series with the thermistor; and a second resistor connected in parallel with the thermistor.

Description

temperature measuring device

[0001] The present invention relates to a temperature measuring device.

[0002] One of the most widely used methods for measuring temperature is the use of a thermistor, whose resistance value varies depending on temperature. A thermistor is a thermally sensitive resistor, and its resistance value changes sensitively in response to temperature changes. It can be an NTC (Negative Temperature Coefficient of Resistance), PTC (Positive Temperature Coefficient of Resistance), or CTR (critical temperature resistor).

[0003] When using a thermistor, the source power is used. However, if a short circuit or open circuit occurs due to external disturbances, it can be difficult to distinguish the thermistor's normal output range. A technology to address this issue is needed.

[0004] The technical problem to be solved by the present invention is to provide a temperature measuring device that can distinguish whether a temperature sensor is in a normal state.

[0005] In order to solve the above technical problem, a temperature measuring device according to one embodiment of the present invention includes a power input unit; a thermistor electrically connected to the power input unit; a first resistor connected in series with the thermistor; and a second resistor connected in parallel with the thermistor.

[0006] In addition, the first resistor may have one end connected to the power input and the other end connected to the thermistor, and the thermistor may have one end connected to the first resistor and the other end connected to a ground.

[0007] Additionally, the first resistor may be a pull-up resistor.

[0008] In addition, the thermistor may have one end connected to the power input and the other end connected to the first resistor, and the first resistor may have one end connected to the thermistor and the other end connected to a ground.

[0009] Additionally, the first resistor may be a pull-down resistor.

[0010] Additionally, it may include a third resistor connected in parallel with the first resistor.

[0011] In addition, the first resistor may have one end connected to the power input and the other end connected to the thermistor, and the thermistor may have one end connected to the first resistor and the other end connected to a ground.

[0012] Additionally, it may include a control unit that measures temperature using the change in resistance of the thermistor.

[0013] In addition, the device includes a first switch connected in series with the second resistor, and the control unit can turn on the first switch when the voltage input through the thermistor is the voltage applied to the power input unit.

[0014] In addition, the control unit can determine that the state is abnormal when the voltage input through the thermistor is the voltage applied to the power input unit while the first switch is on.

[0015] According to embodiments of the present invention, when a short circuit or disconnection occurs due to an external disturbance, it is possible to distinguish between the normal output range of the temperature sensor and the abnormal state. This allows for the determination of whether the temperature sensor is in a normal or abnormal state.

[0016] Figure 1 is a block diagram of a temperature measuring device according to one embodiment of the present invention.

[0017] Figures 2 to 6 are drawings for explaining a temperature measuring device according to an embodiment of the present invention.

[0018] FIGS. 7 to 10 are drawings for explaining a temperature measuring device according to another embodiment of the present invention.

[0019] Figures 11 to 13 are drawings for explaining a temperature measuring device according to another embodiment of the present invention.

[0020] Figures 14 and 15 are block diagrams of a temperature measuring device according to an embodiment of the present invention.

[0021] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0022] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0023] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0024] Additionally, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0025] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0026] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

[0027] And, when a component is described as being 'connected', 'coupled', or 'connected' to another component, it may include not only cases where the component is 'connected', 'coupled', or 'connected' directly to the other component, but also cases where the component is 'connected', 'coupled', or 'connected' by another component between the component and the other component.

[0028] Additionally, when described as being formed or arranged "above" or "below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below," the meaning may include not only the upward direction but also the downward direction based on one component.

[0029] A variation according to the present embodiment may include some components of each embodiment and some components of other embodiments. That is, a variation may include one embodiment among various embodiments, but may omit some components and include some components of the corresponding other embodiment. Or, the opposite may be true. The features, structures, effects, etc. to be described in the embodiments are included in at least one embodiment, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by a person having ordinary skill in the art to which the embodiments belong. Therefore, the contents related to such combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0030] Figure 1 is a block diagram of a temperature measuring device according to one embodiment of the present invention.

[0031] FIGS. 2 to 6 are drawings for explaining a temperature measuring device according to an embodiment of the present invention, FIGS. 7 to 10 are drawings for explaining a temperature measuring device according to another embodiment of the present invention, FIGS. 11 to 13 are drawings for explaining a temperature measuring device according to another embodiment of the present invention, and FIGS. 14 and 15 are block diagrams of a temperature measuring device according to an embodiment of the present invention.

[0032] A temperature measuring device (100) according to an embodiment of the present invention is composed of a thermistor (120), a first resistor (110), and a second resistor (130), and may include a power input unit (140), a ground unit (150), a control unit (160), a third resistor (170), a first switch (180), a second switch (190), a storage unit (not shown), a communication unit (not shown), etc.

[0033] A temperature measuring device (100) according to an embodiment of the present invention may include a temperature sensor that measures the temperature outside of the controller, and may be a temperature measuring device that measures the temperature of an external interface, such as a temperature sensor. In addition, various temperature measuring devices that measure temperature using a thermistor may be included.

[0034] The thermistor (120) has a resistance value that changes depending on the temperature. A thermistor is a thermally sensitive resistor, and is a resistor whose resistance value changes sensitively depending on the temperature change, and may include an NTC (Negative Temperature Coefficient of Resistance), a PTC (Positive Temperature Coefficient of Resistance), a CTR (critical temperature resistor), etc. Here, an NTC uses a resistor whose resistance value decreases as the temperature increases, a PTC uses a resistor whose resistance value increases as the temperature increases, and a CTR may use a resistor whose temperature changes rapidly at a specific temperature.

[0035] The thermistor (120) is electrically connected to the power input unit (140), and a voltage is applied to the thermistor (120) according to the voltage applied to the power input unit (140), and the temperature can be measured using the voltage. When the temperature changes, the resistance value of the thermistor (120) changes, and the voltage applied to the thermistor (120) changes accordingly, and the temperature can be measured using this. The control unit (160) receives the voltage of the thermistor (120), and uses the temperature data to derive the temperature according to the voltage, and the temperature can be measured. The temperature data that stores the temperature information according to the voltage of the thermistor (120) can be stored in a storage unit (not shown).

[0036] The first resistor (110) is connected in series with the thermistor (120). The first resistor (110) is connected in series with the thermistor (120) so that voltage can be applied through voltage division with the thermistor (120). The first resistor (110) may be a pull-up resistor or a pull-down resistor depending on the connection order with the thermistor (120).

[0037] The first resistor (110) may have one end connected to the power input unit (140) and the other end connected to the thermistor (120), and the thermistor (120) may have one end connected to the first resistor (110) and the other end connected to the ground (150). At this time, the first resistor (110) may be a pull-up resistor. As shown in Fig. 2, when connected in the order of power input unit (140) - first resistor (110) - thermistor (120) - ground (150), the first resistor (110) may be a pull-up resistor.

[0038] Fig. 3 is a temperature measuring device according to a comparative example of the present invention, in which a thermistor (R_th) is connected in series with a pull-up resistor (R_pu), and when a voltage source of Vcc is connected, a voltage Vo is applied to the thermistor (R_th) according to the voltage distribution of Vcc between the thermistor (R_th) and the pull-up resistor (R_pu). Here, the thermistor (R_th) may be an NTC thermistor. In this case, the voltage Vo can be calculated as follows.

[0039] [Mathematical Formula 1]

[0040] Vo = Vcc * R_th / (R_pu + R_th)

[0041] The resistance value of the thermistor (R_th) changes depending on the temperature, and as shown in the curve (210) of the graph, the Vo value also changes depending on the temperature. Vo has a voltage value of 0 to Vcc, and if a wire short occurs between the thermistor and the controller due to an external disturbance, etc., Vo may become Vcc. For this reason, in the area (211) where Vo, the voltage of the thermistor (R_th), is close to Vcc, it may be difficult to confirm whether it is a voltage in a normal state or a voltage in an abnormal state where a short circuit has occurred. In other words, diagnosis is not possible in that area (211).

[0042] A second resistor (130) may be included to enable diagnosis even in such an undiagnosable area. The second resistor (130) is connected in parallel with the thermistor (120). As shown in Fig. 4, the thermistor (R_th) may be connected in series with the first resistor (R_pu), and the second resistor (R_pl) may be connected in parallel with the thermistor (R_th). Vcc may be applied to one end of the first resistor (R_pu) through the power input unit (140), and the ground, which is the ground unit (150), may be connected to the thermistor (R_th) and the second resistor (R_pl). At this time, the voltage Vo may be calculated as follows depending on the thermistor (R_th) connected in parallel with the second resistor (R_pl).

[0043] [Equation 2]

[0044] Vo = Vcc * (R_th / R_pl) / (R_pu + (R_th / R_pl))

[0045] By connecting the second resistor (R_pl) in parallel with the thermistor (R_th), Vo at the lowest temperature can be made lower than Vcc. As shown in Fig. 5, the curve (220) when the second resistor (R_pl) is connected has a lower voltage in an area close to Vcc than the curve (210) when the second resistor (R_pl) is not connected, and diagnosis and temperature measurement for a normal or abnormal state can be performed using the area (221). That is, Vo is lower than Vcc in a normal state, and when Vo becomes Vcc, it can be determined that an abnormal state exists.

[0046] The control unit (160) can measure the temperature using the resistance change of the thermistor (120). As shown in Fig. 6, the control unit (160) can receive a voltage from the thermistor (120) and calculate the current temperature. The control unit (160) can read the temperature according to the voltage of the thermistor (120) using preset temperature data. The temperature data can be created as a data table and stored in the storage unit.

[0047] When the second resistor (130) is connected in parallel to the thermistor (120), the control unit (160) can determine that the voltage of the thermistor (120) is the same as the voltage applied to the power input unit (140), and thus, the state is abnormal. The control unit (160) can transmit a notification of the normal or abnormal state to the upper controller through the communication unit. At this time, the control unit (160) can transmit an error code.

[0048] The thermistor (120) may have one end connected to the power input unit (140) and the other end connected to the first resistor (110). The first resistor (110) may have one end connected to the thermistor (120) and the other end connected to the ground unit (150). At this time, the first resistor (110) may be a pull-down resistor. As shown in Fig. 7, when connected in the order of power input unit (140) - thermistor (120) - first resistor (110) - ground unit (150), the first resistor (110) may be a pull-down resistor.

[0049] Fig. 8 is a temperature measuring device according to a comparative example of the present invention, in which a thermistor (R_th) is connected in series with a pull-down resistor (R_pd), and when a voltage source of Vcc is connected, a predetermined voltage is applied to the voltage Vo according to the voltage distribution of the thermistor (R_th) and the pull-up resistor (R_pd). Here, the thermistor (R_th) may be an NTC thermistor. In this case, the voltage Vo may be calculated as follows.

[0050] [Equation 3]

[0051] Vo = Vcc * R_pd / (R_pd + R_th)

[0052] The resistance value of the thermistor (R_th) varies depending on the temperature, and as shown in the curve (310) of the graph, the Vo value also varies depending on the temperature. Vo has a voltage value of 0 to Vcc, and if a wire break occurs between the thermistor and the controller due to an external disturbance, etc., the voltage of Vo may become 0 V. Therefore, in the area (311) where the voltage of Vo is close to 0 V, it may be difficult to determine whether it is a voltage in a normal state or an abnormal state in which a break has occurred. In other words, diagnosis is not possible in that area (311).

[0053] A second resistor (130) may be included to enable diagnosis even in such an undiagnosable area. The second resistor (130) is connected in parallel with the thermistor (120). As shown in Fig. 9, the thermistor (R_th) may be connected in series with the first resistor (R_pd), and the second resistor (R_pl) may be connected in parallel with the thermistor (R_th). Vcc may be applied to one end of the thermistor (R_th) and the second resistor (R_pl) through the power input unit (140), and the ground (150), which is the ground, may be connected to the first resistor (R_pd). At this time, when the second resistor (R_pl) and the thermistor (R_th) are connected in parallel, the voltage Vo may be calculated as follows.

[0054] [Equation 2]

[0055] Vo = Vcc * (R_pd / R_pl) / (R_th + (R_pd / R_pl))

[0056] By connecting the second resistor (R_pl) in parallel with the thermistor (R_th), Vo at the lowest temperature can be made higher than Vcc. As shown in Fig. 10, the curve (320) when the second resistor (R_pl) is connected has a higher voltage in a region close to 0 V than the curve (310) when the second resistor (R_pl) is not connected, and diagnosis and temperature measurement for a normal or abnormal state can be performed using the corresponding region (321). That is, Vo is higher than 0 V in a normal state, and when Vo becomes 0 V, it can be determined that an abnormal state exists.

[0057] The control unit (160) can calculate the current temperature by receiving the voltage at both ends of the thermistor (120). The control unit (160) can read the temperature according to the voltage at both ends of the thermistor (120) using preset temperature data. The temperature data can be created as a data table and stored in the storage unit.

[0058] When the second resistor (130) is connected in parallel to the thermistor (120), the control unit (160) can determine that the voltage input from the thermistor (120) has a voltage of 0 V, and thus, the control unit (160) is in an abnormal state. The control unit (160) can transmit a notification regarding the normal or abnormal state to the upper controller through the communication unit. At this time, the control unit (160) can transmit an error code.

[0059] The first resistor (110) has one end connected to the power input (140) and the other end connected to the thermistor (120), the thermistor (120) has one end connected to the first resistor (110) and the other end connected to the ground (150), and the third resistor (170) can be connected in parallel with the first resistor (110).

[0060] As shown in Fig. 11, when connecting in the order of power input unit (140) - first resistor (110) - thermistor (120) - ground unit (150), the first resistor (110) may be a pull-up resistor. The second resistor (130) may be connected in parallel with the thermistor (120), and the third resistor (170) may be connected in parallel with the first resistor (110). As shown in Fig. 12, the thermistor (R_th) may be connected in series with the first resistor (R_pu), the second resistor (R_pl2) may be connected in parallel with the thermistor (R_th), and the first resistor (R_pu) and the third resistor (R_pl1) may be connected in parallel. Vcc is applied to one end of the first resistor (R_pu) and the third resistor (R_pl1) through the power input unit (140), and the ground (150) can be connected to the thermistor (R_th) and the second resistor (R_pl). At this time, the voltage Vo can be calculated as follows.

[0061] [Equation 2]

[0062] Vo = Vcc * (R_th / R_pl2) / ((R_pu / R_pl1) + (R_th / R_pl2))

[0063] By connecting the second resistor (R_pl2) and the thermistor (R_th) in parallel, and connecting the first resistor (R_pu) and the third resistor (R_pl1) in parallel, Vo at the lowest temperature can be lowered than Vcc, and Vo at the highest temperature can be higher than 0 V. As shown in Fig. 13, when the second resistor (R_pl2) and the third resistor (R_pl1) are connected, the curve (420) has a lower voltage in an area close to Vcc and a higher voltage in an area close to 0 V than the curve (410) when the second resistor (R_pl2) and the third resistor (R_pl1) are not connected, and the diagnosis and temperature measurement for a normal state or an abnormal state can be performed using the corresponding areas (421, 422). That is, in a normal state, Vo is lower than Vcc or higher than 0 V, and when Vo becomes Vcc or 0 V, it can be determined that an abnormal state exists.

[0064] When the second resistor (130) is connected in parallel to the thermistor (120), the control unit (160) can determine that the thermistor (120) is in an abnormal state if the voltage is the voltage applied to the power input unit (140) or 0 V. The control unit (160) can transmit a notification of the normal or abnormal state to the upper controller through the communication unit. At this time, the control unit (160) can transmit an error code.

[0065] A first switch (180) may be connected in series to a second resistor (130). Here, the first switch (180) may be a semiconductor switch or a power switch, and may include a FET. As shown in Fig. 14, by variably connecting the second resistor (130) to the thermistor (120), diagnosis in a specific area may be enabled. The control unit (160) may turn on the first switch (180) when the voltage input through the thermistor (120) is the voltage applied to the power input unit (140) or 0 V. If the voltage input through the thermistor (120) is the voltage applied to the power input unit (140) or 0 V, and the second resistor (130) is not connected, it is difficult to determine whether it is a normal state or an abnormal state. Therefore, the control unit (160) turns on the first switch (180) to connect the second resistor (130) in parallel to the thermistor (120), and if the voltage input from the thermistor (120) after connecting the second resistor (130) in parallel is the voltage applied to the power input unit (140) or 0 V, it can be determined as an abnormal state. The control unit (160) can transmit a notification about the normal state or the abnormal state to the upper controller. At this time, the control unit (160) can transmit an error code.

[0066] A first switch (180) may be connected in series to a second resistor (130), and a second switch (190) may be connected in series to a third resistor (170). Here, the first switch (180) and the second switch (190) may be semiconductor switches or power switches, and may include FETs. As shown in Fig. 15, by variably connecting the second resistor (130) in parallel with a thermistor (120), or variably connecting the third resistor (170) in parallel with the first resistor (110), diagnosis in a specific area may be enabled.

[0067] The control unit (160) can turn on the first switch (180) when the voltage input through the thermistor (120) is the voltage applied to the power input unit (140). When the voltage input through the thermistor (120) is the voltage applied to the power input unit (140), if the second resistor (130) is not connected, it is difficult to determine whether it is a normal state or an abnormal state. Therefore, the control unit (160) turns on the first switch (180) to connect the second resistor (130) in parallel to the thermistor (120), and if the voltage input from the thermistor (120) after the second resistor (130) is connected in parallel is the voltage applied to the power input unit (140), it can determine that it is an abnormal state.

[0068] The control unit (160) can turn on the second switch (190) when the voltage input through the thermistor (120) is 0 V. When the voltage input through the thermistor (120) is 0 V and the third resistor (170) is not connected, it is difficult to determine whether it is a normal state or an abnormal state. Therefore, the control unit (160) turns on the second switch (190) to connect the third resistor (130) in parallel to the first resistor (110), and when the voltage input from the thermistor (120) is 0 V after the third resistor (170) is connected in parallel, it can determine that it is an abnormal state. The control unit (160) can transmit a notification about the normal state or the abnormal state to the upper controller. At this time, the control unit (160) can transmit an error code.

[0069] As described above, by connecting the second resistor in parallel with the thermistor or the third resistor in parallel with the first resistor, it is possible to distinguish between the normal output range of the temperature sensor in the event of a short circuit / open circuit due to external disturbance. This allows for the determination of whether the temperature sensor is in a normal or abnormal state.

[0070] Meanwhile, embodiments of the present invention can be implemented as computer-readable code on a computer-readable recording medium. Computer-readable recording media include all types of recording devices that store data that can be read by a computer system.

[0071] Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices. In addition, the computer-readable recording media can be distributed across network-connected computer systems, so that computer-readable code can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers in the technical field to which the present invention pertains.

[0072] Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from the essential characteristics of the above-described description. Therefore, the disclosed methods should be considered illustrative rather than restrictive. The scope of the present invention is set forth in the claims, not the foregoing description, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

Claims

1. Power input; A thermistor electrically connected to the above power input; A first resistor connected in series with the thermistor; and A temperature measuring device comprising a second resistor connected in parallel with the thermistor.

2. In paragraph 1, The above first resistance is, One end is connected to the power input section, and the other end is connected to the thermistor. The above thermistor, A temperature measuring device having one end connected to the first resistor and the other end connected to the ground.

3. In paragraph 2, A temperature measuring device wherein the first resistor is a pull-up resistor.

4. In paragraph 1, The above thermistor, One end is connected to the power input section, and the other end is connected to the first resistor. The above first resistance is, A temperature measuring device in which one end is connected to the above thermistor and the other end is connected to the ground.

5. In paragraph 4, A temperature measuring device wherein the first resistor is a pull-down resistor.

6. In paragraph 1, A temperature measuring device comprising a third resistor connected in parallel with the first resistor.

7. In paragraph 6, The above first resistance is, One end is connected to the power input section, and the other end is connected to the thermistor. The above thermistor, A temperature measuring device having one end connected to the first resistor and the other end connected to the ground.

8. In paragraph 1, A temperature measuring device including a control unit that measures temperature using the change in resistance of the thermistor.

9. In paragraph 8, including a first switch connected in series with the second resistor; The above control unit A temperature measuring device that turns on the first switch when the voltage input through the thermistor is the voltage applied to the power input unit.

10. In paragraph 9, The above control unit, A temperature measuring device that determines an abnormal state when the voltage input through the thermistor is the voltage applied to the power input section while the first switch is on.

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