CN212903630U - Temperature detection device of thermistor and intelligent household appliance - Google Patents
Temperature detection device of thermistor and intelligent household appliance Download PDFInfo
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- CN212903630U CN212903630U CN202021709225.1U CN202021709225U CN212903630U CN 212903630 U CN212903630 U CN 212903630U CN 202021709225 U CN202021709225 U CN 202021709225U CN 212903630 U CN212903630 U CN 212903630U
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Abstract
The utility model relates to a thermistor's temperature-detecting device and intelligent household electrical appliances, include: the method comprises the following steps: the circuit comprises a controller, a first voltage-dividing resistor, a thermistor, an active filter circuit, at least one voltage-dividing resistor switching circuit and at least one second voltage-dividing resistor; one end of the first divider resistor is respectively connected with one end of the second divider resistor and one end of the thermistor, and the other end of the first divider resistor is grounded; the input end of the active filter circuit is connected with the first divider resistor, and the output end of the active filter circuit is connected with the AD port of the controller; the other end of the thermistor is used for connecting input voltage; the other end of the second voltage-dividing resistor is connected with the first end of the corresponding voltage-dividing resistor switching circuit; the second end of the divider resistance switching circuit is connected with the corresponding IO port of the controller, and the third end of the divider resistance switching circuit is grounded. The utility model discloses circuit structure is comparatively perfect and easy to be realized, and the interference killing feature is stronger simultaneously.
Description
Technical Field
The utility model relates to a temperature measurement technical field, in particular to thermistor's temperature-detecting device and intelligent household electrical appliances.
Background
Along with the improvement of the temperature measuring range and precision of the thermistor at present, a scheme of segmented temperature measurement appears, so that the requirement on a temperature measuring circuit of the thermistor is higher and higher. In the scheme of the traditional technology for segmented temperature measurement, most circuits are simple, and the situation that the measurement accuracy is affected due to unstable work exists. Even though the prior art provides improvement on the circuit in the scheme of segmented temperature measurement, the prior art also has the problems that part of the circuit is too complicated and high in cost, so that the possibility of electrical interference is increased, and the realization is inconvenient.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a thermistor's temperature-detecting device and intelligent household electrical appliances to the not enough of conventional art.
In one embodiment, the present invention provides a temperature detection device of a thermistor, including: the circuit comprises a controller, a first voltage-dividing resistor, a thermistor, an active filter circuit, at least one voltage-dividing resistor switching circuit and at least one second voltage-dividing resistor;
one end of the first divider resistor is respectively connected with one end of the second divider resistor and one end of the thermistor, and the other end of the first divider resistor is grounded; the input end of the active filter circuit is connected with the first divider resistor, and the output end of the active filter circuit is connected with the AD port of the controller; the other end of the thermistor is used for connecting input voltage; the other end of the second voltage-dividing resistor is connected with the first end of the corresponding voltage-dividing resistor switching circuit; the second end of the divider resistance switching circuit is connected with the corresponding IO port of the controller, and the third end of the divider resistance switching circuit is grounded.
In one embodiment, the voltage dividing resistor switching circuit comprises a switching tube and a third voltage dividing resistor;
the first end of the switch tube is used as the first end of the divider resistance switching circuit, the second end of the switch tube is connected with one end of the third divider resistance, and the third end of the switch tube is used as the third end of the divider resistance switching circuit; the other end of the third divider resistor is used as the second end of the divider resistor switching circuit.
In one embodiment, the voltage dividing resistance switching circuit further comprises a pull-down resistor; the pull-down resistor is connected between the third end of the switching tube and one end of the third voltage dividing resistor.
In one embodiment, the switch tube is a triode or a field effect tube.
In one embodiment, the active filter circuit comprises an RC filter circuit and a voltage follower;
the input end of the RC filter circuit is used as the input end of the active filter circuit and is connected with one end of the first divider resistor, the output end of the RC filter circuit is connected with the non-inverting input end of the voltage follower, and the grounding end of the RC filter circuit is connected with the other end of the first divider resistor; the output end of the voltage follower is used as the output end of the active filter circuit and is respectively connected with the reverse input end of the voltage follower and the AD port of the controller.
In one embodiment, the RC filter circuit comprises a filter resistor and a filter capacitor;
one end of the filter resistor is used as the input end of the RC filter circuit, the other end of the filter resistor is connected with one end of the filter capacitor, and the connection point of the filter resistor and the filter capacitor is used as the output end of the RC filter circuit; the other end of the filter capacitor is used as the grounding end of the RC filter circuit.
In one embodiment, the thermistor has a temperature measurement range of-40 ℃ to 300 ℃; the resistance range of the first divider resistor is 800k omega-10 k omega; the resistance value of the second divider resistor ranges from 10k omega to 0.1k omega.
In one embodiment, the thermistor is an NTC thermistor.
In one embodiment, the utility model also provides an intelligent household electrical appliances, temperature-detecting device including thermistor.
In one embodiment, the intelligent household appliance comprises any one or any combination of a cooker, an electric oven and a hot box.
The utility model provides a thermistor's temperature-detecting device and intelligent household electrical appliances have following technological effect:
the utility model discloses a thermistor's temperature-detecting device and intelligent household electrical appliances, including controller, first divider resistance, thermistor, active filter circuit, at least one divider resistance switching circuit and at least one second divider resistance. The first voltage dividing resistor is respectively connected with the second voltage dividing resistor and the thermistor, the active filter circuit is connected between the first voltage dividing resistor and the AD port of the controller, and the voltage dividing resistor switching circuit is connected between the second voltage dividing resistor and the corresponding IO port of the controller. The utility model discloses each embodiment accessible controller is based on first divider resistance, when second divider resistance and thermistor realize the segmentation temperature measurement, accessible active filter circuit filters the signal of telecommunication, and can prevent the change of the relation of connection between first divider resistance and the second divider resistance when the segmentation temperature measurement, thereby cause the change of load power to exert an influence to the filtering characteristic, lead to the cut-off frequency to rise so that the problem of the AD sampling shake of controller produces, thereby make and to stabilize the sampling when the segmentation temperature that corresponds detects. Further, the second voltage dividing resistor may be completely grounded to be connected in parallel with the first voltage dividing resistor by the voltage dividing resistor switching circuit. The utility model discloses a thermistor's temperature-detecting device and intelligent household electrical appliances, circuit structure is comparatively perfect and easily realize, helps reducing the utilization of resources to controller 110's data port, effectively reduces the hardware cost. Meanwhile, the anti-interference capability is high, high-precision data can be collected through the AD port when the corresponding temperature section is measured, and the reliability of temperature detection of the thermistor can be improved.
Drawings
Fig. 1 is a schematic structural diagram of a temperature detection device of a thermistor according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a voltage dividing resistor switching circuit of a temperature detection device of a thermistor according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an active filter circuit of a temperature detection device of a thermistor according to an embodiment of the present invention;
fig. 4 is another schematic structural diagram of an active filter circuit of a temperature detection device of a thermistor according to an embodiment of the present invention;
fig. 5 is another schematic structural diagram of a temperature detection device of a thermistor according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of an intelligent appliance according to an embodiment of the present invention.
Detailed Description
Hereinafter, various embodiments of the present invention will be described more fully. The present invention is capable of various embodiments and of being modified and varied therein. However, it should be understood that: there is no intention to limit the scope of the invention to the specific embodiments disclosed herein, but rather, the invention is to cover all modifications, equivalents, and/or alternatives falling within the spirit and scope of the various embodiments of the invention.
Hereinafter, the terms "includes" or "may include" used in various embodiments of the present invention indicate the presence of the disclosed functions, operations, or elements, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in various embodiments of the present invention, the terms "comprises," "comprising," "includes," "including," "has," "having" and their derivatives are intended to refer only to the particular feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as first excluding the existence of, or adding to, one or more other features, numbers, steps, operations, elements, components, or combination of the foregoing.
In various embodiments of the present invention, the expression "at least one of a or/and B" includes any or all combinations of the words listed simultaneously. For example, the expression "a or B" or "at least one of a or/and B" may include a, may include B, or may include both a and B.
Expressions (such as "first", "second", and the like) used in various embodiments of the present invention may modify various constituent elements in various embodiments, but may not limit the respective constituent elements. For example, the above description does not limit the order and/or importance of the elements. The foregoing description is for the purpose of distinguishing one element from another. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of various embodiments of the present invention.
It should be noted that: if it is described that one constituent element is "connected" to another constituent element, the first constituent element may be directly connected to the second constituent element, and a third constituent element may be "connected" between the first constituent element and the second constituent element. In contrast, when one constituent element is "directly connected" to another constituent element, it is understood that there is no third constituent element between the first constituent element and the second constituent element.
The term "user" as used in various embodiments of the present invention may indicate a person using an electronic device or a device using an electronic device (e.g., an artificial intelligence electronic device).
The terminology used in the various embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the various embodiments of the invention. 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 the various embodiments of the present invention belong. Terms such as those defined in commonly used dictionaries will be interpreted as having a meaning that is the same as a contextual meaning in the related art and will not be interpreted as having an idealized or overly formal meaning unless expressly so defined herein in various embodiments of the present invention.
Referring to fig. 1, in one embodiment, the present invention provides a temperature detection device for a thermistor, including: the circuit comprises a controller 110, a first voltage-dividing resistor R1, a thermistor R0, an active filter circuit 120, at least one voltage-dividing resistor switching circuit 130, and at least one second voltage-dividing resistor R2.
One end of the first divider resistor R1 is connected with one end of the second divider resistor R2 and one end of the thermistor R0 respectively, and the other end of the first divider resistor R1 is grounded; the input end of the active filter circuit 120 is connected to the first voltage dividing resistor R1, and the output end of the active filter circuit 120 is connected to the AD port of the controller 110; the other end of the thermistor R0 is used for connecting an input voltage VCC; the other end of the second voltage-dividing resistor R2 is connected to the first end of the voltage-dividing resistor switching circuit 130; a second terminal of the divider resistor switching circuit 130 is connected to the corresponding IO port of the controller 110, and a third terminal of the divider resistor switching circuit 130 is grounded.
The thermistor R0 can be, but is not limited to, a positive temperature coefficient thermistor or a negative temperature coefficient thermistor. The active filter circuit 120 includes an RC network circuit and an integrated operational amplifier circuit, wherein the integrated operational amplifier circuit may be, but is not limited to, a voltage follower or a low pass filter.
The first voltage dividing resistor can be used as a temperature sampling resistor, or the first voltage dividing resistor R1 and the corresponding second voltage dividing resistor R2 are connected in parallel to form temperature sampling resistors with different resistance values, and then the temperature sampling resistors are matched with the connected thermistor R0 to carry out detection in different temperature sections, so that the measurement accuracy is improved. Specifically, can be divided into a plurality of detection temperature sections according to actual detection demand, every temperature section corresponds different temperature sampling resistance value, inserts the second divider resistance R2 of corresponding number according to each temperature sampling resistance value to pass through the corresponding IO mouth of controller 110 according to detecting different temperature sections and change temperature sampling resistance value. For example, the embodiment of the present invention can be divided into temperature measurement and temperature measurement in a high temperature range and temperature measurement in a low temperature range, and then at least one second voltage-dividing resistor R2 and at least one voltage-dividing resistor switching circuit 130 connected thereto are required. For example, when a certain temperature segment is detected, the controller 110 may control the corresponding IO port to output, for example, a high-level conducting signal according to the temperature sampling resistance value corresponding to the temperature segment, so that the corresponding second voltage-dividing resistor R2 is connected in parallel with the first voltage-dividing resistor R1 through the connected voltage-dividing resistor switching circuit 130, thereby achieving the purpose of switching and changing the temperature sampling resistance value. When the parallel connection with the corresponding second voltage-dividing resistor R2 is not needed, the IO port corresponding to the controller 110 may output a low impedance state or change to an input state, so that the corresponding second voltage-dividing resistor R2 is disconnected from the parallel connection with the first voltage-dividing resistor R1. Further, the AD port of the controller 110 collects temperature measurements through the active filter circuit 120.
Further, since the corresponding IO port of the controller 110 is grounded, when the corresponding IO port of the controller 110 outputs a conducting signal such as a high level, the corresponding voltage-dividing resistor switching circuit 130 is turned on, which is equivalent to grounding of the corresponding second voltage-dividing resistor R2, thereby achieving the purpose of switching the resistance value in parallel with the first voltage-dividing resistor R1. The condition that the output signal of the IO port is unstable or other signal interference causes parallel failure of the corresponding second divider resistor R2 and the first divider resistor R1 can be prevented by the divider resistor switching circuit 130. When the controller 110 is in the low impedance state or in the input state, the voltage dividing resistance switching circuit 130 is turned off, which corresponds to the disconnection between the corresponding second voltage dividing resistance R2 and the ground. Further, the active filter circuit 120 has a characteristic of high input resistance and low output resistance, and its output voltage is equal to the input voltage. Therefore, under the condition that the operational amplifier power consumption allows, the amplification factor is not changed when the load formed by the first voltage-dividing resistor R1 and/or the second voltage-dividing resistor R2 is changed, and therefore the frequency characteristic is not changed. Therefore, the problem that the AD sampling of the controller 110 is jittered due to the fact that the filtering characteristic is affected by the change of the load power caused by the change of the connection relation between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 during temperature measurement in a segmented mode, and the cut-off frequency is increased is prevented.
The utility model discloses thermistor's temperature-detecting device, usable controller 110's an AD mouth through active filter circuit 120 and controller 110's at least one IO mouth through corresponding divider resistance switching circuit 130, the temperature data of gathering thermistor R0 carry out the AD sampling in order to accomplish the temperature detection at corresponding temperature section. The embodiment of the utility model provides a reducible data port's such as AD mouth to controller 110 use to can effectively save controller 110's port resource, reduce hardware cost.
The utility model discloses thermistor's temperature-detecting device, including controller 110, first divider resistance R1, thermistor R0, active filter circuit 120, at least one divider resistance switching circuit 130 and at least one second divider resistance R2. The first voltage dividing resistor R1 is connected to the second voltage dividing resistor R2 and the thermistor R0, respectively, the active filter circuit 120 is connected between the first voltage dividing resistor R1 and the AD port of the controller 110, and the voltage dividing resistor switching circuit 130 is connected between the second voltage dividing resistor R2 and the corresponding IO port of the controller 110. The embodiment of the utility model provides a when realizing segmentation temperature measurement based on first divider resistance R1, second divider resistance R2 and thermistor R0, accessible active filter circuit 120 filters the signal of telecommunication, and can prevent when segmentation temperature measurement, the change of the relation of connection between first divider resistance R1 and the second divider resistance R2, thereby cause the load power to change and produce the influence to filtering characteristic, lead to the cut-off frequency to rise so that controller 110's AD sampling jitter's problem produces, thereby can stabilize the sampling when making the segmentation temperature that corresponds examine. Further, the second voltage-dividing resistor R2 may be fully grounded to be connected in parallel with the first voltage-dividing resistor R1 by the voltage-dividing resistor switching circuit 130. The utility model discloses a thermistor's temperature-detecting device, circuit structure are comparatively perfect and easy to be realized, help reducing the utilization of resources to controller 110's data port, effectively reduce the hardware cost. Meanwhile, the anti-interference capability is high, high-precision data can be collected through the AD port when the corresponding temperature section is measured, and the reliability of temperature detection of the thermistor R0 can be improved.
Referring to fig. 1 and 2, in a specific embodiment, the voltage dividing resistor switching circuit 130 includes a switch transistor T1 and a third voltage dividing resistor R3.
A first end 1 of the switch tube T1 is used as a first end of the voltage-dividing resistor switching circuit 130, a second end 2 of the switch tube T1 is connected to one end of the third voltage-dividing resistor R3, and a third end 3 of the switch tube T1 is used as a third end of the voltage-dividing resistor switching circuit 130; the other end of the third voltage-dividing resistor R3 serves as a second end of the voltage-dividing resistor switching circuit.
The switch transistor T1 can be, but is not limited to, a triode or a field effect transistor. For example, when the switch transistor T1 is an NPN transistor, the collector of the NPN transistor serves as the first terminal of the switch transistor T1, the base thereof serves as the second terminal of the switch transistor T1, and the emitter thereof serves as the third terminal of the switch transistor T1. The corresponding IO port of the controller 110 outputs a conducting signal, such as a high level, the third voltage dividing resistor R3 in the corresponding voltage dividing resistor switching circuit 130 pulls the base potential of the switching tube T1 high, the collector and the emitter are both in forward bias, and at this time, the switching tube T1 is in a saturated state, so that the switching tube T1 is turned on, which is equivalent to the fact that the connected second voltage dividing resistor R2 is grounded, thereby achieving the purpose of being connected in parallel with the first voltage dividing resistor R1. For another example, when the switch transistor T1 is an NMOS transistor, the D-pole of the NMOS transistor is the first terminal of the switch transistor T1, the G-pole is the second terminal of the switch transistor T1, and the S-pole is the third terminal of the switch transistor T1. When the corresponding IO port of the controller 110 outputs a conducting signal, such as a low level, the third voltage-dividing resistor R3 in the corresponding voltage-dividing resistor switching circuit 130 pulls the G pole potential of the switch tube T1 low, and at this time, the switch tube T1 is turned on, which is equivalent to the second voltage-dividing resistor R2 connected to ground, so as to achieve the purpose of parallel connection of the first voltage-dividing resistor R1.
The utility model discloses thermistor's temperature-detecting device, divider resistance switching circuit 130 include switch tube T1 and third divider resistance R3 to the break-make of switch tube T1 is controlled to the IO mouth accessible third divider resistance R3 that corresponds of controller, makes the effective ground connection of second divider resistance R2 that corresponds parallelly connected with first divider resistance R1, or effectively breaks off with ground. The condition that the output signal of the IO port is unstable or other signal interference causes the parallel failure of the corresponding second divider resistor R2 and the corresponding first divider resistor R1 is prevented. The embodiment of the utility model provides a help when carrying out the temperature detection at the temperature section that corresponds, keep temperature sampling resistance at corresponding resistance value reliably and steadily, and then improve the degree of accuracy that the temperature detected.
Referring to fig. 1 and 2, in a specific embodiment, the voltage dividing resistance switching circuit 130 further includes a pull-down resistor R4; the pull-down resistor R4 is connected between the third terminal of the switch transistor T1 and one terminal of the third voltage dividing resistor R3.
The utility model discloses thermistor's temperature-detecting device, pull-down resistance R4 among the divider resistance switching circuit 130 can prevent that switch tube T1 from being switched on because of disturbing, leading to the condition of spurious triggering. The embodiment of the utility model provides a reliability that temperature detection has further been improved.
Referring to fig. 2, in one embodiment, the switch transistor T1 is a transistor or a fet.
The transistor T1 may be an NPN transistor or a PNP transistor, and the fet may be an NMOS transistor or a PMOS transistor.
The utility model discloses thermistor's temperature-detecting device, triode or field effect transistor can regard as the switch tube T1 among the divider resistance switching circuit, can satisfy different assembly requirements, help realizing the temperature measurement demand of different temperature-detecting device at different temperature sections simultaneously.
Referring to fig. 1 and 3, in a particular embodiment, active filter circuit 120 includes an RC filter circuit 310 and a voltage follower 320.
An input end IN of the RC filter circuit 310 serves as an input end of the active filter circuit 120 and is connected to one end of the first voltage-dividing resistor R1, an output end of the RC filter circuit 310 is connected to a non-inverting input end of the voltage follower 320, and a ground end GND of the RC filter circuit 310 is connected to the other end of the first voltage-dividing resistor R1; the output terminal of the voltage follower 320 serves as the output terminal of the active filter circuit 120, and is connected to the inverting input terminal of the voltage follower 320 and the AD port of the controller 110, respectively.
The RC filter circuit 310 and the voltage follower 320 cooperate with each other to form the active filter circuit 120, wherein the input resistance of the voltage follower 320 is infinite, and the output resistance is zero. Therefore, the condition that the band-pass amplification factor and the cut-off frequency thereof are changed along with the change of the connection relation of the first divider resistor R1 and the second divider resistor R2 can be prevented, and the frequency characteristic is ensured to be unchanged.
The utility model discloses thermistor's temperature-detecting device, the structure is comparatively perfect, and through RC filter circuit 310 and the voltage follower 320 that active filter circuit 120 includes, its hardware circuit cost is lower and easily realize, can prevent simultaneously that the load change from leading to the emergence of cutoff frequency rising so that controller 110's AD sampling shake problem, has further improved the interference killing feature.
Referring to fig. 1 and 4, as a preferred embodiment, the active filter circuit 120 includes an RC filter circuit 310 and a low pass filter 330.
The low pass filter 330 includes a resistor R5, a resistor R6, a resistor R7, a capacitor Cd, and an operational amplifier module U1. The inverting input end of the operational amplifier module U1 is connected to the RC filter circuit 310 through a resistor R5, the non-inverting input end is grounded through a resistor R7, the output end is connected to the AD port of the controller 110, and the resistor R6 and the capacitor Cd are respectively connected in parallel between the inverting input end and the output end of the operational amplifier module U1.
The utility model discloses thermistor's temperature-detecting device, the circuit is comparatively perfect, and accessible RC filter circuit 310 and low pass filter 330 are formed with active filter circuit 120, have improved the interference killing feature, can make thermistor's temperature-detecting device can adapt to more electric environment.
Referring to fig. 3, in one particular embodiment, RC filter circuit 310 includes a filter resistor Ra and a filter capacitor Cb.
One end of the filter resistor Ra serves as an input terminal IN of the RC filter circuit 310, the other end of the filter resistor Ra is connected to one end of the filter capacitor Cb, and a connection point of the filter resistor Ra and the filter capacitor Cb serves as an output terminal of the RC filter circuit 310; the other end of the filter capacitor Cb serves as a ground GND of the RC filter circuit 310.
The utility model discloses thermistor's temperature-detecting device, its RC filter circuit 310 include filter resistance Ra and filter capacitor Cb, and circuit structure is simple and easily realize, can cooperate voltage follower 320 to be formed with active filter circuit to improve thermistor's temperature-detecting device's interference killing feature.
In one specific embodiment, the thermistor has a temperature measurement range of-40 ℃ to 300 ℃; the resistance range of the first divider resistor is 800k omega-10 k omega; the resistance value of the second divider resistor ranges from 10k omega to 0.1k omega.
The utility model discloses thermistor's temperature-detecting device, thermistor's temperature measurement scope to and the resistance scope of first divider resistance and second divider resistance is comparatively moderate, can satisfy the temperature measurement demand under the daily different environment. Furthermore, the resistance ranges of the first voltage-dividing resistor and the second voltage-dividing resistor are matched with each other to form temperature sampling resistance values required by different temperature sections in parallel, and meanwhile, the temperature measurement of the low-temperature section and the high-temperature section can be facilitated.
In a specific embodiment, the thermistor is an NTC thermistor.
The utility model discloses thermistor's temperature-detecting device, thermistor are NTC thermistor, and negative temperature coefficient's thermistor variation range is great promptly, but the wide application helps realizing the temperature measurement demand of many temperature sections in various temperature-detecting device.
Referring to fig. 5, as a preferred embodiment, the thermistor R0 of the temperature detection device of the thermistor of the present invention is a negative temperature coefficient thermistor, and the voltage dividing resistor switching circuit includes an NPN transistor T1, a third voltage dividing resistor R3 and a pull-down resistor R4. The active filter circuit includes a filter resistor Rb, a filter capacitor Cb, and a voltage follower 320. Further, the temperature measuring section is divided into a high temperature section and a low temperature section by the thermistor R0, the first voltage dividing resistor R1, the second voltage dividing resistor R2, the voltage dividing resistor switching circuit and the active filter circuit.
For example, in the low temperature stage detection, the controller 110 sets the corresponding IO port to the input state, which corresponds to an open circuit between the second voltage-dividing resistor R2 and the controller 110, and at this time, the temperature sampling resistor is the first voltage-dividing resistor R1. During the high temperature segment detection, the controller 110 outputs a high level to the second voltage-dividing resistor R2 through the voltage-dividing resistor switching circuit, and at this time, the second voltage-dividing resistor R2 is grounded through the controller 110, which is equivalent to be connected in parallel with R1, that is, the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 are connected in parallel as a temperature sampling resistor in the high temperature segment.
Further, when measuring the temperature, the controller 110 may first perform low-temperature segment detection, set the corresponding IO port as an input state, and obtain an AD sampling value acquired by the thermistor R0 through the AD port, if the AD sampling value is less than or equal to a preset open threshold, it indicates that the thermistor R0 is open, and if the AD sampling value is greater than the preset open threshold and less than a preset high-temperature threshold, it indicates that the low-temperature segment is in the current state, and low-temperature segment detection needs to be performed. If the AD sampling value is greater than or equal to the preset high temperature threshold value, which indicates that the temperature is in the high temperature section at this time, and the high temperature section needs to be detected, the controller 110 connects the first voltage dividing resistor R1 and the second voltage dividing resistor R2 in parallel to serve as the temperature sampling resistor. Further, at this time, if the AD sample value is greater than or equal to the preset short-circuit threshold, it indicates that the thermistor R0 is short-circuited, if the AD sample value is smaller than the preset short-circuit threshold and greater than the preset low-temperature threshold, it indicates that the sample is still in the high-temperature section, and if the AD sample value is smaller than or equal to the preset low-temperature threshold, it indicates that the sample is in the low-temperature section, and the low-temperature section detection is required.
The utility model discloses thermistor's temperature-detecting device, circuit structure are comparatively perfect and easily realize, help reducing the utilization of resources to controller 110's data port, effectively reduce the hardware cost. Meanwhile, the anti-interference capability is high, high-precision data can be collected through the AD port when the corresponding temperature section is measured, and the reliability of temperature detection of the thermistor can be improved. Meanwhile, the temperature measurement of high and low temperature sections can be stably and accurately realized, and various temperature measurement requirements are met.
Referring to fig. 6, in one embodiment, the present invention further provides an intelligent home appliance, including a temperature detection device 610 of a thermistor.
It should be noted that, for the limitation description of the temperature detection device 610 of the thermistor according to the embodiment of the present invention, reference may be made to the above limitation description of the temperature detection device of the thermistor, and details are not repeated here.
In a specific embodiment, the smart appliance includes any one or any combination of a cooker, an oven, and an electric griddle.
The utility model discloses intelligent household electrical appliances still include electric water heater and gas heater.
Those skilled in the art will appreciate that the drawings are merely schematic representations of one preferred implementation scenario and that the blocks or flow diagrams in the drawings are not necessarily required to practice the present invention.
Those skilled in the art will appreciate that the modules in the devices in the implementation scenario may be distributed in the devices in the implementation scenario according to the description of the implementation scenario, or may be located in one or more devices different from the present implementation scenario with corresponding changes. The modules of the implementation scenario may be combined into one module, or may be further split into a plurality of sub-modules.
The sequence numbers of the present invention are only for description, and do not represent the advantages and disadvantages of the implementation scenario. The above disclosure is only a few specific implementation scenarios of the present invention, however, the present invention is not limited thereto, and any changes that can be considered by those skilled in the art shall fall within the protection scope of the present invention.
Claims (10)
1. A temperature detection device for a thermistor, comprising: a controller (110), a first voltage dividing resistor (R1), a thermistor (R0), an active filter circuit (120), at least one voltage dividing resistor switching circuit (130), and at least one second voltage dividing resistor (R2);
one end of the first voltage-dividing resistor (R1) is respectively connected with one end of the second voltage-dividing resistor (R2) and one end of the thermistor (R0), and the other end of the first voltage-dividing resistor (R1) is grounded; the input end of the active filter circuit (120) is connected with the first voltage dividing resistor (R1), and the output end of the active filter circuit (120) is connected with the AD port of the controller (110); the other end of the thermistor (R0) is used for connecting an input voltage; the other end of the second voltage-dividing resistor (R2) is connected with the first end of the corresponding voltage-dividing resistor switching circuit (130); the second end of the divider resistance switching circuit (130) is connected with the corresponding IO port of the controller (110), and the third end of the divider resistance switching circuit (130) is grounded.
2. The temperature detecting device of a thermistor according to claim 1, characterized in that the voltage dividing resistance switching circuit (130) comprises a switching tube (T1) and a third voltage dividing resistance (R3);
a first end of the switch tube (T1) is used as a first end of the voltage-dividing resistance switching circuit (130), a second end of the switch tube (T1) is connected with one end of the third voltage-dividing resistance (R3), and a third end of the switch tube (T1) is used as a third end of the voltage-dividing resistance switching circuit (130); the other end of the third voltage dividing resistor (R3) serves as a second end of the voltage dividing resistor switching circuit (130).
3. The thermistor temperature detection device according to claim 2, wherein the voltage-dividing resistance switching circuit (130) further comprises a pull-down resistor (R4); the pull-down resistor (R4) is connected between the third end of the switch tube (T1) and one end of the third voltage-dividing resistor (R3).
4. The thermistor temperature detecting device according to claim 2, characterized in that the switching tube (T1) is a triode or a field effect transistor.
5. The thermistor temperature detecting device according to claim 1, characterized in that the active filter circuit (120) comprises an RC filter circuit (310) and a voltage follower (320);
the input end of the RC filter circuit (310) serves as the input end of the active filter circuit (120) and is connected with one end of the first voltage-dividing resistor (R1), the output end of the RC filter circuit (310) is connected with the non-inverting input end of the voltage follower (320), and the grounding end of the RC filter circuit (310) is connected with the other end of the first voltage-dividing resistor (R1); the output end of the voltage follower (320) is used as the output end of the active filter circuit (120), and is respectively connected with the inverting input end of the voltage follower (320) and the AD port of the controller (110).
6. The thermistor temperature detecting device according to claim 5, characterized in that the RC filter circuit (310) comprises a filter resistor (Rb) and a filter capacitor (Cb);
one end of the filter resistor (Rb) is used as an input end of the RC filter circuit (310), the other end of the filter resistor (Rb) is connected with one end of the filter capacitor (Cb), and a connection point of the filter resistor (Rb) and the filter capacitor (Cb) is used as an output end of the RC filter circuit (310); the other end of the filter capacitor (Cb) serves as a ground terminal of the RC filter circuit (310).
7. The temperature detecting device of a thermistor according to claim 1, characterized in that the temperature measuring range of the thermistor is-40 ℃ -300 ℃; the resistance range of the first divider resistor is 800k omega-10 k omega; the resistance value range of the second divider resistor is 10k omega-0.1 k omega.
8. The temperature detecting device of a thermistor according to claim 1, wherein the thermistor is an NTC thermistor.
9. An intelligent home appliance comprising the thermistor temperature detection device according to any one of claims 1 to 8.
10. The intelligent household appliance according to claim 9, wherein the intelligent household appliance comprises any one or any combination of a kitchen range, an oven and an electric griddle.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114199403A (en) * | 2021-12-07 | 2022-03-18 | 珠海格力电器股份有限公司 | Temperature sampling device, control method thereof and motor control system |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114199403A (en) * | 2021-12-07 | 2022-03-18 | 珠海格力电器股份有限公司 | Temperature sampling device, control method thereof and motor control system |
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