Electric heater detection circuit, electric heating device and refrigerator

Abstract

The utility model relates to an electric heater detection circuit, an electric heating device and a refrigerator, the electric heater detection circuit comprises a switching module, a sampling module and a first power supply, a first end of the switching module is connected with an electric heater, and a second end of the switching module is connected with the sampling module or the first power supply; when the second end of the switching module is connected with the first power supply, the first power supply supplies power to the electric heater; and when the second end of the switching module is connected with the sampling module, the sampling module is used for sampling the voltage at the two ends of the electric heater. According to the invention, the problem that whether the electric heater is in a normal working state cannot be accurately judged is solved.

Description

Technical Field

[0001] The present application relates to the field of electric heating, and in particular to an electric heater detection circuit, an electric heating device, and a refrigerator. Background Art

[0002] Electric heating is a technology that converts electrical energy into thermal energy. It is widely used in many fields such as industrial production, family life, scientific research experiments, etc. Electric heating equipment heats various media or objects by converting electrical energy into thermal energy.

[0003] In the related art, the parameters such as electric heating power and resistance are detected by equipment before leaving the factory. After the electric heater leaves the factory, the existing circuit cannot directly detect the power or resistance of the electric heater, and can only be indirectly measured through the NTC temperature sensor placed next to it. Within the specified time, if the temperature rise detected by the NTC temperature sensor is normal, it is judged that there is no abnormality in the electric heating. However, due to installation differences, differences in ambient temperature and humidity, the results of this detection method are inaccurate. Taking the installation of an electric heater in a refrigerator as an example, the number of times the user opens and closes the door and the water vapor content in the refrigerator will cause huge differences in the amount of ice on the evaporator, which will cause the temperature measured by the NTC temperature sensor to fail to reflect the working status of the electric heating, resulting in inaccurate detection results.

[0004] Currently, no effective solution has been proposed for the problem in the related art that it is impossible to accurately determine whether the electric heater is in a normal working state. Utility Model Content

[0005] The embodiments of the present application provide an electric heater detection circuit, an electric heating device, and a refrigerator, so as to at least solve the problem in the related art that it is impossible to accurately determine whether the electric heater is in a normal working state.

[0006] In a first aspect, an embodiment of the present application provides an electric heater detection circuit, comprising: a switching module, a sampling module and a first power supply, wherein a first end of the switching module is connected to the electric heater, and a second end of the switching module is connected to the sampling module or the first power supply; wherein,

[0007] When the second end of the switching module is connected to the first power supply, the first power supply supplies power to the electric heater;

[0008] When the second end of the switching module is connected to the sampling module, the sampling module is used to sample the voltage across the electric heater.

[0009] In some embodiments, the switching module includes: a switching switch, a first contact located at a first end of the switching module, a second contact and a third contact located at a second end of the switching module, the first contact is connected to the electric heater, the second contact is connected to the sampling module, and the third contact is connected to the first power supply; wherein,

[0010] The switch is used to conduct an electrical path between the first contact and the second contact or between the first contact and the third contact.

[0011] In some embodiments, the sampling module includes: a sampling resistor and a second power supply, wherein a first end of the second power supply is connected to the switching module, a second end of the second power supply is connected to a first end of the sampling resistor, and a second end of the sampling resistor is connected to the switching module.

[0012] In some embodiments, the sampling module further comprises: a computing unit; wherein,

[0013] The calculation unit is used to obtain the voltage value across the electric heater.

[0014] In some embodiments, the switching module further includes a driving unit, one end of the driving unit is connected to the computing unit, and the other end of the driving unit is connected to the switching module.

[0015] In some embodiments, a supply voltage of the second power supply is lower than a supply voltage of the first power supply.

[0016] In some embodiments, it further includes: a display module, the display module is connected to the sampling module; wherein,

[0017] The display module is used to display the sampling result of the sampling module.

[0018] In a second aspect, an embodiment of the present application provides an electric heating device, comprising: a heating module, a switching module, a sampling module and a first power supply, wherein a first end of the switching module is connected to the heating module, and a second end of the switching module is connected to the sampling module or the first power supply; wherein,

[0019] When the switching module is connected to the first power supply and the heating module, the electric heating device performs a heating function based on the first power supply;

[0020] When the switching module is connected to the sampling module and the heating module, the electric heating device performs a detection function based on the sampling module.

[0021] In some embodiments, the heating module includes: a mounting portion and a heating tube, and the heating tube is fixed to the mounting portion.

[0022] In a third aspect, an embodiment of the present application provides a refrigerator, comprising: a refrigerator body, an evaporator, and the electric heating device described in the first aspect above.

[0023] An electric heater detection circuit, an electric heating device, and a refrigerator can control the electric heater to not only be connected to the first power supply by changing the connection object of the switching module so that the electric heater can work normally, but also be connected to the sampling module to realize the voltage sampling function, thereby making it possible to judge whether the electric heater is in a normal working state according to the voltage value, thereby solving the problem of being unable to accurately judge whether the electric heater is in a normal working state.

[0024] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 is a schematic diagram of the structure of an electric heater detection circuit in one embodiment;

[0027] Figure 2 is a schematic diagram of the structure of an electric heating detection circuit in an embodiment;

[0028] Figure 3 is a structural schematic diagram of an electric heating detection circuit in another embodiment;

[0029] Figure 4 is a schematic structural diagram of an electric heating device in one embodiment;

[0030] Figure 5 It is a schematic diagram of the structure of a refrigerator in one embodiment.

[0031] Figure numerals: 1. electric heater detection circuit; 10. first power supply; 11. switching module; 110. switching device; 111. driving unit; 12. sampling module; 120. sampling resistor; 121. second power supply; 2. electric heater; 20. heating module; 3. electric heating device; 4. refrigerator body; 5. evaporator. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means, and should not be understood as insufficient contents disclosed in the present application.

[0033] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0034] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to greater than or equal to two. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", "third" and the like involved in the present application are merely used to distinguish similar objects and do not represent a specific ordering of the objects.

[0035] In one embodiment, an electric heater detection circuit 1 is provided. Figure 1Schematic diagram of the structure of the electric heater detection circuit 1 in this embodiment. Figure 1 As shown, it includes: a switching module 11, a sampling module 12 and a first power supply 10, the first end of the switching module 11 is connected to the electric heater 2, and the second end of the switching module 11 is connected to the sampling module 12 or the first power supply 10; wherein, when the second end of the switching module 11 is connected to the first power supply 10, the first power supply 10 supplies power to the electric heater 2; when the second end of the switching module 11 is connected to the sampling module 12, the sampling module 12 is used to sample the voltage at both ends of the electric heater 2.

[0036] The first power supply 10 is an AC power supply or a DC power supply that meets the working conditions of the electric heater 2. The switching module 11 can be a mechanical switch that changes the on / off state of the circuit through physical contact, or a device such as a relay that controls the switch state based on electromagnetic principles.

[0037] When the second end of the switching module 11 is connected to the first power supply 10, the electric heater 2, the switching module 11, and the first power supply 10 are connected in sequence, and the electric heater 2 can work normally based on the electrical signal provided by the first power supply 10, for example, perform a heating function. When the second end of the switching module 11 is connected to the sampling module 12, the electric heater 2, the switching unit, and the sampling module 12 are connected in sequence, and the sampling module 12 samples the voltage value at both ends of the electric heater 2. Optionally, the sampling module 12 can sample the voltage value at both ends of the electric heater 2 through a resistance sampling circuit.

[0038] In this embodiment, the object connected to the electric heater 2 is switched by the switching module 11, so that the electric heater 2 can be connected to the first power supply 10 for normal operation, and can also be connected to the sampling device to obtain the voltage across the electric heater 2, making it possible to judge whether the electric heater 2 is in a normal working state based on the voltage, thereby solving the problem of being unable to accurately judge whether the electric heater 2 is in a normal working state.

[0039] In one embodiment, the switching module 11 includes: a switching switch, a first contact located at the first end of the switching module 11, a second contact and a third contact located at the second end of the switching module 11, the first contact is connected to the electric heater 2, the second contact is connected to the sampling module 12, and the third contact is connected to the first power supply source 10; wherein the switching switch is used to conduct an electrical path between the first contact and the second contact or between the first contact and the third contact.

[0040] Among them, the switching switch is an electrical component used to change the circuit connection path. The switching switch can be a manual switch that realizes the switching function by sliding, pressing, rotating, etc., or it can be an existing programmable switch that performs the circuit switching function in response to a built-in program or an external control signal. The switching switch can be selected according to application requirements.

[0041] The first contact, the second contact and the third contact are components made of conductors, which may be metal sheets, points, rings and other components with conductive functions. When the switch is operated, the contacts are in contact with each other, allowing current to pass; when the contacts are not in contact, the circuit is disconnected, preventing the current from flowing.

[0042] This embodiment realizes electrical conduction between the first contact and the second contact, or electrical conduction between the first contact and the second contact through the first contact, the second contact and the third contact and the switching module 11 of the switching switch, and has a simple structure and low cost.

[0043] In one embodiment, the sampling module 12 includes: a sampling resistor 120 and a second power supply 121, wherein a first end of the second power supply 121 is connected to the switching module 11, a second end of the second power supply 121 is connected to a first end of the sampling resistor 120, and a second end of the sampling resistor 120 is connected to the switching module 11; wherein a supply voltage of the second power supply 121 is lower than a supply voltage of the first power supply 10.

[0044] The sampling resistor 120 may be one or more resistors. After a loop is formed by the second power supply 121, the sampling resistor 120, and the electric heater 2, the sampling resistor 120 divides the voltage of the electric heater 2. Optionally, the first end of the sampling resistor 120 is connected to the second end of the second power supply 121, and the second end of the sampling resistor 120 is connected to the second contact in the switching module 11.

[0045] Optionally, the supply voltage of the second power supply 121 is lower than the supply voltage of the first power supply 10. By supplying power to the sampling module 12 through the second power supply 121 having a supply voltage lower than that of the first power supply 10, the stability during the voltage sampling process can be improved, and the integration of the sampling module 12 can also be improved.

[0046] Furthermore, in one embodiment, the sampling module 12 further includes: a calculation unit; wherein the calculation unit is used to obtain the voltage value at both ends of the electric heater 2. Optionally, one end of the calculation unit is connected to the first end of the electric heater, and the other end of the calculation unit is connected to the second end of the electric heater. After the second power supply 121, the sampling resistor 120, and the electric heater 2 form a loop, the calculation unit can convert the analog signal at both ends of the electric heater 2 into a digital signal, thereby obtaining the analog value of the voltage value at both ends of the electric heater 2, so that it is possible to judge the state of the electric heater 2 based on the voltage value of the electric heater 2.

[0047] Optionally, after obtaining the digital signal of the voltage applied to the two ends of the electric heater 2, the calculation unit can also obtain the resistance value of the sampling resistor 120 in the sampling module 12 and the voltage of the second power supply 121, and deduce the resistance value, power and other parameters of the electric heater 2 based on the voltage division principle, thereby making it possible to judge the state of the electric heater 2 based on the resistance value and power of the electric heater 2.

[0048] Furthermore, in one embodiment, the switching module 11 further includes a driving unit 111 , one end of the driving unit 111 is connected to the computing unit, and the other end of the driving unit 111 is connected to the switching module 11 .

[0049] Among them, the driving module is used to output a signal to change the connectivity state of the switching module 11, so that the second end of the switching module 11 is connected to the first power supply 10, or the second end of the switching module 11 is connected to the sampling module 12. Optionally, the driving unit 111 can also be used to assist the work of the computing unit. Optionally, the driving unit 111 is formed based on the existing driving circuit to provide necessary amplification, filtering, level conversion and other signal processing functions for the input and output signals of the computing module, or to provide protection mechanisms such as current limiting and short circuit protection for the computing module.

[0050] In one embodiment, it further includes: a display module, the display module is connected to the sampling module 12; wherein the display module is used to display the sampling result of the sampling module 12. Optionally, the display module can be used to display the voltage value sampled by the sampling module 12. Alternatively, if the sampling module 12 includes a calculation unit, when the calculation unit calculates the resistance value, power and other parameters of the electric heater 2 based on the voltage division principle, it can also be used to display the corresponding resistance value, power and other parameters. In this embodiment, the display unit is used to intuitively display the working state of the electric heater 2.

[0051] The embodiments of the present application are described and illustrated below through preferred embodiments.

[0052] In one embodiment, Figure 2A structural schematic diagram of an electric heating detection circuit is provided, and the electric heating detection circuit includes an MCU, a sampling module 12, a switching module 11 and an electric heater 2. When the electric heater 2 works normally, the switching module 11 is connected to a strong power supply. When driving the electric heating, the MCU controls the switching module 11 to connect the electric heating to the live wire and the neutral wire of the strong power, and drives the electric heating to work. Among them, the strong power is the mains power with an input voltage of AC220V, 50Hz. When there is a detection demand for the electric heater 2, the connection with the strong power is disconnected through the switching module 11, and it is connected to the sampling module 12 containing a DC power supply. Among them, the MCU includes a computing module. Optionally, after the electric heater 2 is connected to the sampling module 12, the voltage at both ends of the electric heater 2 is obtained through the sampling module 12, and an analog signal is sent to the calculation module in the MCU, and the calculation module converts the analog signal at both ends of the electric heater 2 into a data signal, and the voltage at both ends of the electric heater 2, the voltage of the DC power supply and the resistance of the sampling resistor 120 are calculated based on the voltage division principle to obtain the specific resistance value of the electric heating, and the specific resistance value of the electric heating is compared with the preset resistance value to obtain a conclusion on whether the electric heating is in an abnormal state. A weak current circuit refers to a circuit whose input voltage is less than DC 36V. In this embodiment, DC 5V is selected as the second power supply 121. Optionally, after obtaining a conclusion on whether the electric heating is in an abnormal state, the conclusion is displayed through a display module to prompt the user to replace the electric heater. The display module can use an existing display panel.

[0053] Figure 3 Another schematic diagram of the electric heating detection circuit is provided. Figure 3 As shown, the first power supply 10 is an AC power supply, and the second power supply 121 is a DC power supply. The switching module 11 is mainly composed of a driving unit 111 and a switching device 110. Among them, the switching device 110 has 6 contacts, the two leftmost contacts are third contacts, directly connected to the AC power supply; the two middle contacts are first contacts, connected to the electric heater 2; the two rightmost contacts are second contacts, connected to the voltage sampling module 12.

[0054] Wherein, when driving the electric heater 2, the MCU (Microcontroller Unit) controls the switching circuit so that the first contact of the switching device 110 contacts the third contact, so that the electric heating can be connected to the AC power supply and drive the electric heating to work. When detecting electric heating, the MCU controls the switching circuit so that the first contact of the switching device 110 contacts the second contact, so that the electric heating can be switched to a low-voltage weak current circuit powered by a DC power supply and connected to the sampling module 12. Wherein, the sampling resistor 120 is a precision pull-up resistor with a known resistance value. At this time, the sampling module 12 can obtain an accurate sampling voltage at both ends of the electric heating and send it to the MCU, wherein the MCU includes a calculation module to perform AD conversion on the sampling voltage value. Optionally, the MCU can also calculate the resistance value of the electric heater 2, and compare it with a preset value, so as to accurately confirm whether the current electric heating is in a normal working state according to the comparison result. Optionally, obtaining the resistance value according to the voltage includes: obtaining the DC power supply V0, the resistance value R0 of the sampling resistor 120, and the voltage divider value V1 at both ends of the electric heater; according to Ohm's law, obtaining the resistance value of the electric heater: R1=V1R0 / (V0-V1). If the resistance value of the electric heater is greater than the threshold value, it is confirmed that the user needs to replace the electric heater; if the resistance value of the electric heater is less than or equal to the threshold value, it is confirmed that the user does not need to replace the electric heater. It is understandable that the AD conversion function in the calculation unit is also performed based on existing devices other than the MCU, or the calculation and comparison functions of the resistance value of the electric heater 2 are realized.

[0055] Compared with the traditional technology that the resistance of the electric heater cannot be directly detected after leaving the factory, and whether the electric heater is damaged can only be determined based on the temperature sensor next to the electric heater, in this embodiment, this circuit can not only drive the electric heater, but also accurately detect the current electrical parameters of the electric heater, such as the voltage, resistance and other parameters of the electric heater, so as to accurately determine whether the user needs to replace the electric heater, thereby solving the problem of not being able to accurately judge whether the electric heater is in normal working condition.

[0056] This embodiment also provides an electric heating device 3, which is used to implement the above embodiments and preferred embodiments, and will not be repeated for what has been described. As used below, the terms "module", "unit", "subunit" and the like can implement a combination of software and / or hardware of a predetermined function. Although the device described in the following embodiments is preferably implemented in hardware, the implementation of a combination of existing software and hardware is also possible and conceivable.

[0057] Figure 4 is a schematic diagram of the structure of the electric heating device 3 according to an embodiment of the present application. Figure 4As shown, the device includes: a heating module 20, a switching module 11, a sampling module 12 and a first power supply 10, the first end of the switching module 11 is connected to the heating module 20, and the second end of the switching module 11 is connected to the sampling module 12 or the first power supply 10; wherein, when the switching module 11 is connected to the first power supply 10 and the heating module 20, the electric heating device 3 performs a heating function based on the first power supply 10; when the switching module 11 is connected to the sampling module 12 and the heating module 20, the electric heating device 3 performs a detection function based on the sampling module 12. Optionally, the heating module 20 includes: a mounting portion and a heating tube, and the heating tube is fixed to the mounting portion.

[0058] In one embodiment, the switching module 11 includes: a switching switch, a first contact located at the first end of the switching module 11, a second contact and a third contact located at the second end of the switching module 11, the first contact is connected to the electric heater 2, the second contact is connected to the sampling module 12, and the third contact is connected to the first power supply source 10; wherein the switching switch is used to conduct an electrical path between the first contact and the second contact or between the first contact and the third contact.

[0059] In one embodiment, the sampling module 12 includes: a sampling resistor 120 and a second power supply 121, wherein the first end of the second power supply 121 is connected to the switching module 11, the second end of the second power supply 121 is connected to the first end of the sampling resistor 120, and the second end of the sampling resistor 120 is connected to the switching module 11. Optionally, in some embodiments, the sampling module 12 further includes: a calculation unit; wherein the calculation unit is used to obtain the voltage value across the electric heater 2. Optionally, the supply voltage of the second power supply 121 is lower than the supply voltage of the first power supply 10.

[0060] Optionally, the switching module 11 further includes a driving unit 111 , one end of the driving unit 111 is connected to the computing unit, and the other end of the driving unit 111 is connected to the switching module 11 .

[0061] In one embodiment, it further includes: a display module, which is connected to the sampling module 12; wherein the display module is used to display the sampling results of the sampling module 12.

[0062] In some of the embodiments, this embodiment further provides a refrigerator, which is used to implement the above embodiments and preferred implementation modes, and those that have been described will not be repeated here. Figure 5 is a schematic diagram of the structure of the refrigerator in the embodiment of the present application. Figure 5 As shown, the refrigerator comprises: a refrigerator body 4, an evaporator 5 and an electric heating device 3, wherein the electric heating device 3 is a device in any of the above device embodiments.

[0063] Those skilled in the art should understand that the technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An electric heater detection circuit, characterized in that: include: A switching module, a sampling module and a first power supply, wherein the first end of the switching module is connected to the electric heater, and the second end of the switching module is connected to the sampling module or the first power supply; wherein, When the second end of the switching module is connected to the first power supply, the first power supply supplies power to the electric heater; When the second end of the switching module is connected to the sampling module, the sampling module is used to sample the voltage across the electric heater.

2. The electric heater detection circuit according to claim 1, characterized in that: The switching module includes: a switching switch, a first contact located at a first end of the switching module, a second contact and a third contact located at a second end of the switching module, the first contact is connected to the electric heater, the second contact is connected to the sampling module, and the third contact is connected to the first power supply; wherein, The switch is used to conduct an electrical path between the first contact and the second contact or between the first contact and the third contact.

3. The electric heater detection circuit according to claim 1, characterized in that: The sampling module includes: a sampling resistor and a second power supply, wherein a first end of the second power supply is connected to the switching module, a second end of the second power supply is connected to a first end of the sampling resistor, and a second end of the sampling resistor is connected to the switching module.

4. The electric heater detection circuit according to claim 3, characterized in that: The sampling module further includes: a calculation unit; wherein, The calculation unit is used to obtain the voltage value across the electric heater.

5. The electric heater detection circuit according to claim 4, characterized in that: The switching module further includes a driving unit, one end of which is connected to the computing unit, and the other end of which is connected to the switching module.

6. The electric heater detection circuit according to claim 3, characterized in that: A supply voltage of the second power supply is lower than a supply voltage of the first power supply.

7. The electric heater detection circuit according to claim 1, characterized in that: Also includes: A display module is connected to the sampling module; wherein: The display module is used to display the sampling result of the sampling module.

8. An electric heating device, characterized in that: include: A heating module, a switching module, a sampling module and a first power supply, wherein the first end of the switching module is connected to the heating module, and the second end of the switching module is connected to the sampling module or the first power supply; wherein, When the switching module is connected to the first power supply and the heating module, the electric heating device performs a heating function based on the first power supply; When the switching module is connected to the sampling module and the heating module, the electric heating device performs a detection function based on the sampling module.

9. The electric heating device according to claim 8, characterized in that: The heating module comprises: a mounting portion and a heating tube, wherein the heating tube is fixed to the mounting portion.

10. A refrigerator, characterized in that: include: A refrigerator body, an evaporator and the electric heating device as claimed in claim 8.

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