CN215187467U - Coupling coil and household appliance - Google Patents

Abstract

The application relates to the technical field of coupling coils and discloses a coupling coil and a household appliance. The coupling coil includes: a first coil configured to be coupleable with an external metal; the second coil is connected with the first coil in series; the third coil is coupled with the second coil; the third coil is an air-core coil and is used for detecting the electric signal of the third coil to obtain the electric signal of the first coil. Through the mode, the influence of temperature change on the coupling coil is reduced, and the accuracy of the electric signal sampled by the coupling coil is improved.

Description

Coupling coil and household appliance

Technical Field

The application relates to the technical field of coupling coils, in particular to a coupling coil and a household appliance.

Background

In the field of electromagnetic heating or wireless excitation, a coupling coil is generally used for sampling signals. For example, the coupling coil is used for metal detection, the coupling is used for heating the cookware in the electromagnetic oven, and signals during heating are collected.

When the coupling coil works, the ambient temperature changes, the change of the ambient temperature can cause the change of the magnetic conductivity of the coupling coil, the change of the magnetic conductivity causes the change of the inductance, and the change of the inductance causes the deviation of the signal sampled by coupling.

SUMMERY OF THE UTILITY MODEL

The main technical problem who solves of this application provides a coupling coil and domestic appliance, can reduce the influence of temperature variation to coupling coil, promotes the accuracy of the signal of telecommunication of coupling coil sampling.

A technical scheme that this application adopted provides a coupling coil, and this coupling coil includes: a first coil configured to be coupleable with an external metal; the second coil is connected with the first coil in series; the third coil is coupled with the second coil; the third coil is an air-core coil and is used for detecting the electric signal of the third coil to obtain the electric signal of the first coil.

The second coil and the third coil are respectively in a planar spiral shape, and are oppositely arranged by taking the plane as a reference.

The second coil and the third coil are respectively in a three-dimensional spiral shape; the second coil is sleeved on the third coil, or the third coil is sleeved on the second coil.

The coupling coil further comprises a first thermistor, and the first thermistor is arranged close to the third coil and used for detecting the temperature of the third coil.

The coupling coil further comprises a second thermistor, and the second thermistor is arranged on the second coil and used for detecting the temperature of the third coil.

The coupling coil further comprises a third thermistor and a fourth thermistor, the third thermistor is arranged on the second coil and used for detecting the temperature of the second coil, and the fourth thermistor is arranged on the third coil and used for detecting the temperature of the third coil.

Wherein, the first coil is an electromagnetic heating coil or an exciting coil.

One technical solution adopted by the present application is to provide a household appliance, which includes the coupling coil provided by the above technical solution.

The household appliance further comprises a sampling unit, wherein the sampling unit is connected with the third coil and used for detecting the electric signal of the third coil to acquire the electric signal of the first coil.

The household appliance further comprises a processing unit, and the processing unit is connected with the sampling unit and used for detecting the electric signal of the first coil.

The beneficial effect of this application is: in contrast to the state of the art, the present application relates to a coupling coil, comprising: a first coil configured to be coupleable with an external metal; the second coil is connected with the first coil in series; the third coil is coupled with the second coil; the third coil is an air-core coil and is used for detecting the electric signal of the third coil to obtain the electric signal of the first coil. Through the mode, the characteristic that the third coil is an air-core coil is utilized, the second coil connected with the first coil in series is mutual inductance, the influence of temperature change on the coupling coil is reduced, and the accuracy of an electric signal sampled by the coupling coil is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts. Wherein:

fig. 1 is a schematic structural diagram of an embodiment of a coupling coil provided in the present application;

FIG. 2 is a schematic diagram of an application scenario of a coupling coil provided herein;

FIG. 3 is a schematic diagram of another application scenario of the coupling coil provided in the present application;

FIG. 4 is a schematic diagram of an embodiment of a second coil and a third coil provided herein;

FIG. 5 is a schematic diagram of another embodiment of the second and third coils provided herein;

FIG. 6 is a schematic diagram of another embodiment of the second and third coils provided herein;

FIG. 7 is a schematic structural diagram of another embodiment of a coupling coil provided herein;

FIG. 8 is a schematic structural diagram of another embodiment of a coupling coil provided herein;

FIG. 9 is a schematic structural diagram of another embodiment of a coupling coil provided herein;

FIG. 10 is a schematic structural diagram of an embodiment of a household appliance provided herein;

fig. 11 is a schematic structural diagram of another embodiment of a household appliance provided by the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the specific embodiments described herein are merely illustrative of the application and are not limiting of the application. It should be further noted that, for the convenience of description, only some of the structures related to the present application are shown in the drawings, not all of the structures. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first", "second", etc. in this application are used to distinguish between different objects and not to describe a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an embodiment of a coupling coil provided in the present application. The coupling coil 100 includes a first coil L1, a second coil L2, and a third coil L3.

Wherein the first coil L1 is configured to be able to couple with external metal, such as for metal detection. The first coil L1 can also be used as a heating coil to heat an object, such as a pot. The second coil L2 is connected in series with the first coil L1. The second coil L2 is coupled to the third coil L3 in a mutual inductance manner. The third coil L3 is an air-core coil, and the electric signal of the first coil L1 can be obtained by detecting the electric signal of the third coil L3.

In some embodiments, the degree of electromagnetic induction between the second coil L2 and the third coil L3 is related not only to the mutual inductance therebetween, but also to their respective self-inductances, and depends on the degree of tightness of the magnetic chain coupling between the two coils.

For example, the degree of tightness representing the magnetic linkage coupling between two coils is represented by a coupling coefficient "k", and since the magnetic flux generated by one coil cannot pass through the other coil, the coupling coefficient k is generally less than 1, and if the leakage magnetic flux is small and negligible, k is 1.

In addition, the mutual inductance M between the two coils is an intrinsic parameter of the coils, and depends on the number of turns, geometry, relative position, and magnetic medium of the two coils. The value of M reflects the ability of one coil to generate magnetic flux in another coil.

In some embodiments, the third coil L3 may be a current transformer for the second coil L2, which samples the resonant current flowing through the second coil L2 in the form of mutual inductance.

In some embodiments, the mutual inductance phenomenon indicates that when the current in the first coil L1 changes, the current will generate a self-induced voltage in the second coil L2, and also generate a mutual-induced voltage in the third coil L3 magnetically coupled thereto. When the terminals with the same name of the second coil L2 and the third coil L3 are determined, the reference direction of each current and each induced voltage generated by each current can be correctly determined.

In some examples, the electrical parameter of the second coil L2 can be the same as or different from the electrical parameter of the third coil L3. The electrical parameters of the second coil L2 may be the same as or different from those of the first coil L1.

In one application scenario, the first coil L1 may be an excitation coil that can be used to measure a metal signal. Specifically, as shown in fig. 2, when the first coil L1 is powered on and works, and when the object a is close to the first coil L1, if the object a contains metal, the object a will interfere with the magnetic field generated by the first coil L1, and at this time, the magnetic field generated by the first coil L1 changes, and it can be determined that the object a contains metal. It is understood that metals are capable of electromagnetic induction with magnetic fields.

The first coil L1 generates heat by the energization operation, and changes the ambient temperature in the vicinity thereof. A change in the ambient temperature causes a change in the magnetic permeability of the first coil L1. The change in magnetic permeability changes the inductance, which causes a deviation in the electric signal sampled from the first coil L1, and the detection accuracy of the first coil L1 is not high when detecting a metal object.

In the present embodiment, the first coil L1 and the second coil L2 have the same current by connecting the second coil L2 in series with the first coil L1, and then the third coil L3 is coupled to the second coil L2, so that the third coil L3 generates a magnetic field by mutual inductance between the third coil L3 and the second coil L2. The electric signal of the first coil L1 can be acquired by detecting the magnetic field generated by the third coil L3.

The third coil L3 has no magnetic core and is an air core coil. When the third coil L3 is mutually inducted with the second coil L2, the temperature of the third coil L3 relatively changes little. The inductance of the third coil L3 is stable with temperature changes. Therefore, the electrical signal of the first coil L1 is determined using the electrical signal of the third coil L3 as a reference, and the accuracy of metal detection can be improved.

Therefore, when the third coil L3 and the second coil L2 are disposed at the relative positions, it is necessary to ensure that the third coil L3 and the second coil L2 do not mutually interact with the target object and are away from the magnetic field interference of the target object.

In another application scenario, the first coil L1 is an electromagnetic heating coil that can be used to heat a target metal object. As shown in fig. 3, the target metal object B is placed above the first coil L1. First coil L1 can carry out electromagnetic induction with the pan, and then makes the pan generate heat to food etc. to holding in the pan heat.

When heating the pan, the ambient temperature near first coil L1 can change because of the large amount of heat that the heating pan produced, and then leads to first coil L1's inductance to change, and the deviation can appear in the electric signal of following the sampling of first coil L1.

The electromagnetic heating is also called electromagnetic induction heating, and the principle of the electromagnetic heating is that an alternating magnetic field is generated by a first coil L1, when a ferrous container is placed on the ferrous container, the surface of the container cuts alternating magnetic lines of force to generate alternating current (i.e. eddy current) on a metal part at the bottom of the container, the eddy current enables carriers at the bottom of the container to move randomly at a high speed, and the carriers collide and rub with atoms to generate heat energy. Thereby achieving the effect of heating the article. Since the iron vessel itself generates heat, the heat conversion is particularly high, and up to 95% is a direct heating method.

When the relative positions are set, the third coil L3 and the second coil L2 are required to be far away from the first coil L1, so that the influence of the temperature of the first coil L1 on the third coil L3 and the second coil L2 in the heating process can be reduced, the stability of the electric signal of the third coil L3 is improved, and the performance of the coupling coil 100 is improved.

The first coil L1 converts the target metal object B into electric energy in the form of a magnetic field and further into heat energy for resonant heating. In the case of resonant heating, the target metal object B, such as various cookware, may be equivalent to a circuit composed of an inductive inductor and a thermal resistor.

In other embodiments, the second coil L2 is also an air core coil.

In this embodiment, the coupling coil 100 utilizes the characteristic that the third coil L3 is an air core coil, and the second coil L2, in which the third coil L3 and the first coil L1 are connected in series, is mutually inductive, so that the influence of temperature change on the coupling coil 100 can be reduced, and the accuracy of the electrical signal sampled by the coupling coil 100 can be improved.

In some embodiments, referring to fig. 4, fig. 4 is a schematic structural diagram of an embodiment of the second and third coils provided herein. The second coil L2 has a planar spiral shape, and the third coil L3 has a planar spiral shape. The second coil L2 and the third coil L3 are disposed to face each other with reference to the plane C. Specifically, the third coil L3 and the second coil L2 are respectively disposed on two sides of the plane C, and the plane on which the second coil L2 is disposed is parallel to the plane C, and the plane on which the third coil L3 is disposed is parallel to the plane C.

In an application scenario, the coupling coil 100 is disposed in a household appliance, such as an induction cooker, an electric cooker, etc. Third coil L3 keeps away from first coil L1 and sets up, and first coil L1 setting is also kept away from to second coil L2, can be not mutual inductance with the target, keeps away from the magnetic field interference of target, makes the signal of telecommunication more stable, promotes coupling coil 100's performance.

In some embodiments, referring to fig. 5, fig. 5 is a schematic structural diagram of another embodiment of the second and third coils provided herein. The second coil L2 has a three-dimensional spiral shape, and the third coil L3 has a three-dimensional spiral shape. The second coil L2 is disposed in the third coil L3 in a sleeved manner, so that the third coil L3 and the second coil L2 are mutually inducted when the second coil L2 is energized. The third coil L3 is an air core coil. Third coil L3 keeps away from first coil L1 with second coil L2 and sets up, can be not mutual-inductive with the target, keeps away from the magnetic field interference of target, makes the signal of telecommunication more stable, promotes coupling coil 100's performance.

The second coil L2 may be a single spiral, and the third coil L3 may be a double spiral.

In some embodiments, referring to fig. 6, fig. 6 is a schematic structural diagram of another embodiment of the second and third coils provided herein. The second coil L2 and the third coil L3 are formed in a three-dimensional spiral shape. The third coil L3 is disposed in the second coil L2 in a sleeved manner. When setting up third coil L3 and second coil, let third coil L3 and second coil L2 keep away from first coil L1 and set up, can not be mutual-inductive with the target, keep away from the magnetic field interference of target, make the signal of telecommunication more stable, promote coupling coil 100's performance.

In other embodiments, the second coil L2 may have a three-dimensional spiral shape and the third coil L3 may have a planar spiral shape.

Referring to fig. 7, fig. 7 is a schematic structural diagram of another embodiment of the coupling coil provided by the present application. The coupling coil 100 includes a first coil L1, a second coil L2, a third coil L3, and a first thermistor R1.

The first coil L1, the second coil L2, and the third coil L3 are arranged according to any of the above embodiments, which is not described herein again.

The first thermistor R1 is disposed close to the third coil L3, and is capable of detecting the temperature of the third coil L3 by its own thermal sensitive characteristics. The first thermistor R1 may be a PTC (Positive Temperature Coefficient) thermistor or an NTC (Negative Temperature Coefficient) thermistor.

Wherein the positive temperature coefficient thermistor (PTC) has a higher resistance value at a higher temperature, and the negative temperature coefficient thermistor (NTC) has a lower resistance value at a higher temperature.

In an application scenario, the coupling coil 100 is disposed in a household appliance, such as an induction cooker, an electric cooker, etc. The third coil L3 and the first thermistor R1 are connected to a processing unit in the household appliance. The processing Unit may be an MCU (Microcontroller Unit) or a processing Unit array composed of multiple MCUs.

The MCU is a computer with a chip level formed by properly reducing the frequency and specification of a Central Processing Unit (CPU) and integrating peripheral interfaces such as a memory (memory), a counter (Timer), a USB, an a/D converter, a UART, a PLC, a DMA, etc., and even an LCD driving circuit on a single chip, and is used for different combination control in different applications.

The processing unit may determine the temperature of the third coil L3 according to the resistance value of the first thermistor R1. The processing unit may obtain the electrical signal of the first coil L1 by detecting the electrical signal collected from both ends of the third coil L3. In addition, a comparison table of temperature and coil internal resistance is also present in the household appliance. The processing unit, after determining the temperature of the third coil L3, may determine the coil internal resistance of the third coil L3 at this temperature. The electric signal of the third coil L3 during mutual inductance is compensated according to the internal resistance of the coil, the internal resistance of the third coil L3 is ensured to be stable by the compensation mode of the internal resistance of the coil, the influence of temperature on the internal resistance of the coil is reduced, and the accuracy of the electric signal of the first coil L1 is improved.

It can be understood that, although the third coil L3 and the second coil L2 are disposed far away from the first coil L1, when the third coil L3 and the second coil L2 are mutually inducted, there is still a temperature change in the third coil L3, so that the internal coil resistance of the third coil L3 changes with the temperature, and the compensation is performed in the above manner, so as to improve the accuracy of the electrical signal of the first coil L1, further reduce the influence of the temperature change on the coupling coil 100, and improve the accuracy of the electrical signal sampled by the coupling coil 100.

Wherein, the thermistor mainly has the following characteristics: the sensitivity is high, the resistance temperature coefficient of the sensor is more than 10-100 times larger than that of metal, and the temperature change of 10-6 ℃ can be detected; the working temperature range is wide, the normal temperature device is suitable for minus 55 ℃ to 315 ℃, the high temperature device is suitable for being higher than 315 ℃ (the highest temperature can reach 2000 ℃) and the low temperature device is suitable for being at minus 273 ℃ to minus 55 ℃; the volume is small, and the temperature of gaps, cavities and blood vessels in a living body which cannot be measured by other thermometers can be measured; the use is convenient, and the resistance value can be randomly selected from 0.1-100 k omega; the product is easy to be processed into a complex shape and can be produced in large batch; good stability and strong overload capacity.

Referring to fig. 8, fig. 8 is a schematic structural diagram of another embodiment of the coupling coil provided by the present application. The coupling coil 100 includes a first coil L1, a second coil L2, a third coil L3, and a second thermistor R2.

The second thermistor R2 is provided on the second coil L2, and is capable of detecting the temperature of the third coil L3 by its own thermal characteristics. The second thermistor R2 may be a PTC thermistor or an NTC thermistor. When the second thermistor R2 is a PTC thermistor, the higher the temperature, the larger the resistance value of the second thermistor R2; when the second thermistor R2 is an NTC thermistor, the resistance value is lower as the temperature is higher.

In an application scenario, the coupling coil 100 is disposed in a household appliance, such as an induction cooker, an electric cooker, etc. The third coil L3 is connected to a processing unit in the home appliance, and the second thermistor R2 is connected to the processing unit in the home appliance.

The processing unit can determine the temperature of the third coil L3 at the present time according to the resistance value of the second thermistor R2.

In addition, a comparison table for storing temperature and coil internal resistance is also stored in the household appliance. The processing unit, after determining the temperature of the third coil L3, may determine the coil internal resistance of the third coil L3 at this temperature. The electric signal generated by the third coil L3 when it is mutually inducted is compensated according to the internal resistance of the coil to improve the accuracy of the electric signal of the first coil L1.

It is understood that, since the third coil L3 and the second coil L2 are coupled to each other in a mutual inductance manner, the temperature corresponding to the resistance value of the second thermistor R2 may be indicative of the temperature of the third coil L3 and may also be indicative of the temperature of the second coil L2. Although the third coil L3 and the second coil L2 are arranged far away from the first coil L1, when the third coil L3 and the second coil L2 are mutually inductive, the third coil L3 still has temperature change, so the coil internal resistance of the third coil L3 changes along with the temperature, and the compensation is performed by the above method, so that the accuracy of the electric signal of the first coil L1 is improved, the influence of the temperature change on the coupling coil 100 is further reduced, and the accuracy of the electric signal sampled by the coupling coil 100 is improved.

In some embodiments, referring to fig. 9, fig. 9 is a schematic structural diagram of another embodiment of the coupling coil provided by the present application. The coupling coil 100 includes a first coil L1, a second coil L2, a third coil L3, a third thermistor R3, and a fourth thermistor R4.

The second coil L2 is provided with a third thermistor R3. The third thermistor R3 can detect the temperature of the second coil L2 by its own thermal characteristics. The third coil L3 is provided with a fourth thermistor R4, and the fourth thermistor R4 can detect the temperature of the third coil L3 at a short distance. The fourth thermistor R4 and the third thermistor R3 may be PTC thermistors or NTC thermistors. Specifically, the fourth thermistor R4 and the third thermistor R3 are both PTC thermistors, or the fourth thermistor R4 and the third thermistor R3 are both NTC thermistors, or one of the fourth thermistor R4 and the third thermistor R3 is a PTC thermistor and the other is an NTC thermistor.

In an application scenario, the coupling coil 100 is disposed in a household appliance, such as an induction cooker, an electric cooker, etc. The third coil L3 is connected to a processing unit in the household appliance, the fourth thermistor R4 is connected to a processing unit in the household appliance, and the third thermistor R3 is connected to a processing unit in the household appliance.

When the processing unit acquires the resistance value of the third thermistor R3, the processing unit may determine the temperature of the second coil L2 at the time of mutual inductance with the third coil L3 from the look-up table by way of a look-up table. The processing unit may determine the temperature of the third coil L3 when it is mutually inductive with the second coil L2 according to the resistance value of the fourth thermistor R4. The processing unit uses the detected electrical signal of the third coil L3 to determine the electrical signal of the first coil L1. In addition, a comparison table of temperature and coil internal resistance is also present in the household appliance. The processing unit, after acquiring the temperature at which the second coil L2 and the third coil L3 are mutually inducted, may determine the coil internal resistances of the third coil L3 and the second coil L2 at this temperature from the look-up table. The collected electric signal of the third coil L3 is compensated according to the internal resistance of the coil to improve the accuracy of the electric signal of the first coil L1.

It can be understood that, although the third coil L3 and the second coil L2 are disposed far away from the first coil L1, when the third coil L3 and the second coil L2 are mutually inductive, temperature changes still exist in the third coil L3 and the second coil L2, and therefore, internal coil resistances of the third coil L3 and the second coil L2 can change with the temperature, and compensation is performed in the above manner, so that accuracy of an electric signal of the first coil L1 is improved, influence of the temperature changes on the coupling coil 100 is further reduced, and accuracy of the electric signal sampled by the coupling coil 100 is improved.

Referring to fig. 10, fig. 10 is a schematic structural diagram of an embodiment of a household appliance provided in the present application. A household appliance 300 comprises a coupling coil 100.

Wherein, the coupling coil 100 may be the coupling coil 100 in any of the above embodiments.

When the first coil L1 in the coupling coil 100 is used for electromagnetic heating or metal measurement, the influence of the first coil L1 in the coupling coil 100 on the coupling coil 100 due to temperature change can be reduced, and the accuracy of the electric signal sampled by the coupling coil 100 is improved.

Referring to fig. 11, fig. 11 is a schematic structural diagram of another embodiment of the household appliance provided in the present application. The household appliance 300 comprises a coupling coil 100, a sampling unit 301 and a processing unit 302.

Wherein the coupling coil 100 includes a first coil L1, a second coil L2, a third coil L3, a third thermistor R3, and a fourth thermistor R4.

The sampling unit 301 is connected to both ends of the third coil L3, and is configured to acquire an electrical signal of the first coil L1 by detecting the electrical signal of the third coil L3. The sampling unit 301 may be an a/D converter, among others. Specifically, in the a/D converter, since the input analog signal is continuous in time, the output digital signal code is discrete. The a/D converter must sample and hold the incoming analog signal at a series of selected instants (at specified points on the time axis) and then convert the samples to digital values. Therefore, the general a/D conversion process is completed by three steps of sample-hold, quantization and encoding, i.e. the input analog voltage is sample-held first, the holding time is entered after the sampling is finished, the sampled voltage is converted into digital quantity in the holding time, the conversion result is given according to a certain encoding form, and then the next sampling is started.

The processing unit 302 is connected to the sampling unit 301, and can detect the electric signal of the first coil L1. By being connected to the sampling unit 301, an electric signal of the first coil L1 is acquired, and then the electric signal is detected to determine the performance of the first coil L1. And when the first coil L1 is used for measuring metal, the electrical signal collected by the sampling unit 301 is detected, and it can be determined whether the first coil L1 detects metal.

In an application scenario, for the convenience of subsequent calculation, the third coil L3 may be corrected in advance: the third coil L3 brings the voltage difference between the two output terminals of the third coil L3 to a preset value when the object is not placed on the first coil L1, thereby completing the correction. Alternatively, the preset value may be 0, so that the return-to-zero correction is completed, so that the measured voltage output by the third coil L3 is caused only by the mutual inductance of the first coil L1 and the target object.

Wherein, the sampling unit 301 is also used for collecting the resistance values of the third thermistor R3 and the fourth thermistor R4 to be sent to the processing unit.

After determining the temperatures of the second coil L2 and the third coil L3 in any of the manners described above, the processing unit 302 may determine the coil internal resistance of the second coil L2 and the coil internal resistance of the third coil L3 at the temperatures. The collected electric signal of the third coil L3 is compensated according to the internal resistance of the coil to improve the accuracy of the electric signal of the first coil L1.

By the above mode, the internal resistance compensation of the coil is performed by utilizing the characteristics of the thermistor, so that the electric signal is compensated, the accuracy of the electric signal of the first coil L1 can be improved, the influence of temperature change on the coupling coil 100 is reduced, and the accuracy of the electric signal sampled by the coupling coil 100 is improved.

In other embodiments, the processing unit 302 includes a bias circuit, a clamp circuit, and an amplification circuit. The bias circuit is connected to two ends of the third coil L3 to positively bias the negative voltage in the collected electrical signal, so as to obtain a bias signal with a complete waveform with a positive amplitude. The clamp circuit is connected with the bias circuit to clamp the high-voltage part of the bias signal, so that a clamp signal is obtained. The amplifying circuit is connected with the clamping circuit to amplify and output the clamping signal, so that a processed electric signal is obtained.

In other embodiments, any of the coils in the above embodiments may be made of metal. For example, metals such as copper and aluminum are used.

In other embodiments, the processing unit 302 may be an FPGA (Field-Programmable Gate Array) chip, an operating system, such as a Linux system, may be installed in the processing unit 302, and the processing unit 302 may load different bit files to configure the FPGA chip.

The processing unit 302 may be Nand Flash, which has a non-linear macro-unit mode therein, and the Nand-Flash memory has the advantages of large capacity, high rewriting speed, and the like.

In some embodiments, the household appliance 300 may be an induction cooker, which allows heat to be directly generated at the bottom of a pan without open flame or conduction heating, thereby greatly improving thermal efficiency. The electromagnetic oven is an electric cooking appliance made by utilizing the electromagnetic induction heating principle. The device consists of a high-frequency induction heating coil, a high-frequency power conversion device, a controller, a ferromagnetic material pot bottom cooker and the like.

The induction cooker mainly comprises two parts: one is an electronic circuit system (including an induction cooker coil panel, i.e., the first coil L1) capable of generating a high-frequency alternating magnetic field; and the other is a structural shell (comprising a furnace panel capable of bearing high temperature and rapid changes of cold and heat) for fixing the electronic circuit system and bearing the cookware.

Wherein, electronic circuit system includes: power board, mainboard, lamp plate (control the display panel), control by temperature change, coil panel and heat-sensitive support, fan, power cord etc..

The structural shell includes: furnace panels (porcelain plates, black crystal plates), plastic upper and lower covers, etc. Wherein, the stove panel is used for bearing the pan.

The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application or are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims (10)

1. A coupling coil, characterized in that the coupling coil comprises:

a first coil configured to be couplable with an external metal;

a second coil in series with the first coil;

a third coil coupled to the second coil;

the third coil is an air-core coil and is used for acquiring the electric signal of the first coil by detecting the electric signal of the third coil.

2. The coupling coil of claim 1,

the second coil and the third coil are respectively in a planar spiral shape, and the second coil and the third coil are oppositely arranged by taking a plane as a reference.

3. The coupling coil of claim 1,

the second coil and the third coil are respectively in a three-dimensional spiral shape;

the second coil is sleeved on the third coil, or the third coil is sleeved on the second coil.

4. The coupling coil according to claim 2 or 3,

the coupling coil further comprises a first thermistor, and the first thermistor is arranged close to the third coil and used for detecting the temperature of the third coil.

5. The coupling coil according to claim 2 or 3,

the coupling coil further comprises a second thermistor, and the second thermistor is arranged on the second coil and used for detecting the temperature of the third coil.

6. The coupling coil according to claim 2 or 3,

the coupling coil further comprises a third thermistor and a fourth thermistor, wherein the third thermistor is arranged on the second coil and used for detecting the temperature of the second coil, and the fourth thermistor is arranged on the third coil and used for detecting the temperature of the third coil.

7. The coupling coil of claim 1,

the first coil is an electromagnetic heating coil or an exciting coil.

8. A household appliance, characterized in that the household appliance comprises a coupling coil according to any one of claims 1-7.

9. Household appliance according to claim 8,

the household appliance further comprises a sampling unit, wherein the sampling unit is connected with the third coil and used for detecting the electric signal of the third coil to obtain the electric signal of the first coil.

10. Household appliance according to claim 9,

the household appliance further comprises a processing unit, and the processing unit is connected with the sampling unit and used for detecting the electric signal of the first coil.

Images