Electric baking pan heating control circuit and electric baking pan

Abstract

The present invention discloses an electric baking pan heating control circuit and an electric baking pan. The electric baking pan heating control circuit includes: an eddy current feedback module, including a current supply module and a coil for being set to a heating plate of the electric baking pan, the current supply module is connected to the coil, and is used to generate an alternating current output to the coil so that it generates an alternating magnetic field to act on the other heating plate of the electric baking pan to form an eddy current; a weighing module, which is used to be set to the heating plate of the electric baking pan to detect its weight; a detection control module, which is connected to the coil and the weighing module, and is used to detect the feedback current generated in the coil by the feedback effect of the eddy current, and adjust the temperature and heating time of the heating plate of the electric baking pan according to the feedback current and the weight detected by the weighing module. The electric baking pan heating control circuit of the present application is applied to the electric baking pan, and can automatically adjust the heating temperature and heating time of the heating plate of the electric baking pan according to the weight and thickness of the food, so that the effect of cooking food with the electric baking pan is easier to control and the taste of the cooked food is better.

Description

Technical Field

[0001] The present invention relates to the technical field of electric baking pans, and in particular to an electric baking pan heating control circuit and an electric baking pan. Background Art

[0002] With the improvement of people's living standards, more and more consumers are choosing to buy electric baking pans to cook food. Electric baking pans are a cooking tool that typically uses electric heating wires, which heat the food by heating the upper and lower heating plates. However, with current electric baking pans, it is difficult for users to control the cooking effect of the food. Users must constantly observe and smell the food to control the cooking effect, such as whether the food is too crispy or too soft. If the cooking time is too long or too short, the food will easily become unpalatable and affect the taste. Summary of the Invention

[0003] The embodiments of the present invention provide an electric baking pan heating control circuit and an electric baking pan, aiming to solve the problem that it is difficult for users to control the cooking effect of food when cooking with a traditional electric baking pan.

[0004] In the first aspect, an embodiment of the present invention provides an electric baking pan heating control circuit, which includes: an eddy current feedback module, including a current supply module and a coil for being set to a heating plate of the electric baking pan, the current supply module is connected to the coil, and is used to generate an alternating current and output it to the coil so that it generates an alternating magnetic field to act on the other heating plate of the electric baking pan to form eddy currents; a weighing module, which is used to be set to the heating plate of the electric baking pan to detect its weight; a detection control module, which is connected to the coil and the weighing module, and is used to detect the feedback current generated in the coil by the feedback action of the eddy current, and adjust the temperature and heating time of the heating plate of the electric baking pan according to the feedback current and the weight detected by the weighing module.

[0005] In the electric griddle heating control circuit provided in an embodiment of the present invention, the detection control module includes a current sampling module and a main control module. The current sampling module is connected to the coil and the main control module, and is used to sample the feedback current in the coil. The main control module is connected to the current supply module, and is used to adjust the temperature and heating time of the heating plate of the electric griddle according to the current sampled by the current sampling module and the weight detected by the weighing module.

[0006] In the electric griddle heating control circuit provided in an embodiment of the present invention, the current supply module includes a plurality of switching tubes, and the plurality of switching tubes are connected to the coil to form an H-bridge circuit. The H-bridge circuit is connected to a power supply, and one end of the coil is connected between two adjacent bridge arms of the H-bridge circuit, and the other end of the coil is connected between the other two adjacent bridge arms of the H-bridge circuit. The main control module is connected to the plurality of switching tubes, and the current sampling module is connected to the main control module and the H-bridge circuit, wherein the main control module provides a pulse signal to control the plurality of switching tubes to be alternately turned on and off.

[0007] In the electric griddle heating control circuit provided in an embodiment of the present invention, the current sampling module includes a sampling resistor and a current limiting resistor, the H-bridge circuit is grounded through the sampling resistor, one end of the current limiting resistor is connected to one end of the sampling resistor, and the other end of the current limiting resistor is connected to the main control module.

[0008] In the electric pancake maker heating control circuit provided in an embodiment of the present invention, the multiple switching tubes include a first MOS tube, a second MOS tube, a third MOS tube and a fourth MOS tube. The gates of the first MOS tube, the second MOS tube, the third MOS tube and the fourth MOS tube are all connected to the main control module, the drains of the first MOS tube and the third MOS tube are both connected to the positive pole of the power supply, and the sources are respectively connected to the drains of the second MOS tube and the fourth MOS tube. The sources of the second MOS tube and the fourth MOS tube are grounded through the sampling resistor, and the two ends of the coil are respectively connected to the drains of the second MOS tube and the fourth MOS tube.

[0009] In the electric griddle heating control circuit provided in an embodiment of the present invention, the current sampling module also includes a first operational amplifier, the non-inverting input terminal of the first operational amplifier is connected to one end of the sampling resistor through the current limiting resistor, the inverting input terminal of the first operational amplifier is connected to the output terminal through the resistor, and the main control module is connected to the output terminal of the first operational amplifier.

[0010] In the electric baking pan heating control circuit provided in an embodiment of the present invention, the weighing module includes a weight conversion module and a signal amplification module. The weight conversion module is used to be set to the bottom of the lower heating plate of the electric baking pan to convert the weight of the heating plate of the electric baking pan into an electrical signal output. The signal amplification module is connected to the weight conversion module and the detection control module, and is used to amplify the electrical signal output by the weight conversion module and output it to the detection control module.

[0011] In the electric griddle heating control circuit provided in an embodiment of the present invention, the weight conversion module includes a differential amplifier and a Wheatstone bridge formed by connecting multiple strain gauges. The multiple strain gauges are used to be set to the bottom of the lower heating plate of the electric griddle. The Wheatstone bridge is connected to a power supply. The positive input end of the differential amplifier is connected between two adjacent bridge arms of the Wheatstone bridge, the negative input end is connected between the other two adjacent bridge arms of the Wheatstone bridge, and the output end is connected to the signal amplification module.

[0012] In the electric griddle heating control circuit provided in an embodiment of the present invention, the signal amplification module includes a second operational amplifier, the non-inverting input terminal of the second operational amplifier is connected to the output terminal, the output terminal of the differential amplifier is connected to the non-inverting input terminal of the second operational amplifier, the inverting input terminal of the second operational amplifier is grounded, and the detection control module is connected to the output terminal of the second operational amplifier.

[0013] In a second aspect, an embodiment of the present invention provides an electric baking pan, which includes the electric baking pan heating control circuit described in the first aspect.

[0014] An embodiment of the present invention provides an electric baking pan heating control circuit and an electric baking pan, the electric baking pan heating control circuit comprising: an eddy current feedback module, comprising a current supply module and a coil for being set to a heating plate of the electric baking pan, the current supply module being connected to the coil, for generating an alternating current output to the coil so that it generates an alternating magnetic field acting on the other heating plate of the electric baking pan to form an eddy current; a weighing module being set to the heating plate of the electric baking pan to detect its weight; a detection control module being connected to the coil and the weighing module, for detecting a feedback current generated in the coil by the feedback effect of the eddy current, and adjusting the temperature and heating time of the heating plate of the electric baking pan according to the feedback current and the weight detected by the weighing module. The electric baking pan heating control circuit of the present application is applied to the electric baking pan, and can automatically adjust the heating temperature and heating time of the heating plate of the electric baking pan according to the weight and thickness of the food, making it easier to control the effect of cooking food with the electric baking pan and making the cooked food taste better. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 A structural block diagram of the electric baking pan heating control circuit provided by an embodiment of the present invention;

[0017] Figure 2 A schematic diagram of the principle of the electric baking pan heating control circuit provided by an embodiment of the present invention;

[0018] Figure 3 Another structural block diagram of the electric baking pan heating control circuit provided by an embodiment of the present invention;

[0019] Figure 4 A partial circuit diagram of the electric baking pan heating control circuit provided by an embodiment of the present invention;

[0020] Figure 5 Another partial circuit diagram of the electric baking pan heating control circuit provided by an embodiment of the present invention;

[0021] Figure 6 Another partial circuit diagram of the electric baking pan heating control circuit provided in an embodiment of the present invention.

[0022] The reference numerals in the figures are:

[0023] 1. Eddy current feedback module; 11. Coil; 12. Current supply module; 2. Weighing module; 21. Weight conversion module; 22. Signal amplification module; 3. Detection and control module; 31. Current sampling module; 32. Main control module; 100. Heating plate. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] Directional terms used herein, such as "upper," "lower," "front," "back," "left," "right," "inner," "outer," and "side," refer only to directions in the accompanying drawings. Therefore, these directional terms are intended to illustrate and facilitate understanding of the present invention and are not intended to limit the present invention. Furthermore, in the accompanying drawings, similar or identical structures are denoted by the same reference numerals.

[0026] In order to facilitate understanding of the present invention, the electric baking pan heating control circuit provided by the embodiment of the present invention is first described. Figures 1 to 6 , please refer to Figure 1 and Figure 2The electric baking pan heating control circuit includes an eddy current feedback module 1, a weighing module 2 and a detection control module 3; the eddy current feedback module 1 includes a current supply module 12 and a coil 11 for being set to a heating plate 100 of the electric baking pan, the current supply module 12 is connected to the coil 11, and is used to generate an alternating current and output it to the coil 11 so that it generates an alternating magnetic field to act on the other heating plate 100 of the electric baking pan to form eddy current; the weighing module 2 is used to be set to the heating plate 100 of the electric baking pan to detect its weight; the detection control module 3 is connected to the coil 11 and the weighing module 2, and is used to detect the feedback current generated by the feedback effect of the eddy current in the coil 11, and adjust the temperature and heating time of the heating plate 100 of the electric baking pan according to the feedback current and the weight detected by the weighing module 2.

[0027] Traditional electric griddles usually provide multiple heating levels for users to choose and control. Users need to manually adjust the temperature of the heating plate to the corresponding level. At the same time, they need to observe with their eyes and smell to control the cooking effect of the food at all times. The taste of the food cannot be well controlled during cooking. Once the cooking time is too long or too short, it is easy to cause the food to taste poor, affecting the user's consumption. Therefore, it is difficult for users to control the cooking effect when cooking food using traditional electric griddles.

[0028] To address the aforementioned issues, this embodiment provides a heating control circuit for an electric baking pan. This circuit is used in an electric baking pan. Typically, an electric baking pan consists of a base, a top cover, upper and lower heating plates 100, a heating module, and a main board. The upper and lower heating plates 100 are made of metal and are the primary components for cooking food. The upper and lower heating plates 100 consist of two parts: an upper heating plate 100 and a lower heating plate 100. The lower heating plate 100 is mounted on the base, while the upper heating plate 100 is mounted on the top cover. The upper and lower heating plates 100 are hingedly connected to the base, allowing them to press food together. The heating module, typically comprised of a heating wire, is located in the non-cooking area behind the upper and lower heating plates 100 and is the primary component for heating the upper and lower heating plates 100. In this embodiment, the heating control circuit can be integrated into the main board of the electric baking pan to control the heating function of the heating module and thereby control the heating of the heating plates 100.

[0029] like Figure 1As shown, the electric baking pan heating control circuit of this embodiment is mainly composed of an eddy current feedback module 1, a weighing module 2 and a detection control module 3. The eddy current feedback module 1 is used to cooperate with the heating plate 100 of the electric baking pan to generate eddy currents. Specifically, the eddy current feedback module 1 is mainly composed of a current supply module 12 and a coil 11. The coil 11 is used to be set to a heating plate 100 of the electric baking pan. It can be set on the upper heating plate 100 of the electric baking pan, or it can be set on the lower heating plate 100. The current supply module 12 is connected to the coil 11, and the current supply module 12 can be integrated into the main board of the electric baking pan. The current supply module 12 is used to generate an alternating current output to the coil 11. The alternating current output to the coil 11 will cause the coil 11 to generate an alternating magnetic field, such as Figure 2As shown, the alternating magnetic field generated by the coil 11 acts on the other heating plate 100 of the electric baking maker, thereby forming eddy currents on the other heating plate 100 of the electric baking maker. Specifically, when the coil 11 is set on the upper heating plate 100 of the electric baking maker, eddy currents are formed on the lower heating plate 100 of the electric baking maker. When the coil 11 is set on the lower heating plate 100 of the electric baking maker, eddy currents are formed on the upper heating plate 100 of the electric baking maker. Eddy current refers to a closed loop current generated by electromagnetic induction in a conductor in a changing magnetic field, and its essence is the electromagnetic induction phenomenon. After the eddy current is formed on the heating plate 100 of the electric baking maker, the eddy current will also act on the coil 11, and a feedback current will be formed in the coil 11 due to electromagnetic induction. The thickness of the food in the electric baking pan 100 determines the distance between the upper and lower heating pans 100. The thinner the food, the smaller the distance between the upper and lower heating pans 100, and the closer the coil 11 is to the other heating pan 100. The heating pan 100 is a metal substrate, and the closer the coil 11 is, the stronger the eddy current generated, and the greater the reflected impedance of the eddy current to the coil 11, and the greater the feedback current generated in the coil 11. In actual application, as the electric baking pan heats, the moisture in the food in the heating pan 100 of the electric baking pan will evaporate and decrease, and the thickness of the food will gradually become thinner, so the feedback current generated in the coil 11 will become larger. The weighing module 2 is set on the heating plate 100 of the electric baking pan and is used to detect the weight of the heating plate 100. Specifically, the weighing module 2 will be set at the bottom of the lower heating plate 100 of the electric baking pan. The weighing module 2 is designed using the gravity sensing principle. When food is placed in the heating plate 100, the weight of the lower heating plate 100 will increase. The weighing module 2 mainly detects the weight of the food in the lower heating plate 100 of the electric baking pan. The weight information detected by the weighing module 2 is sent to the detection control module 3. The detection control module 3 is connected to the eddy current feedback module 1 and the weighing module 2. In actual application, the detection control module 3 is connected to the heating module of the electric baking pan. The detection control module 3 is a module structure including detection function and logic control function. The detection control module 3 can detect the magnitude of the feedback current in the coil 11. The detection control module 3 controls the heating module of the electric baking pan according to the detected feedback current and the weight detected by the weighing module 2, according to the control algorithm preset by the system, thereby adjusting the heating temperature and heating time of the heating plate 100 of the electric baking pan, that is, the temperature and heating time of the heating plate 100 of the electric baking pan are determined by two parameters: the feedback current in the coil 11 and the weight of the food in the heating plate 100 of the electric baking pan.

[0030] In an actual cooking scenario, taking the cooking of pancakes as an example, the user puts the raw pancakes into the heating plate 100 of the electric pancake maker, and the heating plate 100 of the electric pancake maker heats the pancakes. As the heating progresses, the moisture in the pancake evaporates, the body of the pancake changes, and the pancake becomes thinner and lighter. The thinning of the pancake makes the distance between the upper and lower heating plates 100 of the electric pancake maker closer. The detection and control module 3 detects that the feedback current in the coil 11 becomes larger, and at the same time, the weighing module 2 also detects that the weight of the lower heating plate 100 of the electric pancake maker becomes lighter. The detection and control module 3 calculates the most suitable heating temperature and heating time for the pancake in the current state according to the algorithm based on the two parameters of the feedback current and the weight of the heating plate 100 of the electric pancake maker, thereby controlling the heating module of the electric pancake maker to adjust the temperature of the heating plate 100 of the electric pancake maker to the corresponding temperature and control the heating time, thereby dynamically adjusting the heating temperature and heating time of the heating plate 100 of the electric pancake maker according to the weight and thickness of the pancake at different times, automatically adjusting the cooking temperature, and achieving the purpose of intelligent cooking.

[0031] In one embodiment, referring to Figure 3 and Figure 4 , the detection control module 3 includes a current sampling module 31 and a main control module 32. The current sampling module 31 is connected to the coil 11 and the main control module 32, and is used to sample the feedback current in the coil 11. The main control module 32 is connected to the current supply module 12, and is used to adjust the temperature and heating time of the heating plate 100 of the electric baking pan according to the current sampled by the current sampling module 31 and the weight detected by the weighing module 2. In a specific implementation, the detection control module 3 is mainly composed of a current sampling module 31 and a main control module 32. The current sampling module 31 is connected to the coil 11 and the main control module 32, and is used to sample the feedback current in the coil 11. The current sampled by the current sampling module 31 is sent to the main control module 32. The main control module 32 is a module with logical operation and control functions, which can be a MCU module or other IC module with operation and control functions. The main control module 32 is connected to the weighing module 2, and receives the weight of the heating plate 100 of the electric baking pan detected by the weighing module 2. The main control module 32 controls the heating module of the electric baking pan according to the current sampled by the current sampling module 31 and the weight detected by the weighing module 2, according to the control algorithm preset by the system, thereby adjusting the temperature and heating time of the heating plate 100 of the electric baking pan.

[0032] Further, refer to Figure 4The current supply module 12 includes a plurality of switching tubes, which are connected to the coil 11 to form an H-bridge circuit. The H-bridge circuit is connected to a power supply. One end of the coil 11 is connected between two adjacent bridge arms of the H-bridge circuit, and the other end of the coil 11 is connected between the other two adjacent bridge arms of the H-bridge circuit. The main control module 32 is connected to the plurality of switching tubes. The current sampling module 31 is connected to the main control module 32 and the H-bridge circuit, wherein the main control module 32 provides a pulse signal to control the plurality of switching tubes to be alternately turned on and off. In a specific implementation, the current supply module 12 is composed of a plurality of switching tubes, which are connected to the coil 11 to form an H-bridge circuit. The H-bridge circuit formed by the connection of the coil 11 and the plurality of switching tubes can be a single H-bridge. There are four switching tubes, each of which constitutes a bridge arm of the H-bridge circuit, for a total of four bridge arms. The input of the H-bridge circuit is connected to the power supply, one end of the coil 11 is connected between two adjacent arms of the H-bridge circuit, and the other end of the coil 11 is connected between the other two adjacent arms of the H-bridge circuit. The main control module 32 is connected to the control ends of all the switching tubes. The current sampling module 31 is connected to the main control module 32 and the H-bridge circuit, specifically connected between two adjacent arms of the H-bridge circuit. In actual applications, the main control module 32 provides pulse signals to the multiple switching tubes that constitute the H-bridge circuit, thereby controlling the multiple switching tubes to be alternately turned on and off. By combining the different switching tubes, the current of the power supply can flow through the coil 11 in different directions, causing the coil 11 to generate an alternating magnetic field that acts on the other heating plate 100 of the electric baking pan, thereby causing the other heating plate 100 of the electric baking pan to form eddy currents.

[0033] Furthermore, refer to Figure 4, the current sampling module 31 includes a sampling resistor R2 and a current limiting resistor R1, the H-bridge circuit is grounded through the sampling resistor R2, one end of the current limiting resistor R1 is connected to one end of the sampling resistor R2, and the other end of the current limiting resistor R1 is connected to the main control module 32. In a specific implementation, the current sampling module 31 includes a sampling resistor R2 and a current limiting resistor R1, the H-bridge circuit is connected to the ground through the sampling resistor R2, one end of the current limiting resistor R1 is connected to one end of the sampling resistor R2, specifically connected to the end connected to the H-bridge circuit, and the other end of the current limiting resistor R1 is connected to the main control module 32. In actual application, the coil 11 generates a feedback current under the action of the eddy current on the heating plate 100 of the electric griddle, and the voltage across the sampling resistor R2 will change, thereby generating a feedback electrical signal, which is input to the main control module 32 via the current limiting resistor R1, and the current limiting resistor R1 can prevent the current of the feedback electrical signal from being too large to damage the main control module 32 or other devices. When the main control module 32 receives the feedback electrical signal, it can control the heating module of the electric baking pan according to the feedback electrical signal and the weight of the heating plate 100 of the electric baking pan detected by the weighing module 2, thereby adjusting the temperature and heating time of the heating plate 100 of the electric baking pan.

[0034] Furthermore, refer to Figure 5 The current sampling module 31 also includes a first operational amplifier U1, the non-inverting input of the first operational amplifier U1 is connected to one end of the sampling resistor R2 through the current limiting resistor R1, the inverting input of the first operational amplifier U1 is connected to the output end through the resistor, and the main control module 32 is connected to the output end of the first operational amplifier U1. In a specific implementation, the current sampling module 31 also includes a first operational amplifier U1, the non-inverting input of the first operational amplifier U1 is connected to one end of the sampling resistor R2 through the current limiting resistor R1, specifically to the end of the sampling resistor R2 connected to the H-bridge circuit, the inverting input of the first operational amplifier U1 is connected to its own output end through the resistor R3, and the main control module 32 is connected to the output end of the first operational amplifier U1 via the resistor R4. In actual application, the signal collected by the sampling resistor R2 can be amplified by the first operational amplifier U1, and the amplification factor is Au=R3 / R1, thereby improving the sampling accuracy. The main control module 32 can more accurately control the heating module of the electric baking pan, thereby better adjusting the heating temperature and heating time of the heating plate 100 of the electric baking pan.

[0035] In one embodiment, referring to Figure 4 and Figure 5The multiple switching transistors include a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3, and a fourth MOS transistor Q4. The gates of the first MOS transistor Q1, the second MOS transistor Q2, the third MOS transistor Q3, and the fourth MOS transistor Q4 are all connected to the main control module 32. The drains of the first MOS transistor Q1 and the third MOS transistor Q3 are both connected to the positive power supply, and the sources are respectively connected to the drains of the second MOS transistor Q2 and the fourth MOS transistor Q4. The sources of the second MOS transistor Q2 and the fourth MOS transistor Q4 are grounded via the sampling resistor R2. The two ends of the coil 11 are respectively connected to the drains of the second MOS transistor Q2 and the fourth MOS transistor Q4. In a specific implementation, the multiple switching transistors that form an H-bridge circuit together with the coil 11 include the first MOS transistor Q1, the second MOS transistor Q2, the third MOS transistor Q3, and the fourth MOS transistor Q4, for a total of four MOS transistors. The four MOS transistors, together with the coil 11, form an H-bridge circuit. The gates of the first MOS transistor Q1, the second MOS transistor Q2, the third MOS transistor Q3, and the fourth MOS transistor Q4 are all connected to the main control module 32, specifically to the four IO ports of the main control module 32. The drains of the first MOS transistor Q1 and the third MOS transistor Q3 are both connected to the positive electrode of the power supply, and their sources are respectively connected to the drains of the second MOS transistor Q2 and the fourth MOS transistor Q4. The sources of the second MOS transistor Q2 and the fourth MOS transistor Q4 are both connected to ground through a sampling resistor R2. The two ends of the coil 11 are respectively connected to the drains of the second MOS transistor Q2 and the fourth MOS transistor Q4. The main control module 32 outputs pulse signals to the first MOS transistor Q1, the second MOS transistor Q2, the third MOS transistor Q3, and the fourth MOS transistor Q4 through the four ports H1, L1, H2, and L2, respectively. By controlling the combined on and off of the four MOS transistors, the current from the power supply is converted into an alternating current in the coil 11, causing the coil 11 to generate an alternating magnetic field.

[0036] In one embodiment, referring to Figure 3 and Figure 6The weighing module 2 includes a weight conversion module 21 and a signal amplification module 22. The weight conversion module 21 is used to be set at the bottom of the lower heating plate 100 of the electric baking pan to convert the weight of the heating plate 100 of the electric baking pan into an electrical signal output. The signal amplification module 22 is connected to the weight conversion module 21 and the detection control module 3, and is used to amplify the electrical signal output by the weight conversion module 21 and output it to the detection control module 3. In a specific implementation, the weighing module 2 is mainly composed of a weight conversion module 21 and a signal amplification module 22. The weight conversion module 21 can be a weight sensor module or other circuit module that can convert weight into an electrical signal. The lower heating plate 100 of the electric baking pan is the part that carries food. The weight conversion module 21 is mainly used to be set at the bottom of the lower heating plate 100 of the electric baking pan. The weight conversion module 21 can convert the weight of the heating plate 100 of the electric baking pan into an electrical signal and output it to the signal amplification module 22. The signal amplification module 22 is connected to the weight conversion module 21 and the detection control module 3. The signal amplification module 22 can amplify the electrical signal output by the weight conversion module 21 into a signal that can be recognized and calculated by the detection control module 3. The weight of the heating plate 100 of the electric baking pan can be calculated through the detection control module 3, thereby accurately obtaining the change in the weight of the food in the heating plate 100 of the electric baking pan.

[0037] Further, refer to Figure 6The weight conversion module 21 includes a differential amplifier U3 and a Wheatstone bridge formed by connecting multiple strain gauges. The multiple strain gauges are used to be set at the bottom of the lower heating plate 100 of the electric baking pan. The Wheatstone bridge is connected to a power supply. The non-phase input terminal of the differential amplifier U3 is connected between two adjacent bridge arms of the Wheatstone bridge, the inverting input terminal is connected between the other two adjacent bridge arms of the Wheatstone bridge, and the output terminal is connected to the signal amplification module 22. In a specific implementation, the weight conversion module 21 is mainly composed of a differential amplifier U3 and a Wheatstone bridge. The Wheatstone bridge is formed by connecting multiple strain gauges, and each strain gauge corresponds to one bridge arm. Multiple strain gauges are used to be set at the bottom of the lower heating plate 100 of the electric baking pan. The strain gauge is an element composed of a sensitive grid and the like for measuring strain. It will produce mechanical deformation under the action of external force, so that the resistance value changes accordingly. The non-inverting input of differential amplifier U3 is connected between two adjacent arms of a Wheatstone bridge circuit, while its inverting input is connected between the other two adjacent arms of the Wheatstone bridge circuit. The output of differential amplifier U3 is connected to the input of signal amplification module 22. The input of the Wheatstone bridge circuit is connected to a power source. When food is present in the heating plate 100 of the electric griddle, the multiple strain gauges deform to varying degrees, resulting in varying resistance changes. This converts the weight signal of the heating plate 100 into an electrical signal. A voltage difference is generated between the non-inverting and inverting inputs of differential amplifier U3, resulting in the output of differential amplifier U3 outputting voltages of varying magnitudes, Ucd, reflecting the varying weights of the food in the heating plate 100. The output voltage Ucd of differential amplifier U3 is then amplified by signal amplification module 22 and output to detection and control module 3, which can then accurately determine the weight of the heating plate 100.

[0038] Furthermore, refer to Figure 6The signal amplification module 22 includes a second operational amplifier U2, the non-inverting input of which is connected to the output of the second operational amplifier U2, the output of the differential amplifier U3 is connected to the non-inverting input of the second operational amplifier U2, the inverting input of the second operational amplifier U2 is grounded, and the detection control module 3 is connected to the output of the second operational amplifier U2. In a specific implementation, the signal amplification module 22 is primarily composed of the second operational amplifier U2, the non-inverting input of which is connected to the output of the second operational amplifier U2, thereby forming a voltage follower. The non-inverting input of the second operational amplifier U2 is connected to the output of the differential amplifier U3 via a resistor R5, the inverting input of the second operational amplifier U2 is grounded, and the detection control module 3 is connected to the output of the second operational amplifier U2. In actual applications, the voltage signal at the output end of the differential amplifier U3 is input through the non-inverting input end of the second operational amplifier U2. The second operational amplifier U2 amplifies the voltage signal and outputs the amplified voltage signal from the output end to the detection control module 3, so that the detection control module 3 can accurately obtain the weight of the food in the heating plate 100 of the electric baking pan.

[0039] Specifically, refer to Figure 6The multiple strain gauges include a first strain gauge Ra1, a second strain gauge Ra2, a third strain gauge Ra3 and a fourth strain gauge Ra4. One end of the first strain gauge Ra1 and the second strain gauge Ra2 is connected to the positive electrode of the power supply, and the other end is connected to one end of the third strain gauge Ra3 and the fourth strain gauge Ra4 respectively. The other end of the third strain gauge Ra3 and the fourth strain gauge Ra4 is connected to the negative electrode of the power supply. The positive phase input end of the differential amplifier U3 is connected between the first strain gauge Ra1 and the third strain gauge Ra3, and the negative phase input end is connected between the second strain gauge Ra2 and the fourth strain gauge Ra4. In a specific implementation, the multiple strain gauges that constitute the Wheatstone bridge include four strain gauges, namely the first strain gauge Ra1, the second strain gauge Ra2, and the third strain gauge Ra3. One end of the first strain gauge Ra1 and the second strain gauge Ra2 are connected to the positive pole of the power supply, and the other ends of the first strain gauge Ra1 and the second strain gauge Ra2 are connected to one end of the third strain gauge Ra3 and the fourth strain gauge Ra4 respectively, while the other ends of the third strain gauge Ra3 and the fourth strain gauge Ra4 are connected to the negative pole of the power supply. The positive phase input end of the differential amplifier U3 is connected between the first strain gauge Ra1 and the third strain gauge Ra3, and the negative phase input end of the differential amplifier U3 is connected between the second strain gauge Ra2 and the fourth strain gauge Ra4. In practical applications, a power supply provides a voltage input. When food is present on the heating plate 100 of the electric griddle, strain gauges Ra1 through Ra4 deform to varying degrees, resulting in varying resistance changes. ΔRa1, ΔRa2, ΔRa3, and ΔRa4 represent the resistance changes of the first, second, third, and fourth strain gauges Ra1, Ra2, Ra3, and Ra4, respectively. At this point, the input voltage at the differential amplifier U3 is Ucd = 1 / 4 [(ΔRa1 + ΔRa3 - ΔRa2 - ΔRa4) / ΔR0] * Us, where Us is the power supply voltage. The voltage Ucd1 is then passed through the differential amplifier to produce the output voltage Ucd2. Ucd2 is then fed to a voltage follower circuit formed by the second operational amplifier U2, enhancing the electrical signal's anti-interference capability. This signal is then output to the detection control module 3, enabling accurate detection of the weight of food on the heating plate 100 of the electric griddle at various times.

[0040] The electric griddle heating control circuit provided in the embodiment of the present application adopts a current supply module to generate an alternating current output to the coil, so that the coil generates an alternating magnetic field to act on the heating plate of the electric griddle to form eddy currents, and adopts a weighing module to detect the weight of the heating plate. The feedback current generated by the feedback effect of the eddy current in the detection coil is detected by the detection control module, and the temperature and heating time of the heating plate of the electric griddle are adjusted according to the feedback current and the weight detected by the weighing module, so that the effect of cooking food by the electric griddle is easier to control and the cooked food tastes better.

[0041] The embodiment of the present invention also provides an electric baking pan, which includes the electric baking pan heating control circuit described in the above embodiment. In addition, the electric baking pan may also include a base, an upper cover, upper and lower heating plates, a heating module, a main board and other components. The upper and lower heating plates are an upper heating plate and a lower heating plate, the lower heating plate is mounted on the base, the upper heating plate is mounted on the upper cover, and the heating module is mounted on the back of the upper and lower heating plates to heat the upper and lower heating plates. The electric baking pan heating control circuit can be integrated into the main board of the electric baking pan, and is mainly used to control the operation of the heating module of the electric baking pan, including controlling the temperature and heating time, to achieve control of the heating temperature and heating time of the heating plate of the electric baking pan. Among them, since the previous specification has already made a detailed introduction to the specific structure and working principle of the electric baking pan heating control circuit, for the sake of brevity of the specification, it will not be repeated here.

[0042] The electric baking pan in this embodiment adopts the electric baking pan heating control circuit provided by the present invention, so when cooking food, the cooking effect of the food can be better controlled and the cooked food tastes better.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. An electric baking pan heating control circuit, characterized in that: include: An eddy current feedback module includes a current supply module and a coil for being installed on one heating plate of the electric baking pan. The current supply module is connected to the coil and is used to generate an alternating current and output it to the coil so that it generates an alternating magnetic field that acts on the other heating plate of the electric baking pan to form an eddy current. A weighing module is used to be set on the heating plate of the electric baking pan to detect its weight; A detection control module is connected to the coil and the weighing module, and is used to detect the feedback current generated by the feedback effect of the eddy current in the coil, and adjust the temperature and heating time of the heating plate of the electric baking pan according to the feedback current and the weight detected by the weighing module.

2. The electric baking pan heating control circuit according to claim 1, characterized in that: The detection control module includes a current sampling module and a main control module. The current sampling module is connected to the coil and the main control module, and is used to sample the feedback current in the coil. The main control module is connected to the current supply module, and is used to adjust the temperature and heating time of the heating plate of the electric baking pan according to the current sampled by the current sampling module and the weight detected by the weighing module.

3. The electric baking pan heating control circuit according to claim 2, characterized in that: The current supply module includes multiple switching tubes, which are connected to the coil to form an H-bridge circuit. The H-bridge circuit is connected to a power supply. One end of the coil is connected between two adjacent bridge arms of the H-bridge circuit, and the other end of the coil is connected between the other two adjacent bridge arms of the H-bridge circuit. The main control module is connected to the multiple switching tubes, and the current sampling module is connected to the main control module and the H-bridge circuit. The main control module provides a pulse signal to control the multiple switching tubes to be alternately turned on and off.

4. The electric baking pan heating control circuit according to claim 3, characterized in that: The current sampling module includes a sampling resistor and a current limiting resistor. The H-bridge circuit is grounded through the sampling resistor. One end of the current limiting resistor is connected to one end of the sampling resistor, and the other end of the current limiting resistor is connected to the main control module.

5. The electric baking pan heating control circuit according to claim 4, characterized in that: The multiple switching transistors include a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor. The gates of the first MOS transistor, the second MOS transistor, the third MOS transistor, and the fourth MOS transistor are all connected to the main control module, the drains of the first MOS transistor and the third MOS transistor are both connected to the positive electrode of the power supply, and the sources are respectively connected to the drains of the second MOS transistor and the fourth MOS transistor. The sources of the second MOS transistor and the fourth MOS transistor are grounded through the sampling resistor, and the two ends of the coil are respectively connected to the drains of the second MOS transistor and the fourth MOS transistor.

6. The electric baking pan heating control circuit according to claim 4, characterized in that: The current sampling module also includes a first operational amplifier, the non-inverting input terminal of the first operational amplifier is connected to one end of the sampling resistor through the current limiting resistor, the inverting input terminal of the first operational amplifier is connected to the output terminal through the resistor, and the main control module is connected to the output terminal of the first operational amplifier.

7. The electric baking pan heating control circuit according to any one of claims 1 to 6, characterized in that: The weighing module includes a weight conversion module and a signal amplification module. The weight conversion module is used to be set to the bottom of the lower heating plate of the electric baking pan to convert the weight of the heating plate of the electric baking pan into an electrical signal output. The signal amplification module is connected to the weight conversion module and the detection control module, and is used to amplify the electrical signal output by the weight conversion module and output it to the detection control module.

8. The electric baking pan heating control circuit according to claim 7, characterized in that: The weight conversion module includes a differential amplifier and a Wheatstone bridge formed by connecting multiple strain gauges. The multiple strain gauges are used to be set at the bottom of the lower heating plate of the electric griddle. The Wheatstone bridge is connected to a power supply. The positive input end of the differential amplifier is connected between two adjacent bridge arms of the Wheatstone bridge, the negative input end is connected between the other two adjacent bridge arms of the Wheatstone bridge, and the output end is connected to the signal amplification module.

9. The electric baking pan heating control circuit according to claim 8, characterized in that: The signal amplification module includes a second operational amplifier, the non-inverting input terminal of the second operational amplifier is connected to the output terminal, the output terminal of the differential amplifier is connected to the non-inverting input terminal of the second operational amplifier, the inverting input terminal of the second operational amplifier is grounded, and the detection control module is connected to the output terminal of the second operational amplifier.

10. An electric baking pan, characterized in that: The invention comprises the electric baking pan heating control circuit as described in any one of claims 1 to 9.

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