Electric baking pan heating control circuit and electric baking pan

Abstract

The invention discloses an electric baking pan heating control circuit and an electric baking pan, and the electric baking pan heating control circuit comprises an eddy current feedback module which comprises a current supply module and a coil used for being arranged on a heating disc of the electric baking pan, and the current supply module is connected with the coil; the coil is used for generating alternating current and outputting the alternating current to the coil to generate an alternating magnetic field to act on the other heating disc of the electric baking pan to form eddy current; the weighing module is used for being arranged on a heating disc of the electric baking pan to detect the weight of the heating disc; and the detection control module is connected to the coil and the weighing module and used for detecting feedback current generated by the feedback action of the eddy current in the coil and adjusting the temperature and the heating time of a heating disc of the electric baking pan according to the feedback current and the weight detected by the weighing module. The heating control circuit of the electric baking pan is applied to the electric baking pan, the heating temperature and the heating time of the heating disc of the electric baking pan can be automatically adjusted according to the weight and the thickness of food, the food cooking effect of 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 griddles, and in particular to an electric griddle heating control circuit and an electric griddle. Background Art

[0002] At present, with the improvement of people's living standards, more and more consumers choose to buy electric griddles to cook food. An electric griddle is a cooking tool. Usually, the electric griddle uses the heating method of electric heating wires, that is, heat is generated by the electric heating wires in the upper and lower heating plates to heat food, so as to achieve the purpose of cooking food. However, for the current electric griddles, when cooking food, it is difficult for users to control the cooking effect of the food. Users need to constantly observe with their eyes and feel with their sense of smell to control the cooking effect of the food, such as controlling whether the texture of the food is crispy or soft. Once the cooking time is too long or too short, it is easy to cause the texture of the food to be poor, affecting the edibility. Summary of the Invention

[0003] An embodiment of the present invention provides an electric griddle heating control circuit and an electric griddle, aiming to solve the problem that it is difficult for users to control the cooking effect of food when using traditional electric griddles for cooking.

[0004] In a first aspect, an embodiment of the present invention provides an electric griddle heating control circuit, which includes: an eddy current feedback module, including a current supply module and a coil for being arranged on a heating plate of the electric griddle, the current supply module is connected to the coil and is used for generating an alternating current and outputting it to the coil so that an alternating magnetic field is generated to act on another heating plate of the electric griddle to form an eddy current; a weighing module, for being arranged on the heating plate of the electric griddle to detect its weight; a detection and control module, connected to the coil and the weighing module, for detecting a feedback current generated in the coil under the feedback action of the eddy current, and adjusting the temperature and heating time of the heating plate of the electric griddle according to the feedback current and the weight detected by the weighing module.

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

[0006] In the electric baking pan heating control circuit provided by the embodiment of the present invention, the current supply module includes a plurality of switching tubes, 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, one end of the coil is connected between two adjacent bridge arms of the H-bridge circuit, 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. Among them, the main control module provides a pulse signal to control the plurality of switching tubes to alternately turn on and off.

[0007] In the electric baking pan heating control circuit provided by the 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 baking pan heating control circuit provided by the embodiment of the present invention, the plurality of 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 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 baking pan heating control circuit provided by the embodiment of the present invention, the current sampling module further 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 a 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 by the 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 at 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 for 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 then output it to the detection control module.

[0011] In the electric baking pan heating control circuit provided by the embodiments of the present invention, the weight conversion module includes a differential amplifier and a Wheatstone bridge formed by connecting a plurality of strain gauges. The plurality of strain gauges are used to be arranged at the bottom of the lower heating plate of the electric baking pan. The Wheatstone bridge is connected to a power supply. The positive input terminal of the differential amplifier is connected between two adjacent bridge arms of the Wheatstone bridge, the negative 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.

[0012] In the electric baking pan heating control circuit provided by the embodiments of the present invention, the signal amplification module includes a second operational amplifier. The positive input terminal of the second operational amplifier is connected to the output terminal. The output terminal of the differential amplifier is connected to the positive input terminal of the second operational amplifier. The negative input terminal of the second operational amplifier is grounded. The detection and control module is connected to the output terminal of the second operational amplifier.

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

[0014] The embodiments of the present invention provide 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 used to be arranged on 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 an alternating magnetic field is generated to act on the other heating plate of the electric baking pan to form an eddy current; a weighing module, used to be arranged on the heating plate of the electric baking pan to detect its weight; a detection and control module, connected to the coil and the weighing module, and is used to detect the feedback current generated by the feedback action 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. The electric baking pan heating control circuit of the present application is applied to an 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 the effect of cooking food in the electric baking pan easier to control and the taste of the cooked food better. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a structural block diagram of the electric baking pan heating control circuit provided by the embodiments of the present invention; Figure 2Schematic diagram of the heating control circuit of the electric baking pan provided by the embodiment of the present invention; Figure 3 Another structural block diagram of the heating control circuit of the electric baking pan provided by the embodiment of the present invention; Figure 4 A partial circuit diagram of the heating control circuit of the electric baking pan provided by the embodiment of the present invention; Figure 5 Another partial circuit diagram of the heating control circuit of the electric baking pan provided by the embodiment of the present invention; Figure 6 Yet another partial circuit diagram of the heating control circuit of the electric baking pan provided by the embodiment of the present invention.

[0017] Each reference numeral in the figure is as follows: 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 implementation manners

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] The directional terms mentioned in the present invention, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", etc., are only references to the directions in the attached drawings. Therefore, the directional terms used are for explaining and understanding the present invention, rather than for limiting the present invention. In addition, in the drawings, structures that are similar or the same are denoted by the same reference numerals.

[0020] To facilitate the understanding of the present invention, first, the heating control circuit of the electric baking pan provided by the embodiment of the present invention will be described. Please refer to Figures 1 to 6 , and specifically, reference can be made to Figure 1 and Figure 2, the electric baking pan heating control circuit includes an eddy current feedback module 1, a weighing module 2, and a detection and control module 3; the eddy current feedback module 1 includes a current supply module 12 and a coil 11 to be arranged on 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 to generate an alternating magnetic field acting on another heating plate 100 of the electric baking pan to form an eddy current; the weighing module 2 is used to be arranged on the heating plate 100 of the electric baking pan to detect its weight; the detection and control module 3 is connected to the coil 11 and the weighing module 2 and is used to detect the feedback current generated in the coil 11 under the action of the eddy current feedback, 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.

[0021] For traditional electric baking pans, multiple heating gears are usually provided for users to select and control. Users need to manually adjust the temperature of the heating plate to the corresponding gear. At the same time, they also need to constantly observe with their eyes and feel through their sense of smell to control the cooking effect of the food. It is not possible to well control the taste of the food during cooking. Once the cooking time is too long or too short, it is easy to cause the food to have a poor taste, affecting the user's consumption. Therefore, it is very difficult for users to control the cooking effect when using a traditional electric baking pan to cook food.

[0022] To solve the above problems, this embodiment provides an electric baking pan heating control circuit. The electric baking pan heating control circuit is applied in an electric baking pan. Generally, an electric baking pan is structurally composed of a base, an upper cover, upper and lower heating plates 100, a heating module, a main board, etc. The upper and lower heating plates 100 of the electric baking pan are made of metal and are the main components for cooking food. The upper and lower heating plates 100 are divided into two parts, namely an upper heating plate 100 and a lower heating plate 100. The lower heating plate 100 is installed on the base, and the upper heating plate 100 is installed on the upper cover and is hinged to the base through the upper cover. The upper and lower heating plates 100 can press the food together. The heating module of the electric baking pan is usually composed of heating wires and is arranged in the non-cooking area on the back of the upper and lower heating plates 100 and is the main component to realize the heating function of the upper and lower heating plates 100. In this embodiment, the electric baking pan heating control circuit can be integrated into the main board of the electric baking pan to control the heating function of the heating module of the electric baking pan and realize the heating control of the heating plate 100 of the electric baking pan.

[0023] Such as Figure 1As shown in the figure, the electro - magnetic baking pan heating control circuit of this embodiment mainly consists of an eddy current feedback module 1, a weighing module 2, and a detection and control module 3. The eddy current feedback module 1 is used to cooperate with the heating plate 100 of the electro - magnetic baking pan to generate eddy currents. Specifically, the eddy current feedback module 1 mainly consists of a current supply module 12 and a coil 11. The coil 11 is used to be set on a heating plate 100 of the electro - magnetic baking pan. It can be set on the upper heating plate 100 of the electro - magnetic baking pan or 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 onto the main board of the electro - magnetic baking pan. The current supply module 12 is used to generate an alternating current and output it 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 griddle, thereby forming eddy currents on the other heating plate 100 of the electric griddle. Specifically, when the coil 11 is arranged on the upper heating plate 100 of the electric griddle, eddy currents are formed on the lower heating plate 100 of the electric griddle; when the coil 11 is arranged on the lower heating plate 100 of the electric griddle, eddy currents are formed on the upper heating plate 100 of the electric griddle. Eddy currents refer to the closed-loop circular currents generated in a conductor due to electromagnetic induction in a changing magnetic field, and their essence is the electromagnetic induction phenomenon. After eddy currents are formed on the heating plate 100 of the electric griddle, the eddy currents 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 heating plate 100 of the electric griddle determines the distance between the upper and lower heating plates 100 of the electric griddle. The thinner the food thickness, the smaller the distance between the upper and lower heating plates 100, and the closer the distance between the coil 11 and the other heating plate 100 of the electric griddle. The heating plate 100 is a metal matrix. The closer the coil 11 is, the stronger the generated eddy currents, and the greater the reflection impedance of the eddy currents to the coil 11, and the greater the feedback current generated in the coil 11. In practical applications, as the electric griddle heats up, the moisture in the food in the heating plate 100 of the electric griddle will evaporate and decrease, and the thickness of the food will gradually become thinner. Therefore, the feedback current generated in the coil 11 will increase. The weighing module 2 is arranged on the heating plate 100 of the electric griddle to detect the weight of the heating plate 100. Specifically, the weighing module 2 will be arranged at the bottom of the lower heating plate 100 of the electric griddle. The weighing module 2 is designed based on the principle of gravity induction. When there is food 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 griddle, and 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 practical applications, the detection control module 3 is connected to the heating module of the electric griddle. The detection control module 3 is a module structure including detection functions and logic control functions. 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 griddle 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 griddle, that is, the temperature and heating time of the heating plate 100 of the electric griddle are jointly 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 griddle.

[0024] In an actual cooking scenario, taking the cooking of pancakes as an example, the user puts the raw pancake into the heating plate 100 of the electric griddle. The heating plate 100 of the electric griddle heats the pancake. As the heating progresses, the moisture of the pancake evaporates, and the body of the pancake changes. The pancake becomes thinner from thick, and at the same time, the weight becomes lighter. The thinning of the thickness of the pancake makes the distance between the upper and lower heating plates 100 of the electric griddle 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 griddle becomes lighter. The detection and control module 3 calculates the most suitable heating temperature and heating time of the pancake in the current state according to these two parameters, namely the feedback current and the weight of the heating plate 100 of the electric griddle, according to the algorithm, so as to control the heating module of the electric griddle to adjust the temperature of the heating plate 100 of the electric griddle to the corresponding temperature and control the heating time, realizing the dynamic adjustment of the heating temperature and heating time of the heating plate 100 of the electric griddle according to the weight and thickness states of the pancake at different moments, automatically adjusting the cooking heat, and achieving the purpose of intelligent cooking.

[0025] In one embodiment, referring to Figure 3 and Figure 4 , the detection and 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 griddle according to the magnitude of the current sampled by the current sampling module 31 and the magnitude of the weight detected by the weighing module 2. In a specific implementation, the detection and 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 logic operation and control functions. Specifically, it can be an MCU module or other IC modules with operation and control functions. The main control module 32 is connected to the weighing module 2 and receives the magnitude of the weight of the heating plate 100 of the electric griddle detected by the weighing module 2. The main control module 32 controls the heating module of the electric griddle according to the magnitude of the current sampled by the current sampling module 31 and the magnitude of the weight detected by the weighing module 2, according to the control algorithm preset by the system, so as to adjust the temperature and heating time of the heating plate 100 of the electric griddle.

[0026] Further, referring to Figure 4, the power supply module 12 includes a plurality of switching tubes. The plurality of switching tubes 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, and the current sampling module 31 is connected to the main control module 32 and the H-bridge circuit. Among them, the main control module 32 provides a pulse signal to control the plurality of switching tubes to alternately turn on and off. In a specific implementation, the power supply module 12 is composed of a plurality of switching tubes. The plurality of switching tubes are connected to the coil 11 to form an H-bridge circuit. The H-bridge circuit formed by the coil 11 and the plurality of switching tubes can be a single H-bridge. The number of switching tubes is four, and each switching tube forms a bridge arm of the H-bridge circuit, with 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 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 control ends of all the switching tubes, and the current sampling module 31 is connected to the main control module 32 and the H-bridge circuit, specifically connected between two adjacent bridge arms of the H-bridge circuit. In practical applications, the main control module 32 provides a pulse signal to the plurality of switching tubes that form the H-bridge circuit, thereby controlling the plurality of switching tubes to alternately turn on and off. By the combined on and off of 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, and further causing the other heating plate 100 of the electric baking pan to form eddy currents.

[0027] Furthermore, referring 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. The other end of the current limiting resistor R1 is connected to the main control module 32. In practical applications, the coil 11 generates a feedback current under the action of the eddy current on the heating plate 100 of the electric baking pan, and the voltage across the sampling resistor R2 will change, thereby generating a feedback electrical signal. The feedback electrical signal is input to the main control module 32 through the current limiting resistor R1, and the current limiting resistor R1 can prevent the current of the feedback electrical signal from being too large and damaging 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, so as to adjust the temperature and heating time of the heating plate 100 of the electric baking pan.

[0028] Furthermore, referring to Figure 5 , the current sampling module 31 further includes a first operational amplifier U1. The non-inverting input terminal 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 terminal of the first operational amplifier U1 is connected to the output terminal through a resistor, and the main control module 32 is connected to the output terminal of the first operational amplifier U1. In a specific implementation, the current sampling module 31 further includes a first operational amplifier U1. The non-inverting input terminal of the first operational amplifier U1 is connected to one end of the sampling resistor R2 through the current limiting resistor R1, specifically connected to the end of the sampling resistor R2 connected to the H-bridge circuit. The inverting input terminal of the first operational amplifier U1 is connected to its own output terminal through a resistor R3, and the main control module 32 is connected to the output terminal of the first operational amplifier U1 through a resistor R4. In practical applications, 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, so as to better adjust the heating temperature and heating time of the heating plate 100 of the electric baking pan.

[0029] In one embodiment, referring to Figure 4 and Figure 5, the multiple switching tubes 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 through 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 tubes that form an H-bridge circuit together with the coil 11 are the first MOS transistor Q1, the second MOS transistor Q2, the third MOS transistor Q3, and the fourth MOS transistor Q, a total of four MOS transistors. The four MOS transistors and the coil 11 together 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, and the specific connections are respectively at four IO ports of the main control module 32. The drains of the first MOS transistor Q1 and the third MOS transistor Q3 are together connected to the positive pole 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 together grounded through 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. 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 respectively through four ports H1, L1, H2, and L2. By controlling the combined on / off of the four MOS transistors, the current of the power supply is changed into an alternating current in the coil 11, so that the coil 11 generates an alternating magnetic field.

[0030] In one embodiment, referring to Figure 3 and Figure 6, the weighing module 2 includes a weight conversion module 21 and a signal amplification module 22. The weight conversion module 21 is configured to be disposed 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 for output. The signal amplification module 22 is connected to the weight conversion module 21 and the detection and control module 3, and is configured to amplify the electrical signal output by the weight conversion module 21 and then output it to the detection and 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 may specifically be a weight sensor module or other circuit modules that can implement the conversion of weight into an electrical signal. The lower heating plate 100 of the electric baking pan is the part that bears food. The weight conversion module 21 is mainly used to be disposed 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 and 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 and control module 3. Through the detection and control module 3, the weight of the heating plate 100 of the electric baking pan can be calculated, so as to accurately obtain the change in the weight of the food in the heating plate 100 of the electric baking pan.

[0031] Further, referring to Figure 6, the weight conversion module 21 includes a differential amplifier U3 and a Wheatstone bridge formed by connecting a plurality of strain gauges. The plurality of strain gauges are used to be arranged at the bottom of the lower heating plate 100 of the electric griddle. The Wheatstone bridge is connected to a power supply. The positive input terminal of the differential amplifier U3 is connected between two adjacent bridge arms of the Wheatstone bridge, the negative 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 a plurality of strain gauges, and each strain gauge corresponds to a bridge arm. The plurality of strain gauges are used to be arranged at the bottom of the lower heating plate 100 of the electric griddle. A strain gauge is an element for measuring strain composed of a sensitive grid, etc. It will generate mechanical deformation under the action of an external force, and thus its resistance value will change accordingly. The positive input terminal of the differential amplifier U3 is connected between two adjacent bridge arms of the Wheatstone bridge, the negative input terminal of the differential amplifier U3 is connected between the other two adjacent bridge arms of the Wheatstone bridge, and the output terminal of the differential amplifier U3 is connected to the input terminal of the signal amplification module 22. The input of the Wheatstone bridge is connected to a power supply. When there is food in the heating plate 100 of the electric griddle, the plurality of strain gauges will all undergo different degrees of deformation and generate different degrees of resistance changes respectively, thereby converting the weight signal of the heating plate 100 of the electric griddle into an electrical signal. A voltage difference is generated between the positive input terminal and the negative input terminal of the differential amplifier U3, so that the output terminal of the differential amplifier U3 outputs different magnitudes of voltage Ucd, reflecting the parameters of different weights of the food in the heating plate 100 of the electric griddle. The output voltage Ucd of the differential amplifier U3 is then amplified by the signal amplification module 22 and output to the detection and control module 3, and the detection and control module 3 can accurately obtain the weight of the heating plate 100 of the electric griddle.

[0032] Furthermore, referring to Figure 6, the signal amplification module 22 includes a second operational amplifier U2. The non-inverting input terminal of the second operational amplifier U2 is connected to the output terminal. The output terminal of the differential amplifier U3 is connected to the non-inverting input terminal of the second operational amplifier U2. The inverting input terminal of the second operational amplifier U2 is grounded. The detection and control module 3 is connected to the output terminal of the second operational amplifier U2. In a specific implementation, the signal amplification module 22 is mainly composed of the second operational amplifier U2. The non-inverting input terminal of the second operational amplifier U2 is connected to the output terminal, thereby forming a voltage follower. The non-inverting input terminal of the second operational amplifier U2 is connected to the output terminal of the differential amplifier U3 through a resistor R5. The inverting input terminal of the second operational amplifier U2 is grounded. The detection and control module 3 is connected to the output terminal of the second operational amplifier U2. In practical applications, the voltage signal at the output terminal of the differential amplifier U3 is input through the non-inverting input terminal of the second operational amplifier U2. The second operational amplifier U2 amplifies the voltage signal and outputs the amplified voltage signal from the output terminal to the detection and control module 3, so that the detection and control module 3 can accurately obtain the weight of the food in the heating plate 100 of the electric baking pan.

[0033] Specifically, referring to Figure 6, the 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 pole of the power supply, and the other ends are respectively connected to one end of the third strain gauge Ra3 and the fourth strain gauge Ra4. 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 input terminal of the differential amplifier U3 is connected between the first strain gauge Ra1 and the third strain gauge Ra3, and the negative input terminal is connected between the second strain gauge Ra2 and the fourth strain gauge Ra4. In a specific implementation, there are a total of four strain gauges, namely the first strain gauge Ra1, the second strain gauge Ra2, and the third strain gauge Ra3, which form a Wheatstone bridge. One end of both the first strain gauge Ra1 and the second strain gauge Ra2 is connected together to the positive pole of the power supply, and the other ends of both the first strain gauge Ra1 and the second strain gauge Ra2 are respectively connected to one end of the third strain gauge Ra3 and the fourth strain gauge Ra4. The other ends of both the third strain gauge Ra3 and the fourth strain gauge Ra4 are connected to the negative pole of the power supply. The positive input terminal of the differential amplifier U3 is connected between the first strain gauge Ra1 and the third strain gauge Ra3, and the negative input terminal of the differential amplifier U3 is connected between the second strain gauge Ra2 and the fourth strain gauge Ra4. In practical applications, the power supply provides voltage input. When there is food in the heating plate 100 of the electric baking pan, the first strain gauge Ra1 to the fourth strain gauge Ra4 will all undergo different degrees of deformation, respectively generating different degrees of resistance changes. Let ΔRa1, ΔRa2, ΔRa3, and ΔRa4 represent the resistance changes of the first strain gauge Ra1, the second strain gauge Ra2, the third strain gauge Ra3, and the fourth strain gauge Ra4 respectively. At this time, the input voltage at the input terminal of 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 output as the voltage Ucd2 after passing through the differential amplifier. The voltage follower composed of the second operational amplifier U2 enhances the anti-interference ability of the electrical signal of the output voltage Ucd2 at the output terminal of the differential amplifier U3, and then outputs the signal to the detection and control module 3, so that the weight of the food in the heating plate 100 of the electric baking pan at different times can be accurately detected.

[0034] The electric baking pan heating control circuit provided by the embodiment of the present application uses a current supply module to generate an alternating current and output it to the coil, so that the coil generates an alternating magnetic field acting on the heating plate of the electric baking pan to form eddy currents, and uses a weighing module to detect the weight of the heating plate. The detection and control module detects the feedback current generated by the feedback action of the eddy currents in the coil, and then adjusts 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, so that the effect of cooking food in the electric baking pan is easier to control and the taste of the cooked food is better.

[0035] An embodiment of the present invention further provides a electric baking pan, which includes the electric baking pan heating control circuit described in the above embodiment. In addition, the electric baking pan may further include components such as a base, an upper cover, upper and lower heating plates, a heating module, a main board, etc. The upper and lower heating plates are the upper heating plate and the lower heating plate. The lower heating plate is installed on the base, the upper heating plate is installed on the upper cover, and the heating module is installed 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, so as to realize the control of the heating temperature and heating time of the heating plate of the electric baking pan. Among them, since the specific structure and working principle of the electric baking pan heating control circuit have been introduced in detail in the previous specification, for the sake of simplicity of the specification, it will not be repeated here.

[0036] In the electric baking pan of this embodiment, due to the adoption of the electric baking pan heating control circuit provided by the present invention, the cooking effect of the food can be better controlled during cooking, and the taste of the cooked food is better.

[0037] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An electric baking pan heating control circuit, characterized in that: include: The eddy current feedback module includes a current supply module and a coil used to be set on a heating plate of the electric baking pan, wherein 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 an eddy current; A weighing module, used for being arranged 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 a plurality of switch tubes, and the plurality of switch tubes are connected with 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 plurality of switch 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 switch 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 switch 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 all connected to the positive electrode 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.

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, a non-phase input terminal of the first operational amplifier is connected to one end of the sampling resistor through the current limiting resistor, an inverting input terminal of the first operational amplifier is connected to an output terminal through a 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 at 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 baking pan, the Wheatstone bridge is connected to a power supply, the non-phase input end of the differential amplifier is connected between two adjacent bridge arms of the Wheatstone bridge, the inverting 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: It comprises the electric baking pan heating control circuit as described in any one of claims 1 to 9.

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