Cookware detection circuit and method of global heating electromagnetic range and electromagnetic range

Abstract

The invention discloses a cookware detection circuit and method of a global heating electromagnetic range and the electromagnetic range, and relates to the technical field of electromagnetic heating, the circuit comprises a plurality of groups of LC resonance circuits and an MCU control unit, and any group of LC resonance circuits is connected with a coupling feedback circuit and an inversion circuit; the first output end of the MCU control unit is connected with the input end of the coupling feedback loop; the first output end of the coupling feedback loop is connected with the LC resonance loop; the second output end of the coupling feedback loop is connected with the input end of the MCU control unit. A second output end of the MCU control unit is connected with the LC resonance circuit; the third output end of the MCU control unit is connected with the input end of the inversion loop; and the output end of the inverter circuit is connected with the LC resonance circuit. According to the application, non-intermittent detection can be carried out on the induction coils of the plurality of LC resonance circuits for global heating, so that the heating efficiency of the global heating electromagnetic range can be effectively improved, and the user experience is further improved.

Description

Technical Field

[0001] The present application relates to the field of electromagnetic heating technology, and in particular to a pot detection circuit and method for a full-area heating electromagnetic cooker, and an electromagnetic cooker. Background Art

[0002] In the existing technology, each burner of the full-range heating induction cooker is equipped with an array of LC resonant circuits. All LC resonant circuits of each burner are connected to an inverter. The inverters of multiple burners are connected in parallel or non-parallel through electronic switches, thereby realizing a single LC resonant circuit working in non-parallel, or multiple LC resonant circuits working simultaneously in parallel, thereby meeting the power output requirements of different pots and different heating needs.

[0003] However, when the existing full-area heating electromagnetic cooker polls the detection coil position and outputs the heating power, the electronic switch needs to switch at zero voltage and zero current, causing the inverter to suspend work first, thereby stopping the oscillation of the LC resonant circuit that is heating, causing intermittent non-heating. Moreover, when a certain LC resonant circuit is working, the user randomly places the pots and uses a polling method to detect whether there are pots on other LC resonant circuits. As the number of LC resonant circuits increases, the polling time becomes longer and the intermittent time becomes longer, resulting in poor heating efficiency of the full-area heating electromagnetic cooker, which seriously affects the user experience. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the relevant technology, the purpose of this application is to provide a pot detection circuit, method and electromagnetic cooker for a full-area heating electromagnetic cooker, which can perform uninterrupted detection on whether there are pots on the induction coils of multiple LC resonant circuits for full-area heating, and can effectively improve the heating efficiency of the full-area heating electromagnetic cooker, thereby improving the user experience.

[0005] To achieve the above objectives, this application provides the following solutions: In a first aspect, the present application provides a method for detecting pots in a global heating electromagnetic cooker, comprising: multiple groups of LC resonant circuits and an MCU control unit, wherein any group of the LC resonant circuits is connected to a coupling feedback circuit and an inverter circuit; Among them, the first output end of the MCU control unit is connected to the input end of the coupling feedback loop; the first output end of the coupling feedback loop is connected to the LC resonant circuit; the second output end of the coupling feedback loop is connected to the input end of the MCU control unit; the second output end of the MCU control unit is connected to the LC resonant circuit; the third output end of the MCU control unit is connected to the input end of the inverter circuit; the output end of the inverter circuit is connected to the LC resonant circuit; when the global heating induction cooker is in the on state, the coupling feedback loop receives the pulse detection signal sent by the MCU control unit, and excites the L based on the pulse detection signal. The C resonant circuit generates an equivalent impedance and generates a feedback signal based on the equivalent impedance; the MCU control unit is used to determine whether there is a cookware on the induction coil of the LC resonant circuit based on the feedback signal, and when there is a cookware, connect the inverter circuit and the LC resonant circuit, generate a heating control signal, and send the heating control signal to the inverter circuit; the inverter circuit is used to generate a high-frequency square wave voltage based on the heating control signal, and drive the induction coil of the LC resonant circuit to generate an alternating magnetic field based on the high-frequency square wave voltage; the LC resonant circuit is used to form a closed loop with the cookware in the alternating magnetic field to generate eddy current, and heat the cookware based on the eddy current.

[0006] Optionally, the LC resonant circuit includes a resistor Rs1_1, an induction coil L1_1, and a relay K1_1; wherein one end of the resistor Rs1_1 is connected to the first output end of the coupling feedback loop, and the other end of the resistor Rs1_1 is connected to one end of the induction coil L1_1; the other end of the induction coil L1_1 is connected to one end of the relay K1_1, the other end of the relay K1_1 is connected to the output end of the inverter circuit, and the input end of the relay K1_1 is connected to the second output end of the MCU control unit; the relay K1_1 is used to conduct the inverter circuit and the LC resonant circuit under the control of the MCU control unit; the induction coil L1_1 is used to generate an alternating electromagnetic field under the drive of a high-frequency square wave voltage when the relay K1_1 is in an energized state, and form a closed loop with the pot placed on the induction coil L1_1 to generate eddy current.

[0007] Optionally, the coupling feedback loop includes: a capacitor C10_3, a capacitor C10_4, a capacitor C10_5, and a comparator U1; wherein one end of the capacitor C10_3 is connected to the first output end of the MCU control unit, the other end of the capacitor C10_3 is connected to one end of the capacitor C10_5, the other end of the capacitor C10_5 is connected to one end of the capacitor C10_4, and the other end of the capacitor C10_4 is connected to the input end of the LC resonant circuit; the midpoint of the connection between the capacitor C10_3 and the capacitor C10_5 is a detection point, and the detection point is connected to the positive input end of the comparator U1; the negative input end of the comparator U1 is connected to the MCU control The fourth output terminal of the control unit is connected, and the output terminal of the comparator U1 is connected to the input terminal of the MCU control unit; when the relay K1_1 is disconnected, the capacitors C10_3, C10_4 and C10_ form a coupling loop, which is used to couple the pulse detection signal to generate a coupling signal, and stimulate the LC resonant circuit to generate an equivalent impedance based on the coupling signal, and generate a detection signal at the detection point under the action of the equivalent impedance; the comparator U1 is used to compare the detection signal with the reference voltage output by the MCU control unit to generate a feedback signal; the feedback signal is a square wave signal with different duty cycles.

[0008] Optionally, the coupling feedback loop further includes: a diode D10_1 and a resistor R10_6; the detection point is connected to the positive input terminal of the comparator U1 through the diode D10_1 and the resistor R10_6; the diode D10_1 is used to filter the negative pulse voltage of the detection signal so that the detection signals input to the comparator U1 are all positive pulse voltages.

[0009] Optionally, the coupling feedback loop also includes: a resistor R10_2, a transistor Q1, and a resistor R10_3; one end of the resistor R10_2 is connected to the first output end of the MCU control unit, one end of the resistor R10_2 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to one end of the capacitor C10_3 and the resistor R10_3 respectively, the other end of the resistor R10_3 is connected to VCC, and the capacitor C10_3 is connected to the first output end of the MCU control unit through the resistor R10_2 and the collector of the transistor Q1; the resistor R10_2, the transistor Q1, and the resistor R10_3 form a reverse amplification loop, which is used to reversely amplify the pulse detection signal output by the MCU control unit and output the reversely amplified pulse detection signal to the capacitor C10_3.

[0010] Optionally, any group of the LC resonant circuits is also connected to a first drive circuit and a second drive circuit; the inverter circuit includes a first inverter circuit and a second inverter circuit; the first inverter circuit and the second inverter circuit are connected in series; the first inverter circuit and the second inverter circuit are connected in series to form a bridge arm midpoint, and the bridge arm midpoint is connected to the LC resonant circuit as the input end of the inverter circuit; the third output end OUTA1 of the MCU control unit is connected to the input end of the first inverter circuit through the first drive circuit, and the third output end OUTB1 of the MCU control unit is connected to the input end of the second inverter circuit through the second drive circuit; the MCU control unit outputs a first heating control signal to the first inverter circuit through the first drive circuit; and outputs a second heating control signal to the second inverter circuit through the second drive circuit; the first heating control signal and the second heating control signal are complementary square wave signals; the first inverter circuit and the second inverter circuit are used to work alternately under the drive of two groups of complementary square wave signals to generate a high-frequency square wave voltage.

[0011] Optionally, the first drive circuit includes a resistor R3, a driver U2, and a resistor R5; one end of the resistor R5 is connected to the third output terminal OUTA1 of the MCU control unit, and the other end of the resistor R5 is connected to the input terminal of the driver U2, the output terminal of the driver U2 is connected to one end of the resistor R3, and the other end of the resistor R3 is connected to the input terminal of the first inverter circuit; the first drive circuit is used to amplify the first heating control signal and output the amplified first heating control signal to the first inverter circuit; the second drive circuit includes a resistor R4, a driver U3, and a resistor R6; one end of the resistor R6 is connected to the third output terminal OUTB1 of the MCU control unit, and the other end of the resistor R6 is connected to the input terminal of the driver U3, the output terminal of the driver U3 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the input terminal of the second inverter circuit; the second drive circuit is used to amplify the second heating control signal and output the amplified second heating control signal to the second inverter circuit.

[0012] In a second aspect, the present application provides a method for detecting pots in a full-range heating electromagnetic cooker, the method being applied to the MCU control unit described in any one of the above items, the method comprising: When the global heating electromagnetic cooker is in the on state, a pulse detection signal is sent to the coupling feedback loop; and a feedback signal output by the coupling feedback loop is obtained; based on the feedback signal, it is determined whether there is a cookware on the induction coil of the LC resonant circuit; when there is a cookware, the inverter circuit and the LC resonant circuit are turned on, and a heating control signal is generated and sent to the inverter circuit, so that the inverter circuit generates a high-frequency square wave voltage based on the heating control signal, and drives the induction coil of the LC resonant circuit to generate an alternating magnetic field based on the high-frequency square wave voltage; the LC resonant circuit forms a closed loop with the cookware in the alternating magnetic field to generate eddy current, and heats the cookware based on the eddy current.

[0013] Optionally, the feedback signal is a square wave signal with different duty cycles; and judging whether there is a cookware on the induction coil of the LC resonant circuit based on the feedback signal includes: reading the duty cycle value of the feedback signal; if the duty cycle of the feedback signal is greater than a reference duty cycle value, there is a cookware on the induction coil of the LC resonant circuit; if the duty cycle of the feedback signal is less than or equal to the reference duty cycle value, there is no cookware on the induction coil of the LC resonant circuit.

[0014] In a third aspect, the present application provides a full-area heating electromagnetic cooker, comprising a control board, on which is integrated the pot detection circuit of the full-area heating electromagnetic cooker described in any one of the above items, or the control board is used to execute the pot detection method of the full-area heating electromagnetic cooker described in any one of the above items.

[0015] According to the specific embodiments provided in this application, this application discloses the following technical effects: The present application provides a pot detection circuit, method and electromagnetic cooker for a global heating electromagnetic cooker, which receives a pulse detection signal sent by an MCU control unit through a coupled feedback loop, and excites an LC resonant circuit to generate an equivalent impedance based on the pulse detection signal, and generates a feedback signal based on the equivalent impedance; receives the feedback signal through the MCU control unit, and determines whether there is a pot on the induction coil of the LC resonant circuit according to the feedback signal, and turns on the inverter circuit and the LC resonant circuit when there is a pot, generates a heating control signal and sends the heating control signal to the inverter circuit; drives the inverter circuit to generate a high-frequency square wave voltage through the high-frequency square wave voltage. The wave voltage drives the induction coil of the LC resonant circuit to generate an alternating magnetic field; the LC resonant circuit forms a closed loop with the cookware in the alternating magnetic field to generate eddy current, and heats the cookware based on the eddy current; when there are already cookware being heated on the full-area heating induction cooker, it is possible to detect whether there are normal cookware placed on the induction coil of other LC resonant circuits without switching the electronic switch, which will not affect the cookware that has been heated normally and can effectively improve the heating efficiency of the full-area heating induction cooker; in addition, the detection process is not affected by the number of LC resonant circuits, and has the advantages of low system loss and high detection efficiency, which can effectively improve the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram of the pot detection circuit structure of a global heating electromagnetic cooker provided in this application; Figure 2 A pot detection circuit diagram for a global heating electromagnetic cooker provided in this application; Figure 3 A schematic flow chart of a method for detecting pots in a global heating electromagnetic cooker is provided for one embodiment of the present application; Figure 4 A schematic diagram of the functional modules of a full-area heating electromagnetic cooker provided in this application. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0019] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the technical solution claimed in the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0020] In an exemplary embodiment, Figure 1 As shown, a pot detection circuit for a global heating electromagnetic cooker is provided. The pot detection circuit for the global heating electromagnetic cooker can include multiple groups of LC resonant circuits and an MCU control unit 10. Any group of LC resonant circuits 20 is connected to a coupling feedback circuit 30 and an inverter circuit 40. The first output end of the MCU control unit 10 is connected to the input end of the coupling feedback circuit 30; the first output end of the coupling feedback circuit 30 is connected to the LC resonant circuit 20; the second output end of the coupling feedback circuit 30 is connected to the input end of the MCU control unit 10; the second output end of the MCU control unit 10 is connected to the LC resonant circuit 20; the third output end of the MCU control unit 10 is connected to the input end of the inverter circuit 40; and the output end of the inverter circuit 40 is connected to the LC resonant circuit 20.

[0021] When the global heating induction cooktop is powered on, the coupled feedback loop 30 receives a pulse detection signal from the MCU control unit 10. Based on the pulse detection signal, it excites the LC resonant tank 20 to generate an equivalent impedance and generates a feedback signal based on the equivalent impedance. Based on the feedback signal, the MCU control unit 10 determines whether a cookware is present on the induction coil of the LC resonant tank 20. If a cookware is present, the MCU control unit 10 conducts between the inverter circuit 40 and the LC resonant tank 20, generates a heating control signal, and transmits the heating control signal to the inverter circuit 40. Based on the heating control signal, the inverter circuit 40 generates a high-frequency square wave voltage, which in turn drives the induction coil of the LC resonant tank 20 to generate an alternating magnetic field.

[0022] It should be noted that the pulse detection signal sent by the MCU control unit 10 is received through the coupling feedback loop 30, and the LC resonant circuit 20 is stimulated to generate an equivalent impedance based on the pulse detection signal, and a feedback signal is generated based on the equivalent impedance; the feedback signal is received by the MCU control unit 10, and it is determined whether there is a pot on the induction coil of the LC resonant circuit 20 according to the feedback signal, and when there is a pot, the inverter circuit 40 and the LC resonant circuit 20 are turned on, and a heating control signal is generated and sent to the inverter circuit 40; the inverter circuit 40 is driven by the heating control signal to generate a high-frequency square wave voltage, and the high-frequency square wave voltage is used to drive the LC resonant circuit 20 to generate a high-frequency square wave voltage. The induction coil of the C resonant circuit 20 generates an alternating magnetic field; the LC resonant circuit 20 forms a closed loop with the cookware in the alternating magnetic field to generate eddy current, and the cookware is heated based on the eddy current; when there is already a cookware being heated on the global heating electromagnetic cooker, it is possible to detect whether there is a normal cookware placed on the induction coil of other LC resonant circuits 20 without switching the electronic switch, without affecting the cookware that has been heated normally, and can effectively improve the heating efficiency of the global heating electromagnetic cooker; in addition, the detection process is not affected by the number of LC resonant circuits 20, and has the advantages of low system loss and high detection efficiency, which can effectively improve the user experience.

[0023] Furthermore, if Figure 2 As shown, the LC resonant circuit 20 includes a resistor Rs1_1, an induction coil L1_1, and a relay K1_1; wherein one end of the resistor Rs1_1 is connected to the first output end of the coupling feedback loop 30, and the other end of the resistor Rs1_1 is connected to one end of the induction coil L1_1; the other end of the induction coil L1_1 is connected to one end of the relay K1_1, the other end of the relay K1_1 is connected to the output end of the inverter circuit 40, and the input end of the relay K1_1 is connected to the second output end of the MCU control unit 10; under the control of the MCU control unit, the relay K1_1 conducts the inverter circuit and the LC resonant circuit; when the relay K1_1 is in the energized state, the induction coil L1_1 generates an alternating electromagnetic field driven by the high-frequency square wave voltage, and forms a closed loop with the pot placed on the induction coil L1_1 in the alternating electromagnetic field to generate eddy current.

[0024] Furthermore, if Figure 2As shown, the coupling feedback loop 30 includes: capacitor C10_3, capacitor C10_4, capacitor C10_5, and comparator U1; wherein, one end of capacitor C10_3 is connected to the CHECK_PWM pin of the MCU control unit 10, the other end of capacitor C10_3 is connected to one end of capacitor C10_5, the other end of capacitor C10_5 is connected to one end of capacitor C10_4, and the other end of capacitor C10_4 is connected to the input end of the LC resonant circuit 20; the midpoint between capacitor C10_3 and capacitor C10_5 is the detection point A, and the detection point A is connected to the positive input end of the comparator U1; the negative input end of the comparator U1 is connected to the MCU control pin. The fourth output terminal of the control unit 10 is connected, and the output terminal of the comparator U1 is connected to the LOAD1 pin of the MCU control unit 10; when the relay K1_1 is disconnected, the capacitors C10_3, C10_4, and C10_5 form a coupling loop, which is used to couple the pulse detection signal to generate a coupling signal, and stimulate the LC resonant circuit 20 to generate an equivalent impedance based on the coupling signal, and generate a detection signal at the detection point A under the action of the equivalent impedance; the comparator U1 compares the detection signal with the reference voltage output by the MCU control unit 10 to generate a feedback signal; the feedback signal is a square wave signal with different duty cycles.

[0025] It should be noted that when the pulse detection signal output by the MCU control unit 10 is injected into the LC resonant circuit 20 through the coupling circuit, the rising and falling edges of the pulse detection signal will stimulate the LC resonant circuit 20 to produce a transient response; that is, if there is no pot: the impedance of the LC resonant circuit 20 is low, the transient response is manifested as rapid oscillation attenuation, and the detection signal edge is steep; if there is a pot: the impedance of the LC resonant circuit 20 is high, the transient response attenuation is accelerated, and the detection signal edge becomes smoother.

[0026] Furthermore, if Figure 2 As shown, the coupling feedback loop 30 also includes: a diode D10_1 and a resistor R10_6; wherein, the detection point A is connected to the positive input terminal of the comparator U1 through the diode D10_1 and the resistor R10_6; the anode of the diode D10_1 is connected to the detection point A, the cathode of the diode D10_1 is connected to one end of the resistor R10_6, and the other end of the resistor R10_6 is connected to the positive input terminal of the comparator U1; the diode D10_1 is used to filter the negative pulse voltage of the detection signal so that the detection signal input to the comparator U1 is all positive pulse voltage.

[0027] Furthermore, if Figure 2As shown, the coupling feedback loop 30 further includes: a resistor R10_2, a transistor Q1, and a resistor R10_3; wherein, one end of the resistor R10_2 is connected to the first output end of the MCU control unit 10, one end of the resistor R10_2 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to one end of the capacitor C10_3 and the resistor R10_3 respectively, the other end of the resistor R10_3 is connected to VCC, and the capacitor C10_3 is connected to the first output end of the MCU control unit 10 through the resistor R10_2 and the collector of the transistor Q1.

[0028] It should be noted that resistor R10_2, transistor Q1, and resistor R10_3 form an inverse amplification circuit, which is used to inversely amplify the pulse detection signal output by the MCU control unit 10 and output the inversely amplified pulse detection signal to capacitor C10_3. The first output terminal of the MCU control unit 10 is the CHECK_PWM pin, the second output terminal of the MCU control unit 10 is the JDQ1 pin, and the third output terminals of the MCU control unit 10 are the OUTA1 pin and the OUTB1 pin. The input terminal of the MCU control unit 10 is the LOAD1 pin.

[0029] In some specific embodiments, Figure 2 As shown, any group of LC resonant circuits 20 is also connected to a driving circuit 50, which includes a first driving circuit and a second driving circuit; the inverter circuit 40 includes a first inverter circuit and a second inverter circuit; the first inverter circuit and the second inverter circuit are connected in series; the first inverter circuit and the second inverter circuit are connected in series to form a bridge arm midpoint B, and the bridge arm midpoint B is connected to the LC resonant circuit 20 as the input end of the inverter circuit 40; the third output end OUTA1 of the MCU control unit 10 is connected to the input end of the first inverter circuit through the first driving circuit, and the third output end OUTB1 of the MCU control unit 10 is connected to the input end of the second inverter circuit through the second driving circuit; the MCU control unit 10 outputs a first heating control signal to the first inverter circuit through the first driving circuit; and outputs a second heating control signal to the second inverter circuit through the second driving circuit; the first heating control signal and the second heating control signal are complementary square wave signals; the first inverter circuit and the second inverter circuit are used to work alternately under the drive of two sets of complementary square wave signals to generate a high-frequency square wave voltage.

[0030] It should be noted that the first inverter circuit and the second inverter circuit involved in the present application are both IGBT (insulated gate bipolar transistor) power circuits. In other embodiments, MOSFET power circuits or SiC MOSFET power circuits may also be used.

[0031] Furthermore, if Figure 2As shown, the above-mentioned first drive circuit includes a resistor R3, a driver U2, and a resistor R5; one end of the resistor R5 is connected to the third output terminal OUTA1 of the MCU control unit 10, and the other end of the resistor R5 is connected to the input terminal of the driver U2, the output terminal of the driver U2 is connected to one end of the resistor R3, and the other end of the resistor R3 is connected to the input terminal of the first inverter circuit; the second drive circuit includes a resistor R4, a driver U3, and a resistor R6; one end of the resistor R6 is connected to the third output terminal OUTB1 of the MCU control unit 10, and the other end of the resistor R6 is connected to the input terminal of the driver U3, the output terminal of the driver U3 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the input terminal of the second inverter circuit.

[0032] It should be noted that the first drive circuit is used to amplify the first heating control signal and output the amplified first heating control signal to the first inverter circuit; the second drive circuit is used to amplify the second heating control signal and output the amplified second heating control signal to the second inverter circuit.

[0033] refer to Figure 2 As can be understood from the above embodiments, the external AC power supply is connected to both ends of the capacitor C1 after rectification, namely DC+ and GND respectively. The capacitors C10_1 and C10_2 are connected in series and then in parallel to the capacitor C1. The resistor Rs1_1 represents the equivalent resistance of the combination of the induction coil L1_1 and the cookware, wherein the values of the resistor Rs1_1 and the induction coil L1_1 change with the changes in the cookware. One end of the resistor Rs1_1 is connected to the connection point of the capacitor C10_1 and the capacitor C10_2, the other end of the resistor Rs1_1 is connected to the induction coil L1_1, and the other end of the induction coil L1_1 is connected to the relay K1_1; the other end of the relay K1_1 is connected to the midpoint of the bridge arm composed of the first inverter circuit and the second inverter circuit; the first The inverter circuit includes capacitor C4 and IGBT1 (insulated gate bipolar transistor), the collector of IGBT1 is connected to the DC+ terminal of capacitor C1, the gate of IGBT1 is connected to driver U2 via resistor R3, and capacitor C4 is connected in parallel with IGBT1; the second inverter circuit includes capacitor C5 and IGBT2, the gate of IGBT2 is connected to driver U3 via resistor R4; the collector of IGBT2 is connected to the emitter of IGBT1, the emitter of IGBT2 is connected to the GND terminal of capacitor C1, and capacitor C5 is connected in parallel with IGBT2; driver U2 is connected to the OUTA1 pin of the MCU control unit 10 via resistor R5, and driver U3 is connected to the OUTB1 pin of the MCU control unit 10 via resistor R6.

[0034] The CHECK_PWM pin of the MCU control unit 10 is connected to the resistor R10_2. The CHECK_PWM pin of the MCU control unit 10 sends a PWM signal (pulse detection signal) to the resistor R10_2. The transistor Q1 amplifies the PWM signal and applies it to the capacitor C10_3. One end of the capacitor C10_4 is connected to the midpoint of the capacitor C10_1 and the capacitor C10_2, and the other end of the capacitor C10_4 is connected to the capacitor C10_5; the other end of the capacitor C10_5 is connected to the capacitor C10_3, the diode D10_1, and the resistor R10 _4, the other end of resistor R10_4 is connected to the GND terminal of capacitor C1, the other end of diode D10_1 is connected to resistor R10_6 and then enters the positive input terminal of comparator U1; the DAC_PWM pin of MCU control unit 10 is connected to resistor R10_7, the other end of resistor R10_7 is connected to capacitor C10_6 and connected to the negative input terminal of comparator U1, and the other end of capacitor C10_6 is connected to GND; the output terminal of comparator U1 is connected to LOAD1 pin of MCU control unit 10 after passing through pull-up resistor R10_8. When relay K1_1 is energized, capacitor C1, capacitor C10_1, capacitor C10_2, resistor Rs1_1, induction coil L1_1, relay K1_1, capacitor C4, capacitor C5, IGBT1, and IGBT2 form a typical half-bridge resonant inverter circuit, in which capacitor C10_1, capacitor C10_2, resistor Rs1_1, induction coil L1_1, and relay K1_1 form an LC oscillation circuit.

[0035] When the global heating induction cooktop is powered on, the detection process is as follows: When the global heating induction cooktop begins operating, relay K1_1 remains disconnected. MCU control unit 10 first applies a PWM signal with a specific frequency and duty cycle to resistor R10_2 via the CHECK_PWM pin. After reverse amplification by transistor Q1, it is directly applied to capacitor C10_3. The rising edge of the PWM signal is rapidly coupled through capacitors C10_3, C10_5, and C10_4 to the LC oscillating circuit consisting of capacitors C10_1, C10_2, resistor Rs1_1, induction coil L1_1, and relay K1_1. Because the LC oscillating circuit operates at a certain frequency, if a suitable pot is placed on induction coil L1_1, the value of resistor Rs1_1 increases, significantly reducing the rising edge spike of the detection signal applied to detection point A. Simultaneously, the detection signal's amplitude rapidly decreases before slowly charging to VCC. Considering that the detection signal will inevitably have a negative pulse when it is coupled through the capacitor at the detection point A, the detection signal is passed through the diode D10_1 to remove the negative pulse voltage before being connected to the positive input of the comparator U1. At the same time, the DAC_PWM pin of the MCU control unit 10 sets the reference voltage of the negative input of the comparator U1 through D / A conversion. The output of the comparator U1 outputs a feedback signal (square wave signal) with different duty cycles based on the voltage signals at the positive and negative inputs of the comparator U1. The MCU control unit 10 reads the change in the duty cycle value of the feedback signal through the LOAD1 pin to determine whether there is a pot suitable for heating placed on the induction coil L1_1 on the LC resonant circuit 20; if there is a pot suitable for heating placed on the induction coil L1_1, the MCU control unit 10 By raising the voltage at the third output terminal, JDQ1, the corresponding relay, K1_1, is energized. After a debounce delay, a first heating control signal, driver U2, is output from pin OUTA1. A second heating control signal, driver U3, is output from pin OUTB1. Drivers U2 and U3 then drive IGBT1 and IGBT2 to alternately operate. These alternating operations invert high-frequency currents flowing through induction coil L1_1, generating an alternating magnetic field that heats the pot directly above induction coil L1_1 and initiates cooking. If there are multiple LC resonant circuits 20, the MCU control unit 10 can simply execute the above detection process for each corresponding LC resonant circuit 20.

[0036] Based on the same inventive concept, embodiments of the present application also provide a method for detecting pots in a global heating electromagnetic cooker, which is applied to the pot detection circuit of the global heating electromagnetic cooker involved in the above embodiments. The implementation solution provided by this method is similar to the implementation solution described in the above-mentioned pot detection circuit of the global heating electromagnetic cooker. Therefore, the specific limitations in one or more embodiments of the pot detection method for the global heating electromagnetic cooker provided below can be found in the above-mentioned limitations on the pot detection circuit of the global heating electromagnetic cooker, and will not be repeated here.

[0037] In an exemplary embodiment, Figure 3 As shown, a method for detecting pots of a global heating electromagnetic cooker is provided. The execution subject of the method is the MCU control unit in the above embodiment; the method may include the following steps S301 to S303, specifically: Step S301: When the global heating electromagnetic cooker is in the on state, a pulse detection signal is sent to the coupling feedback loop; and a feedback signal output by the coupling feedback loop is obtained; Step S302, determining whether there is a cookware on the induction coil of the LC resonant circuit based on the feedback signal; Step S303: In the presence of a cookware, the inverter circuit and the LC resonant circuit are turned on, and a heating control signal is generated and sent to the inverter circuit, so that the inverter circuit generates a high-frequency square wave voltage based on the heating control signal, and drives the induction coil of the LC resonant circuit based on the high-frequency square wave voltage to generate an alternating magnetic field; the LC resonant circuit forms a closed loop with the cookware in the alternating magnetic field to generate eddy current, and the cookware is heated based on the eddy current.

[0038] As an optional implementation, the generation of the feedback signal in the above step S301 includes: when the global heating induction cooker is in the on state, the reverse amplification circuit reversely amplifies the pulse detection output by the received MCU control unit, and outputs the reverse-amplified pulse detection signal to the coupling circuit; the coupling circuit generates a coupling signal based on the pulse detection signal, and excites the LC resonant circuit to generate an equivalent impedance based on the coupling signal, and generates a detection signal at the detection point under the action of the equivalent impedance; the comparator U1 compares the detection signal with the reference voltage output by the MCU control unit to generate a feedback signal; the feedback signal is a square wave signal with different duty cycles.

[0039] It should be noted that the reference duty cycle value involved in the embodiment of the present application is the duty cycle value set inside the MCU control unit. The reference duty cycle value and reference voltage are subject to actual application, and the embodiment of the present application does not impose any specific restrictions.

[0040] As an optional implementation, the above-mentioned step S302 may include: reading the duty cycle value of the feedback signal; if the duty cycle of the feedback signal is greater than a reference duty cycle value, there is a pot on the induction coil of the LC resonant circuit; if the duty cycle of the feedback signal is less than or equal to the reference duty cycle value, there is no pot on the induction coil of the LC resonant circuit.

[0041] As an optional implementation, the above-mentioned step S303 may include: outputting a first heating control signal to the first inverter circuit through the first drive circuit; outputting a second heating control signal to the second inverter circuit through the second drive circuit; the first heating control signal and the second heating control signal are complementary square wave signals; the first inverter circuit and the second inverter circuit operate alternately under the drive of two sets of complementary square wave signals to generate a high-frequency square wave voltage.

[0042] In this embodiment, a pulse detection signal sent by an MCU control unit is received through a coupled feedback loop, and the LC resonant circuit is stimulated to generate an equivalent impedance based on the pulse detection signal, and a feedback signal is generated based on the equivalent impedance; the feedback signal is received by the MCU control unit, and whether there is a cookware on the induction coil of the LC resonant circuit is determined based on the feedback signal. If there is a cookware, the inverter circuit and the LC resonant circuit are turned on, and a heating control signal is generated and sent to the inverter circuit; the inverter circuit is driven by the heating control signal to generate a high-frequency square wave voltage, and the high-frequency square wave voltage is used to drive the induction coil of the LC resonant circuit to generate an alternating magnetic field; the LC resonant circuit forms a closed loop with the cookware in the alternating magnetic field to generate eddy current, and the cookware is heated based on the eddy current; when a cookware is already being heated on the global heating electromagnetic cooker, it is possible to detect whether a normal cookware is placed on the induction coil of another LC resonant circuit without switching an electronic switch, without affecting the cookware that is already being heated, and effectively improving the heating efficiency of the global heating electromagnetic cooker; in addition, the detection process is not affected by the number of LC resonant circuits, and has the advantages of low system loss and high detection efficiency.

[0043] In an exemplary embodiment, Figure 4 As shown, a full-area heating electromagnetic cooker 400 is provided, which includes a control board 401, on which the pot detection circuit of the full-area heating electromagnetic cooker in the above embodiment is integrated.

[0044] In an exemplary embodiment, the control board includes an MCU control unit, and the MCU control unit is used to execute the pot detection method of the global heating induction cooker of the above embodiment.

[0045] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0046] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A pot detection circuit for a global heating electromagnetic cooker, characterized in that: The circuit includes multiple groups of LC resonant circuits and MCU control units, and any group of the LC resonant circuits is connected to a coupling feedback circuit and an inverter circuit; Wherein, the first output end of the MCU control unit is connected to the input end of the coupling feedback loop; the first output end of the coupling feedback loop is connected to the LC resonant circuit; the second output end of the coupling feedback loop is connected to the input end of the MCU control unit; The second output terminal of the MCU control unit is connected to the LC resonant circuit; The third output terminal of the MCU control unit is connected to the input terminal of the inverter circuit; the output terminal of the inverter circuit is connected to the LC resonant circuit; When the global heating induction cooker is in the on state, the coupling feedback loop is used to receive the pulse detection signal sent by the MCU control unit, and to stimulate the LC resonant circuit to generate an equivalent impedance based on the pulse detection signal, and to generate a feedback signal based on the equivalent impedance; The MCU control unit is configured to determine whether there is a cookware on the induction coil of the LC resonant circuit based on the feedback signal, conduct the inverter circuit and the LC resonant circuit if there is a cookware, generate a heating control signal, and send the heating control signal to the inverter circuit; The inverter circuit is used to generate a high-frequency square wave voltage based on the heating control signal, and drive the induction coil of the LC resonant circuit to generate an alternating magnetic field based on the high-frequency square wave voltage; The LC resonant circuit is used to form a closed loop with the pot in an alternating magnetic field to generate eddy current, and heat the pot based on the eddy current.

2. The pot detection circuit of the global heating electromagnetic cooker according to claim 1, characterized in that: The LC resonant circuit includes a resistor Rs1_1, an induction coil L1_1, and a relay K1_1; One end of the resistor Rs1_1 is connected to the first output end of the coupling feedback loop, and the other end of the resistor Rs1_1 is connected to one end of the induction coil L1_1; the other end of the induction coil L1_1 is connected to one end of the relay K1_1, the other end of the relay K1_1 is connected to the output end of the inverter loop, and the input end of the relay K1_1 is connected to the second output end of the MCU control unit; The relay K1_1 is used to conduct the inverter circuit and the LC resonant circuit under the control of the MCU control unit; the induction coil L1_1 is used to generate an alternating electromagnetic field driven by a high-frequency square wave voltage when the relay K1_1 is in the energized state, and form a closed circuit with the pot placed on the induction coil L1_1 to generate eddy current.

3. The pot detection circuit of the global heating electromagnetic cooker according to claim 2, characterized in that: The coupling feedback loop includes: capacitor C10_3, capacitor C10_4, capacitor C10_5, and comparator U1; One end of the capacitor C10_3 is connected to the first output end of the MCU control unit, the other end of the capacitor C10_3 is connected to one end of the capacitor C10_5, the other end of the capacitor C10_5 is connected to one end of the capacitor C10_4, and the other end of the capacitor C10_4 is connected to the input end of the LC resonant circuit; The midpoint between the capacitor C10_3 and the capacitor C10_5 is a detection point, which is connected to the positive input terminal of the comparator U1; the negative input terminal of the comparator U1 is connected to the fourth output terminal of the MCU control unit, and the output terminal of the comparator U1 is connected to the input terminal of the MCU control unit; When the relay K1_1 is disconnected, the capacitors C10_3, C10_4, and C10_ form a coupling loop, which is used to couple the pulse detection signal to generate a coupling signal, and stimulate the LC resonant circuit to generate an equivalent impedance based on the coupling signal, and generate a detection signal at the detection point under the action of the equivalent impedance; The comparator U1 is used to compare the detection signal with the reference voltage output by the MCU control unit to generate a feedback signal; the feedback signal is a square wave signal with different duty cycles.

4. The pot detection circuit for the global heating electromagnetic cooker according to claim 3, characterized in that: The coupling feedback loop further includes: a diode D10_1 and a resistor R10_6; The detection point is connected to the positive input terminal of the comparator U1 through the diode D10_1 and the resistor R10_6; The diode D10_1 is used to filter the negative pulse voltage of the detection signal so that the detection signal input to the comparator U1 is all positive pulse voltage.

5. The pot detection circuit for the global heating electromagnetic cooker according to claim 3, characterized in that: The coupling feedback loop further includes: a resistor R10_2, a transistor Q1, and a resistor R10_3; One end of the resistor R10_2 is connected to the first output terminal of the MCU control unit, one end of the resistor R10_2 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to one end of the capacitor C10_3 and the resistor R10_3 respectively, the other end of the resistor R10_3 is connected to VCC, and the capacitor C10_3 is connected to the first output terminal of the MCU control unit through the resistor R10_2 and the collector of the transistor Q1; The resistor R10_2, transistor Q1, and resistor R10_3 form a reverse amplification loop, which is used to reversely amplify the pulse detection signal output by the MCU control unit and output the reverse-amplified pulse detection signal to the capacitor C10_3.

6. The pot detection circuit for the global heating electromagnetic cooker according to claim 1, characterized in that: Any group of the LC resonant circuits is further connected to a first drive circuit and a second drive circuit; the inverter circuit includes a first inverter circuit and a second inverter circuit; the first inverter circuit and the second inverter circuit are connected in series; the first inverter circuit and the second inverter circuit are connected in series to form a bridge arm midpoint, and the bridge arm midpoint serves as an input end of the inverter circuit and is connected to the LC resonant circuit; The third output terminal OUTA1 of the MCU control unit is connected to the input terminal of the first inverter circuit through the first drive circuit, and the third output terminal OUTB1 of the MCU control unit is connected to the input terminal of the second inverter circuit through the second drive circuit; The MCU control unit outputs a first heating control signal to the first inverter circuit through the first drive circuit; and outputs a second heating control signal to the second inverter circuit through the second drive circuit; the first heating control signal and the second heating control signal are complementary square wave signals; The first inverter circuit and the second inverter circuit are used to work alternately under the drive of two sets of complementary square wave signals to generate a high-frequency square wave voltage.

7. The pot detection circuit for the global heating electromagnetic cooker according to claim 6, characterized in that: The first drive circuit includes a resistor R3, a driver U2, and a resistor R5; one end of the resistor R5 is connected to the third output terminal OUTA1 of the MCU control unit, and the other end of the resistor R5 is connected to the input terminal of the driver U2. The output terminal of the driver U2 is connected to one end of the resistor R3, and the other end of the resistor R3 is connected to the input terminal of the first inverter circuit; the first drive circuit is used to amplify the first heating control signal and output the amplified first heating control signal to the first inverter circuit; The second drive circuit includes a resistor R4, a driver U3, and a resistor R6; one end of the resistor R6 is connected to the third output terminal OUTB1 of the MCU control unit, and the other end of the resistor R6 is connected to the input terminal of the driver U3. The output terminal of the driver U3 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the input terminal of the second inverter circuit; the second drive circuit is used to amplify the second heating control signal and output the amplified second heating control signal to the second inverter circuit.

8. A method for detecting pots of a full-range heating electromagnetic cooker, characterized in that: The method is applied to the MCU control unit according to claims 1 to 7 above, and the method includes: When the global heating electromagnetic cooker is in a powered-on state, a pulse detection signal is sent to the coupling feedback loop; and a feedback signal output by the coupling feedback loop is obtained; Determining whether there is a pot on the induction coil of the LC resonant circuit based on the feedback signal; In the presence of a cookware, the inverter circuit and the LC resonant circuit are turned on, and a heating control signal is generated and sent to the inverter circuit, so that the inverter circuit generates a high-frequency square wave voltage based on the heating control signal, and drives the induction coil of the LC resonant circuit based on the high-frequency square wave voltage to generate an alternating magnetic field; the LC resonant circuit forms a closed loop with the cookware in the alternating magnetic field to generate eddy current, and the cookware is heated based on the eddy current.

9. The method for detecting pots of a global heating electromagnetic cooker according to claim 8, characterized in that: The feedback signal is a square wave signal with different duty cycles; The method of determining whether there is a cookware on the induction coil of the LC resonant circuit based on the feedback signal includes: Reading the duty cycle value of the feedback signal, if the duty cycle of the feedback signal is greater than the reference duty cycle value, there is a pot on the induction coil of the LC resonant circuit; If the duty cycle of the feedback signal is less than or equal to the reference duty cycle value, there is no pot on the induction coil of the LC resonant circuit.

10. A full-area heating electromagnetic cooker, characterized in that: It includes a control board, on which the pot detection circuit of the global heating electromagnetic cooker described in any one of claims 1 to 7 is integrated, or the control board is used to execute the pot detection method of the global heating electromagnetic cooker described in any one of claims 8 to 9.

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