Heating control circuit, cooking device and heating control method thereof

Abstract

The application discloses a heating control circuit, a cooking device and a heating control method thereof, and relates to the technical field of household appliances. The heating control circuit comprises a zero-crossing detection module, a rectification module, a first driving module, a second driving module and a control module. The rectification module is used for rectifying an alternating-current power signal output by an alternating-current power supply and outputting a direct-current power signal; the first driving module is used for driving an infrared heating wire of an infrared disc assembly to work based on the direct-current power signal; the second driving module is used for driving an electromagnetic coil of an electromagnetic disc assembly to work based on the direct-current power signal; and the control module is used for triggering the first driving module to drive the infrared heating wire to work for a first preset time according to a zero-crossing signal sent by the zero-crossing detection module, and controlling the second driving module to drive the electromagnetic coil to work when a second preset time is reached at a trigger control time node. The above heating control circuit can avoid damage to a switching device inside the second driving module.

Description

Technical Field

[0001] This application relates to the field of household appliance technology, and in particular to a heating control circuit, cooking equipment and heating control method thereof. Background Technology

[0002] Cooking equipment that uses a combination of electromagnetic heating and infrared heating typically employs a hybrid heating coil with both electromagnetic coils and infrared heating wires to achieve heating. Electromagnetic heating is achieved by driving the electromagnetic coils, while infrared heating is achieved by driving the infrared heating wires.

[0003] Currently, when this cooking device uses electromagnetic heating, it primarily controls the switching of the power supply circuit between the DC power supply and the electromagnetic coil via an electromagnetic drive circuit to drive the electromagnetic coil. However, when the power supply circuit between the DC power supply and the electromagnetic coil is switched on, the electromagnetic drive circuit is susceptible to high current surges, which can easily damage the switching devices inside the electromagnetic drive circuit. Summary of the Invention

[0004] The main purpose of this application is to propose a heating control circuit, cooking equipment and heating control method thereof, which aims to avoid damage to the switching devices inside the electromagnetic drive circuit.

[0005] To achieve the above objectives, in a first aspect, this application proposes a heating control circuit, which is used for heating control of a heating coil, the heating coil comprising an infrared coil assembly and an electromagnetic coil assembly; the heating control circuit includes:

[0006] A zero-crossing detection module, wherein the first input terminal of the zero-crossing detection module is connected to an AC power source, and the second input terminal of the zero-crossing detection module is grounded, and the zero-crossing detection module is used to detect the zero-crossing interval of the AC power source signal to generate a zero-crossing signal;

[0007] A rectifier module is connected to the AC power supply. The rectifier module is used to rectify the AC power signal output by the AC power supply and output a DC power signal.

[0008] The first driving module is used to control the switching of the power supply circuit of the infrared disk assembly by the rectifier module, so as to drive the infrared heating wire of the infrared disk assembly to work based on the DC power signal.

[0009] The second driving module is used to control the switching of the power supply circuit of the electromagnetic coil assembly by the rectifier module, so as to drive the electromagnetic coil of the electromagnetic coil assembly to work based on the DC power signal.

[0010] The control module is connected to the output of the zero-crossing detection module, the first driving module, and the second driving module, respectively. The control module is used to trigger the first driving module to drive the infrared heating wire to work for a first preset time according to the zero-crossing signal, and to control the second driving module to drive the electromagnetic coil to work when the timing of the trigger control time node reaches a second preset time. The difference between the second preset time and the first preset time is less than a preset threshold.

[0011] In one embodiment, the control module is further configured to trigger timing in response to the target edge of the zero-crossing signal, and when the timing time reaches a first delay time, control the first driving module to drive the infrared heating wire to work for a first preset time; when the timing time reaches a second delay time, control the second driving module to drive the electromagnetic coil to work, wherein the target edge is one of a rising edge and a falling edge, and the second delay time is the sum of the first delay time and the second preset time.

[0012] In one embodiment, the control module is further configured to output a first pulse width modulation signal to the first driving module and output a second pulse width modulation signal to the second driving module;

[0013] Specifically, when the trigger time reaches the first delay time, the control module controls the first pulse width modulation signal to be set to an effective level until the first preset time is reached; when the trigger time reaches the second delay time, the duty cycle of the second pulse width modulation signal is adjusted according to the target heating power.

[0014] In one embodiment, the first driving module includes:

[0015] A first driving circuit, the first end of which is connected to the control module, is used to output a first driving signal under the control of the control module.

[0016] A first power switch, the control terminal of the first power switch is connected to the first drive circuit, the first terminal of the first power switch is connected to the infrared heating wire, the second terminal of the first power switch is grounded, and the first power switch is used to turn on in response to the first drive signal.

[0017] In one embodiment, the second driving module includes:

[0018] A second driving circuit, the first end of which is connected to the control module, is used to output a second driving signal under the control of the control module.

[0019] The resonant heating circuit is connected to the second terminal of the second driving circuit, the rectifier module, and the electromagnetic coil, respectively, and is used to drive the electromagnetic coil of the electromagnetic coil assembly to work based on the DC power supply signal in response to the on / off state of the second driving signal.

[0020] In one embodiment, the resonant heating circuit includes:

[0021] A filter inductor, wherein the first end of the filter inductor is connected to the first output end of the rectifier module;

[0022] A filter capacitor, the first end of which is connected to the second end of the filter inductor, and the second end of which is connected to the common ground and the second output terminal of the rectifier module.

[0023] A resonant capacitor, wherein the first terminal of the resonant capacitor is connected to the first terminal of the filter capacitor, the second terminal of the filter inductor, and the first terminal of the electromagnetic coil, and the second terminal of the resonant capacitor is connected to the second terminal of the electromagnetic coil;

[0024] The second power switch has its first terminal connected to the second terminal of the resonant capacitor and the second terminal of the electromagnetic coil, its second terminal connected to the second terminal of the filter capacitor, and its control terminal connected to the second terminal of the second drive circuit.

[0025] In one embodiment, the zero-crossing detection module includes:

[0026] A diode, wherein the positive terminal of the diode is connected to the AC power supply;

[0027] A first resistor, the first end of which is connected to the negative terminal of the diode;

[0028] An optical coupler, comprising a light-emitting diode (LED) and a light-receiving element, wherein the positive terminal of the LED is connected to a first terminal of a first resistor, the negative terminal of the LED is grounded, and the first terminal of the light-receiving element is grounded;

[0029] The second resistor has a first end for receiving a power signal and a second end connected to the second end of the light-receiving element.

[0030] The third resistor has its first end connected to the second end of the second resistor and the second end of the light-receiving element, and its second end connected to the control module.

[0031] In one embodiment, the heating control circuit further includes:

[0032] An electromagnetic compatibility (EMC) module is provided, wherein the input terminal of the EMC module is connected to the AC power supply, and the output terminal of the EMC module is connected to the rectifier module.

[0033] Secondly, this application also provides a cooking device, including: a heating coil and a heating control circuit as described in the first aspect, wherein the heating coil includes an infrared coil assembly and an electromagnetic coil assembly, and the heating control circuit is connected to the infrared coil assembly and the electromagnetic coil assembly respectively.

[0034] Thirdly, this application also provides a heating control method for a cooking device, the heating control method being applied to the cooking device as described in the second aspect, the heating control method comprising:

[0035] Receive the zero-crossing signal output by the zero-crossing detection module;

[0036] The zero-crossing signal triggers the first driving module to drive the infrared heating wire of the infrared disk assembly to work for a first preset time.

[0037] When the timing of the trigger control time node reaches the second preset time, the second drive module is controlled to drive the electromagnetic coil of the electromagnetic coil assembly to work, wherein the difference between the second preset time and the first preset time is less than a preset threshold.

[0038] The aforementioned heating control circuit and cooking device include a zero-crossing detection module, a rectifier module, a first drive module, a second drive module, and a control module. The zero-crossing detection module can detect the zero-crossing range of the AC power signal and generate a zero-crossing signal. The rectifier module can rectify the AC power signal output by the AC power supply and output a DC power signal. The first drive module can control the switching of the power supply circuit of the infrared coil assembly by the rectifier module to drive the infrared heating wire of the infrared coil assembly to work based on the DC power signal. The second drive module can control the switching of the power supply circuit of the electromagnetic coil assembly by the rectifier module to drive the electromagnetic coil of the electromagnetic coil assembly to work based on the DC power signal. Based on this, the control module can receive a zero-crossing signal and trigger the first drive module to drive the infrared heating wire to work for a first preset time according to the zero-crossing signal. Since the infrared heating wire is a resistive element, it can consume the electrical energy stored in the rectifier module relatively quickly, causing the output voltage of the rectifier module to decrease. Since the difference between the second preset time and the first preset time is less than the preset threshold, the output voltage of the rectifier module is low when the timing of the trigger control node reaches the second preset time. At this time, the switching device in the second drive module (corresponding to the aforementioned electromagnetic drive circuit) is turned on when the voltage is low, and its turn-on current will not exceed the rated value of the switching device, thereby avoiding the impact of large current on the switching device, improving the safety of the switching device, and helping to ensure the normal use of the cooking equipment.

[0039] The heating control method of the above-mentioned cooking equipment receives the zero-crossing signal output by the zero-crossing detection module, and triggers the first driving module to drive the infrared heating wire to work for a first preset time according to the zero-crossing signal. Since the infrared heating wire is a resistive element, it can consume the electrical energy stored in the rectifier module relatively quickly, thereby reducing the output voltage of the rectifier module. Since the difference between the second preset time and the first preset time is less than the preset threshold, the output voltage of the rectifier module is low when the timing of the trigger control node reaches the second preset time. At this time, the switching device in the second driving module (corresponding to the aforementioned electromagnetic drive circuit) is turned on when the voltage is low, and its turning current will not exceed the rated value of the switching device, thereby avoiding the impact of large current on the switching device, improving the safety of the switching device, and helping to ensure the normal use of the cooking equipment. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the heating control circuit in one embodiment of this application;

[0042] Figure 2 This is a schematic diagram of the heating coil structure in one embodiment of this application;

[0043] Figure 3 This is a waveform diagram of the AC power signal and the zero-crossing signal in one embodiment of this application;

[0044] Figure 4 This is a schematic diagram of the heating control circuit in another embodiment of this application;

[0045] Figure 5 This is a schematic diagram of the waveforms of the zero-crossing signal and the first pulse width modulation signal in one embodiment of this application;

[0046] Figure 6 This is a schematic diagram of the waveforms of the zero-crossing signal, the first pulse width modulation signal, and the second pulse width modulation signal in one embodiment of this application;

[0047] Figure 7 This is a waveform diagram of the voltage across the switching device in the second driving module in one embodiment of this application;

[0048] Figure 8 This is a schematic diagram of the zero-crossing detection module in one embodiment of this application;

[0049] Figure 9 This is a schematic diagram of the structure of a cooking device according to one embodiment of this application;

[0050] Figure 10 This is a schematic flowchart of a heating control method for a cooking device according to an embodiment of this application.

[0051] Explanation of reference numerals in the attached figures:

[0052] 11-Zero-crossing detection module, 12-Rectifier module, 13-First drive module, 131-First drive circuit, 14-Second drive module, 141-Second drive circuit, 142-Resonant heating circuit, 15-Control module, 16-Electromagnetic compatibility module, 20-AC power supply, 30-Heating coil, 31-Infrared coil assembly, 311-Infrared heating wire, 32-Electromagnetic coil assembly, 321-Electromagnetic coil, 40-Base, 50-Stove panel.

[0053] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0054] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0055] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0056] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0057] Cooking equipment that uses a combination of electromagnetic heating and infrared heating typically employs a hybrid heating coil with both electromagnetic coils and infrared heating wires to achieve heating. Electromagnetic heating is achieved by driving the electromagnetic coils, while infrared heating is achieved by driving the infrared heating wires.

[0058] Currently, when cooking equipment uses electromagnetic heating, it primarily controls the switching of the power supply circuit between the DC power supply and the electromagnetic coil via an electromagnetic drive circuit, thereby driving the electromagnetic coil to operate. However, when the power supply circuit between the DC power supply and the electromagnetic coil is switched on, the electromagnetic drive circuit is susceptible to large current surges, which can easily damage the switching devices inside the electromagnetic drive circuit.

[0059] Based on this, embodiments of this application provide a heating control circuit, such as... Figure 1 and Figure 2 As shown, the heating control circuit is used to control the heating of the heating coil 30, which includes an infrared coil assembly 31 and an electromagnetic coil assembly 32. The heating control circuit includes: a zero-crossing detection module 11, a rectification module 12, a first drive module 13, a second drive module 14, and a control module 15.

[0060] The first input terminal of the zero-crossing detection module 11 is connected to the AC power supply 20, and the second input terminal of the zero-crossing detection module 11 is grounded. The zero-crossing detection module 11 is used to detect the zero-crossing interval of the AC power supply 20 signal in order to generate a zero-crossing signal.

[0061] In applications, the AC voltage signal (AC power supply 20 signal) is typically a sine wave, crossing the zero-volt point twice within one cycle (the boundary between the positive and negative half-cycles). The zero-crossing detection module 11 can accurately capture these moments of zero voltage and output the corresponding zero-crossing signal. Taking a comparator-based zero-crossing detection circuit as an example, the AC signal is first reduced to a suitable amplitude by a step-down circuit, and then input to one input terminal of the comparator. The other input terminal of the comparator is connected to a reference voltage (typically 0V). When the AC signal voltage is higher than 0V, the comparator outputs a high level; when the AC signal voltage is lower than 0V, the comparator outputs a low level. Thus, each time the AC signal crosses zero, the comparator output level changes. By detecting this level change, the zero-crossing moment of the AC signal can be determined. It should be noted that the structure of the zero-crossing detection module 11 is not limited to the comparator-based zero-crossing detection circuit described above; other types of circuit structures can also be used.

[0062] The rectifier module 12 is connected to the AC power supply 20. The rectifier module 12 is used to rectify the AC power supply signal output by the AC power supply 20 and output a DC power supply signal.

[0063] For example, the rectifier module 12 may include a rectifier bridge. The two AC input terminals of the rectifier bridge are connected to the two output terminals of the AC power supply 20, respectively. The two DC input terminals of the rectifier bridge serve as the positive and negative terminals, outputting DC power signals, with the negative terminal grounded. Taking a full-bridge rectifier as an example, the rectifier bridge includes four diodes, divided into two parallel diode sets, with two diodes in each set connected in reverse parallel and series. When the input AC current is in the positive half-cycle, two diodes conduct, and current flows from one diode into the load and then out through the other diode; when the input AC current is in the negative half-cycle, the other two diodes conduct, and the current direction remains unchanged, thereby converting the AC current into unidirectional DC current.

[0064] The first drive module 13 controls the switching on and off of the power supply circuit of the rectifier module 12 to the infrared disk assembly 31, so as to drive the infrared heating wire 311 of the infrared disk assembly 31 to work based on the DC power signal. When the first drive module 13 controls the rectifier module 12 to conduct the power supply circuit of the infrared disk assembly 31, the DC power signal output by the rectifier module 12 supplies power to the infrared disk assembly 31, thereby driving the infrared heating wire 311 of the infrared disk assembly 31 to work.

[0065] The second drive module 14 controls the on / off state of the power supply circuit of the rectifier module 12 to the electromagnetic coil assembly 32, thereby driving the electromagnetic coil 321 of the electromagnetic coil assembly 32 to work based on the DC power signal. By controlling the on / off state of the power supply circuit, the second drive module 14 can ensure that the DC power signal is applied to the electromagnetic coil 321 according to specific requirements (such as frequency, duty cycle, etc.), thereby driving the electromagnetic coil 321 to work and generate the required magnetic field to complete the corresponding task, such as achieving heating with a target heating power.

[0066] The control module 15 is connected to the output of the zero-crossing detection module 11, the first drive module 13, and the second drive module 14. The control module 15 triggers the first drive module 13 to drive the infrared heating wire 311 to operate for a first preset time based on the zero-crossing signal. When the timing reaches a second preset time at the trigger control time node, the control module 15 drives the electromagnetic coil 321 to operate. The difference between the second preset time and the first preset time is less than a preset threshold. The control module 15 can be a microcontroller unit (MCU).

[0067] It is understandable that when the first drive module 13 controls the rectifier module 12 to conduct the power supply circuit to the infrared disk assembly 31, the DC power signal will supply power to the infrared heating wire 311 of the infrared disk assembly 31, driving the infrared heating wire 311 to work. Since the infrared heating wire 311 is a resistive element, its operation will cause the voltage output of the DC side of the rectifier module 12 to decrease. Therefore, the control module 15 triggers the first drive module 13 to drive the infrared heating wire 311 to work for a first preset time according to the zero-crossing signal, which will cause the voltage output of the DC side of the rectifier module 12 to gradually decrease. When the timing of the trigger control node reaches the second preset time, the output voltage of the rectifier module 12 is low. At this time, controlling the second drive module 14 to drive the electromagnetic coil 321 to work can turn on the switching device in the second drive module 14 when the voltage is low, and its turning current will not exceed the rated value of the switching device, thereby avoiding the impact of large current on the switching device.

[0068] The heating control circuit described above includes a zero-crossing detection module 11, a rectification module 12, a first drive module 13, a second drive module 14, and a control module 15. The zero-crossing detection module 11 can detect the zero-crossing interval of the AC power supply 20 signal and generate a zero-crossing signal. The rectification module 12 can rectify the AC power supply 20 signal output by the AC power supply 20 and output a DC power supply signal. The first drive module 13 can control the switching on and off of the power supply circuit of the infrared coil assembly 31 by the rectification module 12 to drive the infrared heating wire 311 of the infrared coil assembly 31 to work based on the DC power supply signal. The second drive module 14 can control the switching on and off of the power supply circuit of the electromagnetic coil assembly 32 by the rectification module 12 to drive the electromagnetic coil 321 of the electromagnetic coil assembly 32 to work based on the DC power supply signal. Based on this, the control module 15 can receive a zero-crossing signal and trigger the first drive module 13 to drive the infrared heating wire 311 to work for a first preset time according to the zero-crossing signal. Since the infrared heating wire 311 is a resistive element, it can consume the electrical energy stored in the rectifier module 12 relatively quickly, thereby reducing the output voltage of the rectifier module 12. Since the difference between the second preset time and the first preset time is less than the preset threshold, the output voltage of the rectifier module 12 is low when the timing of the trigger control node reaches the second preset time. At this time, the switching device in the second drive module 14 (corresponding to the aforementioned electromagnetic drive circuit) is turned on when the voltage is low, and its turn-on current will not exceed the rated value of the switching device, thereby avoiding the impact of large current on the switching device, improving the safety of the switching device, and helping to ensure the normal use of the cooking equipment.

[0069] In an embodiment, the control module 15 is further configured to trigger timing in response to a target edge of the zero-crossing signal, when the timing duration reaches a first delay time, control the first driving module 13 to drive the infrared heating wire 311 to operate for a first preset time; when the timing duration reaches a second delay time, control the second driving module 14 to drive the electromagnetic coil 321 to operate, wherein the target edge is one of a rising edge and a falling edge, and the second delay time is the sum of the first delay time and a second preset time.

[0070] Wherein, the zero-crossing signal has a rising edge and a falling edge, and the positive half-cycle and the negative half-cycle of the signal of the AC power supply 20 can be distinguished through the falling edge and the rising edge of the zero-crossing. The target edge may be the nth upper edge or the nth lower edge of the zero-crossing signal, where n is a positive integer.

[0071] It should be noted that, as shown in Figure 3 , due to the limitation of the hardware circuit, the output zero-crossing signal ZERO is not truly at the zero-crossing point of the alternating current, the high-level time tH of the zero-crossing signal ZERO is less than its low-level time tL, tH<1 / (2f)<tL, f is the frequency of the signal of the AC power supply 20, 1 / (2f) is half the cycle time of the signal of the AC power supply 20, which may be 50HZ, for example. In this embodiment, triggering timing in response to the target edge of the zero-crossing signal ZERO, and when the timing duration reaches the first delay time, controlling the first driving module 13 to drive the infrared heating wire 311 to operate for the first preset time can compensate for the difference between the zero-crossing point of the zero-crossing signal ZERO and the zero-crossing point of the signal of the AC power supply 20, so as to realize calibration of the zero-crossing point.

[0072] It should also be noted that, in the initial state, the first driving module 13 controls the rectifier module 12 to disconnect the power supply loop of the infrared disc assembly 31, so that the infrared heating wire 311 is in a non-operating state. The second driving module 14 controls the rectifier module 12 to disconnect the power supply loop of the electromagnetic coil disc assembly 32, so that the electromagnetic coil 321 is in a non-operating state.

[0073] Exemplarily, the first delay time t1 may be 10.5-10.7ms, the first preset time may be 0.3-0.5ms, and the second delay time t2 may be the sum of the first delay time and the first preset time. It should be noted that, in applications, the first delay time t1 and the first preset time may also be other values, which may be specifically set according to actual requirements.

[0074] It is understandable that when the timing reaches the first delay time, the first drive module 13 drives the infrared heating wire 311 to work for a first preset time. When the timing reaches the second delay time, the second drive module 14 drives the electromagnetic coil 321 to work. Since the second delay time is longer than the first delay time, the infrared heating wire 311 can work before the electromagnetic coil 321. The operation of the infrared heating wire 311 will cause the voltage output of the DC side of the rectifier module 12 to gradually decrease. Therefore, when the timing reaches the second preset time at the trigger control time node, the output voltage of the rectifier module 12 is low. At this time, controlling the second drive module 14 to drive the electromagnetic coil 321 can turn on the switching device in the second drive module 14 when the voltage is low, and its turning current will not exceed the rated value of the switching device, thereby avoiding the impact of large current on the switching device.

[0075] In one embodiment, such as Figure 4 As shown, the control module 15 is also used to output the first pulse width modulation signal PWM1 to the first drive module 13 and the second pulse width modulation signal PWM2 to the second drive module 14.

[0076] Specifically, when the trigger time reaches the first delay time, the control module 15 controls the first pulse width modulation signal PWM1 to be set to an active level until the first preset time is reached; when the trigger time reaches the second delay time, the duty cycle of the second pulse width modulation signal PWM2 is adjusted according to the target heating power. For example, as shown... Figure 5 As shown, when the trigger time reaches the first delay time t1, the control module 15 controls the first pulse width modulation signal PWM1 to be set to a high level until the first preset time t is reached. As another example, as... Figure 6 As shown, the second delay time is the sum of the first delay time t1 and the first preset time t. When the trigger time reaches the second delay time, the control module 15 adjusts the second pulse width modulation signal PWM2 to a signal with the corresponding duty cycle.

[0077] The effective level can be high.

[0078] It should be noted that pulse width modulation (PWM) signals are a special type of electrical signal, characterized by a pulse width (i.e., the duration of the high-level signal) that varies according to a certain pattern. Control module 15 can precisely control the first drive module 13 and the second drive module 14 by changing the pulse duty cycle (the ratio of the high-level time to the entire cycle).

[0079] It can be understood that the first driving module 13 controls the switching of the power supply circuit of the rectifier module 12 to the infrared disk assembly 31 based on the received first pulse width modulation signal PWM1. Specifically, when the first pulse width modulation signal PWM1 is high, the switching device in the first driving module 13 is turned on, so that the power supply circuit is formed and the current can flow from the rectifier module 12 to the infrared disk assembly 31; when the signal is low, the electronic switch is turned off, the power supply circuit is cut off, and the current cannot pass through. Therefore, the control module 15 can control the switching of the power supply circuit of the rectifier module 12 to the infrared disk assembly 31 by controlling the level state of the first pulse width modulation signal PWM1. Thus, when the timing time reaches the first delay time, the first driving module 13 can be controlled to drive the infrared heating wire 311 to work for a first preset time, and the power supply circuit of the rectifier module 12 to the infrared disk assembly 31 can be controlled to be disconnected at other times, so that the infrared heating wire 311 is in a non-working state.

[0080] Similarly, the second drive module 14 controls the on / off state of the power supply circuit of the rectifier module 12 to the electromagnetic coil assembly 32 based on the second pulse width modulation signal PWM2. When the trigger time reaches the second delay time, the duty cycle of the second pulse width modulation signal PWM2 is adjusted according to the target heating power, so that the second drive module 14 can control the power supply circuit to be turned on and off with a corresponding duty cycle, thereby controlling parameters such as the magnetic field strength and frequency generated by the electromagnetic coil 321, and ultimately achieving control over the heating power and effect. In addition, as Figure 7 As shown, the operation of the infrared heating wire 311 will gradually reduce the voltage output of the DC side of the rectifier module 12. When the timing of the trigger control time node reaches the second preset time, the second drive module 14 is controlled to drive the electromagnetic coil 321 to work. This allows the switching device in the second drive module 14 to turn on when the voltage is low, and its turn-on current will not exceed the rated value of the switching device, thereby avoiding the impact of large current on the switching device.

[0081] In one embodiment, such as Figure 4 As shown, the first drive module 13 includes: a first drive circuit 131 and a first power switch Q1.

[0082] The first terminal of the first driving circuit 131 is connected to the control module 15. The first driving circuit 131 is used to output a first driving signal under the control of the control module 15.

[0083] The control terminal of the first power switch Q1 is connected to the first drive circuit 131. The first terminal of the first power switch Q1 is connected to the infrared heating wire 311, and the second terminal of the first power switch Q1 is grounded. The first power switch Q1 is used to turn on in response to the first drive signal. It should be noted that the infrared heating wire 311 is connected to the output terminal of the DC side of the rectifier module 12 so that the first drive circuit 131, the rectifier module 12, and the first power switch Q1 form a circuit.

[0084] The first power switch Q1 can be an insulated gate bipolar transistor (IGBT), a metal oxide semiconductor field-effect transistor (MOSFET), or other types of power switches, which can be selected according to actual needs.

[0085] It can be understood that the first driving circuit 131 outputs a first driving signal under the control of the control module 15, and the first power switch Q1 is turned on in response to the first driving signal. Therefore, the control module 15 can control the on / off state of the first power switch Q1 through the first driving circuit 131. Since the first terminal of the first power switch Q1 is connected to the infrared heating wire 311 and the second terminal of the first power switch Q1 is grounded, when the first power switch Q1 is turned on, the infrared heating wire 311 and the rectifier module 12 form a conducting circuit. The rectifier module 12 can supply power to the infrared heating wire 311, making the infrared heating wire 311 work. In summary, the control module 15 can control the on / off state of the first power switch Q1 through the first drive circuit 131 to control whether the infrared heating wire 311 works. This allows the control module 15 to control the infrared heating wire 311 to work at a corresponding time based on the zero-crossing signal ZERO, so that the infrared heating wire 311 works for a certain period of time before the electromagnetic coil 321, reducing the output voltage of the rectifier module 12. Thus, when the control module 15 controls the second drive module 14 to drive the electromagnetic coil 321, the switching device in the second drive module 14 can be turned on when the voltage is low, and its turn-on current will not exceed the rated value of the switching device. This avoids the impact of large current on the switching device in the second drive module 14, improving the safety and stability of the heating control circuit.

[0086] In one embodiment, such as Figure 4 As shown, the second driving module 14 includes a second driving circuit 141 and a resonant heating circuit 142.

[0087] The first end of the second drive circuit 141 is connected to the control module 15. The second drive circuit 141 is used to output a second drive signal under the control of the control module 15.

[0088] The resonant heating circuit 142 is connected to the second terminal of the second driving circuit 141, the rectifier module 12 and the electromagnetic coil 321 respectively, and is used to respond to the on and off of the second driving signal to drive the electromagnetic coil 321 of the electromagnetic coil assembly 32 to work based on the DC power signal.

[0089] When the resonant heating circuit 142 is in the ON state, the power supply circuit between the rectifier module 12 and the electromagnetic coil 321 is connected. When the resonant heating circuit 142 is in the OFF state, the power supply circuit between the rectifier module 12 and the electromagnetic coil 321 is disconnected.

[0090] It is understood that the resonant heating circuit 142 responds to the level state of the second drive signal to switch on and off, so as to convert the DC power signal into a high-frequency alternating current and then apply it to the electromagnetic coil 321. According to the principle of electromagnetic induction, the high-frequency alternating current passing through the electromagnetic coil 321 will generate a high-frequency alternating magnetic field. When the metal pot is placed above the electromagnetic coil, the alternating magnetic field will induce a current (eddy current) in the pot. The eddy current generates heat on the pot's resistance, thereby heating the food. In addition, the second drive circuit 141 outputs a second drive signal based on the second pulse width modulation signal PWM2. The control module 15 adjusts the duty cycle of the second pulse width modulation signal PWM2 according to the target heating power, which can control the parameters of the second drive signal. This allows the resonant heating circuit 142 to be turned on and off with a corresponding duty cycle, controlling the power supply circuit between the rectifier module 12 and the electromagnetic coil 321 to be turned on and off with a corresponding duty cycle. This allows control of parameters such as the magnetic field strength and frequency generated by the electromagnetic coil 321, ultimately achieving control over the heating power and effect.

[0091] In one embodiment, such as Figure 4 As shown, the resonant heating circuit 142 includes: a filter inductor L, a filter capacitor C1, a resonant capacitor C2, and a second power switch Q2.

[0092] The first end of the filter inductor L is connected to the first output end of the rectifier module 12.

[0093] The first end of the filter capacitor C1 is connected to the second end of the filter inductor L, and the second end of the filter capacitor C1 is connected to the common ground and the second output terminal of the rectifier module 12.

[0094] The first end of the resonant capacitor C2 is connected to the first end of the filter capacitor C1, the second end of the filter inductor L, and the first end of the electromagnetic coil 321. The second end of the resonant capacitor C2 is connected to the second end of the electromagnetic coil 321.

[0095] The first terminal of the second power switch Q2 is connected to the second terminal of the resonant capacitor C2 and the second terminal of the electromagnetic coil 321, respectively. The second terminal of the second power switch Q2 is connected to the second terminal of the filter capacitor C1. The control terminal of the second power switch Q2 is connected to the second terminal of the second drive circuit 141.

[0096] The second power switch Q2 can be an insulated gate bipolar transistor (IGBT).

[0097] The first terminal of the second drive circuit 141 is connected to the control module 15, and the second terminal of the second drive circuit 141 is connected to the control terminal of the second power switch Q2. The second drive circuit 141 can receive the second pulse width modulation signal PWM2 output by the control module 15, generate a second drive signal, and transmit it to the control terminal of the second power switch Q2. The second power switch Q2 turns on or off in response to the second drive signal.

[0098] It can be understood that the filter inductors L1 and L2 are connected in parallel, forming an LC filter circuit. The resonant capacitor C2 is connected in parallel with the electromagnetic coil 321, forming a resonant heating circuit 142. Since the second power switch Q2 can be turned on or off in response to the second drive signal, the control module 15 can control the second power switch Q2 to turn on and off. The second power switch Q2 inverts the DC power signal into a high-frequency AC signal. This high-frequency AC signal is converted into an alternating electromagnetic signal by the resonant heating circuit 142. The pot generates eddy currents and hysteresis motion in the alternating electromagnetic signal, thus generating heat and realizing resonant heating of the corresponding area of ​​the pot. In this process, the LC filter circuit can filter the input DC power signal, improving the anti-interference capability of the second drive circuit 141.

[0099] In one embodiment, such as Figure 8 As shown, the zero-crossing detection module 11 includes: diode D, first resistor R1, optocoupler IC1, second resistor R2 and third resistor R3.

[0100] The positive terminal of diode D is connected to the alternating current. Diode D has unidirectional conductivity. Through diode D, the signal output from rectifier module 12 can be processed to ensure that only current conforming to a specific direction can pass through, preventing reverse current from damaging the circuit. At the same time, it may perform preliminary signal shaping to prepare for subsequent zero-crossing detection.

[0101] The first terminal of the first resistor R1 is connected to the negative terminal of the diode D. As a current-limiting element, the first resistor R1 limits the current flowing through the diode D and the subsequent optocoupler IC1's LED D, preventing excessive current from damaging the components.

[0102] Optocoupler IC1 includes a light-emitting diode (LED) D and a light-receiving element. The positive terminal of LED D is connected to the first end of the first resistor R1, and the negative terminal of LED D is grounded. The first end of the light-receiving element is also grounded. Optocoupler IC1 enables electrical isolation and signal transmission. When a suitable current flows from the first resistor R1 into LED D of optocoupler IC1, LED D emits light, causing a corresponding electrical signal change in the light-receiving element. Optocoupler IC1 can then detect the direction of the AC power supply 20 signal, thereby enabling zero-crossing detection of the AC power supply 20 signal. Furthermore, since there is no direct electrical connection between the input and output of optocoupler IC1, it effectively isolates circuit sections at different potentials, preventing the transmission of interference signals and improving circuit stability and reliability. Simultaneously, it converts the input electrical signal into an optical signal and then back into an electrical signal, completing signal transmission and conversion.

[0103] The first terminal of the second resistor R2 is used to receive the power supply signal VCC, and the second terminal of the second resistor R2 is connected to the second terminal of the light-receiving element. For example, the power supply signal VCC can be a 5V voltage signal. Through the current limiting and voltage division of the second resistor R2, the light-receiving element can receive an appropriate current, ensuring that the light-receiving element can convert the optical signal and output the corresponding electrical signal under normal operating conditions.

[0104] The first end of the third resistor R3 is connected to the second end of the second resistor R2 and the second end of the light-receiving element, respectively. The second end of the third resistor R3 is connected to the control module 15. The third resistor R3 serves as a voltage divider and signal output matching mechanism. The third resistor R3, the second resistor R2, and the light-receiving element together form a circuit. The third resistor R3 can perform voltage division processing on the signal output from the light-receiving element, ensuring that the signal level output to the control module 15 meets the requirements of the control module 15, so that the control module 15 can accurately identify and process the zero-crossing signal ZERO. At the same time, the third resistor R3 also has a certain current-limiting function, protecting the input port of the control module 15 from damage caused by excessive current.

[0105] In one embodiment, such as Figure 4 As shown, the heating control circuit also includes an electromagnetic compatibility module 16.

[0106] The input terminal of the electromagnetic compatibility module 16 is connected to the AC power supply 20, and the output terminal of the electromagnetic compatibility module 16 is connected to the rectifier module 12.

[0107] Electromagnetic compatibility (EMC) refers to the ability of an electronic device or system to function normally in its electromagnetic environment without causing unacceptable electromagnetic interference to other devices in that environment. The EMC module 16 is a collection of electronic components used to achieve this capability.

[0108] It is understood that by connecting the input terminal of the electromagnetic compatibility module 16 to the AC power supply 20 and the output terminal of the electromagnetic compatibility module 16 to the rectifier module 12, the electromagnetic compatibility module 16 can process the electrical energy output by the AC power supply 20 before it enters the subsequent electrical equipment. Therefore, the electromagnetic compatibility module 16 can filter the signal output by the AC power supply 20, removing high-frequency noise, harmonics, and other electromagnetic interference components that may be present, preventing these interferences from entering the heating control circuit and affecting its normal operation. In addition, the electromagnetic compatibility module 16 can also prevent electromagnetic interference generated during the operation of electrical equipment from being fed back to the power grid through the power line and interfering with other equipment.

[0109] This application also provides a cooking device, including: a heating coil and a heating control circuit as described in any of the above embodiments. The heating coil includes an infrared coil assembly and an electromagnetic coil assembly, and the heating control circuit is connected to the infrared coil assembly and the electromagnetic coil assembly respectively.

[0110] For example, the cooking device can be such as Figure 9 The structure shown indicates that the cooking device includes a heating coil 30, a base 40, and a cooktop 50. The heating coil 30 includes an infrared coil assembly 31 and an electromagnetic coil assembly 2. The base 40 has an internal accommodating space, within which the heating coil 30 is located. The cooktop 50 is stacked on the base. A heating control circuit can be installed on the cooktop 50 or the base 40.

[0111] The advantages of the aforementioned cooking equipment relative to related technologies are the same as the advantages of the aforementioned heating control circuit relative to related technologies, and will not be repeated here.

[0112] This application also provides a heating control method for a cooking device, such as... Figure 10 As shown, the heating control method is applied to the cooking device described above, and the heating control method includes the following steps S1001 to S1003.

[0113] S1001: Receives the zero-crossing signal output by the zero-crossing detection module.

[0114] The AC voltage signal (AC power signal) is typically a sine wave, which crosses the zero-volt point twice within one cycle (the boundary between the positive and negative half-cycles). The zero-crossing detection module can accurately capture these moments of zero voltage and output the corresponding zero-crossing signal.

[0115] S1002: Based on the zero-crossing signal, the first drive module is triggered to drive the infrared heating wire of the infrared disk assembly to work for a first preset time.

[0116] S1003: When the timing of the trigger control time node reaches the second preset time, control the second drive module to drive the electromagnetic coil of the electromagnetic coil assembly to work, wherein the difference between the second preset time and the first preset time is less than a preset threshold.

[0117] It is understandable that when the first drive module controls the rectifier module to turn on the power supply circuit to the infrared disk assembly, the DC power signal will supply power to the infrared heating wire of the infrared disk assembly, driving the infrared heating wire to work. Since the infrared heating wire is a resistive element, its operation will cause a decrease in the DC output voltage of the rectifier module. Therefore, the control module triggers the first drive module to drive the infrared heating wire to work for a first preset time based on the zero-crossing signal, causing the DC output voltage of the rectifier module to gradually decrease. When the trigger control time reaches the second preset time, the output voltage of the rectifier module is low. At this time, controlling the second drive module to drive the electromagnetic coil allows the switching device in the second drive module to turn on when the voltage is low, ensuring that the turning current does not exceed the rated value of the switching device, thus avoiding the impact of large current on the switching device.

[0118] The heating control method of the above-mentioned cooking equipment receives the zero-crossing signal output by the zero-crossing detection module, and triggers the first driving module to drive the infrared heating wire to work for a first preset time according to the zero-crossing signal. Since the infrared heating wire is a resistive element, it can consume the electrical energy stored in the rectifier module relatively quickly, thereby reducing the output voltage of the rectifier module. Since the difference between the second preset time and the first preset time is less than the preset threshold, the output voltage of the rectifier module is low when the timing of the trigger control node reaches the second preset time. At this time, the switching device in the second driving module (corresponding to the aforementioned electromagnetic drive circuit) is turned on when the voltage is low, and its turning current will not exceed the rated value of the switching device, thereby avoiding the impact of large current on the switching device, improving the safety of the switching device, and helping to ensure the normal use of the cooking equipment.

[0119] In one embodiment, step S1002, which triggers the control of the first driving module to drive the infrared heating wire of the infrared disk assembly to work for a first preset time according to the zero-crossing signal, includes: responding to the target edge of the zero-crossing signal to trigger timing, and when the timing time reaches a first delay time, controlling the first driving module to drive the infrared heating wire to work for a first preset time.

[0120] In step S1003, when the timing of the trigger control time node reaches the second preset time, controlling the second drive module to drive the electromagnetic coil of the electromagnetic coil assembly to work includes: when the timing time reaches the second delay time, controlling the second drive module to drive the electromagnetic coil to work.

[0121] It should be noted that, due to the limitation of the hardware circuit, the output zero-crossing signal is not truly at the zero-crossing point of the alternating current. The high-level time tH of the zero-crossing signal is less than its low-level time tL, i.e., tH<1 / (2f)<tL, where f is the frequency of the AC power supply signal, and 1 / (2f) is half the cycle time of the AC power supply signal, which can be 50 Hz for example. In this embodiment, the timing is triggered in response to the target edge of the zero-crossing signal. When the timing duration reaches the first delay time, the first driving module is controlled to drive the infrared heating wire to operate for a first preset time, which can compensate for the difference between the zero-crossing point of the zero-crossing signal and the zero-crossing point of the AC power supply signal, so as to realize the calibration of the zero-crossing point.

[0122] It can be understood that when the timing duration reaches the first delay time, the first driving module is controlled to drive the infrared heating wire to operate for the first preset time, and when the timing duration reaches the second delay time, the second driving module is controlled to drive the electromagnetic coil to operate. Since the second delay time is longer than the first delay time, the infrared heating wire can be made to operate before the electromagnetic coil. The operation of the infrared heating wire will gradually reduce the voltage output from the DC side of the rectifier module. Therefore, when the timing at the trigger control time node reaches the second preset time, the output voltage of the rectifier module is relatively low. At this time, the second driving module is controlled to drive the electromagnetic coil to operate, so that the switching device in the second driving module can be turned on at a relatively low voltage, and the turn-on current will not exceed the rated value of the switching device, thereby avoiding the impact of large current on the switching device.

[0123] The foregoing description is merely an exemplary embodiment of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structural transformations made using the content of the specification and accompanying drawings of the present application under the technical concept of the present application, or direct / indirect application in other related technical fields, are all included in the patent protection scope of the present application.

Claims

1. A heating control circuit, characterized in that, The heating control circuit is used for heating control of the heating coil, which includes an infrared coil assembly and an electromagnetic coil assembly; the heating control circuit includes: A zero-crossing detection module, wherein the first input terminal of the zero-crossing detection module is connected to an AC power source, and the second input terminal of the zero-crossing detection module is grounded, and the zero-crossing detection module is used to detect the zero-crossing interval of the AC power source signal to generate a zero-crossing signal; A rectifier module is connected to the AC power supply. The rectifier module is used to rectify the AC power signal output by the AC power supply and output a DC power signal. The first driving module is used to control the switching of the power supply circuit of the infrared disk assembly by the rectifier module, so as to drive the infrared heating wire of the infrared disk assembly to work based on the DC power signal. The second driving module is used to control the switching of the power supply circuit of the electromagnetic coil assembly by the rectifier module, so as to drive the electromagnetic coil of the electromagnetic coil assembly to work based on the DC power signal. The control module is connected to the output of the zero-crossing detection module, the first driving module, and the second driving module, respectively. The control module is used to trigger the first driving module to drive the infrared heating wire to work for a first preset time according to the zero-crossing signal, and to control the second driving module to drive the electromagnetic coil to work when the timing of the trigger control time node reaches a second preset time. The difference between the second preset time and the first preset time is less than a preset threshold.

2. The heating control circuit as described in claim 1, characterized in that, The control module is also used to trigger timing in response to the target edge of the zero-crossing signal. When the timing time reaches the first delay time, it controls the first driving module to drive the infrared heating wire to work for a first preset time. When the timing time reaches the second delay time, it controls the second driving module to drive the electromagnetic coil to work. The target edge is either a rising edge or a falling edge, and the second delay time is the sum of the first delay time and the second preset time.

3. The heating control circuit as described in claim 2, characterized in that, The control module is also used to output a first pulse width modulation signal to the first driving module and output a second pulse width modulation signal to the second driving module; Specifically, when the trigger time reaches the first delay time, the control module controls the first pulse width modulation signal to be set to an effective level until the first preset time is reached; when the trigger time reaches the second delay time, the duty cycle of the second pulse width modulation signal is adjusted according to the target heating power.

4. The heating control circuit as described in claim 1, characterized in that, The first driving module includes: A first driving circuit, the first end of which is connected to the control module, is used to output a first driving signal under the control of the control module. A first power switch, the control terminal of the first power switch is connected to the first drive circuit, the first terminal of the first power switch is connected to the infrared heating wire, the second terminal of the first power switch is grounded, and the first power switch is used to turn on in response to the first drive signal.

5. The heating control circuit as described in claim 1, characterized in that, The second drive module includes: A second driving circuit, the first end of which is connected to the control module, is used to output a second driving signal under the control of the control module. The resonant heating circuit is connected to the second terminal of the second driving circuit, the rectifier module, and the electromagnetic coil, respectively, and is used to drive the electromagnetic coil of the electromagnetic coil assembly to work based on the DC power supply signal in response to the on / off state of the second driving signal.

6. The heating control circuit as described in claim 5, characterized in that, The resonant heating circuit includes: A filter inductor, wherein the first end of the filter inductor is connected to the first output end of the rectifier module; A filter capacitor, the first end of which is connected to the second end of the filter inductor, and the second end of which is connected to the common ground and the second output terminal of the rectifier module. A resonant capacitor, wherein the first terminal of the resonant capacitor is connected to the first terminal of the filter capacitor, the second terminal of the filter inductor, and the first terminal of the electromagnetic coil, and the second terminal of the resonant capacitor is connected to the second terminal of the electromagnetic coil; The second power switch has its first terminal connected to the second terminal of the resonant capacitor and the second terminal of the electromagnetic coil, its second terminal connected to the second terminal of the filter capacitor, and its control terminal connected to the second terminal of the second drive circuit.

7. The heating control circuit as described in claim 1, characterized in that, The zero-crossing detection module includes: A diode, wherein the positive terminal of the diode is connected to the AC power supply; A first resistor, the first end of which is connected to the negative terminal of the diode; An optical coupler, comprising a light-emitting diode (LED) and a light-receiving element, wherein the positive terminal of the LED is connected to a first terminal of a first resistor, the negative terminal of the LED is grounded, and the first terminal of the light-receiving element is grounded; The second resistor has a first end used to receive a power signal and a second end connected to the second end of the light-receiving element. The third resistor has its first end connected to the second end of the second resistor and the second end of the light-receiving element, and its second end connected to the control module.

8. The heating control circuit according to any one of claims 1 to 7, characterized in that, The heating control circuit also includes: An electromagnetic compatibility (EMC) module is provided, wherein the input terminal of the EMC module is connected to the AC power supply, and the output terminal of the EMC module is connected to the rectifier module.

9. A cooking device, characterized in that, include: The heating coil and the heating control circuit as described in any one of claims 1 to 8, wherein the heating coil includes an infrared coil assembly and an electromagnetic coil assembly, and the heating control circuit is connected to the infrared coil assembly and the electromagnetic coil assembly respectively.

10. A heating control method for a cooking device, characterized in that, The heating control method is applied to the cooking apparatus as described in claim 9, and the heating control method includes: Receive the zero-crossing signal output by the zero-crossing detection module; The zero-crossing signal triggers the first driving module to drive the infrared heating wire of the infrared disk assembly to work for a first preset time. When the timing of the trigger control time node reaches the second preset time, the second drive module is controlled to drive the electromagnetic coil of the electromagnetic coil assembly to work, wherein the difference between the second preset time and the first preset time is less than a preset threshold.

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