CN220139755U - Electromagnetic oven and control circuit thereof - Google Patents

Abstract

The utility model relates to the technical field of intelligent household appliances, and discloses an electromagnetic oven and a control circuit thereof. The control circuit of the induction cooker comprises a rectifying module, at least two groups of resonant modules connected in parallel, a group of high-frequency switching devices and a control module; the rectification module is used for accessing external alternating current mains supply; the resonance module is connected with the rectification module and is used for being connected with a direct current power supply output by the rectification module, and an alternating magnetic field can be generated when the resonance module is turned on; the high-frequency switch device is connected with each resonance module, forms a loop with the resonance module when the high-frequency switch device is opened, and generates high-frequency switch energy to drive the resonance module to generate an alternating magnetic field when the high-frequency switch device forms a loop with the resonance module; the control module is connected with each resonance module and the high-frequency switching device and is used for controlling the high-frequency switching device to be turned on, and when the high-frequency switching device is turned on, the plurality of groups of resonance modules are controlled to be turned on in a time interval. The embodiment of the utility model can reduce the complexity of the electric control structure of the multi-burner electromagnetic oven.

Description

Electromagnetic oven and control circuit thereof

Technical Field

The utility model relates to the technical field of intelligent household appliances, in particular to an electromagnetic oven and a control circuit thereof.

Background

The induction cooker is a common cooking appliance for people, and the multi-burner induction cooker comprises a plurality of burners, so that a plurality of dishes can be cooked at the same time, and the cooking time is greatly shortened.

In the prior art, the multi-burner induction cooker adopts the design that the burner corresponds to one set of electric control structure respectively, for example, the double-burner induction cooker is designed with two sets of independent electric control structures, or adopts the design that one set of electric control structure with a plurality of groups of control branches, and the burner corresponds to one group of driving branches respectively.

However, the number of electric control structures required for the former increases with the number of burners, and the latter requires a high-frequency switching device for each group of driving branches, and both require a high-frequency switching device, which has a drawback of complicated electric control structure.

Disclosure of Invention

The utility model aims to provide an induction cooker and a control circuit thereof, and aims to overcome the defect that a plurality of high-frequency switching devices are required to be arranged for the induction cooker with a multi-burner in the prior art, and the electric control structure is complex.

The embodiment of the utility model provides a control circuit of an induction cooker, which comprises the following components:

the rectification module is used for accessing external alternating current mains supply;

at least two groups of parallel resonance modules are connected with the rectification module and used for being connected with a direct current power supply output by the rectification module, and can generate an alternating magnetic field when being switched on;

the high-frequency switch device is connected with each resonance module, forms a loop with the resonance module when the resonance module is opened, and generates high-frequency switch energy to drive the resonance module to generate an alternating magnetic field when the resonance module forms a loop with the resonance module; and

the control module is connected with each resonance module and the high-frequency switching device and is used for controlling the high-frequency switching device to be turned on, and when the high-frequency switching device is turned on, a plurality of groups of resonance modules are controlled to be turned on at intervals.

Preferably, the resonance module comprises a low frequency switching device, a resonance capacitor and a resonance coil;

the control end of the low-frequency switching device is connected with the control module, the first end of the low-frequency switching device is connected with the rectifying module, the second end of the low-frequency switching device is connected with one end of the resonance capacitor, the other end of the resonance capacitor is connected with the high-frequency switching device, and the resonance coil is connected with the resonance capacitor in parallel.

Preferably, the low frequency switching device is a silicon controlled rectifier.

Preferably, the control circuit of the induction cooker further comprises:

the voltage acquisition module is connected with the rectification module and the high-frequency switching device and is used for acquiring a first voltage and a second voltage; the first voltage is the voltage of the direct current power supply output by the rectifying module, and the second voltage is the voltage at the joint of the resonant module and the high-frequency switching device;

the control module is connected with the voltage acquisition module and used for controlling the resonance module to be turned on when the difference between the first voltage and the second voltage is within a preset voltage interval.

Preferably, the voltage acquisition module comprises a first acquisition unit and a second acquisition unit;

the first end of the first acquisition unit is connected with the rectification module, the second end of the first acquisition unit is grounded, and the detection end of the first acquisition unit is connected with the control module;

the first end of the second acquisition unit is connected with the high-frequency switching device, the second end of the second acquisition unit is grounded, and the detection end of the second acquisition unit is connected with the control module.

Preferably, the control circuit of the induction cooker further comprises:

the current sensing module is connected with the rectifying module and the high-frequency switching device and is used for collecting the current of the direct-current power supply output by the rectifying module;

the control module is connected with the current sensing module and receives a current acquisition signal obtained by acquiring the current of the direct-current power supply by the current sensing module.

Preferably, the control circuit of the induction cooker further comprises:

the zero-crossing detection module is connected with the rectification module and used for detecting zero crossing points of alternating current mains supply;

the control module is connected with the zero-crossing detection module and used for controlling the on-off of the resonance module according to the zero-crossing point of the alternating current mains supply.

Preferably, the control module controls the high-frequency switching device to be turned on or off at a zero crossing point of the alternating-current commercial power.

Preferably, the high frequency switching device is an IGBT device.

The embodiment of the utility model also provides an induction cooker, which comprises the control circuit of the induction cooker.

The utility model has the beneficial effects that: a plurality of resonance modules are driven simultaneously by using a single high-frequency switching device, and the high-frequency switching device and the resonance modules to be turned on are controlled to be turned on, so that the on time of each turned-on resonance module in the working period of the induction cooker is distributed when at least two resonance modules are turned on simultaneously, the simultaneous heating of a plurality of burners is realized, and the defects that the induction cooker with a plurality of burners needs to be provided with the high-frequency switching device and has a complex electric control structure are overcome.

Drawings

Fig. 1 is a schematic structural diagram of a control circuit of an induction cooker according to a first embodiment.

Fig. 2 is a schematic structural diagram of a control circuit of an induction cooker according to a second embodiment.

Fig. 3 is a waveform diagram of controlling the on of the resonance module according to the first embodiment.

Fig. 4 is a waveform diagram of controlling the on of the resonance module according to the second embodiment.

Fig. 5 is a waveform diagram of controlling the turning-on of the resonance module according to the third embodiment.

Fig. 6 is a waveform diagram of controlling the turning-on of the resonance module according to the fourth embodiment.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

It should be noted that although functional block division is performed in a device diagram and a logic sequence is shown in a flowchart, in some cases, the steps shown or described may be performed in a different order than the block division in the device, or in the flowchart. The terms first, second and the like in the description and in the claims and in the above-described figures, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein is for the purpose of describing embodiments of the utility model only and is not intended to be limiting of the utility model.

In the related art, there are two designs of the induction cooker with multiple heads, the first is that multiple induction heating heads (for example, two heads, three heads and four heads) are respectively configured with a set of independent electric control structures, the number of the electric control structures to be matched increases with the increase of the number of heads, and the second is that one set of electromagnetic wave generator is used in one chip, a plurality of sets of driving branches are adopted, the multiple induction heating heads are respectively configured with a set of driving branches, and each set of driving branches is provided with a high-frequency switching device, for example, a multi-head induction cooker disclosed in chinese patent No. CN213818242U and a control circuit thereof.

It can be seen that both designs have the defect of complex electric control structure. The first is that the number of electric control structures is increased along with the increase of the number of the furnace heads, the layout difficulty is high, the internal space of the induction cooker is compact, the interval between the resonant modules of two adjacent sets of electric control structures is too close, so that larger noise can be generated when two heating furnace heads work simultaneously, the specification of a power supply lead or a power supply plug limits the maximum power of the induction cooker, but in order to ensure that the heating power of a single furnace head is not too low, the design power of each furnace head needs to be left with enough allowance, the power specification of an electronic device selected by the electric control structure of each furnace head is higher, and the cost is increased. The second is that each group of driving branches needs to be provided with a high-frequency switching device, synchronous control is needed to start vibration, a plurality of sets of synchronous circuits are also arranged in a circuit switched by the high-frequency switching device, and the high-frequency switching device is also needed to be switched and controlled, so that the control logic and the circuit structure are complex.

Based on the above, the embodiment of the utility model provides an electromagnetic oven and a control circuit thereof, wherein a single high-frequency switching device is used for driving a plurality of resonance modules simultaneously, and the high-frequency switching device and the resonance modules to be turned on are controlled to be turned on so as to realize simultaneous heating of a plurality of oven heads, thereby overcoming the defects that the electromagnetic oven with the plurality of oven heads needs to be provided with the high-frequency switching device and has a complex electric control structure.

Referring to fig. 1, a control circuit of an induction cooker according to an embodiment of the present utility model includes a rectifying module 100, at least two sets of resonant modules 200, a set of high-frequency switching devices 300, and a control module 400.

The rectifying module 100 is used for accessing external ac mains. When the rectification module 100 is connected to an external ac mains supply, rectification filtering processing is performed on the connected ac mains supply, and a dc power supply is obtained and output.

The resonance module 200 is connected to the rectification module 100, and is used for being connected to a direct current power supply output by the rectification module 100, and can generate an alternating magnetic field when being turned on. The groups of resonance modules 200 are mutually connected in parallel, one group of resonance modules 200 is used for heating a group of furnace heads of the electromagnetic oven, an alternating magnetic field can be generated when the resonance modules 200 are connected with a direct current power supply output by the rectification module 100, and electromagnetic vortex heating is carried out on a heating vessel on the furnace heads, so that vortex heat is generated by magnetic materials on the furnace surface, and the furnace surface heats.

It will be appreciated that the resonant module 200 is essentially a resonant module 200, and that for a passive port network comprising capacitive and inductive and resistive elements, the ports may exhibit capacitive, inductive and resistive properties, and that when the voltage and current at the ports of the circuit are in phase, the circuit is resistive, referred to as a resonant phenomenon, such a circuit is referred to as a resonant module 200. The essence of resonance is that the electric field energy in the capacitor and the magnetic field energy in the inductor are mutually converted, and the increase and decrease are fully compensated. The sum of the electric field energy and the magnetic field energy is kept unchanged at all times, and the power supply does not need to convert energy back and forth with a capacitor or an inductor, and only needs to supply the electric energy consumed by a resistor in the circuit.

The high frequency switching device 300 is connected to each of the resonance modules 200, and forms a loop with the opened resonance module 200 when opened, and generates high frequency switching energy to drive the resonance module 200 to generate an alternating magnetic field when forming a loop with the resonance module 200. The high-frequency switching device 300 may have one end connected to the resonant module 200 and the other end grounded, when both the resonant module 200 and the high-frequency switching device 300 are turned on, the direct current power to which the resonant module 200 is connected flows to the high-frequency switching device 300, the resonant module 200 and the high-frequency switching device 300 form a loop, and when the high-frequency switching device 300 is turned on, high-frequency (about 20KHz or more) high-power switching energy is generated to drive the resonant module 200 to generate high-frequency resonant electromagnetic waves, so as to form an alternating magnetic field.

The control module 400 is connected to each of the resonance modules 200 and the high-frequency switching device 300, and is used for controlling the high-frequency switching device 300 to be turned on, and controlling the plurality of groups of resonance modules 200 to be turned on in time periods when the high-frequency switching device 300 is turned on. The control module 400 receives an input adjustment signal and controls on-off of each of the resonance modules 200 and the high-frequency switching device 300, wherein the adjustment signal is used for setting on-off of the resonance module 200 and corresponding resonance power. When the high-frequency switching device 300 is controlled, the control module 400 sets the total resonance power of each resonance module 200 according to the adjustment signal to control the on width of the high-frequency switching device 300, so that the larger the total resonance power of each resonance module 200 is, the larger the on width of the high-frequency switching device 300 is, whereas the smaller the total resonance power of each resonance module 200 is, the smaller the on width of the high-frequency switching device 300 is, so as to meet the total power requirement in the operating period of the electromagnetic oven. When controlling the resonance modules 200, the control module 400 sets the resonance modules 200 to be turned on and the corresponding resonance power thereof according to the adjustment signals to control the on/off and the on time of each resonance module 200, and distributes the on time of each turned-on resonance module 200 in the working period of the induction cooker, wherein the ratio of the on time of each resonance module 200 and the ratio of the resonance power of each resonance module 200 are positively correlated, and the total resonance power of each resonance module 200 is equal to the total output power of the induction cooker.

When the power supply is in operation, the rectifying module 100 is connected with external alternating current commercial power and is converted into direct current power, a user generates an adjusting signal through a key of the induction cooker, the control module 400 starts the high-frequency switching device 300 and at least one group of resonant modules 200 to be started by the adjusting signal, the starting width of the high-frequency switching device 300 is controlled according to the total resonant power set by the received adjusting signal, when the number of resonant modules 200 to be started is at least two, the control module 400 distributes the starting time of each started resonant module 200 in the working period of the induction cooker, so that the resonant modules 200 are started in the time-division period when the high-frequency switching device 300 is started, and the ratio of the starting time of the resonant modules 200 and the ratio of the resonant power of the resonant modules are positively correlated, thereby realizing the power distribution of a plurality of resonant modules 200.

Referring to fig. 2, in some embodiments, a resonant module 200 includes a low frequency switching device 210, a resonant capacitor 220, and a resonant coil 230. The control end of the low-frequency switching device 210 is connected with the control module 400, the first end of the low-frequency switching device 210 is connected with the rectifying module 100, the second end of the low-frequency switching device 210 is connected with one end of the resonant capacitor 220, the other end of the resonant capacitor 220 is connected with the high-frequency switching device 300, and the resonant coil 230 is connected with the resonant capacitor 220 in parallel.

In the resonance module 200, the resonance coil 230 and the resonance capacitor 220 store electric fields and magnetic fields, respectively, so that energy is continuously transferred between the resonance coil 230 and the resonance capacitor 220, and when the low frequency switching device 210 is closed, the power variation of the resonance module 200 is periodic, and is continuously transferred between the resonance coil 230 and the resonance capacitor 220, thereby achieving stable energy transfer and conversion.

When the electric charges flow out of the resonance capacitor 220, the electric charges of the resonance capacitor 220 are reduced, but the electric energy is not lost but transferred to the resonance coil 230, and at the same time, the current in the resonance coil 230 is continuously increased, because the potential difference caused by the resonance capacitor 220 causes the current to flow back and forth between the resonance coil 230 and the resonance capacitor 220. When the amount of electricity in the resonance capacitor 220 is minimized, the current in the resonance coil 230 is maximized, and at this time, the electric energy is entirely stored in the resonance coil 230. As the resonant capacitor 220 charges gradually increases, the resonant coil 230 energy decreases and the resonant capacitor 220 energy increases. The resonance module 200 maintains a stable oscillation state at a specific frequency by repeating this process, thereby generating electromagnetic waves of a certain frequency.

Preferably, the low frequency switching device 210 is a silicon controlled rectifier.

Referring to fig. 2, in some embodiments, the control circuit of the induction cooker further includes a voltage acquisition module 500, where the voltage acquisition module 500 is connected to the rectification module 100 and the high-frequency switching device 300, and is used to acquire a first voltage and a second voltage, and the control module 400 is connected to the voltage acquisition module 500, and controls the resonance module 200 to be turned on when a difference between the first voltage and the second voltage is within a preset voltage interval. The first voltage is a voltage of the rectifying module 100 outputting the dc power, and the second voltage is a voltage at a junction between the resonant module 200 and the high-frequency switching device 300.

Specifically, the voltage acquisition module 500 acquires the voltage of the direct current power supply output by the rectification module 100 and the voltage at the connection position of the resonance module 200 and the high-frequency switching device 300 respectively and transmits the acquired two voltage signals to the control module 400, the control module 400 compares the acquired two voltage signals, when the difference between the two voltage signals is within a preset voltage interval, it is judged that the voltage at the positions of the sampling points just reaches the position exceeding the balance point, the control module 400 controls the resonance module 200 to be turned on at the moment, so that the resonance module 200 is turned on when the electromagnetic potential energy is in the lowest state, and the resonance module 200 works in the optimal state. Illustratively, the control module 400 compares the two collected voltage signals, and when the difference between the first voltage and the second voltage is within the voltage interval [50mV,150mV ], the control module 400 controls the resonance module 200 to be turned on.

More specifically, the voltage acquisition module 500 includes a first acquisition unit 510 and a second acquisition unit 520. The first end of the first collecting unit 510 is connected to the rectifying module 100, the second end of the first collecting unit 510 is grounded, the detecting end of the first collecting unit 510 is connected to the control module 400, the first end of the second collecting unit 520 is connected to the high-frequency switching device 300, the second end of the second collecting unit 520 is grounded, and the detecting end of the second collecting unit 520 is connected to the control module 400.

Referring to fig. 2, in some embodiments, the control circuit of the induction cooker further includes a current sensing module 600, where the current sensing module 600 is connected to the rectifying module 100 and the high-frequency switching device 300, and is used for collecting a current of the direct-current power supply output by the rectifying module 100, and the control module 400 is connected to the current sensing module 600, and receives a current collection signal obtained by collecting the current of the direct-current power supply by the current sensing module 600.

Specifically, the current sensing module 600 collects the current of the dc power source output by the rectifying module 100, the control module 400 receives the current collection signal of the current sensing module 600, and can calculate the current input dc power in combination with the voltage of the current power source output by the rectifying module 100 collected by the voltage collection module 500, and adjust the turn-on width of the high frequency switching device 300 in combination with the total resonance power set by the adjustment signal.

Referring to fig. 2, in some embodiments, the control circuit of the induction cooker further includes a zero-crossing detection module 700, where the zero-crossing detection module 700 is connected to the rectification module 100 and is used to detect a zero crossing point of the ac mains, and the control module 400 is connected to the zero-crossing detection module 700 and controls the on-off of the resonance module 200 according to the zero crossing point of the ac mains.

Specifically, the control module 400 detects the zero crossing point of the ac mains supply through the zero crossing detection module 700, so as to determine the zero crossing point of the dc power supply formed by rectifying and converting the ac mains supply, and controls the on-off of the resonance module 200 at the zero crossing point of the dc power supply, or controls the on-off of the resonance module 200 near the zero crossing point according to the detected zero crossing point of the ac mains supply, so as to reduce the noise when the resonance module 200 is turned on.

Preferably, the control module 400 controls the high frequency switching device 300 to be turned on and off at the zero crossing point of the ac mains.

Preferably, the high frequency switching device 300 is an IGBT device.

The following describes in detail a specific technical scheme of allocating on time of each opened resonance module 200 in an operating period of the induction cooker according to the embodiment of the present utility model.

In the first embodiment, in the on period, the on period of each on resonant module 200 is set according to the corresponding resonant power and the on width of the high-frequency switching device 300, so that the on period of the resonant module 200 is positively correlated with the resonant power of the resonant module 200, the ratio of the on period of each resonant module 200 is positively correlated with the ratio of the resonant power of each resonant module 200, the total resonant power is equal to the total output power of the induction cooker, and each resonant module 200 is controlled to be turned on in any period in each on period, and the on period is the set on period.

Referring to fig. 3, taking a dual-burner induction cooker as an example, the time duration of the on period is equal to the time duration of the H dc pulse waves, when the first burner and the second burner are turned on simultaneously and the power of the first burner is greater than the power of the second burner, the first resonant power (i.e. the resonant power of the resonant module 200 of the first burner, the same applies hereinafter) is greater than the second resonant power (i.e. the resonant power of the resonant module 200 of the second burner, the ratio of the two is M/N, the first resonant module turns on the time duration of the M dc pulse waves in the on period, and the second resonant module turns on the time duration of the N dc pulse waves in the on period. Wherein M is more than 1 and less than or equal to H, and N is more than 1 and less than or equal to H.

In this embodiment, each resonance module 200 may be turned on in any period of the on period, where the on period is the set on period. For example, the first resonance module may be a time length for continuously turning on M direct current ripple waves at the start of the on period, and the second resonance module may be a time length for continuously turning on N direct current ripple waves at the start of the on period. For another example, the first resonance module may be a time length for which M direct current ripple waves are turned on at intervals in an arbitrary period of the on period, and the second resonance module may be a time length for which N direct current ripple waves are turned on at intervals in an arbitrary period of the on period.

In the second embodiment, in the on period, the on period of each on resonant module 200 is set according to the corresponding resonant power and the on width of the high-frequency switching device 300, so that the on period of the resonant module 200 is positively correlated with the resonant power of the resonant module 200, the ratio of the on period of each resonant module 200 is positively correlated with the ratio of the resonant power of each resonant module 200, the total resonant power is equal to the total output power of the induction cooker, and each resonant module 200 is controlled to be alternately turned on in any period in each on period, and the on period is the set on period.

Referring to fig. 4, taking a dual-burner induction cooker as an example, the time duration of the on period is equal to the time duration of H dc pulse waves, when the first burner and the second burner are turned on simultaneously and the power of the first burner is greater than that of the second burner, that is, the first resonant power is greater than the second resonant power, where the ratio of the first resonant power to the second resonant power is M/N, the first resonant module turns on the time duration of M dc pulse waves in the on period, the second resonant module turns on the time duration of N dc pulse waves in the non-on period of the first resonant module in the on period, the first resonant power is M/(m+n) of the total power, and the second resonant power is N/(m+n) of the total power, where m+n is equal to or less than H.

In this embodiment, each resonance module 200 is turned on alternately in any period of each on period, and the on duration is the set on duration. For example, the first resonant module may be a time length for continuously turning on M dc ripple waves before the end of the turn-on period, and the second resonant module may be a time length for continuously turning on N dc ripple waves at the beginning of the turn-on period, so that turn-on times of the first resonant module and the second resonant module are staggered, and the first resonant module and the second resonant module are alternately turned on in the turn-on period. For another example, the first resonance module may be a time length for which M direct current ripple waves are turned on at intervals in an arbitrary period of the on period, and the second resonance module may be a time length for which N direct current ripple waves are turned on at intervals in a non-on period of the first resonance module in the on period.

In the third embodiment, in the on period, the on period of each on resonant module 200 is set according to the corresponding resonant power and the on width of the high-frequency switching device 300, so that the on period of the resonant module 200 is positively correlated with the resonant power of the resonant module 200, the ratio of the on period of each resonant module 200 is positively correlated with the ratio of the resonant power of each resonant module 200, the total resonant power is equal to the total output power of the induction cooker, each resonant module 200 is controlled to be turned on at intervals in any period in each on period, the interval period between two adjacent on periods is the same, and the on period is the set on period.

Referring to fig. 5, taking a dual-burner induction cooker as an example, the time duration of the on period is equal to the time duration of H dc pulse waves, when the first burner and the second burner are turned on simultaneously and the power of the first burner is greater than that of the second burner, that is, the first resonant power is greater than the second resonant power, the ratio of the first resonant power to the second resonant power is M/N, the first resonant module turns on the time duration of M dc pulse waves in the on period, and the second resonant module turns on the time duration of N-N dc pulse waves at the beginning of the on period, and turns on the time duration of N dc pulse waves at the end of the on period. Wherein M is more than 1 and less than H, and N is more than 1 and less than H.

In this embodiment, the interval duration between two adjacent turn-on periods is the same between two adjacent turn-on periods of each resonance module 200. For example, the first resonance module may be a time length of continuously turning on M dc ripple waves at the beginning of the turn-on period, a time length of turning off H-M dc ripple waves before the end of the turn-on period, a time length of spacing H-M dc ripple waves between two adjacent turns on of the first resonance module between two adjacent turn-on periods, and the second resonance module may be a time length of continuously turning on N-N (N < N) dc ripple waves at the beginning of the turn-on period, a time length of continuously turning on N dc ripple waves before the end of the turn-on period, and a time length of spacing H-N dc ripple waves between two adjacent turns on of the second resonance module between two adjacent turn-on periods. For another example, the first resonant module may be turned on at intervals when the turn-on period starts, the duration of the first turn-on and the last turn-on in the turn-on period is the time length of M dc ripple waves, the interval between two adjacent turn-on periods of the first resonant module and two adjacent turn-on periods is the time length of H-M dc ripple waves, the second resonant module may be turned on at intervals when the turn-on period starts and before the turn-on period ends, the duration of the first turn-on and the last turn-on period of the two interval turn-on periods is the time length of N-N (N < N) dc ripple waves and the time length of N dc ripple waves, respectively, and the interval between two adjacent turn-on periods of the second resonant module is 0 dc ripple waves.

In the fourth embodiment, in the on period, the on period of each on resonant module 200 is set according to the corresponding resonant power and the on width of the high-frequency switching device 300, so that the on period of the resonant module 200 is positively correlated with the resonant power of the resonant module 200, the ratio of the on period of each resonant module 200 is positively correlated with the ratio of the resonant power of each resonant module 200, the total resonant power is equal to the total output power of the induction cooker, and the same on period of each resonant module 200 in each on period is controlled to open the set on width, and the on period is the set on period.

Referring to fig. 6, taking a dual-burner induction cooker as an example, the time duration of the on period is equal to the time duration of H dc pulse waves, when the first burner and the second burner are turned on simultaneously and the power of the first burner is greater than that of the second burner, that is, the first resonant power is greater than the second resonant power, the first resonant module and the second resonant module both turn on the time duration of M dc pulse waves in the on period, the on width of the first resonant module at each turn on is T, the first resonant module is turned on M times in the time duration of M dc pulse waves, the total on time is t×m, the on width of the second resonant module at each turn on is T, and the total on time of the second resonant module at each turn on M times in the time duration of M dc pulse waves is t×m. Wherein, when T is less than or equal to H and T is less than or equal to T/2, the ratio of the first resonant power to the second resonant power is 1/2sin (2 pi T/T), and when T is more than T/2, the ratio of the first resonant power to the second resonant power is 1/2 (1-sin (2 pi T/T)).

In summary, the induction cooker and the control circuit thereof provided by the embodiment of the utility model use a single high-frequency switching device 300 to drive a plurality of resonance modules 200 simultaneously, and at least two resonance modules 200 are simultaneously opened to allocate the opening time of each opened resonance module 200 in the working period of the induction cooker by controlling the high-frequency switching device 300 and the resonance modules 200 to be opened, so as to realize simultaneous heating of multiple burner heads, and overcome the defects that the induction cooker with multiple burner heads needs to be provided with the high-frequency switching device 300 and has complex electric control structure.

The terms "first," "second," "third," "fourth," and the like in the description of the utility model and in the above figures, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the utility model described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It should be understood that in the present utility model, "at least one (item)" means one or more, and "a plurality" means two or more. "and/or" for describing the association relationship of the association object, the representation may have three relationships, for example, "a and/or B" may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

In the several embodiments provided by the present utility model, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the above-described division of units is merely a logical function division, and there may be another division manner in actual implementation, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described above as separate components may or may not be physically separate, and components shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The preferred embodiments of the present utility model have been described above with reference to the accompanying drawings, and are not thereby limiting the scope of the claims of the embodiments of the present utility model. Any modifications, equivalent substitutions and improvements made by those skilled in the art without departing from the scope and spirit of the embodiments of the present utility model shall fall within the scope of the claims of the embodiments of the present utility model.

Claims (10)

1. A control circuit for an induction cooker, comprising:

the rectification module (100) is used for accessing external alternating current mains supply;

at least two groups of parallel resonance modules (200) connected with the rectification module (100) and used for being connected with a direct current power supply output by the rectification module (100) to generate an alternating magnetic field when being switched on;

a group of high-frequency switching devices (300) connected with each resonance module (200), wherein the high-frequency switching devices and the resonance modules (200) are turned on to form a loop, and high-frequency switching energy is generated to drive the resonance modules (200) to generate an alternating magnetic field when the high-frequency switching devices and the resonance modules (200) are turned on to form a loop; and

and the control module (400) is connected with each resonance module (200) and the high-frequency switching device (300) and is used for controlling the high-frequency switching device (300) to be turned on and controlling the groups of resonance modules (200) to be turned on in a time-sharing mode when the high-frequency switching device (300) is turned on.

2. The control circuit of an induction hob according to claim 1, characterized in, that the resonance module (200) comprises a low frequency switching device (210), a resonance capacitor (220) and a resonance coil (230);

the control end of the low-frequency switching device (210) is connected with the control module (400), the first end of the low-frequency switching device (210) is connected with the rectifying module (100), the second end of the low-frequency switching device (210) is connected with one end of the resonant capacitor (220), the other end of the resonant capacitor (220) is connected with the high-frequency switching device (300), and the resonant coil (230) is connected with the resonant capacitor (220) in parallel.

3. The control circuit of an induction hob according to claim 2, characterized in, that the low frequency switching device (210) is a silicon controlled rectifier.

4. The control circuit of an induction hob according to claim 1, further comprising:

the voltage acquisition module (500) is connected with the rectifying module (100) and the high-frequency switching device (300) and is used for acquiring a first voltage and a second voltage; the first voltage is the voltage of the direct current power supply output by the rectifying module (100), and the second voltage is the voltage at the joint of the resonant module (200) and the high-frequency switching device (300);

the control module (400) is connected with the voltage acquisition module (500) and controls the resonance module (200) to be turned on when the difference between the first voltage and the second voltage is within a preset voltage interval.

5. The control circuit of an induction hob according to claim 4, characterized in, that the voltage acquisition module (500) comprises a first acquisition unit (510) and a second acquisition unit (520);

a first end of the first acquisition unit (510) is connected with the rectification module (100), a second end of the first acquisition unit (510) is grounded, and a detection end of the first acquisition unit (510) is connected with the control module (400);

the first end of the second acquisition unit (520) is connected with the high-frequency switching device (300), the second end of the second acquisition unit (520) is grounded, and the detection end of the second acquisition unit (520) is connected with the control module (400).

6. The control circuit of an induction hob according to claim 4, further comprising:

the current sensing module (600) is connected with the rectifying module (100) and the high-frequency switching device (300) and is used for collecting the current of the direct-current power supply output by the rectifying module (100);

the control module (400) is connected with the current sensing module (600) and receives a current acquisition signal obtained by acquiring the current of the direct-current power supply by the current sensing module (600).

7. The control circuit of an induction hob according to claim 1, further comprising:

the zero-crossing detection module (700) is connected with the rectification module (100) and is used for detecting a zero crossing point of alternating current mains supply;

the control module (400) is connected with the zero-crossing detection module (700) and controls the on-off of the resonance module (200) according to the zero-crossing point of alternating current mains supply.

8. The control circuit of an induction hob according to claim 7, characterized in, that the control module (400) controls the switching on and off of the high frequency switching device (300) at zero crossing of the ac mains.

9. The control circuit of an induction hob according to any one of the claims 1 to 8, characterized in, that the high frequency switching device (300) is an IGBT device.

10. An induction hob, characterized in, that it comprises a control circuit of an induction hob according to any one of the claims 1 to 9.