WO2019205548A1

WO2019205548A1 - Power supply apparatus and microwave cooking electric appliance

Info

Publication number: WO2019205548A1
Application number: PCT/CN2018/112624
Authority: WO
Inventors: 覃承勇; 黎青海; 增田慎一; 张云祥
Original assignee: 广东美的厨房电器制造有限公司; 美的集团股份有限公司
Priority date: 2018-04-26
Filing date: 2018-10-30
Publication date: 2019-10-31

Abstract

A power supply apparatus (100) and a microwave cooking electric appliance (1000). The power supply apparatus (100) comprises a rectifier module (10) connected to an alternating-current source (60), a transformer (20) connected to the rectifier module (10), a switch module (30), a control module (40) connected to the switch module (30), and a power supply module (50), wherein the transformer (20) comprises a primary winding (22) and an auxiliary winding (24), the auxiliary winding (24) being connected to a primary side of the transformer (20); the switch module (30) is configured to provide an on-off signal to the transformer (20); the control module (40) is configured to control the turning-on and turning-off of the switch module (30) according to a comparison result of a reference voltage and the voltage of the auxiliary winding (24); and the power supply module (50) is connected to the auxiliary winding (24) and the control module (40) and is configured to provide power for the control module (40) by using electric energy provided by the auxiliary winding (24).

Description

Power supply unit and microwave cooking appliance

Priority information

The present application claims priority to and the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit.

Technical field

The present application relates to the field of household appliances, and more particularly to a power supply device and a microwave cooking appliance.

Background technique

In the related art, the power supply device of the microwave cooking appliance takes power from the mains port and then supplies a stable voltage to the relevant components of the microwave cooking appliance by rectification or the like. However, this type of power supply generates large power loss and requires a large volume, high power cement resistor. In addition, the power supply device directly takes a voltage signal from both ends of the primary winding of the transformer, and then generates a synchronous detection signal through a plurality of resistor dividers and comparators to control the on and off of the switch tube. Since the two ends of the primary winding are high voltage, it is necessary to take more voltage dividers from the two ends of the primary winding. At the same time, in the layout of the circuit board, the high voltage line needs to have a wider safety distance from the surrounding lines. Increase the size of the board.

Summary of the invention

Embodiments of the present application provide a power supply device and a microwave cooking appliance.

The power supply device of the embodiment of the present application includes:

a rectifier module for connecting an AC source;

a transformer connected to the rectifier module, the transformer comprising a primary winding and an auxiliary winding, the auxiliary winding being connected to a primary side of the transformer;

a switch module, the switch module being disposed to provide an on/off signal to the transformer;

Connecting a control module of the switch module, the control module being configured to control on and off of the switch module according to a comparison result of a reference voltage and a voltage of the auxiliary winding;

a power supply module, the power supply module connecting the auxiliary winding and the control module, and being disposed to supply power to the control module by using electrical energy provided by the auxiliary winding.

The power supply device of the embodiment of the present application can provide a stable operating voltage to the control module by adding an auxiliary winding on the primary side of the transformer. At the same time, the control module can control the switching of the switch module according to the comparison result of the reference voltage and the voltage of the auxiliary winding. . Since the opposite ends of the auxiliary winding produce a relatively low voltage, only a small resistance is used to divide the voltage, thereby reducing the safety distance between the lines. In this way, the cost is reduced and the space of the power supply device is saved, and the size of the power supply device can be further reduced.

In some embodiments, the rectifier module includes a full wave rectifier circuit of four diodes.

In some embodiments, the rectifier module is configured to convert an AC voltage generated by the AC source to a DC voltage.

In some embodiments, the power supply device includes a filtering module that connects the rectifier module and the transformer.

In some embodiments, the switch module includes a switch transistor and a resonant capacitor.

In certain embodiments, the turns ratio of the auxiliary winding to the primary winding is 1:N; wherein N is greater than 10 and less than 25.

In certain embodiments, the transformer includes a bobbin that is open with a single primary winding slot, the auxiliary winding and the primary winding being wound in the primary winding slot.

In some embodiments, the power supply device includes a sampling module, the control module includes a synchronization detection module and a controller, the sampling module is connected to the auxiliary winding and the synchronous detection module, and the sampling module is disposed on Detecting a voltage of the auxiliary winding, the synchronization detecting module is disposed to compare the voltage of the reference voltage and the auxiliary winding, and the controller is set to compare according to a voltage of the reference voltage and the auxiliary winding As a result, the on/off of the switch module is controlled.

In some embodiments, the synchronization detection module includes a comparator, the sampling module includes a first resistor and a second resistor, the first resistor is connected in series with the second resistor and connected at both ends of the auxiliary winding The positive input end of the comparator is connected between the first resistor and the second resistor, the negative input end of the comparator is connected to the other end of the second resistor, and the output end of the comparator is connected Controller.

In some embodiments, the power supply module includes a rectifying unit and a voltage stabilizing unit, the rectifying unit is connected to the auxiliary winding, the voltage stabilizing unit is connected to the rectifying unit and the control module, and the voltage stabilizing unit It is arranged to provide at least two different operating voltages to the control module.

In some embodiments, the voltage stabilizing unit includes a first voltage regulator and a second voltage regulator, the first voltage regulator connecting the rectifying unit, the second voltage regulator, and the control module The second voltage regulator is connected to the first voltage regulator and the control module, the first voltage regulator is disposed to provide a first voltage to the control module, and the second voltage regulator is Provided to provide the control module with a second voltage that is less than the first voltage.

In some embodiments, the control module includes a controller and a drive module, the drive module is coupled to the controller, the switch module, and the power supply module, and the power supply module is configured to provide the second And a voltage is applied to the controller, and the first voltage is supplied to the driving module.

In some embodiments, the first voltage regulator comprises an 18V Zener.

In some embodiments, the second regulator comprises a three-terminal regulator.

In some embodiments, the power supply module includes a step-down resistor connected between the rectifying unit and the voltage stabilizing unit.

In some embodiments, the transformer includes a secondary winding, the power supply device includes a voltage doubler rectifier module, the voltage doubler rectifier module is coupled to the secondary winding, and the voltage doubler rectifier module is disposed at an augmentation The output voltage of the transformer.

In some embodiments, the voltage doubler rectifier module includes a first voltage doubler diode, a second voltage doubled diode, a first voltage doubled capacitor, and a second voltage doubled capacitor, the first voltage doubled diode and the second The voltage doubler diodes are connected in series, the first voltage doubled capacitor and the second voltage doubled capacitor are connected in series, and the circuit composed of the first voltage doubled diode and the second voltage doubled diode and the first voltage doubled capacitor And a circuit composed of the second voltage doubler capacitor is connected in parallel.

The microwave cooking appliance of the embodiment of the present application includes the power supply device of any of the above embodiments and a microwave generator, and the power supply device is connected to the microwave generator.

The microwave cooking appliance of the embodiment of the present application can provide a stable working voltage to the control module by adding an auxiliary winding to the transformer. At the same time, the control module can control the on/off of the switch module according to the comparison result of the reference voltage and the voltage of the auxiliary winding. Since the opposite ends of the auxiliary winding produce a relatively low voltage, only a small resistance is used to divide the voltage, thereby reducing the safety distance between the lines. In this way, the cost is reduced and the space of the circuit board is saved, and the size of the circuit board can be further reduced.

In some embodiments, the microwave cooking appliance includes a cavity, a door body, and a fan, the door body being rotatably disposed in front of the cavity and for opening or closing an opening of the cavity, the fan It is used for cooling and cooling the power supply device.

In some embodiments, the microwave generator and the power supply device are mounted on an outer side of the cavity and disposed in a blowing direction of the fan.

The additional aspects and advantages of the embodiments of the present application will be set forth in part in the description which follows.

DRAWINGS

The above and/or additional aspects and advantages of the present application will become apparent and readily understood from

1 is a circuit diagram of a power supply device according to an embodiment of the present application;

2 is a schematic structural view of a winding bracket of a transformer according to an embodiment of the present application;

3 is a voltage waveform diagram between two points A and B in the power supply device of FIG. 1;

Figure 4 is a voltage waveform diagram of point C in the power supply device of Figure 1;

5 is a voltage waveform diagram of a power supply device in the related art;

FIG. 6 is a schematic perspective view of a microwave cooking appliance according to an embodiment of the present application.

The main component symbol description:

Power supply device 100, rectifier module 10, transformer 20, primary winding 22, auxiliary winding 24, secondary winding 26, winding support 28, primary winding slot 282, secondary winding slot 284, filament winding slot 286, filament winding 21, the switch module 30, the switch tube 32, the resonant capacitor 34, the control module 40, the synchronization detection module 42, the comparator 422, the controller 44, the drive module 46, the power supply module 50, the rectifier unit 52, the voltage regulator unit 54, the first Voltage regulator 542, second voltage regulator 544, step-down resistor 56, AC source 60, filter module 70, filter inductor 72, filter capacitor 74, sampling module 80, first resistor 82, second resistor 84, voltage doubler rectifier Module 90, first voltage doubler diode 92, second voltage doubler diode 94, first voltage doubler capacitor 96, second voltage doubler capacitor 98, microwave cooking appliance 1000, microwave generator 200, cavity 300, fan 400, tray 500 .

detailed description

The embodiments of the present application are described in detail below, and the examples of the embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are intended to be illustrative, and are not to be construed as limiting.

In the description of the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only, and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" or "second" may include one or more of the described features either explicitly or implicitly. In the description of the embodiments of the present application, the meaning of "a plurality" is two or more unless specifically and specifically defined otherwise.

In the description of the embodiments of the present application, it should be noted that the terms "installation", "connected", and "connected" should be understood broadly, and may be a fixed connection, for example, or It is a detachable connection, or is integrally connected; it may be directly connected or indirectly connected through an intermediate medium, and may be an internal connection of two elements or an interaction relationship of two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood on a case-by-case basis.

The following disclosure provides many different embodiments or examples for implementing different structures of the embodiments of the present application. In order to simplify the disclosure of embodiments of the present application, the components and settings of the specific examples are described below. Of course, they are merely examples and are not intended to limit the application. In addition, the embodiments of the present application may repeat reference numerals and/or reference letters in different examples, which are for the purpose of simplicity and clarity, and do not in themselves indicate the relationship between the various embodiments and/or arrangements discussed. . Moreover, embodiments of the present application provide examples of various specific processes and materials, but one of ordinary skill in the art will recognize the use of other processes and/or the use of other materials.

Referring to FIG. 1 , the power supply device 100 of the embodiment of the present application includes a rectifier module 10 , a transformer 20 , a switch module 30 , a control module 40 , and a power supply module 50 . The rectifier module 10 is used to connect the AC source 60. The transformer 20 is connected to the rectifier module 10. Transformer 20 includes a primary winding 22 and an auxiliary winding 24 that is coupled to the primary side of transformer 20. The switch module 30 is arranged to provide an on/off signal to the transformer 20. The control module 40 is connected to the switch module 30. The control module 40 is arranged to control the on and off of the switch module 30 based on the comparison of the reference voltage and the voltage of the auxiliary winding 24. The power supply module 50 is coupled to the auxiliary winding 24 and the control module 40 and is configured to power the control module 40 with electrical energy provided by the auxiliary winding 24.

The power supply device 100 of the embodiment of the present application can provide the control module 40 with a stable operating voltage by adding the auxiliary winding 24 on the primary side of the transformer 20. At the same time, the control module 40 can compare the reference voltage with the voltage of the auxiliary winding 24. The switching of the switch module 30 is controlled. Since the opposite ends of the auxiliary winding 24 are relatively low voltage, only a small resistance is used to divide the voltage, thereby reducing the safety distance between the lines. In this way, the cost of the power supply device 100 is reduced and the size of the power supply device 100 can be further reduced.

The power supply device 100 of the embodiment of the present application may be a power supply device that can be applied to the microwave cooking appliance 1000, such as a frequency converter or an electronic transformer, and is not specifically limited herein.

In the related art, the power supply device obtains 220V AC power from the mains input port, and is rectified by a diode, and the electrolytic capacitor is filtered into a DC voltage of about 310V, and then stepped down by a large-volume, high-power cement resistor, and finally an 18V The voltage regulator is regulated to generate a DC voltage of 18V to supply power to the driver module. At the same time, a three-terminal regulator is connected to the 18V circuit to generate a 5V DC voltage to supply power to the controller. In addition, the power supply device forms a voltage dividing circuit from the two ends of the primary winding of the transformer through a plurality of resistors, and obtains voltage signals at both ends of the primary winding of the transformer, which are input to the positive and negative input terminals of the comparator, and then generated by the comparator. The detection signal is synchronously controlled to control the on/off of the switch module, and finally achieves the purpose of controlling the input power of the power supply device. However, existing power supply devices generate large power losses and require large volume, high power cement resistors. In addition, since the two ends of the primary winding are high voltage, it is necessary to take more voltage division from the two ends of the primary winding; at the same time, the high voltage line needs to be wider with the surrounding lines when the circuit board layout of the power supply device is laid. The safety distance must increase the size of the board of the power supply unit.

In the embodiment of the present application, an auxiliary winding 24 is added on the primary side of the transformer 20, and the control module 40 can be supplied with a stable operating voltage through the auxiliary winding 24. At the same time, the control module 40 can be based on the reference voltage and the voltage of the auxiliary winding 24. The comparison result controls the on and off of the switch module 30.

In the present embodiment, the voltage of the auxiliary winding 24 is smaller than the voltage of the primary winding 22. Therefore, the opposite ends of the auxiliary winding 24 are generated with a relatively low voltage, and only a small resistance is used to divide the voltage, thereby reducing the safety distance between the lines. Thus, the cost of the power supply device 100, such as the board space, is reduced, and the size of the power supply device 100 can be further reduced. In one example of the present application, the size of the board can be reduced by 20%-30%. The power supply device 100 of the embodiment of the present invention not only eliminates the power supply circuit that uses a large volume of high-power cement resistor to step down, but also reduces the number of voltage dividing resistors and saves costs.

In the embodiment of the present application, the transformer 20 is a step-up transformer. The rectifier module 10 includes a full-wave rectifier circuit composed of four diodes. The rectifier module 10 can convert the AC voltage generated by the AC source 60 into a DC voltage. It should be noted that, in one example, the AC source 60 generates an AC voltage of approximately 220 V and a frequency of approximately 50 Hz. It will be appreciated that the rectifier module 10 may also employ other forms of circuitry and is not limited to being comprised of four diodes.

Further, the power supply device 100 further includes a filtering module 70, and the filtering module 70 is connected to the rectifier module 10 and the transformer 20. The filtering module 70 includes a filter inductor 72 and a filter capacitor 74. One end of the filter capacitor 74 is grounded. The anti-interference ability of the power supply device 100 can be improved by the filter capacitor 74 and the filter inductor 72, and the interference of the power supply device 100 with other devices can also be reduced.

It should be noted that in the present embodiment, the transformer 20 may be a high frequency transformer. The high frequency transformer is a power transformer with a working frequency greater than the intermediate frequency (10 kHz). The high frequency transformer transmits a high frequency pulse square wave signal. The control signal generated by control module 40 can be a high frequency signal, such as a signal greater than 10 kHz.

The switch module 30 includes a switch tube 32 and a resonant capacitor 34. The base of the switch tube 32 is connected to the control module 40. The collector of the switch tube 32 is connected to one end of the primary winding 22 of the transformer 20 and one end of the resonant capacitor 34. The emitter of the switch tube 32 is connected to the rectifier module 10 and the filter capacitor 74. The other end of the 34 is connected to the other end of the primary winding 22 of the transformer 20 and the rectifier module 10. The DC voltage outputted by the rectifier module 10 is inverted by the switching transistor 32, the resonant capacitor 34, and the transformer 20 to a high frequency AC voltage of 20 kHz to 50 kHz. When the switch tube 32 is turned on, the electrical energy can be converted into magnetic energy by the resonant capacitor 34 and stored in the primary winding 22 of the transformer 20 to maintain the voltage of the transformer 20; when the switch tube 32 is turned off, the transformer 20 and the resonant capacitor 34 resonate with each other to make When the switch tube 32 is turned on next time, the voltage of the collector of the switch tube 32 starts from 0 V, so that the switching loss of the switch tube 32 can be reduced, and at the same time, the magnetic energy in the primary winding 22 is converted into electric energy. In the example of the present application, the switching transistor 32 is an IGBT (Insulated Gate Bipolar Transistor).

In certain embodiments, the turns ratio of the auxiliary winding 24 to the primary winding 22 is 1:N; wherein N is greater than 10 and less than 25.

As such, a low voltage is generated across the auxiliary winding 24 relative to the primary winding 22. Based on the turns ratio relationship, Ucp=U'/N can be determined, where Ucp is the voltage of the auxiliary winding 24 and U' is the voltage of the primary winding 22. Preferably, the value of N is controlled between 15 and 18, and the voltage across the auxiliary winding 24 can be guaranteed to be between 20 and 30 V, so that the voltage can be stepped down by a small chip resistor.

In certain embodiments, referring to FIG. 2, transformer 20 includes a winding bracket 28. The bobbin holder 28 is provided with a single primary winding slot 282, and the auxiliary winding 24 and the primary winding 22 are wound around the primary winding slot 282.

It will be appreciated that the winding bracket 28 includes a single primary winding slot 282 and a single secondary winding slot 284. The auxiliary winding 24 and the primary winding 22 are wound in the same primary winding slot 282, and the voltage Ucp of the auxiliary winding 24, that is, the voltage at point C, can be maintained at a stable value, as shown in FIG. That is to say, the voltage U' of the primary winding 22 is maintained substantially at a fixed value as shown in FIG. If the auxiliary winding 24 is wound on the secondary side of the transformer 20, for example wound in the secondary winding slot 284, affected by the secondary leakage inductance of the transformer 20, once the power supply unit 100 carries a large load, the voltage at point C The top of the waveform will be partially cut off, as shown in FIG. 5, causing the voltage at point C to be lower when the power supply device 100 has a larger load than when the power is applied, so that the power supply voltage of the control module 40 is insufficient to cause the power supply device 100. Not working properly. In the present embodiment, when the load is normally operated, the power is greater than 500 W, which is a large load, such as a magnetron; when the load is less than 500 W, the load is a light load, such as a cooling fan. 4 shows the voltage waveform at point C when the auxiliary winding 24 and the primary winding 22 are wound in the same primary winding groove; or the auxiliary winding 24 and the secondary winding 26 are wound in the same secondary winding groove, and the power supply device 100 Voltage waveform at point C with light load. Figure 5 shows the voltage waveform at point C when the auxiliary winding 24 and the secondary winding 26 are wound in the same secondary winding slot with the power supply device 100 carrying a large load.

Further, the auxiliary winding 24 and the primary winding 22 are wound in a single primary winding slot 282, which stabilizes the output of the transformer 20 and is wound with respect to the auxiliary winding 24 in the secondary winding slot 284, the winding required for the auxiliary winding 24. Less coils and insulation. The auxiliary winding 24 is wound around the primary winding slot 282, which reduces the cost of the transformer 20 and reduces the size of the transformer 20.

In some embodiments, the power supply device 100 includes a sampling module 80. The control module 40 includes a synchronization detection module 42 and a controller 44. The sampling module 80 is connected to the auxiliary winding 24 and the synchronization detection module 42. The sampling module 80 is disposed on the detection auxiliary winding. The voltage of 24, the synchronization detecting module 42 is set to compare the voltage of the reference voltage and the auxiliary winding 24, and the controller 44 is arranged to control the switching of the switching module 30 according to the comparison result of the voltage of the reference voltage and the auxiliary winding 24.

Specifically, in the present embodiment, the synchronization detecting module 42 includes a comparator 422. The sampling module 80 includes a first resistor 82 and a second resistor 84. The first resistor 82 is connected in series with the second resistor 84 and connected to both ends of the auxiliary winding 24. The positive input terminal of the comparator 422 is connected between the first resistor 82 and the second resistor 84, the negative input terminal of the comparator 422 is connected to the other end of the second resistor 84, and the output terminal of the comparator 422 is connected to the controller 44.

It can be understood that the voltages of the primary winding 22 and the auxiliary winding 24 are alternating voltages. In the present embodiment, the synchronization detecting module 42 includes a comparator 422. One end of the auxiliary winding 24 is grounded, and one end is connected to the sampling module 80. The control module 40 includes a controller 44 and a drive module 46 (eg, a drive circuit) that connects the controller 44, the switch module 30, and the power supply module 50. The controller 44 can be an MCU (Microcontroller Unit).

Specifically, the voltage of the primary winding 22 is mapped by the auxiliary winding 24, the voltage of the point B is proportionally mapped to the point C, and then the voltage of the point C is sampled by the sampling module 80, that is, the first resistor 82 and the second resistor 84, and then transmitted to the voltage. The positive input terminal of the comparator 422 is connected to the negative input terminal of the comparator 422 as a reference terminal to provide a reference voltage, that is, the reference voltage is zero. When the positive input terminal voltage of the comparator 422 is less than the negative input terminal voltage, that is, the voltage at the C point is less than 0, the output voltage of the comparator 422 is inverted, and the controller 44 communicates with the drive module 46 to drive the switch 32 to be turned on. The present application utilizes the auxiliary winding 24 for synchronous detection signal sampling. Since one end of the auxiliary winding 24 is grounded, and this terminal is just connected to the negative input terminal of the comparator 422 as a reference terminal and provides a reference voltage, the circuit also adds a synchronous detection signal. The stability ensures the stability of the input power. In the present embodiment, the fluctuation of the input power is ±2W. It can be understood that in other embodiments, the reference end can also be set as the other end except the ground end, and the reference voltage can also be other values.

It should be noted that, when the power supply device 100 is in operation, the input power of the transformer 20 is controlled by the on/off of the switch tube 32. The longer the on-time of the switch tube 32, the greater the power input to the primary winding 22. When the power supply device 100 starts to work, the control module 40 is powered by a starting resistor (not shown), so that the controller 44 can communicate to the driving module 46 to drive the switch 32 to conduct to enable the transformer 20 to obtain electrical energy. In the present embodiment, a starting resistor can be connected between the rectifier module 10 and the controller 44.

In some embodiments, the power supply module 50 includes a rectifying unit 52 and a voltage stabilizing unit 54, the rectifying unit 52 is connected to the auxiliary winding 24, the voltage stabilizing unit 54 is connected to the rectifying unit 52 and the control module 40, and the voltage stabilizing unit 54 is set to control Module 40 provides at least two different operating voltages.

Specifically, a capacitor is connected between the rectifying unit 52 and the voltage stabilizing unit 54. The voltage across the auxiliary winding 24 is an alternating voltage, and the voltage of the auxiliary winding 24 passes through the rectifying unit 52 to charge the capacitor. The voltage stabilizing unit 54 stabilizes the voltage of the capacitor and provides at least two different operating voltages to the control module 40. In the illustrated example, the rectifying unit 52 is a rectifying diode.

In some embodiments, the voltage stabilizing unit 54 includes a first voltage regulator 542 and a second voltage regulator 544. The first voltage regulator 542 is connected to the rectifying unit 52, the second voltage regulator 544, and the control module 40, and second. The voltage regulator 544 is connected to the first voltage regulator 542 and the control module 40. The first voltage regulator 542 is disposed to provide a first voltage to the control module 40, and the second voltage regulator 544 is disposed to provide less than the control module 40. The second voltage of a voltage.

It can be understood that in some examples, the first regulator 542 is an 18V Zener and the second regulator 544 is a three-terminal regulator. The voltage across the auxiliary winding 24 is rectified to a DC voltage by the rectifying unit 52, and the Zener diode supplies a first voltage, that is, a 18V DC voltage to the driving module 46 of the control module 40, and the 18V DC voltage is outputted through the three-terminal regulator to output a second voltage, that is, 5V. The DC voltage is supplied to the controller 44 of the control module 40.

It can be understood that, in one example, the controller 44 requires a stable DC voltage of 5V for normal operation, and a stable DC voltage of 18V is required for the drive module 46 to operate normally. The power supply module 50 provides a stable and reasonable voltage for operation of the controller 44 and the drive module 46.

In some embodiments, the power supply module 50 includes a buck resistor 56 coupled between the rectifying unit 52 and the stabilizing unit 54.

It can be understood that in the embodiment of the present application, the voltage across the auxiliary winding 24 can be controlled between 20 and 30 V, which is slightly higher than the operating voltage (18 V) required by the driving module 46. Therefore, a step-down resistor 56 is connected between the rectifying unit 52 and the stabilizing unit 54 to lower the voltage to 18 V after the voltage of the auxiliary winding 24 is rectified.

In some embodiments, the transformer 20 includes a secondary winding 26, the power supply device 100 includes a voltage doubler rectifier module 90, the voltage doubler rectifier module 90 is coupled to the secondary winding 26, and the voltage doubler rectifier module 90 is disposed to increase the output of the transformer 20. Voltage.

In this way, the output voltage of the transformer 20 can be multiplied by the voltage doubler rectifier module 90, and the circuit structure is simple. Specifically, the voltage doubler rectifier module 90 includes a first voltage doubler diode 92, a second voltage doubler diode 94, a first voltage doubler capacitor 96, and a second voltage doubler capacitor 98. The first voltage doubler diode 92 and the second voltage doubled diode 94 are connected in series. The first voltage doubler capacitor 96 and the second voltage doubler capacitor 98 are connected in series. A circuit composed of a first voltage doubler diode 92 and a second voltage doubler diode 94 is connected in parallel with a circuit composed of a first voltage doubler capacitor 96 and a second voltage doubler capacitor 98. One end of the secondary winding 26 of the transformer 20 is connected between the first voltage doubler diode 92 and the second voltage doubler diode 94, and the other end is connected between the first voltage doubler capacitor 96 and the second voltage doubler capacitor 98. In addition, transformer 20 also includes a filament winding 21 wound around a filament winding slot 286, which may be connected to an electrical load, such as microwave generator 200. The microwave generator 200 can be a magnetron. Secondary winding slot 284 is located between filament winding slot 286 and primary winding slot 282.

Referring to FIG. 1 and FIG. 6 , the microwave cooking appliance 1000 of the embodiment of the present application includes the power supply device 100 of any of the above embodiments and the microwave generator 200 , and the power supply device 100 is connected to the microwave generator 200 .

The microwave cooking appliance 1000 of the embodiment of the present application can provide a stable operating voltage to the control module 40 by adding the auxiliary winding 24 on the primary side of the transformer 20. At the same time, the control module 40 can compare the voltage of the reference voltage and the auxiliary winding 24. As a result, the on/off of the switch module 30 is controlled. Since the opposite ends of the auxiliary winding 24 are relatively low voltage, only a small resistance is used to divide the voltage, thereby reducing the safety distance between the lines. In this way, the cost of the power supply device 100 is reduced and the size of the power supply device 100 can be further reduced.

It can be understood that the filament winding 21 of the transformer 20 is connected to the microwave generator 200. Specifically, the microwave generator 200 may be a magnetron. A magnetron is an electrical vacuum device used to generate microwave energy. The electrons in the magnetron interact with the high-frequency electromagnetic field under the control of a constant magnetic field and a constant electric field perpendicular to each other, and convert the energy obtained from the output power of the power supply device 100 into microwave energy, thereby achieving the purpose of generating microwave energy. .

Specifically, the microwave cooking appliance 1000 further includes a cavity 300, a door body (not shown) and a fan 400. A tray 500 is disposed in the cavity 300. The tray 500 is used for placing food to be heated, and the door body is rotatably disposed in front of the cavity 300 for opening or closing the opening of the cavity 300, the microwave generator 200 and the power supply device 100. It is installed outside the cavity 300 and is disposed in the blowing direction of the fan 400. When the microwave cooking appliance 1000 is in operation, the power supply device 100 supplies an operating current to the microwave generator 200, and the microwave generator 200 generates microwave energy for heating the food in the cavity 300. At the same time, the fan 400 can absorb the air from the outside and form a gas flow, the air flow can be conducted through the air channel in the power supply device 100, and the power supply device 100 is cooled and cooled. After the power supply device 100 is cooled, the air flow can be re-energized from the power supply device. 100 is discharged to the outside of the microwave cooking appliance 1000.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example" or "some examples", etc. Specific features, structures, materials, or characteristics described in the manner of example or example are included in at least one embodiment or example of the application. In the present specification, the schematic representation of the above terms does not necessarily mean the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

Any process or method description in the flowcharts or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a particular logical function or process. And the scope of the preferred embodiments of the present application includes additional implementations, in which the functions may be performed in a substantially simultaneous manner or in the reverse order depending on the functions involved, in accordance with the illustrated or discussed order. It will be understood by those skilled in the art to which the embodiments of the present application pertain.

The logic and/or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be embodied in any computer readable medium, Used in conjunction with, or in conjunction with, an instruction execution system, apparatus, or device (eg, a computer-based system, a system including a processing module, or other system that can fetch instructions and execute instructions from an instruction execution system, apparatus, or device) Or use with equipment. For the purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport a program for use in an instruction execution system, apparatus, or device, or in conjunction with the instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer readable media include the following: electrical connections (control methods) having one or more wires, portable computer disk cartridges (magnetic devices), random access memory (RAM), Read only memory (ROM), erasable editable read only memory (EPROM or flash memory), fiber optic devices, and portable compact disk read only memory (CDROM). In addition, the computer readable medium may even be a paper or other suitable medium on which the program can be printed, as it may be optically scanned, for example by paper or other medium, followed by editing, interpretation or, if appropriate, other suitable The method is processed to obtain the program electronically and then stored in computer memory.

It should be understood that portions of the embodiments of the present application can be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or combination of the following techniques well known in the art: having logic gates for implementing logic functions on data signals. Discrete logic circuits, application specific integrated circuits with suitable combinational logic gates, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

One of ordinary skill in the art can understand that all or part of the steps carried by the method of implementing the above embodiments can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium. When executed, one or a combination of the steps of the method embodiments is included.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. The integrated modules, if implemented in the form of software functional modules and sold or used as stand-alone products, may also be stored in a computer readable storage medium.

The above mentioned storage medium may be a read only memory, a magnetic disk or an optical disk or the like.

While the embodiments of the present application have been shown and described above, it is understood that the foregoing embodiments are illustrative and are not to be construed as limiting the scope of the present application. Implementations are subject to change, modification, substitution, and variation.

Claims

A power supply device, comprising:

a rectifier module for connecting an AC source;

a transformer connected to the rectifier module, the transformer comprising a primary winding and an auxiliary winding, the auxiliary winding being connected to a primary side of the transformer;

a switch module, the switch module being disposed to provide an on/off signal to the transformer;

Connecting a control module of the switch module, the control module being configured to control on and off of the switch module according to a comparison result of a reference voltage and a voltage of the auxiliary winding;

a power supply module, the power supply module connecting the auxiliary winding and the control module, and being disposed to supply power to the control module by using electrical energy provided by the auxiliary winding.
The power supply apparatus according to claim 1, wherein said rectifying module comprises a full-wave rectifying circuit composed of four diodes.
The power supply apparatus according to claim 1, wherein said rectifying module is configured to convert an alternating current voltage generated by said alternating current source into a direct current voltage.
The power supply apparatus according to claim 1, wherein said power supply means comprises a filter module, and said filter module is connected to said rectifier module and said transformer.
The power supply apparatus according to claim 1, wherein said switch module comprises a switch tube and a resonance capacitor.
The power supply apparatus according to claim 1, wherein a ratio of turns of said auxiliary winding to said primary winding is 1:N; wherein N is greater than 10 and less than 25.
A power supply apparatus according to claim 1, wherein said transformer comprises a bobbin holder, said bobbin holder being provided with a single primary winding groove, said auxiliary winding and said primary winding being wound at said primary Winding groove.
The power supply apparatus according to claim 1, wherein said power supply means comprises a sampling module, said control module comprises a synchronization detecting module and a controller, said sampling module is connected to said auxiliary winding and said synchronous detecting module, The sampling module is disposed to detect a voltage of the auxiliary winding, the synchronization detecting module is configured to compare the reference voltage and a voltage of the auxiliary winding, and the controller is disposed according to the reference voltage and the The comparison result of the voltage of the auxiliary winding controls the on and off of the switching module.
The power supply apparatus according to claim 8, wherein said synchronization detecting module comprises a comparator, said sampling module comprising a first resistor and a second resistor, said first resistor being connected in series with said second resistor and connected The two ends of the auxiliary winding, the positive input end of the comparator is connected between the first resistor and the second resistor, and the negative input end of the comparator is connected to the other end of the second resistor, The output of the comparator is connected to the controller.
The power supply apparatus according to claim 1, wherein said power supply module comprises a rectifying unit and said stabilizing unit, said rectifying unit is connected to said auxiliary winding, said stabilizing unit is connected to said rectifying unit and said control a module, the voltage stabilizing unit being arranged to provide at least two different operating voltages to the control module.
The power supply apparatus according to claim 10, wherein said voltage stabilizing unit comprises a first voltage regulator and a second voltage regulator, said first voltage regulator being connected to said rectifying unit, said second stable a voltage regulator and the control module, the second voltage regulator is connected to the first voltage regulator and the control module, the first voltage regulator is arranged to provide a first voltage to the control module, The second voltage regulator is configured to provide the control module with a second voltage that is less than the first voltage.
The power supply apparatus according to claim 11, wherein said control module comprises a controller and a drive module, said drive module is connected to said controller, said switch module and said power supply module, said power supply module being Provided to provide the second voltage to the controller, and to provide the first voltage to the drive module.
The power supply apparatus according to claim 11, wherein said first voltage regulator comprises an 18V voltage regulator.
The power supply apparatus according to claim 11, wherein said second regulator comprises a three-terminal regulator.
The power supply apparatus according to claim 10, wherein said power supply module includes a step-down resistor, and said step-down resistor is connected between said rectifying unit and said voltage stabilizing unit.
A power supply apparatus according to claim 1, wherein said transformer comprises a secondary winding, said power supply means comprises a voltage doubler rectifier module, said voltage doubler rectifier module is connected to said secondary winding, said voltage doubler rectification The module is arranged to increase the output voltage of the transformer.
The power supply device according to claim 1, wherein said voltage doubler rectifier module comprises a first voltage doubler diode, a second voltage doubled diode, a first voltage doubled capacitor and a second voltage doubled capacitor, said first multiple a voltage diode and the second voltage doubler diode are connected in series, the first voltage doubled capacitor and the second voltage doubled capacitor are connected in series, and the first voltage doubled diode and the second voltage doubled diode comprise a circuit and a circuit The circuit composed of the first voltage doubler capacitor and the second voltage doubler capacitor is connected in parallel.
A microwave cooking appliance characterized by comprising the power supply device according to any one of claims 1 to 17 and a microwave generator, the power supply device being connected to the microwave generator.
A microwave cooking appliance according to claim 18, wherein said microwave cooking appliance comprises a cavity, a door body and a fan, said door body being rotatably disposed in front of said cavity and for opening or closing said said An opening of the cavity, the fan is configured to cool and cool the power supply device.
A microwave cooking apparatus according to claim 19, wherein said microwave generator and said power supply means are mounted outside said cavity and disposed in a blowing direction of said fan.