CN211525158U

CN211525158U - Centrifugal fan and cigarette machine

Info

Publication number: CN211525158U
Application number: CN201921849742.6U
Authority: CN
Inventors: 陈建平
Original assignee: Zhejiang Shaoxing Supor Domestic Electrical Appliance Co Ltd
Current assignee: Zhejiang Shaoxing Supor Domestic Electrical Appliance Co Ltd
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2020-09-18
Anticipated expiration: 2029-10-30

Abstract

The utility model provides a centrifugal fan and cigarette machine for cigarette machine. This centrifugal fan includes power supply circuit, induction coil, at least partly by the wind wheel of iron-containing material making, the motor that is used for driving the wind wheel and the motor drive circuit who is used for driving motor, induction coil sets up to make the wind wheel be located the magnetic field that induction coil circular telegram back produced, wherein, centrifugal fan still includes: the main control component is connected with the power supply circuit and used for intermittently generating and outputting a power supply signal lasting for a first time period under the condition that the power supply circuit supplies power; an electromagnetic heating control assembly connected between the main control assembly and the induction coil for controlling the passage of the alternating current through the induction coil based on the power supply signal. The centrifugal fan utilizes electromagnetic induction to cause the wind wheel to heat, the heating mode is high in efficiency, and oil stains can be quickly and effectively melted to achieve the purpose of cleaning the oil stains. In addition, the heating mode is efficient and energy-saving, and the production cost can be reduced.

Description

Centrifugal fan and cigarette machine

Technical Field

The utility model relates to a kitchen utensil's technical field specifically, relates to a centrifugal fan and cigarette machine.

Background

In recent years, as the technology of integrated cooker products advances, the demand of users for integrated cookers is also increasing. The user not only has higher and higher requirement to the clean oil smoke function of integrated kitchen, still rinses integrated kitchen simultaneously, greasy dirt handles and also attaches more and more attention to.

In the prior art, an integrated cooker is generally provided with a deoiling device, but if the integrated cooker is used for a long time, a large amount of oil stains still can be accumulated in a fan box, so that the integrated cooker is difficult to clean and has fire hazard. Therefore, steam washing and resistance radiation heating are available in the market, and oil removal and heating are performed on the steam washing and resistance radiation heating. To a great extent, the use of the user is facilitated, and the service life is prolonged.

Although the above cleaning methods can clean the oil stains in the fan box to a certain extent, they have respective disadvantages. The steam washing mode is that the oil stain is heated on the surface of the oil stain by means of the heat of steam, the whole oil is difficult to dissolve, and part of the oil is remained in the fan box, so that the oil stain is not thoroughly washed and the time spent is long. In addition, steam cleaning also needs to additionally provide a water path system in the integrated cooker, resulting in a complex structure of the integrated cooker. Although the resistance radiation heating does not need to additionally arrange a waterway system, the thermal efficiency of the resistance radiation heating is only about 60%, the energy consumption is very high, and the resistance radiation heating is not beneficial to energy conservation and environmental protection.

SUMMERY OF THE UTILITY MODEL

To at least partially solve the problems in the prior art, there is provided a centrifugal fan for a cigarette making machine, comprising a power supply circuit, an induction coil, a wind wheel at least a part of which is iron, a motor for driving the wind wheel, and a motor driving circuit for driving the motor, the induction coil being arranged to locate the wind wheel within a magnetic field generated by energization of the induction coil, wherein the centrifugal fan further comprises:

the main control component is connected with the power supply circuit and used for intermittently generating and outputting a power supply signal lasting for a first time period under the condition that the power supply circuit supplies power;

an electromagnetic heating control assembly connected between the main control assembly and the induction coil for controlling an alternating current through the induction coil based on the power supply signal.

The utility model provides a centrifugal fan adopts electromagnetic heating's mode to melt the greasy dirt, because electromagnetic heating's thermal efficiency is higher (can reach 95% the highest), consequently can melt the greasy dirt fast effectively, plays the purpose of clearance greasy dirt. In addition, compared with a steam washing or resistance heating mode, the electromagnetic heating mode has a simple structure and is low in use cost. And the induction coil which is responsible for heating does not generate heat, so that the service life is long, and the later maintenance cost can be reduced. Finally, in the scheme, the wind wheel is heated at intervals based on the control of the power supply signal on the electromagnetic heating control assembly, so that the cleanness of the cigarette machine is ensured, and the energy consumption is saved.

Illustratively, the master control assembly includes:

a control circuit for generating a control signal; and

a relay for intermittently outputting the power supply signal to the electromagnetic heating control assembly based on the control signal.

By utilizing the relay, a desired power supply signal can be flexibly output based on the control signal so as to supply power to the electromagnetic heating control assembly at a proper time, and the reliability is high. In addition, the relay has low cost and easy switch control.

Illustratively, the control circuit includes:

the first timer is used for timing the system time to generate a first timing signal;

and the first control chip is used for generating the control signal based on the first timing signal.

The system time is time irrelevant to any operation of the cigarette machine, and is automatically timed by the first timer and generates a timing signal so that the first control chip can generate a control signal based on the timing signal. Thus, misoperation is avoided, and the reliability of the cleaning work of the centrifugal fan is improved.

Illustratively, the control circuit includes:

the second timer is used for timing the working time of the cigarette machine so as to generate a second timing signal;

and the second control chip is used for generating the control signal based on the second timing signal.

Through the second timer, the using time of the cigarette machine can be counted in an accumulated mode, and a timing signal is automatically generated to be used for the second control chip to generate a control signal based on the timing signal. According to the technical scheme, the wind wheel is automatically cleaned only when the range hood is dirty, so that the wind wheel is kept clean, and unnecessary cleaning work is avoided.

Illustratively, the main control component is connected with the motor driving circuit and is further used for driving and controlling the motor through the motor driving circuit, wherein when the main control component outputs the power supply signal, the power supply frequency of the motor is a constant value lower than a frequency threshold value; and in a second time period after the main control assembly stops outputting the power supply signal, the main control assembly is specifically used for driving the motor to alternately execute a forward rotation mode and a reverse rotation mode.

The main control assembly is connected with the motor driving circuit, so that the overall control of the centrifugal fan can be facilitated, and control errors are avoided. In the heating process of the wind wheel, the wind wheel is driven to rotate at a low speed and a uniform speed, so that the wind wheel can be heated uniformly, and oil stains on each part of the wind wheel can be melted. After the wind wheel is heated, the wind wheel is rotated back and forth, oil stains dissolved by heating are thrown away more favorably, and the oil removal effect is improved.

Illustratively, the motor drive circuit and the main control assembly are integrated on one circuit board.

The motor driving circuit and the main control assembly are integrated on one circuit board, so that the motor driving circuit and the main control assembly are convenient to install, and the assembly cost and the later maintenance cost are reduced.

According to another aspect of the present invention, there is also provided a cigarette making machine, wherein the cigarette making machine comprises: the centrifugal fan is provided.

Based on foretell centrifugal fan's automation, high-efficient degreasing function, the cigarette machine can reduce user's maintenance cost, improves user experience.

A series of concepts in a simplified form are introduced in the disclosure, which will be described in further detail in the detailed description section. The summary of the invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

The advantages and features of the present invention are described in detail below with reference to the accompanying drawings.

Drawings

The following drawings of the present invention are used herein as part of the present invention for understanding the present invention. There are shown in the drawings, embodiments and descriptions thereof, which are used to explain the principles of the invention. In the drawings, there is shown in the drawings,

fig. 1 is a block diagram schematically illustrating a centrifugal fan according to an exemplary embodiment of the present invention;

fig. 2 is a perspective view of a centrifugal fan according to an exemplary embodiment of the present invention.

Wherein the figures include the following reference numerals:

110. a power supply circuit; 120. a main control assembly; 130. an electromagnetic heating control assembly; 140. an induction coil; 150. a motor drive circuit; 160. a motor; 170. a wind wheel; 180. a volute.

Fig. 3 is a block diagram schematically illustrating a centrifugal fan according to another exemplary embodiment of the present invention. Wherein the figures include the following reference numerals:

310. a power supply circuit; 320. a main control assembly; 321. a control circuit; 322. a relay; 330. An electromagnetic heating control assembly; 340. an induction coil; 370. and a wind wheel.

Fig. 4 is a block diagram schematically illustrating a centrifugal fan according to still another exemplary embodiment of the present invention. Wherein the figures include the following reference numerals:

410. a power supply circuit; 420. a main control assembly; 421. a control circuit; 422. a relay; 423. A first control chip; 424. a first timer; 430. an electromagnetic heating control assembly; 440. an induction coil; 470. and a wind wheel.

Fig. 5 is a block diagram schematically illustrating a centrifugal fan according to still another exemplary embodiment of the present invention. Wherein the figures include the following reference numerals:

510. a power supply circuit; 520. a main control assembly; 521. a control circuit; 522. a relay; 523. A second control chip; 524. a second timer; 530. an electromagnetic heating control assembly; 540. an induction coil; 570. and a wind wheel.

Detailed Description

In the following description, numerous details are provided to provide a thorough understanding of the present invention. One skilled in the art, however, will understand that the following description illustrates only a preferred embodiment of the invention and that the invention may be practiced without one or more of these details. In addition, some technical features that are well known in the art are not described in detail in order to avoid obscuring the present invention.

As described above, the conventional heating device for removing oil stains from the wind wheel has low heating efficiency, and is not suitable for long-term safe and stable operation because the heating device is easy to age due to heat generated by the heating device. From this, a centrifugal fan for cigarette machine of this application adopts the electromagnetic induction heating mode, and not only heating efficiency is high, but also can reduce the later maintenance cost, attracts the user to purchase. Fig. 1 is a block diagram illustrating a centrifugal fan 100 according to an exemplary embodiment of the present invention. As shown in FIG. 1, the centrifugal fan 100 includes a power circuit 110, a main control assembly 120, an electromagnetic heating control assembly 130, an induction coil 140, a motor drive circuit 150, a motor 160, and a wind wheel 170.

The power circuit 110 may be connected to the main control module 120 and the motor driving circuit 150, respectively, to supply power to the main control module 120 and the motor driving circuit 150, respectively.

The motor driving circuit 150 is connected to the motor 160, and the motor driving circuit 150 is configured to output a control signal to drive the motor 160 to move. When the motor 160 moves, the wind wheel 170 is driven to move correspondingly, and accordingly cooking oil smoke can be sucked away.

The main control assembly 120 is connected to the electromagnetic heating control assembly 130, and the electromagnetic heating control assembly 130 is connected to the induction coil 140. The main control component 120 is used for intermittently generating and outputting a power supply signal lasting for a first time period when the power supply circuit 110 supplies power. It will be understood by those skilled in the art that the main control component 120 may be implemented by any existing chip or circuit, as long as it can generate and output the above power supply signal, and the present application is not limited thereto. The power signal is output to the electromagnetic heating control assembly 130 to power the electromagnetic heating control assembly 130.

The electromagnetic heating control assembly 130 is connected to an induction coil 140, the electromagnetic heating control assembly 130 being configured to control an alternating current through the induction coil 140 based on a power supply signal. Whereby the induction coil 140 generates an alternating magnetic field based on the alternating current. The alternating current may be a high frequency alternating current. When a power signal is present to power the electromagnetic heating control assembly 130, the electromagnetic heating control assembly 130 controls an alternating current through the induction coil 140; otherwise, no alternating current passes through the induction coil 140.

At least a portion of the wind wheel 170 is ferrous, i.e., made of a ferrous material, to form an electromagnetic heating portion. The ferrous material may be stainless steel, plain carbon steel, or the like.

The wind wheel 170 is not directly connected with the induction coil 140, and the wind wheel 170 is positioned in the magnetic field generated after the induction coil 140 is electrified. Wherein at least a portion of the wind wheel 170 is made of a ferrous material. It is thereby possible to utilize the principle of electromagnetic induction of ferrous material, in case the magnetic field generated by the induction coil 140 is an alternating magnetic field, the lines of force of said magnetic field generating strong eddy currents when passing through at least a part of the wind rotor 170 made of ferrous material. The eddy current makes the free electrons in the wind wheel 170 move randomly at a high speed, causing atoms therein to collide and rub against each other to generate heat energy. Since electromagnetic heating causes the iron-containing material to generate heat, the heat conversion rate is particularly high, and can reach 95% at most. Thereby causing the wind wheel 170 to rapidly heat itself. The heat generated by the wind wheel 170 can be directly transferred to the oil stain attached to the wind wheel 170, so that the oil stain can be rapidly melted, and the purpose of cleaning the oil stain is achieved.

Fig. 2 is a perspective view of centrifugal fan 100 according to an exemplary embodiment of the present invention. As shown in fig. 2, the centrifugal fan 100 includes an induction coil 140, a scroll 180, and a wind wheel 170. The induction coil 140 is fixed on the volute 180, the wind wheel 170 is arranged inside the volute 180, negative pressure is generated inside the volute 180 through the rotation of the wind wheel 170 inside the volute 180, and oil smoke is sucked into the volute 180 from the inlet and is discharged from the outlet. It can be understood that the wind wheel 170 of the centrifugal fan 100 sucks away oil smoke generated by cooking through rotation, oil particles can adhere to the wind wheel 170 in the process of sucking away the oil smoke, and after the wind wheel 170 works for a period of time, for example, about one month or 60 hours of cumulative work, a layer of oil stain can be formed on the wind wheel 170, and the oil stain needs to be cleaned in time.

The main control assembly 120 intermittently generates and outputs a power supply signal to the electromagnetic heating control assembly 130. The intermittent nature may refer to discrete, intermittent periods of time. The wind wheel 170 may be operated for a period of time, such as one month, to complete the operation of sucking away the oil smoke. During this operating period (one month), the main control component 120 does not generate a power supply signal. The main control module 120 may generate and output a power supply signal lasting for a first time period after the wind wheel 170 operates for a certain time period, so as to start the related modules to operate, thereby achieving the purpose of cleaning the wind wheel 170.

The first time period refers to the duration of the power supply signal. The electromagnetic heating control assembly 130, in the presence of said power supply signal, is able to control the alternating circuit through the induction coil 140, whereby the wind rotor 170 itself may be caused to heat up. Because the wind wheel 170 generates heat quickly and efficiently under the action of the alternating magnetic field of the induction coil 140, the working time of the induction coil 140 does not need to be too long. In particular, the first period of time may be any value between 20 seconds and 3 minutes.

The utility model provides a centrifugal fan adopts electromagnetic heating's mode to melt the greasy dirt, because electromagnetic heating's thermal efficiency is higher, consequently can melt the greasy dirt fast effectively, plays the purpose of clearance greasy dirt. In addition, compared with a steam washing or resistance heating mode, the electromagnetic heating mode has a simple structure and is low in use cost. Finally, in the scheme, the wind wheel is heated at intervals based on the control of the power supply signal on the electromagnetic heating control assembly, so that the cleanness of the cigarette machine is ensured, and the energy consumption is saved.

Illustratively, the main control assembly 120 is connected to a motor drive circuit 150 and is also used to control a motor 160 via the motor drive circuit 150. The main control assembly is connected with the motor driving circuit, so that the overall control of the centrifugal fan can be facilitated, and control errors are avoided.

When the main control component 120 outputs the power supply signal, the power frequency of the motor 160 is a constant value lower than a frequency threshold. It is understood that the frequency threshold may be a preset value. The reduction of the power frequency of the motor 160 may cause the rotation speed of the motor 160 to be reduced, and those skilled in the art can understand the implementation principle of the motor 160, which will not be described herein.

It is understood that, as described above, when the main control assembly 120 outputs the power supply signal, the electromagnetic heating control assembly 130 controls the alternating current to pass through the induction coil 140 based on the power supply signal, so that the induction coil 140 generates the alternating magnetic field, causing the wind rotor 170 to automatically heat in the alternating magnetic field. Since the portion of the rotor 170 near the induction coil 140 heats up faster than the portion far from the induction coil 140, the rotor 170 heats up unevenly. The power frequency of the motor 160 may be controlled to a constant value lower than the frequency threshold based on the motor driving circuit 150 when the main control module 120 outputs the power supply signal, so that the motor 160 rotates at a constant speed at a low speed. Such as 30 revolutions per minute. The motor 160 rotates at a low speed and a constant speed to drive the wind wheel 170 to rotate at the same low speed and the constant speed. Whereby the wind wheel 170 can be heated uniformly by itself. It is advantageous to melt and clean the oil dirt of each portion on the wind wheel 170.

In a second time period after the main control component 120 stops outputting the power supply signal, the main control component 120 is specifically configured to drive the motor 160 to alternately execute a forward rotation mode and a reverse rotation mode.

After the wind wheel 170 is heated, that is, after the oil stain on the wind wheel 170 is melted, the main control module 120 may stop outputting the power supply signal, that is, the operation of heating the wind wheel 170 is not performed any more. At this time, although the oil stain on the wind wheel 170 has been melted, most of it may be still adhered to the wind wheel 170. In order to smoothly discharge the oil smoke, in a second time period after the main control module 120 stops outputting the power supply signal, the main control module 120 outputs a control signal to the motor driving circuit 150 for controlling the motor driving circuit 150 to drive the motor 160 to alternately perform forward rotation and reverse rotation, so that the wind wheel 170 can be rotated back and forth, and the oil stain dissolved by heating can be conveniently thrown out. The second time period may be a preset time. For the oil to be thrown clean, it may last for a little longer, such as 2 to 3 minutes.

In the heating process of the wind wheel 170, the wind wheel 170 is driven to rotate at a low speed and a constant speed, so that the wind wheel 170 can be heated uniformly, and oil stains on each part of the wind wheel 170 can be melted. After the wind wheel 170 is heated, the wind wheel 170 is rotated repeatedly, so that oil stains dissolved by heating can be thrown away more favorably, and the oil removing effect is improved.

Illustratively, the motor drive circuit 150 and the main control assembly 120 are integrated on one circuit board. The motor driving circuit 150 and the main control assembly 120 are integrated on one circuit board, so that the installation is convenient, and the assembly cost and the later maintenance cost are reduced.

Fig. 3 is a block diagram illustrating a centrifugal fan 300 according to another exemplary embodiment of the present invention. The centrifugal fan 300 includes a power circuit 310, a primary control assembly 320, an electromagnetic heating control assembly 330, an induction coil 340, and a wind wheel 370. Wherein the power circuit 310, the electromagnetic heating control assembly 330, the induction coil 340 and the wind wheel 370 are similar in function and structure to the power circuit 110, the electromagnetic heating control assembly 130, the induction coil 140 and the wind wheel 370 of the centrifugal fan 100, respectively. For brevity, no further description is provided. Centrifugal fan 300 also includes a motor drive circuit 350 and a motor 360. Both of which function similarly to motor drive circuit 150 and motor 160, respectively, in centrifugal fan 100. In the centrifugal fan 300, however, the motor drive circuit 150 is directly connected to the power supply circuit 310 to be directly supplied with power from the power supply circuit 310.

Illustratively, the main control assembly 320 includes a control circuit 321 and a relay 322.

As shown in fig. 3, the control circuit is connected to the power circuit 310 and the relay 322, respectively, the power circuit 310 is used for supplying power to the control circuit 321, and the control circuit 321 is used for generating a control signal.

The relay 322 is respectively connected with the control circuit 321 and the electromagnetic heating control assembly 330, and the relay 322 is used for intermittently outputting the power supply signal to the electromagnetic heating control assembly 330 based on the control signal generated by the control circuit 321.

Here, it is possible to flexibly control to output a desired power supply signal based on the control circuit 321 and the relay 322 to supply power to the electromagnetic heating control assembly 330 at an appropriate time, and reliability is high. In addition, the relay has low cost and easy switch control.

Fig. 4 is a block diagram illustrating a centrifugal fan 400 according to still another exemplary embodiment of the present invention. The centrifugal fan 400 includes a power circuit 410, a main control assembly 420, an electromagnetic heating control assembly 430, an induction coil 440, a motor drive circuit 450, a motor 460, and a fan wheel 470. The main control assembly 420 includes a control circuit 421 and a relay 422. The power circuit 410, the relay 422, the electromagnetic heating control assembly 430, the induction coil 440, the motor drive circuit 450, the motor 460, and the wind wheel 470 are functionally and structurally similar to the power circuit 310, the relay 322, the electromagnetic heating control assembly 330, the induction coil 340, the motor drive circuit 350, the motor 360, and the wind wheel 370, respectively, of the centrifugal fan 300. For brevity, no further description is provided.

Illustratively, the control circuit 420 includes: a first timer 424 and a first control chip 423.

The first timer 424 is used for timing the system time to generate a first timing signal. The first timer 424 starts counting when the power circuit 410 starts supplying power. The first timing signal may be a periodic time signal. In one example, the first timing signal is low since the start of timing. When the timing reaches a first timing threshold, the first timing signal transitions to a high level. The first timing threshold is a preset time period, such as 30 days. The first timing signal remains high for a first period of time, such as 1 minute, and then goes low again. Then the timing is restarted and so on.

As described above, generally, after the centrifugal fan 400 starts to supply power for about one month, a layer of oil stains is formed on the wind wheel 470, and needs to be cleaned in time. The timing may be performed based on the first timer, and the first timing signal may be generated after the timing reaches approximately one month. A self-cleaning control signal for the centrifugal fan 400 can be generated based on the first timing signal for the centrifugal fan to start the self-cleaning function.

The first control chip 423 is connected to the power supply circuit 410 and the relay 422, respectively, in addition to the first timer. The power circuit 410 is configured to supply power to the first control chip 423, and the first control chip 423 is configured to generate a control signal based on the first timing signal. Since the first timing signal is a periodic signal, the control signal is also a periodic signal. Based on the periodic control signal, the first control chip 423 controls the relay 422 to perform a periodic action.

The system time is a time that is not relevant to any operation of the cigarette machine, and is automatically timed by the first timer 424 and generates a timing signal for the first control chip 423 to generate a control signal based on the timing signal. Thus, misoperation is avoided, and the reliability of the cleaning work of the centrifugal fan is improved.

Fig. 5 is a block diagram schematically illustrating a centrifugal fan 500 according to another exemplary embodiment of the present invention. The centrifugal fan 500 includes a power circuit 510, a main control assembly 520, an electromagnetic heating control assembly 530, an induction coil 540, a motor drive circuit 550, a motor 560, and a wind wheel 570. The main control assembly 520 includes a control circuit 521 and a relay 522. The power circuit 510, the relay 522, the electromagnetic heating control assembly 530, the induction coil 540, the motor drive circuit 550, the motor 560, and the wind wheel 570 are similar in function and structure to the power circuit 310, the relay 322, the electromagnetic heating control assembly 330, the induction coil 340, the motor drive circuit 350, the motor 360, and the wind wheel 370, respectively, of the centrifugal fan 300. For brevity, no further description is provided.

Illustratively, the control circuit 521 includes: a second timer 524 and a second control chip 523.

The second timer 524 is used to time the operating time of the cigarette maker to generate a second timing signal. It will be appreciated that the operation of a range hood is to draw away cooking fumes. The second timer 524 counts the time when the cigarette maker starts to work, and stops counting the time when the cigarette maker stops working, so that the second timer 524 can record the accumulated working time of the cigarette maker. The second timing signal may be a pulse signal. Whenever the timing reaches the second timing threshold, the second timing signal transitions to a high level of short duration, and the second timer 524 restarts timing, and so on. The second timing threshold is, for example, 60 hours.

The second control chip 523 is connected to the second timer 524, and is also connected to the power circuit 510 and the relay 522, wherein the power circuit 510 is configured to supply power to the second control chip 523, and the second control chip 523 is configured to generate a control signal based on the second timing signal. Based on the control signal, the second control chip 523 controls the relay to perform a corresponding action.

Through the second timer 524, the using time of the cigarette machine can be cumulatively timed, and a timing signal is automatically generated for the second control chip 523 to generate a control signal based on the timing signal. According to the technical scheme, the wind wheel is automatically cleaned only when the range hood is dirty, so that the wind wheel is kept clean, and unnecessary cleaning work is avoided.

According to another aspect of the present invention, there is also provided a cigarette making machine, wherein the cigarette making machine comprises: the centrifugal fan 100 described above.

Based on the above-mentioned centrifugal fan 100's automatic, high-efficient degrease function, the cigarette machine can reach automatic, high-efficient degrease function, can reduce user's maintenance cost, improves user experience.

In the description of the present invention, it is to be understood that the term "connected" may include direct connection or indirect connection. Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe the spatial relationship of one or more components or features shown in the figures to other components or features. It is to be understood that the spatially relative terms are intended to encompass not only the orientation of the component as depicted in the figures, but also different orientations of the component in use or operation. For example, if an element in the drawings is turned over in its entirety, the articles "over" or "on" other elements or features will include the articles "under" or "beneath" the other elements or features. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". Further, these components or features may also be positioned at various other angles (e.g., rotated 90 degrees or other angles), all of which are intended to be encompassed herein.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, elements, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The present invention has been described in terms of the above embodiments, but it is to be understood that the above embodiments are for purposes of illustration and description only and are not intended to limit the invention to the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many more modifications and variations are possible in light of the teaching of the present invention and are within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A centrifugal fan for a range hood, comprising a power supply circuit, an induction coil, a wind wheel, a motor for driving the wind wheel, and a motor drive circuit for driving the motor, the wind wheel being at least partially ferrous, the induction coil being arranged such that the wind wheel is located within a magnetic field generated by energizing the induction coil, the centrifugal fan further comprising:

2. The centrifugal fan of claim 1, wherein the main control assembly comprises:

a control circuit for generating a control signal; and

3. The centrifugal fan of claim 2, wherein the control circuit comprises:

4. The centrifugal fan of claim 2, wherein the control circuit comprises:

5. The centrifugal fan of claim 1, wherein the main control assembly is connected to the motor drive circuit and is further configured to drive the motor through the motor drive circuit, wherein a power supply frequency of the motor is a constant value below a frequency threshold when the main control assembly outputs the power supply signal; and in a second time period after the main control assembly stops outputting the power supply signal, the main control assembly is specifically used for driving the motor to alternately execute a forward rotation mode and a reverse rotation mode.

6. The centrifugal fan of claim 5, wherein the motor drive circuit and the main control assembly are integrated on a single circuit board.

7. A range hood, characterized in that said range hood comprises: a centrifugal fan according to any one of claims 1 to 6.