Refrigerator and fan rotating speed control method thereof

Abstract

According to the refrigerator and the fan rotating speed control method thereof, the input voltage of a control panel to a fan power source can be automatically adjusted, when it is found that the voltage of the control panel power source is reached and the fan rotating speed does not reach the target rotating speed, a booster circuit is automatically started for control, and the input voltage of the fan can exceed the power source voltage of the control panel; the rotating speed of the fan exceeds the rated rotating speed.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigerators, and in particular to a refrigerator and a method for controlling the speed of a fan thereof. Background Art

[0002] The fan speed is the rated speed under the rated voltage, and the rated voltage of the fan is often the power supply voltage of the control board. To control the change of the fan speed, the circuit adjusts the change of the input voltage at the fan end. The higher the expected fan speed, the higher the voltage output to the fan by the control board. However, the maximum adjustment of the fan output voltage can only reach the rated voltage of the control board, so the maximum speed of the fan can only reach the rated speed, while the actual fan power supply voltage can exceed the rated voltage value within a certain range, and the fan input voltage can be increased to obtain a higher fan speed. In order to increase the speed of the fan, there are two solutions: the first is to design a new fan and increase its speed under the rated voltage, but this will lead to an increase in the number of fan types, poor generalization, and easy installation errors on site; the second is to increase the power supply voltage of the control board, but because the power supply voltage of the control board is higher than that of the damper, LED light, relay, etc., increasing this voltage will increase the energy consumption of the control board under normal operation, resulting in an increase in the energy consumption of the entire machine, and the power supply cost of the control board will also increase significantly. Summary of the invention

[0003] The purpose of the embodiment of the present invention is to provide a refrigerator and a method for controlling the fan speed thereof, which can automatically adjust the input voltage of the control board to the fan power supply. When it is found that the voltage of the control board power supply is reached and the fan speed has not reached the target speed, the boost circuit control is automatically started, which can increase the input voltage of the fan to exceed the power supply voltage of the control board, thereby achieving the purpose of using the fan speed exceeding the rated speed.

[0004] To achieve the above object, an embodiment of the present invention provides a refrigerator, comprising:

[0005] a box body, in which a storage chamber and an air duct are formed;

[0006] A door, used for opening and closing the storage room;

[0007] A fan, arranged in the air duct, is used to allow air to enter the evaporator in the refrigerator for heat exchange and send the heat-released air to the storage chamber, and the fan is provided with a voltage control terminal, a feedback signal output terminal and a ground terminal;

[0008] A control board, composed of a single-chip microcomputer and a peripheral circuit, for controlling the speed of the fan, wherein the single-chip microcomputer is provided with a first PWM output terminal, a second PWM output terminal and a feedback signal receiving terminal, wherein the first PWM output terminal and the second PWM output terminal are respectively connected to the voltage control terminal through the peripheral circuit, and the feedback signal receiving terminal is connected to the feedback signal output terminal through the peripheral circuit;

[0009] The control board is configured to:

[0010] When it is detected that the fan is started and is running at a rated voltage, a target speed of the fan is obtained;

[0011] adjusting the PWM duty cycle to be output by the first PWM output terminal according to the target speed, and controlling the first PWM output terminal to output a pulse control signal to the voltage control terminal;

[0012] When the PWM duty cycle of the first PWM output terminal reaches 100%, obtaining the actual rotation speed of the fan received by the feedback signal receiving terminal;

[0013] When the actual speed does not reach the target speed, the second PWM output end is controlled to output a pulse control signal to the voltage control end.

[0014] As an improvement of the above solution, the control board is further configured as follows:

[0015] When the actual speed reaches the target speed, the second PWM output end is controlled not to output a pulse control signal to the voltage control end.

[0016] As an improvement of the above solution, the peripheral circuit between the first PWM output terminal and the voltage control terminal includes:

[0017] A first PWM control module, configured to be turned on when receiving a pulse signal input from the first PWM output terminal, so as to transmit the pulse signal to a power control module;

[0018] A power supply control module, comprising a voltage input terminal, configured to be turned on upon receiving the pulse signal and to transmit the voltage inputted from the voltage input terminal to the energy storage module;

[0019] The energy storage module is used to store energy of the input voltage according to the pulse signal.

[0020] As an improvement of the above solution, the peripheral circuit between the second PWM output terminal and the voltage control terminal includes a second PWM control module, and the second PWM control module is used to be turned on when receiving a pulse signal input from the second PWM output terminal to transmit the pulse signal to the energy storage module.

[0021] As an improvement of the above-mentioned scheme, the peripheral circuit connecting the feedback signal receiving end and the feedback signal output end includes a transistor control circuit, and the transistor control circuit is used to be turned on when receiving the speed feedback signal output by the feedback signal output end, so as to transmit the speed feedback signal to the feedback signal receiving end; wherein, the speed feedback signal is the real-time speed of the fan.

[0022] To achieve the above-mentioned purpose, an embodiment of the present invention further provides a method for controlling the speed of a fan of a refrigerator, wherein the refrigerator is provided with a fan and a control board, wherein the fan is provided with a voltage control terminal, a feedback signal output terminal and a ground terminal; the control board is composed of a single-chip microcomputer and a peripheral circuit, and is used to control the speed of the fan, wherein the single-chip microcomputer is provided with a first PWM output terminal, a second PWM output terminal and a feedback signal receiving terminal, wherein the first PWM output terminal and the second PWM output terminal are respectively connected to the voltage control terminal through the peripheral circuit, and the feedback signal receiving terminal is connected to the feedback signal output terminal through the peripheral circuit; then, the method for controlling the speed of a fan of a refrigerator comprises:

[0023] When it is detected that the fan is started and is running at a rated voltage, a target speed of the fan is obtained;

[0024] adjusting the PWM duty cycle to be output by the first PWM output terminal according to the target speed, and controlling the first PWM output terminal to output a pulse control signal to the voltage control terminal;

[0025] When the PWM duty cycle of the first PWM output terminal reaches 100%, obtaining the actual rotation speed of the fan received by the feedback signal receiving terminal;

[0026] When the actual speed does not reach the target speed, the second PWM output end is controlled to output a pulse control signal to the voltage control end.

[0027] As an improvement of the above solution, the method further includes:

[0028] When the actual speed reaches the target speed, the second PWM output end is controlled not to output a pulse control signal to the voltage control end.

[0029] As an improvement of the above solution, the peripheral circuit between the first PWM output terminal and the voltage control terminal includes:

[0030] A first PWM control module, configured to be turned on when receiving a pulse signal input from the first PWM output terminal, so as to transmit the pulse signal to a power control module;

[0031] A power supply control module, comprising a voltage input terminal, configured to be turned on upon receiving the pulse signal and to transmit the voltage inputted from the voltage input terminal to the energy storage module;

[0032] The energy storage module is used to store energy of the input voltage according to the pulse signal.

[0033] As an improvement of the above solution, the peripheral circuit between the second PWM output terminal and the voltage control terminal includes a second PWM control module, and the second PWM control module is used to be turned on when receiving a pulse signal input from the second PWM output terminal to transmit the pulse signal to the energy storage module.

[0034] As an improvement of the above-mentioned scheme, the peripheral circuit connecting the feedback signal receiving end and the feedback signal output end includes a transistor control circuit, and the transistor control circuit is used to be turned on when receiving the speed feedback signal output by the feedback signal output end, so as to transmit the speed feedback signal to the feedback signal receiving end; wherein, the speed feedback signal is the real-time speed of the fan.

[0035] Compared with the prior art, the refrigerator and the fan speed control method thereof disclosed in the present invention can automatically adjust the input voltage of the control board to the fan power supply. When it is found that the voltage of the control board power supply is reached and the fan speed has not reached the target speed, the boost circuit control is automatically started, which can increase the input voltage of the fan to exceed the power supply voltage of the control board, thereby achieving the purpose of using the fan speed exceeding the rated speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of the external structure of a refrigerator provided by an embodiment of the present invention;

[0037] Figure 2 is a schematic diagram of the internal structure of a refrigerator provided by an embodiment of the present invention;

[0038] Figure 3 is a schematic structural diagram of a refrigeration system in a refrigerator provided by an embodiment of the present invention;

[0039] Figure 4 is another schematic diagram of the internal structure of a refrigerator provided by an embodiment of the present invention;

[0040] Figure 5 It is a schematic diagram of the port connection between the fan and the single-chip microcomputer provided in an embodiment of the present invention;

[0041] Figure 6 is a first working flow diagram of a control panel in a refrigerator provided by an embodiment of the present invention;

[0042] Figure 7 is a second working flow chart of a control panel in a refrigerator provided by an embodiment of the present invention;

[0043] Figure 8 It is a circuit diagram of a peripheral circuit for connecting a fan and a single-chip microcomputer provided by an embodiment of the present invention;

[0044] Fig. 9 is a schematic diagram of a remote-controlled refrigerator provided by an embodiment of the present invention;

[0045] Fig.10 The present invention is a flowchart of a method for controlling the fan speed of a refrigerator provided by an embodiment of the present invention.

[0046] Among them, 100, refrigerator; 200, client; 300, router; 400, cloud server; 1, compressor; 2, evaporator; 3, capillary; 4, condenser; 10, cold storage room; 20, freezer; 30, fan; 40, air duct; 101, air outlet; 102, return air outlet; 11, first PWM control module; 12, power supply control module; 13, energy storage module; 14, second PWM control module; 15, transistor control circuit. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0049] The terms "first", "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0050] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] See also Figure 1 , Figure 1 1 is a schematic diagram of the external structure of a refrigerator 100 provided in an embodiment of the present invention. The refrigerator 100 of this embodiment is approximately rectangular in shape. The refrigerator includes a box body defining a storage space and a plurality of door bodies arranged at the opening of the box body, wherein the door body includes a door body shell located outside the box body, a door body liner located inside the box body, an upper end cover, a lower end cover, and an insulation layer located between the door body shell, the door body liner, the upper end cover, and the lower end cover; usually, the insulation layer is filled with foam. The box body is provided with a chamber, wherein the chamber includes a component storage chamber for placing components in the refrigerator, such as a press cabin, etc., and also includes a storage space for storing food, etc.

[0052] See also Figure 2 , Figure 2 : is a schematic diagram of the internal structure of a refrigerator provided by an embodiment of the present invention. The storage space can be divided into multiple storage rooms. The storage rooms can be configured as refrigerators and freezers according to different uses. They can also include variable temperature rooms, vacuum drawers, moisturizing drawers, etc. Each storage room corresponds to one or more door bodies, for example, Figure 1 The upper storage room is provided with a double-opening door body. The door body can be pivotally arranged at the opening of the box body, and can also be opened in a drawer-like manner to achieve drawer-like storage. The refrigerator door is provided with a display screen, which is used to display prompt information and receive user touch operations.

[0053] See also Figure 3 , Figure 3The schematic diagram of the structure of the refrigeration system in the refrigerator provided by the embodiment of the present invention, the refrigeration system includes a compressor 1, an evaporator 2, a drying filter (not shown in the figure), a capillary tube 3, a condenser 4 and a gas-liquid separator (not shown in the figure). The working process of the refrigeration system includes a compression process, a condensation process, a throttling process and an evaporation process. The compression process is: plug in the power cord of the refrigerator, when the contacts of the thermostat are connected, the compressor 1 starts to work, the low-temperature and low-pressure refrigerant is sucked into the compressor 1, and is compressed into a high-temperature and high-pressure superheated gas in the cylinder of the compressor 1 and then discharged to the condenser 4; the condensation process is: the high-temperature and high-pressure refrigerant gas dissipates heat through the condenser 4, the temperature continues to drop, and is gradually cooled to a saturated vapor of normal temperature and high pressure, and is further cooled to a saturated liquid, and the temperature no longer drops. The temperature at this time is called the condensation temperature, and the pressure of the refrigerant remains almost unchanged during the entire condensation process; The flow process is as follows: the saturated liquid refrigerant after condensation is filtered out of moisture and impurities by a drying filter and then flows into the capillary tube 3 through which the refrigerant is throttled and depressurized to become wet steam at room temperature and low pressure; the evaporation process is as follows: the wet steam at room temperature and low pressure begins to absorb heat and vaporize in the evaporator 2, which not only reduces the temperature of the evaporator 2 and its surroundings, but also turns the refrigerant into a low-temperature and low-pressure gas. The refrigerant coming out of the evaporator 2 passes through the gas-liquid separator and then returns to the compressor 1, repeating the above process to transfer the heat in the refrigerator to the air outside the box, thereby achieving the purpose of refrigeration.

[0054] See also Figure 4 , Figure 4 1 is another schematic diagram of the internal structure of a refrigerator provided in an embodiment of the present invention, wherein the storage chamber of the refrigerator 100 includes a refrigerating chamber 10 and a freezing chamber 20, and includes a fan 30 and an air duct 40. The air duct 40 is arranged on one side of the refrigerating chamber 10, and its interior is a cavity structure, and at least one air outlet 101 and at least one return air outlet 102 are arranged on the side close to the refrigerating chamber 10; when the fan 30 is turned on, the refrigerated gas in the refrigerating chamber 10 is output to the evaporator 2 through the return air outlet 102, and after being cooled by the evaporator 2, it is transported to the refrigerating chamber 10 through the air outlet 101.

[0055] It is understandable that the position of the internal structure of the refrigerator in this application is not limited to Figure 4 As shown in the positional relationship, in other embodiments, the fan may be installed at a lower position of the refrigerator, and the refrigerator may adopt a dual evaporator system or a single evaporator system, all of which are within the protection scope of the present invention.

[0056] See also Figure 5 , Figure 5This is a port connection diagram of a fan and a single-chip microcomputer provided in an embodiment of the present invention. The fan is provided with a voltage control terminal Vcc, a feedback signal output terminal FG and a ground terminal GND. The speed of the fan has a positive relationship with the power supply voltage, that is, the higher the power supply voltage, the faster the fan speed. The internal circuit of the fan simultaneously outputs the real-time speed of the fan through the feedback signal output terminal FG. The control board is composed of a single-chip microcomputer and a peripheral circuit, and is used to control the speed of the fan. The single-chip microcomputer is provided with a first PWM output terminal P1, a second PWM output terminal P2 and a feedback signal receiving terminal P3, wherein the first PWM output terminal P1 and the second PWM output terminal P2 are respectively connected to the voltage control terminal Vcc through the peripheral circuit, and the feedback signal receiving terminal P3 is connected to the feedback signal output terminal FG through the peripheral circuit.

[0057] In the embodiment of the present invention, the input voltage of the fan is adjusted by adjusting the PWM duty cycle, so as to achieve the purpose of adjusting the fan speed. The PWM duty cycle input by the PWM signal line controls the speed of the PWM fan, and the corresponding relationship is that the duty cycle of 0 to 100% corresponds to the PWM fan stopping and the fan running at full speed. The change of the fan speed is controlled by adjusting the change of the input voltage of the fan end through the circuit. The higher the desired fan speed, the higher the voltage output to the fan by the control board. However, the maximum adjustment of the output voltage of the fan can only reach the rated voltage of the control board, so that the maximum speed of the fan can only reach the rated speed, and the actual fan can use the power supply voltage beyond the rated voltage value within a certain range, and the fan input voltage can be increased to obtain a higher fan speed. Therefore, in order to achieve the purpose of universal fan without increasing the number of fans, a boost circuit for increasing the fan speed is designed. When the fan speed cannot be met under the rated voltage, the voltage of the voltage control terminal Vcc is increased, thereby increasing the fan speed. It is worth noting that the voltage of the voltage control terminal Vcc cannot be increased too high at this time, and needs to be within the set range obtained by pre-measurement in the laboratory, so as to prevent the fan from being damaged due to overload.

[0058] Specifically, the control board is configured to: when it is detected that the fan is started and running at the rated voltage, obtain the target speed of the fan; adjust the PWM duty cycle required to be output by the first PWM output terminal according to the target speed, and control the first PWM output terminal to output a pulse control signal to the voltage control terminal; when the PWM duty cycle of the first PWM output terminal reaches 100%, obtain the actual speed of the fan received by the feedback signal receiving terminal; when the actual speed does not reach the target speed, control the second PWM output terminal to output a pulse control signal to the voltage control terminal.

[0059] Specifically, the control board is further configured to: when the actual speed reaches the target speed, control the second PWM output end not to output a pulse control signal to the voltage control end.

[0060] For example, see Figures 6-7 , the control board is configured to perform steps S11 to S18. Under the rated voltage, by adjusting the PWM duty cycle of the first PWM output terminal P1, the voltage of the fan Vcc can be adjusted to achieve the target speed of the fan. At this time, the second PWM output terminal P2 of the single-chip microcomputer outputs a low level, and the voltage of the fan Vcc is only affected by the PWM duty cycle of the first PWM output terminal P1; when the PWM duty cycle of the first PWM output terminal P1 has reached 100%, and the feedback signal receiving terminal P3 detects that the real-time speed detected by the fan speed feedback signal does not reach the target speed, at this time, the second PWM output terminal P2 performs PWM modulation. At this time, the voltage of the fan Vcc is superimposed with the pulse signal of 100% duty cycle output by the first PWM output terminal P1 and the pulse signal of n% duty cycle output by the second PWM output terminal P2, so that the voltage of the fan Vcc can exceed the rated voltage of the control board, and the speed of the fan exceeds the rated speed of the fan. Wherein, n% is determined by the difference between the real-time speed and the target speed and is proportional to the difference, but cannot exceed the preset maximum adjustable duty cycle threshold.

[0061] Specifically, the peripheral circuit between the first PWM output terminal and the voltage control terminal includes: a first PWM control module 11, which is used to be turned on when receiving a pulse signal input from the first PWM output terminal to transmit the pulse signal to the power control module; a power control module 12, including a voltage input terminal, which is used to be turned on when receiving the pulse signal and transmit the voltage input from the voltage input terminal to the energy storage module; an energy storage module 13, which is used to store the input voltage according to the pulse signal.

[0062] For example, see Figure 8 , Figure 8: is a circuit diagram of a peripheral circuit for connecting a fan and a single-chip microcomputer provided by an embodiment of the present invention, wherein the first PWM control module 11 includes a second transistor V2, a third resistor R3, a seventh resistor R7 and an eighth resistor R8, wherein the second transistor V2 is an NPN transistor, the base of the second transistor V2 is connected to the first end of the seventh resistor R7, the second end of the seventh resistor R7 is connected to the first PWM output terminal P1, the base of the second transistor V2 is also connected to the first end of the eighth resistor R8, the second end of the eighth resistor R8 is grounded, the collector of the second transistor V2 is connected to the first end of the third resistor R3, the second end of the third resistor R3 is connected to the power control module 12, and the emitter of the second transistor V2 is grounded. When the first PWM output terminal P1 outputs a pulse signal, the second transistor V2 is turned on, and the pulse signal can be transmitted to the power control module 12 at this time, and the third resistor R3, the seventh resistor R7 and the eighth resistor R8 play a current limiting role.

[0063] The power supply control module 12 includes a voltage input terminal, a first transistor V1, a second resistor R2, a second diode D2, a third diode D3 and a first inductor L1; wherein the first transistor V1 is a PNP transistor, the base of the first transistor V1 is connected to the first PWM control module 11, the base of the first transistor V1 is also connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the emitter of the first transistor V1, the emitter of the first transistor V1 is also connected to the voltage input terminal and the cathode of the second diode D2, the anode of the second diode D2 is respectively connected to the first end of the first inductor L1, the collector of the first transistor V1, and the cathode of the third diode D3, the anode of the third diode D3 is grounded, and the second end of the first inductor L1 is connected to the energy storage module 13. The voltage input terminal is used for a 12V input voltage. When the power control module 12 receives the pulse signal from the first PWM control module 11 and the 12V input voltage from the voltage input terminal, the first transistor V1 is turned on, and can transmit the pulse signal and the 12V input voltage to the energy storage module 13. The second resistor R2 plays a current limiting role, the first inductor L1 is used for energy storage, and the second diode D2 and the third diode D3 play a voltage stabilizing role.

[0064] The energy storage module 13 includes a first diode D1, a first capacitor C1, a second capacitor C2 and a first resistor R1; wherein the positive electrode of the first diode D1 is connected to the power control module 12, the negative electrode of the first diode D1 is connected to the voltage control terminal Vcc of the fan, the first ends of the first resistor R1, the first capacitor C1 and the second capacitor C2 are respectively connected to the voltage control terminal Vcc and the negative electrode of the first diode D1, and the second ends of the first resistor R1, the first capacitor C1 and the second capacitor C2 are all grounded. The first capacitor C1 and the second capacitor C2 play an energy storage role, the first resistor R1 plays a current limiting role, and the first diode D1 plays a voltage stabilizing role. When the first capacitor C1 and the second capacitor C2 receive a 12V input voltage, they will store energy, and this 12V voltage can be directly transmitted to the voltage control terminal Vcc of the fan, providing voltage input to the fan, so that the fan rotates.

[0065] Specifically, the peripheral circuit between the second PWM output terminal and the voltage control terminal includes a second PWM control module 14, and the second PWM control module is used to be turned on when receiving a pulse signal input from the second PWM output terminal to transmit the pulse signal to the energy storage module.

[0066] For example, see Figure 8 The second PWM control module 14 includes a third transistor V3, a ninth resistor R9 and a tenth resistor R10; wherein the third transistor V3 is an NPN transistor, the base of the third transistor V3 is connected to the first end of the ninth resistor R9, the second end of the ninth resistor R9 is connected to the second PWM output end P2, the base of the third transistor V3 is also connected to the first end of the tenth resistor R10, the second end of the tenth resistor R10 is grounded, the collector of the third transistor V3 is connected to the energy storage module 13, and the emitter of the third transistor V3 is grounded. When the duty cycle output by the first PWM output terminal P1 is 100%, but the real-time speed has reached the target speed, the second PWM output terminal P2 outputs a low level, the third transistor V3 is cut off, and the voltage of the fan Vcc is only affected by the PWM duty cycle of the first PWM output terminal P1; when the duty cycle output by the first PWM output terminal P1 is 100%, but the real-time speed has not reached the target speed, the second PWM output terminal P2 performs PWM modulation and outputs a pulse signal, and the third transistor V3 is turned on. At this time, the voltage of the fan Vcc is superimposed with the pulse signal with a duty cycle of 100% output by the first PWM output terminal P1 and the pulse signal with a duty cycle of n% output by the second PWM output terminal P2, so that the voltage of the fan Vcc can exceed the rated voltage of the control board, and the speed of the fan exceeds the rated speed of the fan.

[0067] Specifically, the peripheral circuit connected to the feedback signal receiving end and the feedback signal output end includes a transistor control circuit 15, and the transistor control circuit is used to be turned on when receiving the speed feedback signal output by the feedback signal output end, so as to transmit the speed feedback signal to the feedback signal receiving end; wherein, the speed feedback signal is the real-time speed of the fan.

[0068] For example, see Figure 8 , the transistor control circuit 15 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, an eleventh resistor R11, a twelfth resistor R12, a third capacitor C3 and a fourth transistor V4; wherein the fourth transistor V4 is an NPN transistor, the collector of the fourth transistor V4 is respectively connected to the first end of the fifth resistor R5 and the first end of the sixth resistor R6, the second end of the sixth resistor R6 is connected to the feedback signal receiving end P3, the second end of the fifth resistor R5 is connected to the 5V input voltage, the base of the fourth transistor V4 is respectively connected to the first end of the eleventh resistor R11 and the first end of the twelfth resistor R12, the second end of the twelfth resistor R12 is grounded, the second end of the eleventh resistor R11 is respectively connected to the feedback signal output end FG of the fan, the first end of the fourth resistor R4, and the first end of the third capacitor C3, the second end of the fourth resistor R4 is connected to the 5V input voltage, the second end of the third capacitor C3 is grounded, and the emitter of the fourth transistor V4 is grounded. When the feedback signal output terminal FG outputs the high level signal of the speed feedback signal, the fourth transistor V4 is turned on to transmit the speed feedback signal to the feedback signal receiving terminal P3. The fifth resistor R5, the sixth resistor R6, the eleventh resistor R11, and the twelfth resistor R12 play a current limiting role, and the fourth resistor R4 and the third capacitor C3 form an RC filter circuit for filtering the speed feedback signal.

[0069] See also Fig. 9 , Fig. 9 : is a schematic diagram of a remote control refrigerator provided by an embodiment of the present invention, wherein the refrigerator 100 establishes a data connection with the client 200 through a router 300 or a cloud server 400. When the refrigerator 100 and the client 200 communicate through the router 300, the refrigerator 100 and the client 200 are close to each other, and the user can view the operation status of the refrigerator placed in the kitchen or the storage status of food in the living room or room. When the refrigerator 100 and the client 200 communicate through the cloud server 400, the refrigerator 100 and the client 200 are far apart, and the user can perform data interaction with the refrigerator 100 through the APP installed in the client 200, and remote control of the refrigerator 100 can also be realized.

[0070] Compared with the prior art, the refrigerator and the fan speed control method thereof disclosed in the present invention can automatically adjust the input voltage of the control board to the fan power supply. When it is found that the voltage of the control board power supply is reached and the fan speed has not reached the target speed, the boost circuit control is automatically started, which can increase the input voltage of the fan to exceed the power supply voltage of the control board, thereby achieving the purpose of using the fan speed exceeding the rated speed.

[0071] See also Fig.10 , Fig.10 The present invention provides a flowchart of a method for controlling the speed of a refrigerator fan provided by an embodiment of the present invention. The method for controlling the speed of a refrigerator fan is implemented by a control board in the refrigerator. The refrigerator is provided with a fan and a control board. The fan is provided with a voltage control terminal, a feedback signal output terminal and a ground terminal. The control board is composed of a single-chip microcomputer and a peripheral circuit, and is used to control the speed of the fan. The single-chip microcomputer is provided with a first PWM output terminal, a second PWM output terminal and a feedback signal receiving terminal, wherein the first PWM output terminal and the second PWM output terminal are respectively connected to the voltage control terminal through the peripheral circuit, and the feedback signal receiving terminal is connected to the feedback signal output terminal through the peripheral circuit. Then, the method for controlling the speed of a refrigerator fan includes:

[0072] S1. When it is detected that the fan is started and is running at rated voltage, a target speed of the fan is obtained;

[0073] S2, adjusting the PWM duty cycle to be output by the first PWM output terminal according to the target speed, and controlling the first PWM output terminal to output a pulse control signal to the voltage control terminal;

[0074] S3, when the PWM duty cycle of the first PWM output end reaches 100%, obtaining the actual rotation speed of the fan received by the feedback signal receiving end;

[0075] S4. When the actual speed does not reach the target speed, control the second PWM output terminal to output a pulse control signal to the voltage control terminal.

[0076] Exemplarily, under rated voltage, by adjusting the PWM duty cycle of the first PWM output terminal, the voltage of the fan Vcc can be adjusted to achieve the target speed of the fan, at which time the second PWM output terminal of the single-chip microcomputer outputs a low level, and the voltage of the fan Vcc is only affected by the PWM duty cycle of the first PWM output terminal; when the PWM duty cycle of the first PWM output terminal has reached 100%, and the feedback signal receiving terminal detects that the real-time speed detected by the fan speed feedback signal does not reach the target speed, at this time, the second PWM output terminal performs PWM modulation, at this time, the voltage of the fan Vcc is superimposed with the pulse signal of 100% duty cycle output by the first PWM output terminal and the pulse signal of n% duty cycle output by the second PWM output terminal, so that the voltage of the fan Vcc can exceed the rated voltage of the control board, and at this time the speed of the fan exceeds the rated speed of the fan. Among them, n% is determined by the difference between the real-time speed and the target speed, and is proportional to the difference, but cannot exceed the preset maximum adjustable duty cycle threshold.

[0077] Specifically, the method further includes: when the actual speed reaches the target speed, controlling the second PWM output end not to output a pulse control signal to the voltage control end.

[0078] Specifically, the peripheral circuit between the first PWM output terminal and the voltage control terminal includes: a first PWM control module, which is used to be turned on when receiving a pulse signal input from the first PWM output terminal to transmit the pulse signal to a power control module; a power control module, including a voltage input terminal, which is used to be turned on when receiving the pulse signal and transmit the voltage input from the voltage input terminal to an energy storage module; and an energy storage module, which is used to store the input voltage according to the pulse signal.

[0079] Specifically, the peripheral circuit between the second PWM output terminal and the voltage control terminal includes a second PWM control module, and the second PWM control module is used to be turned on when receiving a pulse signal input from the second PWM output terminal to transmit the pulse signal to the energy storage module.

[0080] Specifically, the peripheral circuit connected to the feedback signal receiving end and the feedback signal output end includes a transistor control circuit, and the transistor control circuit is used to be turned on when receiving the speed feedback signal output by the feedback signal output end, so as to transmit the speed feedback signal to the feedback signal receiving end; wherein, the speed feedback signal is the real-time speed of the fan.

[0081] It is worth noting that the working process of the fan speed control method of the refrigerator described in the embodiment of the present invention can refer to the working process of the control board in the refrigerator described in the above embodiment, which will not be repeated here.

[0082] Compared with the prior art, the refrigerator and the fan speed control method thereof disclosed in the present invention can automatically adjust the input voltage of the control board to the fan power supply. When it is found that the voltage of the control board power supply is reached and the fan speed has not reached the target speed, the boost circuit control is automatically started, which can increase the input voltage of the fan to exceed the power supply voltage of the control board, thereby achieving the purpose of using the fan speed exceeding the rated speed.

[0083] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A refrigerator, characterized in that: include: a box body, in which a storage chamber and an air duct are formed; A door, used for opening and closing the storage room; A fan, arranged in the air duct, is used to allow air to enter the evaporator in the refrigerator for heat exchange and send the heat-released air to the storage chamber, and the fan is provided with a voltage control terminal, a feedback signal output terminal and a ground terminal; A control board, composed of a single-chip microcomputer and a peripheral circuit, for controlling the speed of the fan, wherein the single-chip microcomputer is provided with a first PWM output terminal, a second PWM output terminal and a feedback signal receiving terminal, wherein the first PWM output terminal and the second PWM output terminal are respectively connected to the voltage control terminal through the peripheral circuit, and the feedback signal receiving terminal is connected to the feedback signal output terminal through the peripheral circuit; The control board is configured to: When it is detected that the fan is started and is running at a rated voltage, a target speed of the fan is obtained; adjusting the PWM duty cycle to be output by the first PWM output terminal according to the target speed, and controlling the first PWM output terminal to output a pulse control signal to the voltage control terminal; When the PWM duty cycle of the first PWM output terminal reaches 100%, obtaining the actual rotation speed of the fan received by the feedback signal receiving terminal; When the actual speed does not reach the target speed, the second PWM output end is controlled to output a pulse control signal to the voltage control end.

2. The refrigerator according to claim 1, characterized in that: The control board is also configured to: When the actual speed reaches the target speed, the second PWM output end is controlled not to output a pulse control signal to the voltage control end.

3. The refrigerator according to claim 1, characterized in that: The peripheral circuit between the first PWM output terminal and the voltage control terminal includes: A first PWM control module, configured to be turned on when receiving a pulse signal input from the first PWM output terminal, so as to transmit the pulse signal to a power control module; A power supply control module, comprising a voltage input terminal, configured to be turned on upon receiving the pulse signal and to transmit the voltage inputted from the voltage input terminal to the energy storage module; The energy storage module is used to store energy of the input voltage according to the pulse signal.

4. The refrigerator according to claim 2, characterized in that: The peripheral circuit between the second PWM output terminal and the voltage control terminal includes a second PWM control module, and the second PWM control module is used to be turned on when receiving a pulse signal input from the second PWM output terminal to transmit the pulse signal to the energy storage module.

5. The refrigerator according to claim 1, characterized in that: The peripheral circuit connecting the feedback signal receiving end and the feedback signal output end includes a transistor control circuit, and the transistor control circuit is used to be turned on when receiving the speed feedback signal output by the feedback signal output end, so as to transmit the speed feedback signal to the feedback signal receiving end; wherein, the speed feedback signal is the real-time speed of the fan.

6. A method for controlling the speed of a refrigerator fan, characterized in that: The refrigerator is provided with a fan and a control board, the fan is provided with a voltage control terminal, a feedback signal output terminal and a ground terminal; the control board is composed of a single-chip microcomputer and a peripheral circuit, and is used to control the speed of the fan, the single-chip microcomputer is provided with a first PWM output terminal, a second PWM output terminal and a feedback signal receiving terminal, wherein the first PWM output terminal and the second PWM output terminal are respectively connected to the voltage control terminal through the peripheral circuit, and the feedback signal receiving terminal is connected to the feedback signal output terminal through the peripheral circuit; then, the fan speed control method of the refrigerator includes: When it is detected that the fan is started and is running at a rated voltage, a target speed of the fan is obtained; adjusting the PWM duty cycle to be output by the first PWM output terminal according to the target speed, and controlling the first PWM output terminal to output a pulse control signal to the voltage control terminal; When the PWM duty cycle of the first PWM output terminal reaches 100%, obtaining the actual rotation speed of the fan received by the feedback signal receiving terminal; When the actual speed does not reach the target speed, the second PWM output end is controlled to output a pulse control signal to the voltage control end.

7. The method for controlling the fan speed of a refrigerator according to claim 6, wherein: The method further comprises: When the actual speed reaches the target speed, the second PWM output end is controlled not to output a pulse control signal to the voltage control end.

8. The method for controlling the fan speed of a refrigerator according to claim 6, wherein: The peripheral circuit between the first PWM output terminal and the voltage control terminal includes: A first PWM control module, configured to be turned on when receiving a pulse signal input from the first PWM output terminal, so as to transmit the pulse signal to a power control module; A power supply control module, comprising a voltage input terminal, configured to be turned on upon receiving the pulse signal and to transmit the voltage inputted from the voltage input terminal to the energy storage module; The energy storage module is used to store energy of the input voltage according to the pulse signal.

9. The method for controlling the fan speed of a refrigerator according to claim 8, characterized in that: The peripheral circuit between the second PWM output terminal and the voltage control terminal includes a second PWM control module, and the second PWM control module is used to be turned on when receiving a pulse signal input from the second PWM output terminal to transmit the pulse signal to the energy storage module.

10. The method for controlling the fan speed of a refrigerator according to claim 6, wherein: The peripheral circuit connecting the feedback signal receiving end and the feedback signal output end includes a transistor control circuit, and the transistor control circuit is used to be turned on when receiving the speed feedback signal output by the feedback signal output end, so as to transmit the speed feedback signal to the feedback signal receiving end; wherein, the speed feedback signal is the real-time speed of the fan.

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