Motor stalling protection circuit, refrigerator and household appliance

Abstract

The utility model discloses a motor stalling protection circuit, a refrigerator and a household appliance. The motor stalling protection circuit comprises a motor, a three-terminal fuse, a current-to-voltage circuit and a control level output circuit. The input end of the three-end fuse is used for accessing a first power supply signal, the output end of the three-end fuse is connected with the input end of the motor, and the control end of the three-end fuse is connected with the output end of the control level output circuit; the input end of the current-to-voltage circuit is connected with the output end of the motor, and the output end of the current-to-voltage circuit is connected with the first input end of the control level output circuit; the second input end of the control level output circuit is used for inputting reference voltage. According to the embodiment of the utility model, the locked-rotor protection of the ice-breaking motor can be realized without software participation, and a large amount of debugging is not needed, so that the operation is simple and convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, and in particular to a motor stall protection circuit, a refrigerator and household appliances. Background Art

[0002] When the ice crushing motor is running, it may stall due to factors such as the size of the ice cubes and the speed. The length of the stall and the size of the stall current may cause damage to the ice crushing motor. Therefore, it is particularly important to study the stall overcurrent protection of the motor.

[0003] Currently, overcurrent protection systems are designed into the motor's internal driver circuit board to cut off power when overcurrent is detected, thus protecting the motor from stalling. However, overcurrent protection systems involve software programming, requiring extensive debugging and a cumbersome process. Utility Model Content

[0004] The utility model provides a motor stall protection circuit, a refrigerator and a household appliance, so as to solve the problem in the prior art that a large amount of debugging is required for software programs and the process is cumbersome.

[0005] To achieve the above-mentioned object, the embodiment of the present utility model provides a motor stall protection circuit, comprising: a motor, a three-terminal fuse, a current-to-voltage circuit, and a control level output circuit;

[0006] The three-terminal fuse has an input end for receiving a first power supply signal, an output end connected to the input end of the motor, and a control end connected to the output end of the control level output circuit;

[0007] The current-to-voltage circuit has an input end connected to the output end of the motor, and an output end connected to the first input end of the control level output circuit;

[0008] The second input terminal of the control level output circuit is used to input a reference voltage.

[0009] As an improvement of the above solution, the current-to-voltage circuit includes: a current-limiting resistor, an RC circuit and an emitter follower;

[0010] The current limiting resistor has a first end connected to the ground and a second end connected to the input end of the current-to-voltage circuit;

[0011] The RC circuit has a first end connected to the input end of the current-to-voltage circuit, a second end for grounding, and a third end connected to the input end of the emitter follower;

[0012] The output end of the emitter follower is connected to the output end of the current-to-voltage circuit.

[0013] As an improvement to the above solution, the RC circuit includes: a resistor and a capacitor;

[0014] The resistor has a first end connected to the first end of the RC circuit and a second end connected to the first end of the capacitor;

[0015] The capacitor has a first end connected to the third end of the RC circuit, and a second end connected to the second end of the RC circuit.

[0016] As an improvement to the above solution, the product of the resistance value of the resistor and the capacitance value of the capacitor is less than or equal to the maximum stall time required by the motor.

[0017] As an improvement to the above solution, the emitter follower is a first comparator;

[0018] The positive input terminal of the first comparator is the input terminal of the emitter follower, the output terminal of the first comparator is the output terminal of the emitter follower, and the first comparator is further provided with a negative input terminal connected to the output terminal of the first comparator.

[0019] As an improvement to the above solution, the control level output circuit is a second comparator;

[0020] The positive input terminal of the second comparator is the first input terminal of the control level output circuit, the negative input terminal of the second comparator is the second input terminal of the control level output circuit, and the output terminal of the second comparator is the output terminal of the control level output circuit;

[0021] The second comparator is further provided with a power supply terminal and a ground terminal. The power supply terminal is used to receive a second power supply signal, and the ground terminal is used for grounding.

[0022] To achieve the above-mentioned object, the present invention provides a refrigerator, comprising:

[0023] a box body, wherein a storage chamber is formed in the box body;

[0024] A door is provided at the opening of the storage chamber and is used to open and close the storage chamber;

[0025] A compressor, disposed within the housing, for compressing the refrigerant flowing through the refrigerator's refrigeration cycle to provide power for the refrigeration cycle;

[0026] Such as the motor stall protection circuit mentioned above.

[0027] To achieve the above-mentioned objectives, an embodiment of the present invention provides a household appliance, comprising the motor stall protection circuit as described above.

[0028] Compared to the prior art, the motor stall protection circuit, refrigerator, and household appliance provided by the present invention are configured by providing a motor, a three-terminal fuse, a current-to-voltage circuit, and a control level output circuit. The three-terminal fuse has an input terminal for receiving a first power signal, an output terminal connected to the input terminal of the motor, and a control terminal connected to the output terminal of the control level output circuit. The current-to-voltage circuit has an input terminal connected to the output terminal of the motor and an output terminal connected to the first input terminal of the control level output circuit. The control level output circuit has a second input terminal for inputting a reference voltage. Thus, the present invention implements stall protection for the ice-crushing motor using only a few electronic components, without requiring software or extensive debugging. It is simple, convenient, easy to implement, and low-cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural block diagram of a motor stall protection circuit provided by an embodiment of the utility model;

[0030] Figure 2 This is another structural block diagram of a motor stall protection circuit provided by an embodiment of the present utility model;

[0031] Figure 3 This is another structural block diagram of a motor stall protection circuit provided by an embodiment of the utility model;

[0032] Figure 4 This is another structural block diagram of a motor stall protection circuit provided by an embodiment of the utility model;

[0033] Figure 5 This is another structural block diagram of a motor stall protection circuit provided by an embodiment of the utility model;

[0034] Figure 6 This is a three-dimensional diagram of a refrigerator provided by an embodiment of the present utility model;

[0035] Figure 7 This is a schematic structural diagram of a refrigeration system in a refrigerator provided by an embodiment of the present utility model;

[0036] Figure 8 This is a schematic diagram of the flow direction of the refrigerant during refrigeration provided by an embodiment of the present utility model;

[0037] Figure 9 This is a structural diagram of a fan provided by an embodiment of the utility model;

[0038] Figure 10 It is a structural diagram of a household appliance provided by an embodiment of the utility model.

[0039] Among them, 10000, cabinet; 1, compressor; 2, condenser; 3, anti-condensation tube; 4, drying filter; 5, pressure reducer; 6, evaporator; 7, gas-liquid separator; 8, fan; 11, motor; 12, three-terminal fuse; 13, current-to-voltage circuit; 14, control level output circuit; R1, current-limiting resistor; R2, resistor; C1, capacitor; IC1B, first comparator; IC1A, second comparator. DETAILED DESCRIPTION

[0040] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, unless otherwise specified, "plurality" means two or more.

[0043] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0044] See also Figure 1 , Figure 1 This is a structural block diagram of a motor stall protection circuit provided by an embodiment of the present utility model, comprising: a motor 11, a three-terminal fuse 12, a current-to-voltage circuit 13, and a control level output circuit 14;

[0045] The three-terminal fuse 12 has an input terminal for receiving the first power supply signal VCC1, an output terminal connected to the input terminal of the motor 11, and a control terminal connected to the output terminal of the control level output circuit 14;

[0046] The current-to-voltage circuit 13 has an input end connected to the output end of the motor 11 and an output end connected to the first input end of the control level output circuit 14;

[0047] The second input terminal of the control level output circuit 14 is used to input a reference voltage Vref.

[0048] In the embodiment of the present invention, the three-terminal fuse 12 is a controllable fuse. The control level signal outputted from the output end of the control level output circuit 14 is used to control whether the three-terminal fuse 12 is turned off, thereby completing the cutting off of the first power supply signal VCC1, causing the motor 11 to stop working and avoid continuous stalling of the motor 11.

[0049] The motor 11 starts working by receiving the first power signal VCC1 through the three-terminal fuse 12. Optionally, the motor 11 is any motor such as an ice crushing motor, an ice taking motor, or an ice turning motor, and the voltage of the first power signal VCC1 is 24V.

[0050] The motor 11 outputs different currents when operating normally and when stalled. The current of the motor 11 operating normally is less than the current of the motor 11 when stalled. The current-to-voltage circuit 13 converts the current output by the motor 11 into a voltage, and the voltages output by the current-to-voltage circuit 13 are different. The control level output circuit 14 then outputs different control level signals based on the different voltages output by the current-to-voltage circuit 13.

[0051] Specifically, when the motor 11 is operating normally, the output terminal of the control level output circuit 14 outputs a first control level signal, and the three-terminal fuse 12 is in the on state. That is, the input terminal and the output terminal of the three-terminal fuse 12 are conductive, and the motor 11 can operate. In other words, after power is turned on, the three-terminal fuse 12 is in the on state by default.

[0052] When the motor 11 is stalled, the output end of the control level output circuit 14 outputs a second control level signal, and the three-terminal fuse 12 is in the off state, that is, the input end and the output end of the three-terminal fuse 12 are not conductive. At this time, the motor 11 stops working, so that the motor 11 is protected in a timely and effective manner when it is stalled, avoiding the phenomenon that the motor 11 is damaged due to continuous stalling and cannot work normally.

[0053] The embodiment of the utility model can realize the stall protection of the ice crushing motor by only using a number of electronic components, without the involvement of software and a large amount of debugging, and is simple, convenient, easy to implement and low in cost.

[0054] In an optional embodiment, the current-to-voltage circuit 13 includes: a current-limiting resistor R1, an RC circuit, and an emitter follower;

[0055] The current limiting resistor R1 has a first end connected to the ground and a second end connected to the input end of the current-to-voltage circuit 13;

[0056] The RC circuit has a first end connected to the input end of the current-to-voltage circuit 13, a second end connected to ground, and a third end connected to the input end of the emitter follower;

[0057] The output end of the emitter follower is connected to the output end of the current-to-voltage circuit 13 .

[0058] It is worth noting that when the ice crushing motor is working, occasional ice blockage may cause a small spike to appear in the resistance R2 of the motor 11. However, the ice crushing motor does not stall at this time. Therefore, the embodiment of the present invention not only absorbs interference spikes by setting an RC circuit to avoid malfunction of instantaneous current interference spikes, but also can set a certain control time to complete the power cut-off action.

[0059] For example, see Figure 2 The current-to-voltage circuit 13 includes two ports. The input end of the current-to-voltage circuit 13 is respectively connected to the second end of the current-limiting resistor R1 and the first end of the RC circuit, and the output end of the current-to-voltage circuit 13 is connected to the output end of the emitter follower.

[0060] Specifically, the resistance of the current limiting resistor R1 is 0.4R, and the reference voltage Vref is 3.3V. If the normal operating rated current of the ice crushing motor is set to 3A and the short-time current of the stalled rotor is 9A, then:

[0061] When motor 11 is operating normally, the output terminal of motor 11 outputs a current of 3A. At this time, the voltage across current-limiting resistor R1 is 0.4Ω*3A=1.2V, and the voltage outputted by the output terminal of emitter follower is 1.2V, which is lower than reference voltage Vref 3.3V. At this time, control level output circuit 14 outputs a low level (i.e., a first control level signal), three-terminal fuse 12 remains in the on state, and motor 11 operates normally.

[0062] When motor 11 stalls, the current in motor 11 briefly surges to 9A, and the output terminal of motor 11 outputs a current of 9A. At this point, the voltage across current-limiting resistor R1 charges the RC circuit, causing the voltage at the third terminal of the RC circuit to gradually rise to 0.4Ω*9A=3.6V. During this process, before the voltage at the output terminal of the emitter follower reaches reference voltage Vref, the output of control level output circuit 14 remains low. When the voltage reaches reference voltage Vref, control level output circuit 14 outputs a high level (i.e., a second control level signal), disconnecting three-terminal fuse 12 and stopping motor 11 from stalling.

[0063] In an optional embodiment, the RC circuit includes: a resistor R2 and a capacitor C1;

[0064] The resistor R2 has a first end connected to the first end of the RC circuit and a second end connected to the first end of the capacitor C1;

[0065] The capacitor C1 has a first end connected to the third end of the RC circuit, and a second end connected to the second end of the RC circuit.

[0066] For details, see Figure 3 The embodiment of the utility model provides a simplest RC circuit, which is composed of a resistor R2 and a capacitor C1. It can not only absorb interference spikes and avoid false operations caused by instantaneous current interference spikes, but also can be set to control a certain time to complete the power cut-off action, with a simple structure.

[0067] In the embodiment of the present invention, when motor 11 is stalled, the current in motor 11 briefly surges to 9A, and the output terminal of motor 11 outputs a current of 9A. At this time, the voltage across current-limiting resistor R1 charges capacitor C1 through resistor R2, i.e., capacitor C1 gradually increases from 0V to 0.4Ω*9A=3.6V. During this process, before the voltage outputted by the output terminal of the emitter follower reaches the reference voltage Vref, the output of control level output circuit 14 remains at a low level. When the voltage reaches the reference voltage Vref, control level output circuit 14 outputs a high level, the three-terminal fuse 12 is disconnected, and motor 11 stops stalling.

[0068] In an optional embodiment, the product of the resistance of the resistor R2 and the capacitance of the capacitor C1 is less than or equal to the maximum stall time required by the motor 11 .

[0069] In an embodiment of the present invention, the resistance value of the resistor R2 and the capacitance value of the capacitor C1 are designed according to the maximum stall time required by the motor 11. Specifically, the resistance value of the resistor R2 * the capacitance value of the capacitor C1 ≤ the maximum stall time. For example, the motor 11 is easily burned when stalled at 9A and within 3S, so R*C ≤ 3, so that the RC circuit must reach the reference voltage Vref before the maximum stall time of 3S.

[0070] In an optional embodiment, as Figure 4 , the emitter follower is a first comparator IC1B;

[0071] The positive input terminal of the first comparator IC1B is the input terminal of the emitter follower, and the output terminal of the first comparator IC1B is the output terminal of the emitter follower. The first comparator IC1B also has a negative input terminal connected to the output terminal of the first comparator IC1B. The first comparator IC1B not only implements emitter following, but also can achieve impedance isolation.

[0072] In an optional embodiment, as Figure 5 , the control level output circuit 14 is a second comparator IC1A;

[0073] The positive input terminal of the second comparator IC1A is the first input terminal of the control level output circuit 14, the negative input terminal of the second comparator IC1A is the second input terminal of the control level output circuit 14, and the output terminal of the second comparator IC1A is the output terminal of the control level output circuit 14;

[0074] The second comparator IC1A further includes a power supply terminal and a ground terminal, wherein the power supply terminal is used to receive a second power supply signal VCC2, and the ground terminal is used to be grounded. Optionally, the second power supply signal VCC2 is 5V.

[0075] In an embodiment of the present invention, the second comparator IC1A generates a control level signal by comparing the voltages input to the first input terminal and the voltage input to the second input terminal. For example, when the voltage input to the first input terminal is less than the voltage input to the second input terminal, the second comparator IC1A outputs a low level. When the voltage input to the first input terminal is greater than or equal to the voltage input to the second input terminal, the second comparator IC1A outputs a high level.

[0076] In addition, an embodiment of the present invention further provides a refrigerator, comprising:

[0077] a box body, wherein a storage chamber is formed in the box body;

[0078] A door is provided at the opening of the storage chamber and is used to open and close the storage chamber;

[0079] A compressor, disposed within the housing, for compressing the refrigerant flowing through the refrigerator's refrigeration cycle to provide power for the refrigeration cycle;

[0080] A motor stall protection circuit as described in any of the above embodiments.

[0081] For example, see Figure 6 , Figure 6 It is a three-dimensional diagram of a refrigerator provided by an embodiment of the present invention. The refrigerator of this embodiment has an approximately rectangular shape. The refrigerator includes a box body 100 that defines a storage space and a plurality of door bodies arranged at the opening of the box body 100, wherein the door body includes a door body shell located on the outside of the box body 10000, a door body liner located on the inside of 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 10000 is provided with a chamber, wherein the chamber includes a component storage chamber for placing components in the refrigerator, such as a compressor, etc., and also includes a storage space for storing food, etc. The storage space can be divided into multiple storage rooms, and the storage rooms can be configured as a refrigeration room, a freezer room, and a temperature-changing room (also called a fresh-keeping room) according to different uses. Each storage room corresponds to one or more door bodies, for example, in Figure 6 The storage room in the middle and upper part is provided with a double-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 realize drawer-like storage.

[0082] See also Figure 7 , Figure 7 This is a schematic diagram of the structure of the refrigerator refrigeration system provided by an embodiment of the present invention. The refrigeration system includes a compressor 1, a condenser 2, an anti-condensation tube 3, a drying filter 4, a pressure reducer 5, an evaporator 6, and a gas-liquid separator 7. The working process of the refrigeration system includes a compression process, a condensation process, a throttling process, and an evaporation process.

[0083] Among them, combined Figure 7The compression process is as follows: 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, low-pressure refrigerant is sucked into the compressor 1, and is compressed into a high-temperature, high-pressure superheated gas in the cylinder of the compressor 1 and then discharged into the condenser 2; the condensation process is as follows: the high-temperature, high-pressure refrigerant gas dissipates heat through the condenser 2, the temperature continues to drop, and is gradually cooled to a saturated vapor at room temperature and high pressure, and 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 throttling process is as follows: the refrigerant after condensation After the saturated refrigerant liquid is filtered out of moisture and impurities by the drying filter 4, it flows into the pressure reducer 5 (such as a capillary tube), through which it is throttled and reduced in pressure, and the refrigerant becomes 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 6, which not only reduces the temperature of the evaporator and its surroundings, but also turns the refrigerant into a low-temperature, low-pressure gas. The refrigerant coming out of the evaporator 6 passes through the gas-liquid separator 7 and returns to the compressor 1 again, repeating the above process to transfer the heat in the refrigerator to the air outside the box, thus achieving the purpose of refrigeration. The flow direction of the refrigerant can also be seen in Figure 8 shown.

[0084] Existing refrigerators are generally also equipped with Figure 9 The fan 8 shown in the figure allows air to continuously enter the fins of the evaporator 6 for heat exchange, and at the same time sends the air that has become cold after absorbing heat from the evaporator 6 to the storage room through the air duct. In this way, the air in the storage room continuously circulates to achieve the purpose of lowering the temperature.

[0085] It can be understood that the application of the motor stall protection circuit described in the embodiment of the present invention in a refrigerator can provide timely and effective protection for the motor when it stalls, without the need for software involvement or extensive debugging. It is simple, convenient, easy to implement, and low-cost.

[0086] In addition, refer to Figure 10 An embodiment of the present invention further provides a household appliance, which includes the motor stall protection circuit as described in any of the above embodiments.

[0087] It is understandable that many current household appliances are also equipped with motors and also have the need for motor stall overcurrent protection. Applying the motor stall protection circuit described in the embodiment of the utility model to household appliances can ensure that the motor is protected in a timely and effective manner when it stalls. No software involvement is required, and no extensive debugging is required. It is simple, convenient, easy to implement, and low cost.

[0088] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles 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 motor stall protection circuit, characterized in that: include: Motor, three-terminal fuse, current-to-voltage circuit and control level output circuit; The three-terminal fuse has an input end for receiving a first power supply signal, an output end connected to the input end of the motor, and a control end connected to the output end of the control level output circuit; The current-to-voltage circuit has an input end connected to the output end of the motor, and an output end connected to the first input end of the control level output circuit; The second input terminal of the control level output circuit is used to input a reference voltage.

2. The motor stall protection circuit according to claim 1, wherein: The current-to-voltage circuit includes: a current-limiting resistor, an RC circuit, and an emitter follower; The current limiting resistor has a first end connected to the ground and a second end connected to the input end of the current-to-voltage circuit; The RC circuit has a first end connected to the input end of the current-to-voltage circuit, a second end for grounding, and a third end connected to the input end of the emitter follower; The output end of the emitter follower is connected to the output end of the current-to-voltage circuit.

3. The motor stall protection circuit according to claim 2, wherein: The RC circuit includes: a resistor and a capacitor; The resistor has a first end connected to the first end of the RC circuit and a second end connected to the first end of the capacitor; The capacitor has a first end connected to the third end of the RC circuit, and a second end connected to the second end of the RC circuit.

4. The motor stall protection circuit according to claim 3, characterized in that: The product of the resistance value of the resistor and the capacitance value of the capacitor is less than or equal to the maximum stall time required by the motor.

5. The motor stall protection circuit according to claim 2, wherein: The emitter follower is a first comparator; The positive input terminal of the first comparator is the input terminal of the emitter follower, the output terminal of the first comparator is the output terminal of the emitter follower, and the first comparator is further provided with a negative input terminal connected to the output terminal of the first comparator.

6. The motor stall protection circuit according to claim 1, wherein: The control level output circuit is a second comparator; The positive input terminal of the second comparator is the first input terminal of the control level output circuit, the negative input terminal of the second comparator is the second input terminal of the control level output circuit, and the output terminal of the second comparator is the output terminal of the control level output circuit; The second comparator is further provided with a power supply terminal and a ground terminal. The power supply terminal is used to receive a second power supply signal, and the ground terminal is used for grounding.

7. A refrigerator, characterized in that: include: a box body, wherein a storage chamber is formed in the box body; A door is provided at the opening of the storage chamber and is used to open and close the storage chamber; A compressor, disposed within the housing, for compressing the refrigerant flowing through the refrigerator's refrigeration cycle to provide power for the refrigeration cycle; The motor stall protection circuit according to any one of claims 1 to 6.

8. A household appliance, characterized in that: The invention comprises the motor stall protection circuit according to any one of claims 1 to 6.

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