Defrost and refrigerator circuit including the same

Description

1 / 26 “DEFROSTING AND REFRIGERATING CIRCUIT INCLUDING THE SAME” FIELD OF THE INVENTION

[001] The present description refers to the technical field of refrigerator defrosting, and in particular to a defrosting circuit and to a refrigerator including the same. FUNDAMENTALS OF THE INVENTION

[002] The evaporator of a refrigerator can gradually freeze on its surface during refrigerator cooling, and when the ice layer becomes too thick, it can result in unsatisfactory heat exchange and degradation of the refrigerator's cooling performance. Therefore, the refrigerator needs regular removal of the ice layer from the evaporator surface to ensure normal refrigerator cooling performance.

[003] Currently, some refrigerators have been defrosted by energizing and heating the electric heating wires. During defrosting, dynamic voltage regulation is achieved by switching a silicon-controlled rectifier device on and off. When a high voltage is applied, the silicon-controlled rectifier device has a shorter activation duration or a smaller conduction angle; while when a lower voltage is applied, the silicon-controlled rectifier device has a longer activation duration or a larger conduction angle. However, when high voltage is applied, if the silicon-controlled rectifier device is short-circuited and the abnormality cannot be detected in time, a high current will be constantly applied to the electric heating wires, resulting in abnormal cooling or serious refrigerator safety accidents. SUMMARY OF THE INVENTION

[004] A defrost circuit and a chiller including the same Petition 870240039424, dated 09 / 05 / 2024, p. 14 / 45 2 / 26 are supplied in the configurations described herein, which can prevent abnormally high temperatures of the electric heating wires.

[005] According to a first aspect of the embodiments of the present description, a defrosting circuit is provided which includes: an electric heating unit configured to heat for defrosting; a silicon controlled rectifier module including a silicon controlled rectifier device, wherein a power supply is connected to the electric heating assembly through the silicon controlled rectifier device, so as to provide an operating voltage to the electric heating assembly based on the activation or deactivation of the silicon controlled rectifier device; a first zero-crossing detection module connected to the power supply and configured to emit a first zero-crossing signal in response to a power supply voltage crossing zero; a second zero-crossing detection module connected in parallel with the electric heating assembly and configured to emit a second zero-crossing signal in response to an operating voltage level crossing zero; and a trigger module connected to the first zero-crossing detection module and the second zero-crossing detection module, and configured to trigger the disconnection of the power supply from the silicon-controlled rectifier device in response to the first zero-crossing signal being the same as the second zero-crossing signal.

[006] The defrost circuit according to the embodiment of the first aspect of the present description has at least the following beneficial effects. The first zero-crossing detection module is provided to emit the first zero-crossing signal to a controller to control the activation and Petition 870240039424, dated 09 / 05 / 2024, p. 15 / 45 3 / 26 Deactivation of the silicon controlled rectifier module, in order to provide a suitable operating voltage for the electric heating assembly, and the first zero-crossing detection module is provided to emit the second zero-crossing signal which represents an electrical signal state of the operating voltage emitted by the power supply through the silicon controlled rectifier device.When the silicon-controlled rectifier device operates normally, because the silicon-controlled rectifier device is controlled to exhibit a specific on / off pattern, one phase of an electrical signal from the operating voltage emitted by the power supply via the silicon-controlled rectifier device is different from that of an electrical signal from the power supply, i.e., the first zero-crossing signal is different from the second zero-crossing signal, and in this case, the disconnection of the power supply from the silicon-controlled rectifier device is not triggered.When the silicon-controlled rectifier device malfunctions, such as in a short circuit, the silicon-controlled rectifier device is out of control, and the electrical signal of the operating voltage is equal to the electrical signal of the power supply, i.e., the first zero-crossing signal is equal to the second zero-crossing signal, which triggers the disconnection of the power supply from the silicon-controlled rectifier device. This prevents a high current from being applied to the electric heating assembly continuously, and avoids an abnormally high temperature in the electric heating assembly, thus ensuring proper operation of the cooler.

[007] In some embodiments, the first zero-crossing detection module includes a first optocoupler and a first zero-crossing signal output terminal. An inductive input terminal of the first optocoupler is connected to the power supply, an inductive output terminal of the first optocoupler is connected to the first zero-crossing signal output terminal. Petition 870240039424, dated 09 / 05 / 2024, p. 16 / 45 4 / 26 zero. The first output terminal of the zero-crossing signal is connected to the trigger module.

[008] In some embodiments, the first zero-crossing detection module further includes a constant voltage source, a first voltage divider circuit, a first capacitor, and a ground terminal that are connected in series sequentially. The first voltage divider circuit includes at least two resistors connected in series. The inductive output terminal of the first optocoupler includes a first terminal and a second terminal. The first terminal is connected to a connection between any two adjacent resistors in the first voltage divider circuit. The second terminal is connected to a connection between the first capacitor and the ground terminal. The first zero-crossing signal output terminal is connected to a connection between the first voltage divider circuit and the first capacitor.

[009] In some embodiments, the second zero-crossing detection module includes a second optocoupler and a second zero-crossing signal output terminal. An inductive input terminal of the second optocoupler is connected in parallel with the electric heating assembly, an inductive output terminal of the second optocoupler is connected to the second zero-crossing signal output terminal. The second zero-crossing signal output terminal is connected to the trigger module.

[010] In some embodiments, the second zero-crossing detection module further includes a constant voltage source, a second voltage divider circuit, a second capacitor, and a ground terminal that are connected in series sequentially. The second voltage divider circuit includes at least two resistors connected in series. The inductive output terminal of the second optocoupler includes a third terminal and a fourth terminal. The third terminal is connected to a connection between any two adjacent resistors in the second optocoupler. Petition 870240039424, dated 09 / 05 / 2024, page 17 / 45 5 / 26 voltage divider circuit, the fourth terminal is connected to a connection between the second capacitor and the ground terminal. The second zero-crossing signal output terminal is connected to a connection between the second voltage divider circuit and the second capacitor.

[011] In some embodiments, the silicon-controlled rectifier module also includes a silicon-controlled rectifier optocoupler. An inductive input terminal of the silicon-controlled rectifier optocoupler is configured to receive a pulse control signal. An inductive output terminal of the silicon-controlled rectifier optocoupler includes a fifth terminal and a sixth terminal. The silicon-controlled rectifier device includes a first pin, a second pin, and a control pin. Both the first pin and the fifth terminal are connected to the power supply. The second pin is connected to the electric heating assembly, and the control pin is connected to the sixth terminal.

[012] In some embodiments, the silicon controlled rectifier module further includes a transistor array chip including a first group of input and output pins. A first input pin of the first group of input and output pins is connected to the trigger module to receive an enable signal from the trigger module, and a first output pin of the first group of input and output pins is connected to the inductive input terminal of the silicon controlled rectifier optocoupler.

[013] In some embodiments, the silicon controlled rectifier module also includes a defrost switch. The defrost switch is arranged between the power supply and the first pin, while a control terminal of the defrost switch is connected to the trigger module, so that it is activated to disconnect the power supply from the silicon controlled rectifier device.

[014] In some embodiments, the silicon controlled rectifier module Petition 870240039424, dated 09 / 05 / 2024, p. 18 / 45 6 / 26 also includes a transistor array chip including a second set of input and output pins. A second input pin from the second set of input and output pins is connected to the trigger module, and a second output pin from the second set of input and output pins is connected to the defrost switch control terminal.

[015] According to a second aspect of the embodiments of the present description, a chiller is provided which includes the defrost circuit according to the embodiments of the first aspect.

[016] Other features and advantages of the present description will be presented in the following description and, in part, will be obvious from the description, or may be learned by practicing the present description. The objectives and other advantages of the present description can be achieved and obtained by the structure particularly indicated in the description, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[017] Figure 1 is a circuit diagram of a first zero-crossing detection module according to an embodiment of the present description.

[018] Figure 2 is a circuit diagram of a second zero-crossing detection module according to an embodiment of the present description.

[019] Figure 3 is a circuit diagram of a silicon controlled rectifier module and an electric heating assembly according to an embodiment of the present description. DETAILED DESCRIPTION

[020] In order to make clear the objectives, technical schemes and advantages of the present description, the present description will be described in detail together with the drawings and embodiments. It should be understood that the specific embodiments described in this document are used only to illustrate the present description, and Petition 870240039424, dated 09 / 05 / 2024, p. 19 / 45 7 / 26 are not intended to limit the present description. Furthermore, the features, operations, or characteristics described in the description may be combined in any suitable manner to form various embodiments. However, the steps or actions in the method description may also be changed or adjusted in order in a way that is obvious to those skilled in the art. Therefore, the orders shown in the description and drawings are used only to clearly describe a particular embodiment, but are not intended to be interpreted as necessary orders unless it is otherwise specified that a particular order must be followed.

[021] In the descriptions of this description, “several” means one or more, “a plurality of / multiple” means two or more, “greater than”, “less than”, “exceed” or variants thereof before a number or series of numbers is understood as not including the number adjacent to the term, and “above”, “below”, “within” and the like are understood as including the number. If used in this document, terms such as “first”, “second” and the like are used merely to distinguish technical features, and are not intended to indicate or imply relative importance, or implicitly point to the number of technical features indicated, or implicitly point to the order of precedence of the technical features indicated.

[022] Here, the serial numbers of the parts themselves, such as “first”, “second” and the like, are used only to distinguish described objects and have no sequential or technical meaning. The terms “connection” and “coupling” mentioned in this description include direct and indirect connection (coupling), unless otherwise specified.

[023] Heat inside a refrigerator is transferred to the outside through an evaporator during refrigerator cooling. The surface temperature of the evaporator is usually lower, and prolonged cooling will cause Petition 870240039424, dated 09 / 05 / 2024, page 20 / 45 8 / 26 freezing on the evaporator surface. Therefore, it is necessary to defrost the evaporator after refrigeration for a period of time to prevent the ice on the evaporator surface from becoming too thick and affecting the heat exchange capacity. The control system of a frost-free refrigerator includes an automatic defrost control function, which removes ice from the evaporator by electric heating. Generally, the refrigerator's electric heating assembly is powered by AC, and the way the AC power supply is applied to both ends of the electric heating assembly is controlled by optocouplers. In this case, the silicon controlled rectifier device is connected to a switching device to control the heating of the electric heating assembly, i.e., the refrigerator defrosting is controlled by switching the silicon controlled rectifier device on and off.

[024] Generally, dynamic voltage regulation is achieved by setting an activation duration or a conduction angle of the silicon controlled rectifier device. When a higher voltage is required to be applied to the electric heating assembly, the silicon controlled rectifier device has a longer activation duration or a larger conduction angle; whereas when a lower voltage is required to be applied to the electric heating assembly, the silicon controlled rectifier device has a shorter activation duration or a smaller conduction angle.However, when the silicon-controlled rectifier device is short-circuited and the abnormality cannot be detected in time, a high current is constantly applied to the electric heating assembly, causing the silicon-controlled rectifier device to remain continuously at a high temperature and resulting in abnormal cooling or serious refrigerator safety accidents. Furthermore, the safety specifications of the International Electrotechnical Commission (IEC) require that the surface temperature of the electric heating assembly be controlled within a certain range. Petition 870240039424, dated 09 / 05 / 2024, page 21 / 45 9 / 26 a specific range when it does not operate normally. If a heating control loop is open-loop, it is impossible to control the entire loop to shut down after the silicon-controlled rectifier device short-circuits.

[025] In view of the foregoing, a defrost circuit and a cooler including the same are provided in the embodiments of the present description, in which a first zero-crossing detection module and a second zero-crossing detection module are provided. A first zero-crossing signal emitted by the first zero-crossing detection module represents an electrical signal from the power supply, and a second zero-crossing signal emitted by the second zero-crossing detection module represents an electrical signal of an operating voltage emitted by the silicon-controlled rectifier device. Then, it can be determined whether an abnormality, such as a short circuit, has occurred in the silicon-controlled rectifier device by determining whether the first zero-crossing signal is the same as the second zero-crossing signal.When it is determined that the silicon-controlled rectifier device is malfunctioning, the power supply is disconnected from the silicon-controlled rectifier device, so that an intense current can be avoided from being applied to the electric heating assembly all the time, and an abnormally high temperature of the electric heating assembly can be avoided, thus ensuring the proper operation of the refrigerator.

[026] A method for controlling refrigerator defrosting will be illustrated below in combination with the drawings.

[027] With reference to Figures 1 to 3, a defrosting circuit is provided according to an embodiment of the present description, which includes: an R12 electric heating unit configured for heating to defrost; a silicon controlled rectifier module including a rectifier device Petition 870240039424, dated 09 / 05 / 2024, page 22 / 45 10 / 26 controlled silicon rectifier Q1, where a power supply is connected to the electric heating assembly R12 through the controlled silicon rectifier device Q1, so as to provide an operating voltage to the electric heating assembly R12 based on the activation or deactivation of the controlled silicon rectifier device Q1; A first zero-crossing detection module connected to the power supply and configured to emit a first zero-crossing signal when a power supply voltage passes through zero; a second zero-crossing detection module connected in parallel with the electric heating assembly R12 and configured to emit a second zero-crossing signal when an operating voltage level crosses zero; and a trigger module connected to the first zero-crossing detection module and the second zero-crossing detection module, and configured to trigger the disconnection of the power supply from the silicon-controlled rectifier device Q1 when the first zero-crossing signal is the same as the second zero-crossing signal.

[028] The heating control of the electric heating assembly R12 is achieved by controlling the silicon-controlled rectifier device Q1. In electrical appliances such as refrigerators, there are strong and weak currents in a defrosting circuit. In order to avoid interference between the strong and weak currents, the activation or deactivation of the silicon-controlled rectifier device Q1 is usually controlled by a silicon-controlled rectifier optocoupler IC3. The controller controls the silicon-controlled rectifier optocoupler IC3 to emit a corresponding control signal by emitting a pulse control signal. The control signal is configured to control an activation or deactivation mode of the silicon-controlled rectifier device Q1, so as to obtain different voltages. Petition 870240039424, dated 09 / 05 / 2024, page 23 / 45 11 / 26 operation. The operating voltages are applied to the electric heating element R12 to cause the electric heating element R12 to heat up, thus performing the corresponding defrost control.

[029] Therefore, the silicon-controlled rectifier optocoupler IC3 controls the silicon-controlled rectifier device Q1 according to the pulse control signal from the controller. The pulse control signal is generated by the controller according to the first zero-crossing signal. Specifically, the first zero-crossing signal is a signal generated by the first zero-crossing detection module when a power supply voltage (alternating current) changes from positive to negative or from negative to positive, and the first zero-crossing signal represents a phase of the power supply. Therefore, the controller can determine the phase of the power supply according to the first zero-crossing signal, and control a conduction angle (phase angle) and an activation duration of the silicon-controlled rectifier device Q1 according to the phase of the power supply, thus achieving control of different heating powers.That is, it is a method for performing defrost control of the electric heating assembly R12 by detecting the zero crossing of the power supply and controlling the silicon-controlled rectifier device Q1 by the controller according to a result of the zero crossing detection.

[030] The embodiment of the present description provides protection for a control circuit based on the silicon controlled rectifier device Q1. By providing the second zero-crossing detection module and the trigger module, the connection between the power supply and the silicon controlled rectifier device Q1 can be cut off when the first zero-crossing signal is the same as the second zero-crossing signal.

[031] In one embodiment, the second zero-crossing detection module is connected between the silicon controlled rectifier device Q1 and the assembly Petition 870240039424, dated 09 / 05 / 2024, p. 24 / 45 12 / 26 electric heating element R12, to obtain the operating voltage applied at the output of the electric heating element R12 by the silicon controlled rectifier device Q1. Therefore, it can be determined whether the silicon controlled rectifier device Q1 is normal by determining if the operating voltage is normal. In the embodiment of the present description, the trigger module determines if the first zero-crossing signal is the same as the second zero-crossing signal, so as to determine if the operating voltage is normal. As can be seen above, the first zero-crossing signal represents one phase of an electrical signal from the power supply, and the second zero-crossing detection module is connected to an output terminal of the silicon controlled rectifier device Q1, and therefore, the second zero-crossing signal represents one phase of an electrical signal from the operating voltage.Since the silicon-controlled rectifier optocoupler IC3 is controlled to turn the silicon-controlled rectifier device Q1 on or off according to a specific pattern, the phases corresponding to the first zero-crossing signal and the second zero-crossing signal are different in a case of normal operation of the silicon-controlled rectifier device Q1, and the trigger module obviously receives the first zero-crossing signal and the second zero-crossing signal at different times (without considering the fact that the phases of the first zero-crossing signal and the second zero-crossing signal are different by several 180 degrees), and disconnecting the power supply of the silicon-controlled rectifier device Q1 does not trigger it. When the silicon-controlled rectifier device Q1 is short-circuited, the silicon-controlled rectifier device Q1 cannot be controlled to turn on or off.In this case, the phases of the operating voltage and the power supply are the same, that is, the phases corresponding to the first zero-crossing signal and the second zero-crossing signal are the same, and the trigger module receives the first zero-crossing signal and the second zero-crossing signal. Petition 870240039424, dated 09 / 05 / 2024, page 25 / 45 13 / 26 zero crossing at the same time, which triggers the disconnection of the power supply from the silicon-controlled rectifier device Q1. Therefore, high voltage is prevented from being applied to the electric heating assembly R12, thus ensuring safe operation of the refrigerator.

[032] It can be understood that the trigger module can be a trigger circuit composed only of circuit elements or a trigger circuit with an integrated control chip. For example, in a case where the trigger module is composed only of circuit elements, both the first zero-crossing signal and the second zero-crossing signal are entered in the form of a pulse level, and the trigger module may include a NAND gate circuit, to two input terminals of which the first zero-crossing signal and the second zero-crossing signal are respectively entered.In a case of normal operation of the silicon controlled rectifier device Q1, only one of the first zero-crossing signal and the second zero-crossing signal is at a high level, or both the first zero-crossing signal and the second zero-crossing signal are at a low level at the same time, thus the NAND gate circuit produces a high level, indicating that the connection between the power supply and the silicon controlled rectifier device Q1 is maintained. When the silicon controlled rectifier device Q1 is short-circuited, both the first zero-crossing signal and the second zero-crossing signal are at a high level at the same time, therefore the NAND gate circuit produces a low level, indicating that the power supply is disconnected from the silicon controlled rectifier device Q1.Regarding the trigger module with the integrated control chip, the comparison between the first zero-crossing signal and the second zero-crossing signal can be performed in a program-controlled manner, which can be defined by those skilled in the art according to actual needs, and the details will not be described here. Petition 870240039424, dated 09 / 05 / 2024, page 26 / 45 14 / 26

[033] In some embodiments, the first zero-crossing detection module includes a first ICI optocoupler and a first zero-crossing signal output terminal. An inductive input terminal of the first ICI optocoupler is connected to the power supply, an inductive output terminal of the first ICI optocoupler is connected to the first zero-crossing signal output terminal. The first zero-crossing signal output terminal is connected to the trigger module.

[034] The first zero-crossing detection module further includes a constant voltage source, a first voltage divider circuit, a first capacitor C1, and a ground terminal that are connected in series sequentially. The first voltage divider circuit includes at least two resistors connected in series. The inductive output terminal of the first optocoupler ICI includes a first terminal and a second terminal. The first terminal is connected to a connection between any two adjacent resistors in the first voltage divider circuit, the second terminal is connected to a connection between the first capacitor C1 and the ground terminal. The first zero-crossing signal output terminal is connected to a connection between the first voltage divider circuit and the first capacitor C1.

[035] A specific circuit configuration of the first zero-crossing detection module is shown in Figure 1. Two ends of the inductive input terminal of the first optocoupler IC1 are connected respectively to two AC input-to-output terminals, namely ACL and ACN (which indicate live and zero lines, respectively). A first resistor R1, a second resistor R2, and a first diode D1 are provided. ACL is connected to one of the two ends of the inductive input terminal of the first optocoupler IC1 through the first resistor R1, the other of the two ends of the inductive input terminal of the first optocoupler IC1 is connected to ACN through a first diode D1, and the second Petition 870240039424, dated 09 / 05 / 2024, p. 27 / 45 Resistor R2 (15 / 26) is connected between the two ends of the inductive input terminal of the first optocoupler IC1. The voltage divider resistance of the first voltage divider circuit is indicated by a third resistor R3 and a fourth resistor R4, and a voltage divider point is located at a connection between the third resistor R3 and the fourth resistor R4. At the inductive output terminal of the first optocoupler IC1, the first terminal is connected to the first zero-crossing signal output terminal (which is indicated by the MCU-zero-input in the figure) through the fourth resistor R4. The constant voltage source is connected to the ground terminal through the third resistor R3, the fourth resistor R4, and the first capacitor C1. The second terminal is connected to a connection between the first capacitor C1 and the ground terminal.

[036] When the power supply (alternating current) changes from negative to positive, the inductive input terminal (primary side) of the first optocoupler IC1 is connected, and then the inductive output terminal (secondary side) is connected. A voltage on the zero-input MCU is reduced by the ground terminal, and the first zero-crossing signal emitted by the zero-input MCU is at a low level. When the power supply (alternating current) changes from positive to negative, the inductive input terminal (primary side) of the first optocoupler IC1 is disconnected, and then the inductive output terminal (secondary side) is disconnected. The voltage on the zero-input MCU is increased by the constant voltage source, and the zero-input MCU is at a high level.

[037] In some embodiments, the second zero-crossing detection module includes a second optocoupler IC2 and a second zero-crossing signal output terminal. An inductive input terminal of the second optocoupler IC2 is connected in parallel with the electric heating assembly R12, an inductive output terminal of the second optocoupler IC2 is connected to the second zero-crossing signal output terminal. The second terminal of Petition 870240039424, dated 09 / 05 / 2024, page 28 / 45 The 16 / 26 zero-crossing signal output is connected to the trigger module.

[038] The second zero-crossing detection module further includes a constant voltage source, a second voltage divider circuit, a second capacitor C2, and a ground terminal that are connected in series sequentially. The second voltage divider circuit includes at least two resistors connected in series. The inductive output terminal of the second optocoupler IC2 includes a third terminal and a fourth terminal. The third terminal is connected to a connection between any two adjacent resistors in the second voltage divider circuit, and the fourth terminal is connected to a connection between the second capacitor C2 and the ground terminal. The second zero-crossing signal output terminal is connected to a connection between the second voltage divider circuit and the second capacitor C2.

[039] A specific circuit configuration of the second zero-crossing detection module is shown in Figure 2. Two ends of the inductive input terminal of the second optocoupler IC2 are connected respectively to the output terminal of the silicon controlled rectifier device Q1 and to the zero line, i.e., ACL-OUT and ACN. A fifth resistor R5, a sixth resistor R6, and a second diode D2 are provided. ACL-OUT is connected to one of the two ends of the inductive input terminal of the second optocoupler IC2 through the fifth resistor R5, the other of the two ends of the inductive input terminal of the second optocoupler IC2 is connected to ACN through the second diode D2. The sixth resistor R6 is connected between the two ends of the inductive input terminal of the second optocoupler IC2.The voltage divider resistance of the second voltage divider circuit is indicated by a seventh resistor R7 and an eighth resistor R8, and a voltage divider point is located at a connection between the seventh resistor R7 and the eighth resistor R8. At the inductive output terminal of the first optocoupler ICI, the third terminal is connected to the second output terminal of. Petition 870240039424, dated 09 / 05 / 2024, page 29 / 45 17 / 26 zero-crossing signal (indicated by the MCU-zero-output in the figure) through the first resistor R8. The constant voltage source is connected to the ground terminal through the seventh resistor R7, the eighth resistor R8, and the second capacitor C2. The fourth terminal is connected to a connection between the second capacitor C2 and the ground terminal.

[040] When the operating voltage changes from negative to positive, the inductive input terminal (primary side) of the second optocoupler IC2 is switched on, and then the inductive output terminal (secondary side) is switched on. A voltage on the zero-output MCU is reduced by the ground terminal, and the second zero-crossing signal output by the zero-output MCU is at a low level. When the operating voltage changes from positive to negative, the inductive input terminal (primary side) of the second optocoupler IC2 is switched off, and then the inductive output terminal (secondary side) is switched off. The voltage on the zero-output MCU is increased by the constant voltage source, and the zero-output MCU is at a high level.

[041] It can be understood that the constant voltage source is a DC power supply, which has a value of 5 V in the embodiment of the present description, and the constant voltage sources of the first zero-crossing detection module and the second zero-crossing detection module may have the same voltage.

[042] In some embodiments, an inductive input terminal of the silicon-controlled rectifier optocoupler IC3 is configured to receive a pulse control signal. An inductive output terminal of the silicon-controlled rectifier optocoupler IC3 includes a fifth terminal and a sixth terminal. The silicon-controlled rectifier device Q1 includes a first pin, a second pin, and a control pin. Both the first pin and the fifth terminal are connected to the power supply. The second pin is connected to the electric heating assembly R12, and the control pin is connected to the sixth terminal.

[043] The silicon controlled rectifier optocoupler IC3 is connected to the source Petition 870240039424, dated 09 / 05 / 2024, p. 30 / 45 The 18 / 26 power supply is connected through the fifth terminal, and the first pin of the silicon-controlled rectifier device Q1 is also connected to the power supply. The fifth and sixth terminals of the inductive output terminal of the silicon-controlled rectifier optocoupler IC3 can be conducted. When the fifth and sixth terminals are conducted, the power supply is conducted to the control pin of the silicon-controlled rectifier device Q1 through the fifth and sixth terminals, triggering the silicon-controlled rectifier device Q1 to switch on with a high level. Thus, the first and second pins can be conducted, and the power supply is conducted to the electric heating assembly R12 through the first and second pins, causing the electric heating assembly R12 to heat up.

[044] In some embodiments, the silicon controlled rectifier module also includes a transistor array chip IC4. The transistor array chip IC4 includes a first group of input and output pins. A first input pin of the first group of input and output pins is connected to the trigger module to receive an enable signal from the trigger module, and a first output pin of the first group of input and output pins is connected to the inductive input terminal of the silicon controlled rectifier optocoupler IC3.

[045] The IC4 transistor array chip typically includes a plurality of input and output pin groups, each of which includes two pins that are distributed respectively on one side of the IC4 transistor array chip to form a mode with one pin for input and another for output. In this mode, signal conversion is performed based on the IC4 transistor array chip, in which the first input pin of the first input and output pin group is connected to a heater-MCU in Figure 3, i.e., connected to a controller to receive the enable signal, and the enable signal is related to the first zero-crossing signal and is a signal generated by the controller to control the Petition 870240039424, dated 09 / 05 / 2024, p. 31 / 45 19 / 26 silicon controlled rectifier device Q1 according to the first zero-crossing signal. In Figure 3, the first output pin of the first group of input and output pins is connected to the inductive input terminal of the silicon controlled rectifier optocoupler IC3. The inductive input terminal of the silicon controlled rectifier optocoupler IC3 includes a seventh terminal and an eighth terminal; the seventh terminal is connected to a constant voltage input of 12 V, and the eighth terminal is connected to the first output pin of the first group of input and output pins. Therefore, when the MCU-heater is triggered, the constant voltage of 12 V is applied to a VSS ground pin of the transistor array chip IC4 through the seventh terminal, the eighth terminal, and the first output pin of the first group of input and output pins.In this case, the inductive input terminal of the silicon-controlled rectifier optocoupler IC3 is connected, so the inductive output terminal of the silicon-controlled rectifier optocoupler IC3 is also connected.

[046] In some embodiments, the silicon controlled rectifier module also includes a defrost switch. The defrost switch is located between the power supply and the first pin. A control terminal of the defrost switch is connected to the trigger module, so that it is triggered to disconnect the power supply from the silicon controlled rectifier device Q1.

[047] The defrost switch is a master switch, and the connection between the power supply and the silicon-controlled rectifier device Q1 can be established or interrupted by controlling the defrost switch, so that the trigger module can be connected to the defrost switch. The defrost switch can have various forms, such as a relay, a switching tube, etc. Taking the defrost switch as a relay, as shown in Figure 3, the relay switch consists of pins 3 and 4, while the control terminal comprises pins 1 and 2. Petition 870240039424, dated 09 / 05 / 2024, page 32 / 45 20 / 26 The coil between pins 1 and 2 can be energized to attract the switch, allowing the connection of pins 3 and 4. When entering defrost mode, the trigger module or controller energizes the coil to attract and close the relay switch, so that the ACL power supply is connected to the first pin of the silicon-controlled rectifier device Q1. When the trigger module determines that the first zero-crossing signal and the second zero-crossing signal are equal, the coil is triggered to de-energize, and thus the connection between pin 3 and pin 4 is disconnected. In this case, no voltage is applied to the silicon-controlled rectifier device Q1, and therefore it can be ensured that the silicon-controlled rectifier device Q1 will not short-circuit to cause abnormally high temperature of the electric heating assembly R12.

[048] Similarly, the defrost switch can also be controlled by the IC4 transistor array chip. That is, the IC4 transistor array chip includes a second group of input and output pins. A second input pin from the second group of input and output pins is connected to the trigger module, and a second output pin from the second group of input and output pins is connected to the control terminal of the defrost switch.

[049] The second input pin of the second group of input and output pins is connected to an MCU-relay in Figure 3, i.e., connected to the controller (in this case, the trigger module is the controller) to receive a defrost start signal from the controller. The defrost start signal is triggered by the periodic starting of the refrigerator itself or triggered automatically according to the evaporator temperature, which is not detailed here. The second output pin of the second group of input and output pins is connected to the control terminal of the defrost switch, so that when the defrost start signal is entered on the second input pin, Petition 870240039424, dated 09 / 05 / 2024, pages 33 / 45 21 / 26 the defrost switch can be triggered to be closed, in this case, pin 3 is connected to pin 4. Similarly, when the controller (or the trigger module) determines that the first zero-crossing signal and the second zero-crossing signal are equal, the defrost switch is triggered to be open via the second input pin, in this case, pin 3 is disconnected from pin 4.

[050] It can be seen from the description above that the first zero-crossing detection module is provided to emit the first zero-crossing signal to a controller to control the activation or deactivation of the silicon controlled rectifier module, so as to provide a suitable operating voltage for the electric heating assembly R12, and the second zero-crossing detection module is provided to emit the second zero-crossing signal, which represents an electrical signal state of the operating voltage emitted by the power supply through the silicon controlled rectifier device Q1.When the silicon-controlled rectifier device Q1 operates normally, because the silicon-controlled rectifier device Q1 is controlled to exhibit a specific on / off pattern, one phase of an electrical signal from the operating voltage emitted by the power supply via the silicon-controlled rectifier device Q1 is different from that of an electrical signal from the power supply, that is, the first zero-crossing signal is different from the second zero-crossing signal, and in this case, the disconnection of the power supply from the silicon-controlled rectifier device Q1 is not triggered.When the silicon-controlled rectifier device Q1 malfunctions, such as when short-circuited, the silicon-controlled rectifier device Q1 is out of control, and the electrical signal of the operating voltage is equal to the electrical signal of the power supply, that is, the first zero-crossing signal is the same as the second zero-crossing signal, which triggers the disconnection of the power supply from the silicon-controlled rectifier device Q1, so that... Petition 870240039424, dated 09 / 05 / 2024, pages 34 / 45 22 / 26 an intense current can be avoided from being applied to the R12 electric heating element all the time, and an abnormally high temperature of the R12 electric heating element can be avoided, thus ensuring proper operation of the refrigerator.

[051] Next, the defrosting circuit of the present description will be described in detail with a specific example.

[052] With reference to Figures 1 to 3, the defrost circuit includes an electric heating assembly R12, a first zero-crossing detection module, a second zero-crossing detection module and a silicon controlled rectifier module including the silicon controlled rectifier device Q1.

[053] The first zero-crossing detection module includes the first optocoupler IC1. A pin on the primary side 1 of the first optocoupler module is connected to ACL. A pin on the primary side 2 of the first optocoupler module is connected to ACN, i.e., connected to the AC input power supply. A pin on the secondary side 3 of the first optocoupler module is connected to a connection between the third resistor R3 and the fourth resistor R4, and a pin on the secondary side 4 of the first optocoupler module is connected to a connection between the first capacitor C1 and the ground terminal. A constant voltage source of 5 V is grounded through the third resistor R3, the fourth resistor R4, and the first capacitor C1. A first zero-crossing signal output terminal is connected to a connection between the fourth resistor R4 and the first capacitor C1 and is connected to an MCU--zero-input pin of the controller.

[054] When the alternating current changes from negative to positive, the primary side of the first optocoupler IC1 is switched on, and then the secondary side is switched on, and a voltage on the zero-input MCU is reduced by the ground terminal and a first zero-crossing signal emitted by the zero-input MCU is in a Petition 870240039424, dated 09 / 05 / 2024, pp. 35 / 45 23 / 26 low level. When the alternating current changes from positive to negative, the primary side of the first optocoupler IC1 is switched off, and then the secondary side is switched off. The voltage across the zero-input MCU is increased by the constant voltage source, and the zero-input MCU is at a high level.

[055] The second zero-crossing detection module includes a second optocoupler IC2. A pin on the primary side 1 of the second optocoupler IC2 is connected to ACL-OUT. A pin on the primary side 2 of the second optocoupler IC2 is connected to ACN, that is, connected to the operating voltage emitted by the silicon controlled rectifier device Q1. A pin on the secondary side 3 of the second optocoupler IC2 is connected to a connection between the seventh resistor R7 and the eighth resistor R8, and a pin on the secondary side 4 of the second optocoupler IC2 is connected to a connection between the second capacitor C2 and the ground terminal. The 5V constant voltage source is grounded through the seventh resistor R7, the eighth resistor R8, and the second capacitor C2. A second zero-crossing signal output terminal is connected to a connection between the eighth resistor R8 and the second capacitor C2 and is connected to an MCU-zero-output pin of the controller.

[056] When the operating voltage changes from negative to positive, the primary side of the second optocoupler IC2 is switched on, and then the secondary side is switched on. A voltage across the zero-output MCU is reduced by the ground terminal, and a second zero-crossing signal emitted by the zero-output MCU is at a low level. When the operating voltage changes from positive to negative, the primary side of the second optocoupler IC2 is switched off, and then the secondary side is switched off. The voltage across the zero-output MCU is increased by the constant voltage source, and the zero-output MCU is at a high level.

[057] The silicon controlled rectifier module includes a relay, a transistor array chip IC4, and a silicon controlled rectifier optocoupler IC3. As shown in Figure 3, the transistor array chip IC4 has eight groups of Petition 870240039424, dated 09 / 05 / 2024, pages 36 / 45 The 24 / 26 pin network has pins where pin 8 (VSS) is grounded, pin 9 (COM) is connected to a 12V DC voltage, and pin 8 is connected to pin 9 through a third capacitor (C3). The primary side of the silicon-controlled rectifier optocoupler IC3 includes three pins. Pin 1 of the silicon-controlled rectifier optocoupler IC3 is connected to a 12V DC voltage, pin 2 of the silicon-controlled rectifier IC3 is connected to pin 11 (OUT6) of the transistor array chip IC4, pin 6 (IN6) of the transistor array chip IC4 corresponds to pin 11 (OUT6), and pin 6 (IN6) of the transistor array chip IC4 is connected to an MCU-heater pin of the controller. The secondary side of the silicon-controlled rectifier optocoupler IC3 includes three pins.One pin 6 of the silicon-controlled rectifier optocoupler IC3 is connected to the ACL via the relay switch, one pin 4 of the silicon-controlled rectifier optocoupler IC3 is connected to a control pin 3 of the silicon-controlled rectifier device Q1. A first pin 1 of the silicon-controlled rectifier device Q1 is connected to the ACL via the relay switch, and a second pin 2 of the silicon-controlled rectifier device Q1 outputs to ACL-OUT. A relay control terminal is connected to a pin 12 OUT5 of the transistor array chip IC4, and pin 12 OUT5 of the transistor array chip IC4 corresponds to a pin 5 IN5 of the transistor array chip IC4, and pin 5 IN5 of the transistor array chip IC4 is connected to an MCU-relay pin of the controller.

[058] In defrost mode, the compressor stops and defrosting begins. At this moment, the controller triggers a high level through the MCU-relay to drive pin 5 of the IC4 transistor array chip to pull down pin 12. The 12V DC voltage passes through the relay control terminal, triggering and controlling a relay switch to be attracted and closed. Contacts 3 and 4 of the relay switch are connected to each other, and the ACL is connected to the first pin 1 of the silicon controlled rectifier device Q1.

[059] The MCU-heater pin of the controller fires a high-level signal of Petition 870240039424, dated 09 / 05 / 2024, pp. 37 / 45 25 / 26 according to the first zero-crossing signal, and triggers pin 6 of the IC4 transistor array chip to correspondingly pull down pin 11, and the 12V DC voltage passes sequentially through a tenth resistor R10, pin 1 of the IC3 silicon-controlled rectifier optocoupler, pin 2 of the IC3 silicon-controlled rectifier optocoupler, pin 11 of the IC4 transistor array chip, and pin 8 of the IC4 transistor array chip, to the ground terminal.

[060] At this moment, the primary side of the silicon-controlled rectifier optocoupler IC3 is switched on, and then the secondary side of the silicon-controlled rectifier optocoupler is switched on. The ACL sequentially passes through the relay switching contacts, a ninth resistor, pin 6 of the silicon-controlled rectifier optocoupler IC3, pin 4 of the silicon-controlled rectifier optocoupler IC3, and control pin 3 of the silicon-controlled rectifier device Q1, and then the silicon-controlled rectifier device Q1 is switched on.

[061] The first pin 1 and the second pin 2 of the silicon controlled rectifier device Q1 are conducted, and the ACL passes sequentially through the relay switching contacts, the first pin 1, the second pin 2 and the electric heating assembly R12, to the ground terminal.

[062] The relay is the master switch. The relay coil needs to be drawn in and closed when defrosting is required, and then the silicon-controlled rectifier device Q1 is controlled to be switched on or off by the silicon-controlled rectifier optocoupler IC3. When defrosting is complete, the control of the silicon-controlled rectifier device Q1 is removed first, and then the relay is switched off.

[063] In a case of abnormal operations, the silicon-controlled rectifier device Q1 short-circuits and fails, and a zero-crossing signal from the MCU zero-input and a zero-crossing signal from the MCU zero-output may be the same, which triggers the controller to change the MCU relay to a low level and, Petition 870240039424, dated 09 / 05 / 2024, pp. 38 / 45 26 / 26 then triggers the relay switch to be opened via pin 5 and pin 12 of the IC4 transistor array chip, so that the heating of the R12 electric heating assembly stops.

[064] According to a second aspect of the present description, a control device is provided that includes at least one processor and a memory for communication with at least one processor. The memory stores an instruction executable by at least one processor which, when executed by at least one processor, causes at least one processor to implement the method in the embodiment of the first aspect.

[065] According to a third aspect of the present description, a refrigerator is provided which includes a drawer, the control device in the embodiment of the second aspect, and an air outlet is provided in a rear side wall of the drawer and communicated with an air duct of the refrigerator.

[066] The above description is a detailed description of preferred implementations of the present description, but the present description is not limited to them. Various equivalent variations or substitutions may be made by those skilled in the art without departing from the scope of the present description, all of which are included within the scope defined by the claims of the present description. Petition 870240039424, dated 09 / 05 / 2024, pp. 39 / 45

Claims

1 / 4 CLAIMS 1. Defrosting circuit CHARACTERIZED in that it comprises: an electric heating assembly (R12) configured to heat for defrosting; a silicon controlled rectifier module comprising a silicon controlled rectifier device (Q1), through which a power supply is connected to the electric heating, so as to provide an operating voltage to the electric heating assembly (R12) based on the activation or deactivation of the silicon controlled rectifier device (Q1); a first zero-crossing detection module connected to the power supply and configured to emit a first zero-crossing signal in response to a zero-crossing power supply voltage;a second zero-crossing detection module connected in parallel with the electric heating assembly (R12) and configured to emit a second zero-crossing signal in response to an operating voltage level crossing zero; and a trigger module connected to the first zero-crossing detection module and the second zero-crossing detection module, and configured to trigger disconnection of the power supply from the silicon controlled rectifier device (Q1) in response to the first zero-crossing signal being the same as the second zero-crossing signal.

2. Defrosting circuit, according to claim 1, CHARACTERIZED in that the first zero-crossing detection module comprises a first optocoupler (IC1) and a first zero-crossing signal output terminal, an inductive input terminal of the first optocoupler (IC1) is connected to the power supply, an inductive output terminal of the first optocoupler (IC1) is connected to the first zero-crossing signal output terminal, and the first zero-crossing signal output terminal is connected to the trigger module.

3. Defrosting circuit, according to claim 2, CHARACTERIZED in that the first zero-crossing detection module further comprises a constant voltage source, a first voltage divider circuit, a first capacitor (C1) and a ground terminal that are connected in series sequentially, the first voltage divider circuit comprises at least two resistors (R3, R4) connected in series, the inductive output terminal of the first optocoupler (IC1) comprises a first terminal and a second terminal, the first terminal is connected in a connection between any two adjacent resistors in the first voltage divider circuit, the second terminal is connected in a connection between the first capacitor (C1) and the ground terminal, and the first zero-crossing signal output terminal is connected in a connection between the first voltage divider circuit and the first capacitor (C1).

4. Defrosting circuit, according to claim 1, CHARACTERIZED in that the second zero-crossing detection module comprises a second optocoupler (IC2) and a second zero-crossing signal output terminal, an inductive input terminal of the second optocoupler (IC2) is connected in parallel with the electric heating assembly (R12), and an inductive output terminal of the second optocoupler (IC2) is connected to the second zero-crossing signal output terminal, and the second zero-crossing signal output terminal is connected to the trigger module.

5. Defrosting circuit, according to claim 4, CHARACTERIZED in that the second zero-crossing detection module additionally comprises a constant voltage source, a second Petition 870240039424, dated 09 / 05 / 2024, page.41 / 45 3 / 4 voltage divider circuit, a second capacitor (C2) and a ground terminal that are connected in series in sequence, the second voltage divider circuit comprises at least two resistors (R7, R8) connected in series, and the inductive output terminal of the second optocoupler (IC2) comprises a third terminal and a fourth terminal, the third terminal is connected in a connection between any two adjacent resistors in the second voltage divider circuit, the fourth terminal is connected in a connection between the second capacitor (C2) and the ground terminal, and the second zero-crossing signal output terminal is connected in a connection between the second voltage divider circuit and the second capacitor (C2).

6. Defrosting circuit, according to claim 1, CHARACTERIZED in that the silicon controlled rectifier module further comprises a silicon controlled rectifier optocoupler (IC3), an inductive input terminal of the silicon controlled rectifier optocoupler (IC3) is configured to receive a pulse control signal, and an inductive output terminal of the silicon controlled rectifier optocoupler (IC3) comprises a fifth terminal and a sixth terminal; and the silicon controlled rectifier device (Q1) comprises a first pin (1), a second pin (2) and a control pin (3), both the first pin (1) and the fifth terminal are connected to the power supply, the second pin (2) is connected to the electric heating assembly (R12), and the control pin (3) is connected to the sixth terminal.

7. Defrosting circuit, according to claim 6, CHARACTERIZED in that the silicon controlled rectifier module further comprises a transistor array chip (IC4), the transistor array chip (IC4) comprises a first group of input and output pins, a first input pin of the first group of input and output pins is connected to the trigger module to receive an enable signal from the trigger module, and a first output pin of the first group of input and output pins is connected to the inductive input terminal of the silicon controlled rectifier optocoupler (IC3).

8. Defrost circuit, according to claim 6, CHARACTERIZED in that the silicon controlled rectifier module further comprises a defrost switch disposed between the power supply and the first pin (1), a control terminal of the defrost switch is connected to the trigger module, so as to be triggered to disconnect the power supply from the silicon controlled rectifier device (Q1).

9. Defrosting circuit, according to claim 8, CHARACTERIZED in that the silicon controlled rectifier module additionally comprises a transistor array chip (IC4), the transistor array chip (IC4) comprises a second group of input and output pins, a second input pin of the second group of input and output pins is connected to the trigger module, and a second output pin of the second group of input and output pins is connected to the control terminal of the defrost switch.

10. Refrigerator CHARACTERIZED by the fact that it comprises the defrosting circuit defined in any one of claims 1 to 9. Petition 870240039424, dated 09 / 05 / 2024, pp. 43 / 45

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