Low-power-consumption circuit and refrigerator

Abstract

The utility model discloses a low power consumption circuit and a refrigerator. The low power consumption circuit comprises a main control circuit; the power supply circuit comprises a live wire terminal, a zero line terminal, a filter capacitor and a rectifying circuit; the discharging circuit comprises a switching circuit, an optocoupler bidirectional silicon controlled rectifier and a discharging resistor; a switching path of the switching circuit is connected in series in a power supply loop of a light-emitting end of the optocoupler bidirectional silicon controlled rectifier, one end of a light-receiving end of the optocoupler bidirectional silicon controlled rectifier is connected with one end of the filter capacitor, and the other end is connected with the other end of the filter capacitor through the discharge resistor; and the voltage detection circuit is used for detecting the AC voltage and outputting a detection signal to the main control circuit, and the main control circuit controls the on-off of the switching circuit according to the received detection signal. According to the low-power-consumption circuit and the refrigerator provided by the utility model, when alternating current is normally supplied, the discharge resistor does not generate power consumption; when the alternating current is cut off, the discharge resistor discharges through the optocoupler bidirectional silicon controlled rectifier, and the technical problem of high power consumption of the discharge resistor during normal power supply in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, and in particular to a low-power consumption circuit and a refrigerator. Background Art

[0002] At present, refrigerators meet the requirements of electromagnetic compatibility, and generally need parallel capacitors to filter out interference. Generally speaking, the larger the capacitor, the better the filtering effect.

[0003] Due to the energy storage characteristics of capacitors, during the safety test of plug discharge, the larger the capacitance, the smaller the discharge resistance is required to release the voltage to the qualified range within the qualified time. However, during normal power supply, the smaller the discharge resistance, the greater the power consumption it generates, resulting in greater power consumption of the product. Summary of the invention

[0004] The utility model provides a low power consumption circuit, which solves the technical problem of large power consumption of the discharge resistor during normal power supply in the prior art.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model provides a low power consumption circuit, comprising:

[0007] Main control circuit;

[0008] A power supply circuit, comprising a live terminal, a neutral terminal, a filter capacitor, and a rectifier circuit; the live terminal is connected to the live wire, the neutral terminal is connected to the neutral wire; the filter capacitor is connected between the live terminal and the neutral terminal; the first input end of the rectifier circuit is connected to the live terminal, the second input end of the rectifier circuit is connected to the neutral terminal, and the output end of the rectifier circuit outputs direct current;

[0009] A discharge circuit, comprising a switch circuit, an optocoupler bidirectional thyristor, and a discharge resistor; a switch path of the switch circuit is connected in series in a power supply circuit of a light-emitting end of the optocoupler bidirectional thyristor, one end of a light-receiving end of the optocoupler bidirectional thyristor is connected to one end of the filter capacitor, and the other end of the light-receiving end of the optocoupler bidirectional thyristor is connected to the other end of the filter capacitor through the discharge resistor;

[0010] A voltage detection circuit is connected to the live terminal and the neutral terminal, and is used to detect the AC voltage and output a detection signal to the main control circuit. The main control circuit controls the on and off of the switch circuit according to the received detection signal.

[0011] In some embodiments of the present application, the voltage detection circuit includes a control unit, a first switch tube, and a first optical coupler;

[0012] The first detection end of the control unit is connected to the live wire terminal;

[0013] The second detection end of the control unit is connected to the neutral terminal;

[0014] The output end of the control unit is connected to the control end of the first switching tube; the switch path of the first switching tube is connected in series in the power supply circuit of the light-emitting end of the first optocoupler, the input end of the light-receiving end of the first optocoupler is connected to a DC power supply, the output end of the light-receiving end of the first optocoupler is grounded through a pull-down resistor, and the output end of the light-receiving end of the first optocoupler is connected to the first detection end of the main control circuit.

[0015] In some embodiments of the present application, the first switch tube is an NPN transistor, the base of the first switch tube is connected to the output end of the control unit, the collector of the first switch tube is connected to the output end of the light-emitting end of the first optocoupler, and the emitter of the first switch tube is grounded.

[0016] In some embodiments of the present application, the switching circuit is a transistor, the base of the transistor is connected to the output end of the main control circuit, one end of the switching path of the transistor is grounded, and the other end is connected to the output end of the light-emitting end of the optocoupler bidirectional thyristor, and the input end of the light-emitting end of the optocoupler bidirectional thyristor is connected to a DC power supply through a pull-up resistor.

[0017] In some embodiments of the present application, the low power consumption circuit further includes:

[0018] The zero-crossing detection circuit is used to convert the input sinusoidal alternating current into a square wave signal and output it to the main control circuit.

[0019] In some embodiments of the present application, the zero-crossing detection circuit includes a second optocoupler and a second switch tube; the input end of the light-emitting end of the second optocoupler is connected to the live wire terminal;

[0020] The output end of the light-emitting end of the second optical coupler is connected to the neutral line terminal;

[0021] The input end of the light receiving end of the second optical coupler is connected to a DC power supply;

[0022] The output end of the light receiving end of the second optical coupler is connected to the control end of the second switch tube;

[0023] One end of the switch path of the second switch tube is connected to a DC power supply via a pull-up resistor, and one end of the switch path of the second switch tube is connected to a second detection end of the main control circuit;

[0024] The other end of the switch path of the second switch tube is grounded.

[0025] In some embodiments of the present application, the second switch tube is an NPN transistor, the base of the second switch tube is connected to the output end of the light receiving end of the second optocoupler, the emitter of the second switch tube is grounded, the collector of the second switch tube is connected to a DC power supply through a pull-up resistor, and the collector of the second switch tube is connected to the second detection end of the main control circuit.

[0026] In some embodiments of the present application, the positive output terminal and the negative output terminal of the rectifier circuit are connected to a switching power supply.

[0027] In some embodiments of the present application, an electrolytic capacitor is connected in parallel between the positive output terminal and the negative output terminal of the rectifier circuit.

[0028] The utility model provides a refrigerator, comprising the low-power consumption circuit.

[0029] The technical solution of the utility model has the following technical effects compared with the prior art: the low-power circuit and refrigerator of the utility model are designed to have a discharge circuit including a switch circuit, an optocoupler bidirectional thyristor, and a discharge resistor; the switch path of the switch circuit is connected in series in the power supply circuit of the light-emitting end of the optocoupler bidirectional thyristor, one end of the light-receiving end of the optocoupler bidirectional thyristor is connected to one end of the filter capacitor, and the other end of the light-receiving end of the optocoupler bidirectional thyristor is connected to the other end of the filter capacitor through the discharge resistor; the voltage detection circuit is designed to detect the AC voltage and output a detection signal to the main control circuit, and the main control circuit controls the on and off of the switch circuit according to the received detection signal; when the AC voltage is detected to be 0, the main control circuit controls the switch circuit to be turned on, and the filter capacitor is discharged through the optocoupler bidirectional thyristor and the discharge resistor to ensure the safety of the circuit; therefore, in the low-power circuit of the utility model, when the AC power is normally supplied, there is no current on the discharge resistor, and the discharge resistor does not generate power consumption; when the AC power is cut off, the filter capacitor is discharged through the optocoupler bidirectional thyristor and the discharge resistor, which meets the discharge requirements, ensures the safety of the circuit, and solves the technical problem of large power consumption of the discharge resistor during normal power supply in the prior art.

[0030] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 This is a principle block diagram of an embodiment of the low power consumption circuit of the utility model;

[0033] Figure 2 is a principle block diagram of an embodiment of a discharge circuit;

[0034] Figure 3 A circuit schematic diagram of an embodiment of a discharge circuit;

[0035] Figure 4 is a principle block diagram of an embodiment of a voltage detection circuit;

[0036] Figure 5 A circuit schematic diagram of an embodiment of a voltage detection circuit;

[0037] Figure 6 A functional block diagram of another embodiment of a low power consumption circuit;

[0038] Figure 7 A circuit schematic diagram of an embodiment of a zero-crossing detection circuit;

[0039] Figure 8 It is a principle block diagram of another embodiment of a low power consumption circuit;

[0040] Fig. 9 is a circuit schematic diagram of an embodiment of a power supply circuit;

[0041] Fig.10 It is a circuit schematic diagram of another embodiment of a low power consumption circuit. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] In the present utility model, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0048] Embodiment 1

[0049] The low power consumption circuit of this embodiment includes a main control circuit, a power supply circuit, a discharge circuit, a voltage detection circuit, etc. Figure 1 shown.

[0050] The power supply circuit includes a live terminal L, a neutral terminal N, a filter capacitor CX1 (safety capacitor), and a rectifier circuit. The live terminal L is connected to the live wire, and the neutral terminal N is connected to the neutral wire; the filter capacitor CX1 is connected between the live terminal L and the neutral terminal N; the first input end of the rectifier circuit is connected to the live terminal L, the second input end of the rectifier circuit is connected to the neutral terminal N, and the output end of the rectifier circuit outputs direct current. After the rectifier circuit rectifies the alternating current, it outputs direct current through the positive output end and the negative output end to supply power to various electrical devices.

[0051] The discharge circuit includes a switch circuit, an optocoupler bidirectional thyristor PQ1, and a discharge resistor R2. Figure 2 , Figure 3 The control end of the switch circuit is connected to the main control circuit, the switch path of the switch circuit is connected in series in the power supply circuit of the light-emitting end of the optocoupler bidirectional thyristor PQ1, one end of the light-receiving end of the optocoupler bidirectional thyristor PQ1 is connected to one end of the filter capacitor CX1, and the other end of the light-receiving end of the optocoupler bidirectional thyristor PQ1 is connected to the other end of the filter capacitor CX1 through the discharge resistor R2.

[0052] The voltage detection circuit is connected to the live terminal and the neutral terminal, and is used to detect the AC voltage (mains voltage) and output a detection signal to the main control circuit (main control MCU). The main control circuit controls the on and off of the switch circuit according to the received detection signal.

[0053] The two input terminals of the voltage detection circuit are connected to the live wire terminal and the neutral wire terminal correspondingly to detect the AC voltage (mains voltage) in real time.

[0054] When the voltage detection circuit detects that the AC voltage is 0, it outputs a detection signal (such as a low level) to the main control circuit. After receiving the low-level detection signal, the main control circuit determines that the AC power is off, and outputs a conduction signal to the switch circuit to control the switch circuit to be turned on, so that the power supply circuit of the light-emitting end of the optocoupler bidirectional thyristor PQ1 is turned on, the light-emitting end of the optocoupler bidirectional thyristor PQ1 emits light, the light-receiving end of the optocoupler bidirectional thyristor PQ1 is turned on, and the charge of the filter capacitor CX1 is discharged through the optocoupler bidirectional thyristor PQ1 and the discharge resistor R2.

[0055] When the voltage detection circuit detects that the AC voltage is not 0, it outputs a detection signal (such as a high level) to the main control circuit. After receiving the high-level detection signal, the main control circuit determines that the AC power is not off, and outputs a shutdown signal to the switch circuit to control the switch circuit to shut down, thereby disconnecting the power supply circuit of the light-emitting end of the optocoupler bidirectional thyristor PQ1, disconnecting the optocoupler bidirectional thyristor PQ1, and there is no current on the discharge resistor R2, so that the discharge resistor R2 will not generate power consumption.

[0056] Therefore, when the AC power is cut off, the AC voltage is 0, the main control circuit controls the switch circuit to turn on, and then the optocoupler bidirectional thyristor PQ1 is turned on, and the filter capacitor CX1 is discharged through the optocoupler bidirectional thyristor PQ1 and the discharge resistor R2, meeting the safety requirements and ensuring the circuit safety.

[0057] When the AC power is supplied normally, the AC voltage is not 0, the main control circuit controls the switch circuit to turn off, and then the optocoupler bidirectional thyristor PQ1 is turned off, there is no current on the discharge resistor R2, and the discharge resistor R2 will not generate power consumption. Therefore, when the power supply is normal, the discharge resistor R2 will not increase the power consumption of the product.

[0058] The low-power circuit of this embodiment is designed to have a discharge circuit including a switch circuit, an optocoupler bidirectional thyristor PQ1, and a discharge resistor R2; the switch path of the switch circuit is connected in series in the power supply circuit of the light-emitting end of the optocoupler bidirectional thyristor PQ1, one end of the light-receiving end of the optocoupler bidirectional thyristor PQ1 is connected to one end of the filter capacitor CX1, and the other end of the light-receiving end of the optocoupler bidirectional thyristor PQ1 is connected to the other end of the filter capacitor CX1 through the discharge resistor R2; a voltage detection circuit is designed to detect the AC voltage and output a detection signal to the main control circuit, and the main control circuit controls the switch according to the received detection signal The on-off of the circuit; when the AC voltage is detected to be 0, the main control circuit controls the switch circuit to be turned on, and the filter capacitor CX1 is discharged through the optocoupler bidirectional thyristor PQ1 and the discharge resistor R2 to ensure the safety of the circuit; therefore, in the low-power circuit of this embodiment, when the AC power is normally supplied, there is no current on the discharge resistor R2, and the discharge resistor R2 does not generate power consumption; when the AC power is cut off, the filter capacitor CX1 is discharged through the optocoupler bidirectional thyristor PQ1 and the discharge resistor R2, which meets the discharge requirements, ensures the safety of the circuit, and solves the technical problem of high power consumption of the discharge resistor during normal power supply in the prior art.

[0059] In some embodiments of the present application, the switch circuit is a transistor N1, and the base of the transistor N1 is connected to the output end of the main control circuit. One end of the switch path of the transistor N1 is grounded, and the other end of the switch path of the transistor N1 is connected to the output end of the light-emitting end of the optocoupler bidirectional thyristor PQ1, and the input end of the light-emitting end of the optocoupler bidirectional thyristor PQ1 is connected to the DC power supply through the pull-up resistor R3.

[0060] By designing the switch circuit as a transistor N1, it is convenient to control the on and off of the switch circuit, and then it is convenient to control the on and off of the optocoupler bidirectional thyristor PQ1.

[0061] In some embodiments of the present application, the transistor N1 is an NPN transistor, the base of the transistor N1 is connected to the output end of the main control circuit through the resistor R5, the emitter of the transistor N1 is grounded, and the collector of the transistor N1 is connected to the output end of the light-emitting end of the optocoupler bidirectional thyristor PQ1, see Figure 3 shown.

[0062] In some embodiments of the present application, the voltage detection circuit includes a control unit (detection MCU), a first switch tube Q1, and a first optical coupler IC1. Figure 4 shown.

[0063] The first detection end of the control unit is connected to the live wire terminal L; the second detection end of the control unit is connected to the neutral wire terminal N.

[0064] The output end of the control unit is connected to the control end of the first switch tube Q1 to control the on and off of the first switch tube Q1. The switch path of the first switch tube Q1 is connected in series in the power supply circuit of the light-emitting end of the first optocoupler IC1, the input end of the light-receiving end of the first optocoupler IC1 is connected to a DC power supply, the output end of the light-receiving end of the first optocoupler IC1 is grounded through a pull-down resistor R12, and the output end of the light-receiving end of the first optocoupler IC1 is connected to the first detection end of the main control circuit.

[0065] When the control unit detects that the AC voltage is 0, it outputs a control signal (such as a low level) to the first switch tube Q1, controls the first switch tube Q1 to turn off, causes the first optocoupler IC1 to turn off, and the output end of the light-receiving end of the first optocoupler IC1 is a low level. The first detection end of the main control circuit receives the low level, controls the switch circuit of the discharge circuit to turn on, and then the optocoupler bidirectional thyristor PQ1 is turned on, and the filter capacitor CX1 is discharged through the optocoupler bidirectional thyristor PQ1 and the discharge resistor R2.

[0066] When the control unit detects that the AC voltage is not 0, it outputs a control signal (such as a high level) to the first switch tube Q1, controls the first switch tube Q1 to turn on, causes the first optocoupler IC1 to turn on, and the output end of the light-receiving end of the first optocoupler IC1 is pulled to a high level. The first detection end of the main control circuit receives the high level, controls the switch circuit of the discharge circuit to turn off, and then turns off the optocoupler bidirectional thyristor PQ1, and the discharge resistor R2 does not generate power consumption.

[0067] By designing the voltage detection circuit of the above structure, not only can the AC voltage be detected, but the on and off of the first optocoupler IC1 can be controlled by the first switch tube Q1, which is simple and convenient to control. In addition, the first optocoupler IC1 is used for isolation to ensure the safety of the subsequent circuit.

[0068] In some embodiments of the present application, the first switch tube Q1 is an NPN transistor, the base of the first switch tube Q1 is connected to the output end of the control unit through a resistor R8, the collector of the first switch tube Q1 is connected to the output end of the light-emitting end of the first optocoupler IC1, the input end of the light-emitting end of the first optocoupler IC1 is connected to the DC power supply through a resistor R10, and the emitter of the first switch tube Q1 is grounded, see Figure 5 shown.

[0069] When the first switch tube Q1 is turned on, the first optocoupler IC1 is turned on; when the first switch tube Q1 is turned off, the first optocoupler IC1 is turned off.

[0070] By designing the first switch tube Q1 to be an NPN transistor, the cost is low and the performance is stable, and it is convenient to control the on and off of the first switch tube Q1, thereby facilitating the on and off control of the first optical coupler IC1.

[0071] In some embodiments of the present application, the first detection terminal of the control unit is connected to the live wire terminal L through the first diode D1. The first diode D1 is used to rectify the live wire voltage.

[0072] The first detection terminal of the control unit is connected to the cathode of the first diode D1 through the resistor R6, and the anode of the first diode D1 is connected to the live wire terminal L. When the live wire voltage is a positive half-wave, the first diode D1 is turned on. When the live wire voltage is a negative half-wave, the first diode D1 is turned off.

[0073] The second detection terminal of the control unit is connected to the neutral line terminal N through the resistor R7.

[0074] A capacitor C1 is connected in parallel between the first detection terminal and the second detection terminal of the control unit (detection MCU) to play a filtering role.

[0075] When the first detection end and the second detection end of the control unit detect that the voltage between the live terminal and the neutral terminal is not 0, the control end of the control unit outputs a high level, controls the first switch tube Q1 to turn on, and then the first optocoupler IC1 is turned on, and the output end of the light receiving end of the first optocoupler IC1 outputs a high level to the main control circuit.

[0076] When the first detection end and the second detection end of the control unit detect that the voltage between the live terminal and the neutral terminal is 0, the control end of the control unit outputs a low level, controls the first switch tube Q1 to turn off, and then turns off the first optocoupler IC1, and the output end of the light receiving end of the first optocoupler IC1 outputs a low level to the main control circuit.

[0077] Therefore, when the AC power is normally supplied, the output end of the light receiving end of the first optical coupler IC1 outputs a low level signal to the main control circuit.

[0078] When the AC power is cut off, the output end of the light receiving end of the first optical coupler IC1 outputs a high level signal to the main control circuit.

[0079] The main control unit can determine whether the AC power is off based on the high and low levels output by the received voltage detection circuit.

[0080] In some embodiments of the present application, the low power consumption circuit further includes a zero crossing detection circuit. Figure 6 shown.

[0081] The zero-crossing detection circuit is used to convert the input sinusoidal alternating current into a square wave signal and output it to the main control circuit.

[0082] The first input end of the zero-crossing detection circuit is connected to the live wire terminal L, and the second input end is connected to the neutral wire terminal N. The zero-crossing detection circuit converts the sinusoidal AC power into a square wave signal.

[0083] When the AC power is supplied normally, the zero-crossing detection circuit outputs a square wave signal to the main control circuit.

[0084] When the AC power is off, the zero-crossing detection circuit outputs a continuous high level or low level to the main control circuit.

[0085] When the main control circuit receives the square wave signal output by the zero-crossing detection circuit and determines that the AC power is normally supplied, the switch circuit of the discharge circuit is controlled to be turned off, and then the optocoupler bidirectional thyristor PQ1 is turned off, and the discharge resistor R2 does not generate power consumption.

[0086] When the main control circuit receives a continuous high level or low level output by the zero-crossing detection circuit, it determines that the AC power is off, and controls the switch circuit of the discharge circuit to be turned on, and then the optocoupler bidirectional thyristor PQ1 is turned on, and the filter capacitor CX1 is discharged through the optocoupler bidirectional thyristor PQ1 and the discharge resistor R2.

[0087] By designing a zero-crossing detection circuit, the main control circuit can accurately determine whether the AC power is off based on the zero-crossing detection circuit and the voltage detection circuit, thereby improving the accuracy of determining when the AC power is off.

[0088] In some embodiments of the present application, the zero-crossing detection circuit includes a second optical coupler IC2 and a second switch tube Q2. Figure 7 shown.

[0089] The input end of the light emitting end of the second optocoupler IC2 is connected to the live terminal L. Specifically, the input end of the light emitting end of the second optocoupler IC2 is connected to the cathode of the second diode D2 through the resistor R14, and the anode of the second diode D2 is connected to the live terminal L.

[0090] The output end of the light emitting end of the second optical coupler IC2 is connected to the neutral line terminal N.

[0091] The input end of the light-receiving end of the second optocoupler IC2 is connected to a DC power supply; the output end of the light-receiving end of the second optocoupler IC2 is connected to the control end of the second switch tube Q2; one end of the switch path of the second switch tube Q2 is connected to the DC power supply through a pull-up resistor R17, and one end of the switch path of the second switch tube Q2 is connected to the second detection end of the main control circuit; the other end of the switch path of the second switch tube Q2 is grounded.

[0092] When the live line voltage is a positive half-wave, the second optocoupler IC2 is turned on, and the output end of the light-receiving end of the second optocoupler IC2 outputs a high level to the control end of the second switch tube Q2, controlling the second switch tube Q2 to be turned on, and one end of the switch path of the second switch tube Q2 is pulled to a low level, and the second detection end of the main control circuit receives the low level.

[0093] When the live line voltage is a negative half-wave, the second optocoupler IC2 is turned off, and the output end of the light-receiving end of the second optocoupler IC2 outputs a low level to the control end of the second switch tube Q2, controlling the second switch tube Q2 to be turned off, and one end of the switch path of the second switch tube Q2 is pulled to a high level, and the second detection end of the main control circuit receives a high level.

[0094] When the AC power passes through zero, the on / off state of the second optocoupler IC2 changes, and then the on / off state of the second switch tube Q2 changes; therefore, when the AC power is normally supplied, the zero-crossing detection circuit outputs a square wave signal to the second detection terminal of the main control circuit.

[0095] Therefore, when the AC power is supplied normally, the zero-crossing detection circuit outputs a square wave signal to the second detection terminal of the main control circuit; when the AC power is cut off, the zero-crossing detection circuit outputs a high level to the second detection terminal of the main control circuit.

[0096] By designing the zero-crossing detection circuit of the above structure, the zero-crossing point of the alternating current and the power failure of the alternating current can be accurately detected, and the circuit structure is simple and easy to implement.

[0097] In some embodiments of the present application, the second switch tube Q2 is an NPN transistor, the base of the second switch tube Q2 is connected to the output end of the light receiving end of the second optocoupler IC2 through a resistor R15, the emitter of the second switch tube Q2 is grounded, and the collector of the second switch tube Q2 is connected to a DC power supply through a pull-up resistor R17. The collector of the second switch tube Q2 is connected to the second detection end of the main control circuit through a resistor R18.

[0098] By designing the second switch tube Q2 as an NPN transistor, the cost is low and the performance is stable, and it is convenient to control the on and off of the first switch tube Q1, and then it is convenient to control the on and off of the second optical coupler IC2.

[0099] In some embodiments of the present application, the positive output terminal and the negative output terminal of the rectifier circuit are connected to a switching power supply, see Figure 8 shown.

[0100] The rectifier circuit rectifies the AC power into DC power and outputs the DC power to the switching power supply. The switching power supply converts the received DC power into a voltage and outputs DC power with a suitable voltage to provide suitable DC power for various electrical devices. For example, the switching power supply supplies power to the main control circuit.

[0101] For example, a switching power supply provides a 5V DC power supply to power the required electrical devices.

[0102] By designing a switching power supply in the power circuit, it is convenient to power each device.

[0103] In some embodiments of the present application, an electrolytic capacitor E1 is connected in parallel between the positive output terminal and the negative output terminal of the rectifier circuit, see Fig. 9 shown.

[0104] The electrolytic capacitor E1 is not only used for filtering to ensure the voltage stability of the direct current transmitted to the switching power supply, but can also be used to store electrical energy.

[0105] When the AC power is supplied normally, the rectifier circuit outputs DC power to charge the electrolytic capacitor E1 and supply power to the switching power supply.

[0106] When the AC power is cut off, the electrolytic capacitor E1 supplies power to the switching power supply. Therefore, it can be ensured that the switching power supply will continue to supply power to the main control circuit for a period of time, so as to ensure that the main control circuit has enough time to control the conduction of the discharge circuit.

[0107] In some embodiments of the present application, the power supply circuit further includes a common mode inductor LX1 to filter out interference signals. The common mode inductor LX1 includes a first winding and a second winding.

[0108] The input end of the first winding is connected to the live terminal L through a fuse FUSE1, and the input end of the second winding is connected to the neutral terminal N. The output end of the first winding is connected to the first input end of the rectifier circuit, and the output end of the second winding is connected to the second input end of the rectifier circuit.

[0109] A varistor RV1 is connected in parallel between the live terminal L and the neutral terminal N. When the voltage across the varistor RV1 exceeds its threshold, the varistor RV1 is turned on, short-circuiting the subsequent circuit, and the current passing through the fuse FUSE1 exceeds the current threshold, and the fuse FUSE1 is blown, preventing the voltage connected to the subsequent circuit from being too high, thereby protecting the circuit.

[0110] The rectifier circuit is a rectifier bridge BD1, which is built with four diodes and has a simple structure.

[0111] The low power consumption circuit of this embodiment eliminates the discharge resistor in the power supply circuit, reduces the power consumption of the product, and controls the discharge circuit to discharge by detecting the voltage value and zero crossing point of the input voltage, thereby meeting the safety requirements of plug discharge.

[0112] The present application relates to a circuit for reducing power consumption of household appliances, which not only meets the safety requirements of discharge, but also reduces power consumption.

[0113] Next, combine Fig.10 , the low power consumption circuit is described in detail.

[0114] The low power consumption circuit of this embodiment mainly includes the following five parts:

[0115] (1) Voltage detection circuit: used to detect AC voltage value.

[0116] (2) Zero-crossing detection circuit: used to detect the zero-crossing point of the AC power.

[0117] (3) Power supply circuit: used to supply power to other parts.

[0118] (4) Discharge circuit: used for discharging after the product is powered off.

[0119] (5) Main control circuit: used to receive signals sent by the zero-crossing detection circuit and the voltage detection circuit, and control the operation of the discharge circuit.

[0120] Working principle:

[0121] (1) The product is connected to the mains, the power circuit is powered, and the main control circuit (main control MCU) detects the square wave signal of 5V and 0V that keeps changing from the zero-crossing detection circuit; the voltage detection circuit detects the normal voltage value through the AD conversion sampling port of the control unit (detection MCU) and outputs a 5V voltage signal to the main control MCU.

[0122] (2) When the product is unplugged and there is no AC power input to the product, the zero-crossing detection circuit only outputs a 5V voltage signal to the main control MCU; however, due to the effect of the electrolytic capacitor E1, it will continue to supply power to the main control MCU for a period of time. At this time, the main control MCU only detects a 5V voltage signal and preliminarily determines that there is no AC power input to the product.

[0123] (3) When the product plug is unplugged, the voltage detection circuit detects that the normal voltage value is continuously decreasing at the AD conversion sampling port of the detection MCU. When it decreases to 0, it is determined that the product has no input AC power and provides a 0V signal to the main control MCU.

[0124] (4) The main control MCU determines that the product has been powered off through the signals output by the zero-crossing detection circuit and the voltage detection circuit, and controls the optocoupler bidirectional thyristor PQ1 of the discharge circuit to turn on. At this time, the residual power of capacitor CX1 is discharged through the optocoupler bidirectional thyristor PQ1 and the discharge resistor R2, ensuring that the product turns on the refrigerator load (such as a high-voltage defrost heater) for 1 second before turning it off, thereby discharging the power of the safety capacitor and meeting the safety requirements for discharge.

[0125] (5) When the product is working normally, the optocoupler bidirectional thyristor PQ1 is disconnected and the discharge resistor R2 does not generate power consumption.

[0126] Embodiment 2

[0127] Based on the design of the low power consumption circuit in the first embodiment, the second embodiment proposes a refrigerator including the low power consumption circuit.

[0128] By designing the low-power circuit in the refrigerator, when the AC power is normally supplied, there is no current on the discharge resistor R2, and the discharge resistor R2 will not generate power consumption; when the AC power is cut off, the filter capacitor CX1 is discharged through the optocoupler bidirectional thyristor PQ1 and the discharge resistor R2, meeting the discharge requirements, ensuring the safety of the circuit, solving the technical problem of high power consumption of the discharge resistor during normal power supply in the prior art, improving the user experience, and improving the competitiveness of the refrigerator.

[0129] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0130] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited to this. Any changes or substitutions that can be easily thought of by technicians familiar with the technical field within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A low power consumption circuit, characterized in that: include: Main control circuit; A power supply circuit, which includes a live terminal, a neutral terminal, a filter capacitor, and a rectifier circuit; The live wire terminal is connected to the live wire, and the neutral wire terminal is connected to the neutral wire; the filter capacitor is connected between the live wire terminal and the neutral wire terminal; the first input end of the rectifier circuit is connected to the live wire terminal, the second input end of the rectifier circuit is connected to the neutral wire terminal, and the output end of the rectifier circuit outputs direct current; A discharge circuit, comprising a switch circuit, an optocoupler bidirectional thyristor, and a discharge resistor; a switch path of the switch circuit is connected in series in a power supply circuit of a light-emitting end of the optocoupler bidirectional thyristor, one end of a light-receiving end of the optocoupler bidirectional thyristor is connected to one end of the filter capacitor, and the other end of the light-receiving end of the optocoupler bidirectional thyristor is connected to the other end of the filter capacitor through the discharge resistor; A voltage detection circuit is connected to the live terminal and the neutral terminal, and is used to detect the AC voltage and output a detection signal to the main control circuit. The main control circuit controls the on and off of the switch circuit according to the received detection signal.

2. The low power consumption circuit according to claim 1, characterized in that: The voltage detection circuit includes a control unit, a first switch tube, and a first optical coupler; The first detection end of the control unit is connected to the live wire terminal; The second detection end of the control unit is connected to the neutral terminal; The output end of the control unit is connected to the control end of the first switching tube; the switch path of the first switching tube is connected in series in the power supply circuit of the light-emitting end of the first optocoupler, the input end of the light-receiving end of the first optocoupler is connected to a DC power supply, the output end of the light-receiving end of the first optocoupler is grounded through a pull-down resistor, and the output end of the light-receiving end of the first optocoupler is connected to the first detection end of the main control circuit.

3. The low power consumption circuit according to claim 2, characterized in that: The first switch tube is an NPN transistor, the base of the first switch tube is connected to the output end of the control unit, the collector of the first switch tube is connected to the output end of the light-emitting end of the first optocoupler, and the emitter of the first switch tube is grounded.

4. The low power consumption circuit according to claim 1, characterized in that: The switching circuit is a transistor, the base of which is connected to the output end of the main control circuit, one end of the switch path of the transistor is grounded, and the other end is connected to the output end of the light-emitting end of the optocoupler bidirectional thyristor, and the input end of the light-emitting end of the optocoupler bidirectional thyristor is connected to a DC power supply through a pull-up resistor.

5. The low power consumption circuit according to claim 1, characterized in that: The low power consumption circuit further comprises: The zero-crossing detection circuit is used to convert the input sinusoidal alternating current into a square wave signal and output it to the main control circuit.

6. The low power consumption circuit according to claim 5, characterized in that: The zero-crossing detection circuit includes a second optical coupler and a second switch tube; The input end of the light emitting end of the second optical coupler is connected to the live wire terminal; The output end of the light-emitting end of the second optical coupler is connected to the neutral line terminal; The input end of the light receiving end of the second optical coupler is connected to a DC power supply; The output end of the light receiving end of the second optical coupler is connected to the control end of the second switch tube; One end of the switch path of the second switch tube is connected to a DC power supply via a pull-up resistor, and one end of the switch path of the second switch tube is connected to a second detection end of the main control circuit; The other end of the switch path of the second switch tube is grounded.

7. The low power consumption circuit according to claim 6, characterized in that: The second switch tube is an NPN transistor, the base of the second switch tube is connected to the output end of the light receiving end of the second optocoupler, the emitter of the second switch tube is grounded, the collector of the second switch tube is connected to a DC power supply through a pull-up resistor, and the collector of the second switch tube is connected to the second detection end of the main control circuit.

8. The low power consumption circuit according to claim 1, characterized in that: The positive output terminal and the negative output terminal of the rectifier circuit are connected to a switching power supply.

9. The low power consumption circuit according to any one of claims 1 to 8, characterized in that: An electrolytic capacitor is connected in parallel between the positive output terminal and the negative output terminal of the rectifier circuit.

10. A refrigerator, characterized in that The method comprises the low power consumption circuit as claimed in any one of claims 1 to 9.

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