Refrigerating and freezing equipment

Abstract

The utility model discloses refrigerating and freezing equipment which comprises a temperature control switch, a heater and a control circuit, and the control circuit comprises a signal output branch and a controller. The temperature control switch is configured to be closed in response to the heating temperature of the heater being less than a first preset temperature to short-circuit the signal output branch, and is configured to be disconnected in response to the heating temperature being greater than or equal to the first preset temperature to stop the short-circuit signal output branch. The signal output branch is configured to output a first level signal to the controller when being short-circuited so as to enable the controller to determine that the heating temperature is smaller than a first preset temperature, and is configured to output a second level signal to the controller when being not short-circuited so as to enable the controller to determine that the heating temperature is larger than or equal to the first preset temperature. In this way, the heating temperature can be determined in a low-cost mode.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of household appliances, and in particular to a refrigeration and freezing device. Background Art

[0002] With the development of society and the continuous improvement of people's living standards, people's pace of life is getting faster and faster, so they are more and more willing to buy a lot of food and put it in refrigeration and freezing equipment. Various types of refrigeration and freezing equipment, such as refrigerators, have become one of the indispensable household appliances in people's daily lives.

[0003] At present, a heater for realizing the defrosting function is usually configured in a refrigeration and freezing device, and a circuit for determining the heating temperature of the heater in real time is configured, such as a circuit realized by an NTC resistor (negative temperature coefficient thermistor). However, since a circuit for determining the heating temperature of the heater in real time needs to be added, the cost will increase. Utility Model Content

[0004] The embodiment of the present application provides a refrigeration and freezing device that can determine the heating temperature in a low-cost manner.

[0005] In a first aspect, an embodiment of the present application provides a refrigeration and freezing device, comprising:

[0006] A temperature control switch, a heater and a control circuit, wherein the control circuit includes a signal output branch and a controller;

[0007] The first end of the temperature control switch is connected to the first end of the AC power supply and the first end of the signal output branch respectively, the second end of the temperature control switch is connected to the first end of the heater and the second end of the signal output branch respectively, the second end of the heater is connected to the second end of the AC power supply, and the third end of the signal output branch is connected to the controller;

[0008] The temperature control switch is configured to close in response to the heating temperature of the heater being less than a first preset temperature to short-circuit the signal output branch, and is configured to open in response to the heating temperature being greater than or equal to the first preset temperature to stop short-circuiting the signal output branch;

[0009] The signal output branch is configured to output a first level signal to the controller when short-circuited, so that the controller determines that the heating temperature is less than the first preset temperature, and is configured to output a second level signal to the controller when not short-circuited, so that the controller determines that the heating temperature is greater than or equal to the first preset temperature.

[0010] In one or more embodiments, the refrigeration and freezing equipment further includes a compressor, and the control circuit further includes a switch branch, a voltage reduction branch for reducing voltage, a rectification branch for rectifying, and a voltage stabilization branch for generating a stable voltage;

[0011] The first end of the compressor is connected to the first end of the switch branch and the first end of the step-down branch respectively, the second end of the step-down branch is connected to the first end of the rectifier branch, the second end of the rectifier branch is connected to the first end of the voltage stabilizing branch, the second end of the voltage stabilizing branch is connected to the third end of the rectifier branch, the fourth end of the rectifier branch is connected to the second end of the switch branch, the first end of the signal output branch and the first end of the temperature control switch respectively, the second end of the compressor is connected to the second end of the AC power supply, the third end of the switch branch is connected to the first end of the AC power supply, and the fourth end of the switch branch is connected to the controller;

[0012] The switch branch is configured to short-circuit its first end and the third end in response to a first control signal output by the controller to power the compressor based on the AC power supply, and is configured to short-circuit its second end and the third end in response to a second control signal output by the controller to power the heater based on the AC power supply.

[0013] In one or more embodiments, the control circuit further comprises a zero-crossing detection branch, a first end of the zero-crossing detection branch and a first end of the step-down branch are connected to a first node, and a second end of the zero-crossing detection branch is connected to the controller;

[0014] The zero-crossing detection branch is configured to output the first level signal to the controller when the voltage of the first node is less than or equal to the first preset voltage, so that the controller determines that the AC power supply has been powered off, and is configured to output the second level signal to the controller when the voltage of the first node is greater than the first preset voltage, so that the controller determines that the AC power supply has not been powered off.

[0015] In one or more embodiments, the refrigeration and freezing equipment further comprises a first interface, a second interface, a third interface, a fourth interface and a printed circuit board;

[0016] The first interface, the second interface, the third interface, the fourth interface and the control circuit are all arranged on the printed circuit board;

[0017] The first interface is connected between the second end of the signal output branch and the second end of the temperature control switch, the second interface is connected between the first end of the switch branch and the first end of the compressor, the third interface is connected between the third end of the switch branch and the first end of the AC power supply, and the fourth interface is connected between the second end of the switch branch and the first end of the temperature control switch.

[0018] In one or more embodiments, the signal output branch includes a first diode, a first resistor, a second resistor, a third resistor and an optical coupler;

[0019] The anode of the first diode is respectively connected to the first end of the heater and the cathode of the light emitter of the optocoupler, the cathode of the first diode is respectively connected to the first end of the first resistor and the anode of the light emitter of the optocoupler, the second end of the first resistor is connected to the second end of the switch branch, the second resistor is connected between the anode and the cathode of the first diode, the first end of the light receiver of the optocoupler is grounded, the second end of the light receiver of the optocoupler is respectively connected to the first end of the third resistor and the controller, and the second end of the third resistor is connected to the first power supply.

[0020] In one or more embodiments, the switch branch includes a first switch tube, a second switch tube, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a relay;

[0021] The first end of the first switch tube is connected to the controller through the fifth resistor, the second end of the first switch tube is connected to the first end of the first switch tube through the fourth resistor, the second end of the first switch tube is connected to the first power supply, the third end of the first switch tube is connected to the first end of the second switch tube through the sixth resistor, the first end of the second switch tube is connected to the second end of the second switch tube through the seventh resistor, the second end of the second switch tube and the first end of the coil of the relay are both connected to the second power supply, the third end of the second switch tube is connected to the ground through the eighth resistor, the second end of the coil is connected to the ground, the first contact of the relay is connected to the first end of the step-down branch, the second contact of the relay is connected to the first end of the temperature control switch, and the third contact of the relay is connected to the first end of the AC power supply, wherein the first contact and the third contact of the relay form a pair of normally closed contacts, and the second contact and the third contact of the relay form a pair of normally open contacts.

[0022] In one or more embodiments, the voltage-reducing branch includes a ninth resistor and a first capacitor;

[0023] The ninth resistor and the first capacitor are connected in parallel between the first end of the switch branch and the first end of the rectifier branch.

[0024] In one or more embodiments, the rectifying branch includes a second diode, a third diode, a fourth diode and a fifth diode;

[0025] The anode of the second diode is respectively connected to the second end of the step-down branch and the cathode of the third diode, the anode of the third diode is respectively connected to the anode of the fifth diode and the second end of the voltage stabilizing branch, and outputs the second power supply, the cathode of the fourth diode is respectively connected to the cathode of the second diode and the first end of the voltage stabilizing branch, and outputs the first power supply, and the anode of the fourth diode is respectively connected to the cathode of the fifth diode and the first end of the signal output branch.

[0026] In one or more embodiments, the voltage stabilizing branch includes a first voltage stabilizing diode, a second voltage stabilizing diode, a second capacitor, a third capacitor, a fourth capacitor, and a fifth capacitor;

[0027] The cathode of the first voltage-stabilizing diode is respectively connected to the first end of the second capacitor, the first end of the third capacitor and the second end of the rectifier branch, and outputs a first power supply. The anode of the first voltage-stabilizing diode, the second end of the second capacitor, the second end of the third capacitor, the first end of the fourth capacitor, the cathode of the second voltage-stabilizing diode and the second end of the fifth capacitor are all connected to the ground. The second end of the fourth capacitor is respectively connected to the anode of the second voltage-stabilizing diode, the second end of the fifth capacitor and the third end of the rectifier branch, and outputs a second power supply.

[0028] In one or more embodiments, the zero-crossing detection branch includes a sixth diode, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a third switch tube;

[0029] The anode of the sixth diode is connected to the first node, the cathode of the sixth diode is connected to the ground through the tenth resistor and the twelfth resistor in sequence, the connection point between the tenth resistor and the twelfth resistor is connected to the first end of the third switch tube through the eleventh resistor, the first end of the third switch tube is connected to the second end of the third switch tube through the thirteenth resistor, the second end of the third switch tube is connected to the ground, the third end of the third switch tube is connected to the first power supply through the fourteenth resistor, and the third end of the third switch tube is connected to the controller.

[0030] The beneficial effects of the present application are as follows: the refrigeration and freezing equipment of the embodiment of the present application includes a temperature control switch, a heater and a control circuit, and the control circuit includes a signal output branch and a controller. Among them, the first end of the temperature control switch is respectively connected to the first end of the AC power supply and the first end of the signal output branch, the second end of the temperature control switch is respectively connected to the first end of the heater and the second end of the signal output branch, the second end of the heater is connected to the second end of the AC power supply, and the third end of the signal output branch is connected to the controller. When the heating temperature of the heater is less than the first preset temperature, the temperature control switch remains closed and short-circuits the signal output branch. At this time, the signal output branch outputs a first level signal to the controller, and the controller determines that the heating temperature is less than the first preset temperature based on the first level signal; when the heating temperature of the heater is greater than or equal to the first preset temperature, the temperature control switch is disconnected and no longer short-circuits the signal output branch. At this time, the signal output branch outputs a second level signal to the controller, and the controller determines that the heating temperature is greater than or equal to the first preset temperature based on the second level signal. Thus, the determination process of the heating temperature is realized, and there is no need to add a circuit for real-time determination of the heating temperature as in the related art, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplary descriptions are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0032] Figure 1 This is a schematic diagram of the structure of the refrigeration and freezing equipment provided in the embodiment of the present application. Figure 1 ;

[0033] Figure 2 This is a schematic diagram of the structure of the refrigeration and freezing equipment provided in the embodiment of the present application. Figure 2 ;

[0034] Figure 3 This is a schematic diagram of the structure of the refrigeration and freezing equipment provided in the embodiment of the present application. Figure 3 ;

[0035] Figure 4 This is a schematic diagram of the structure of the refrigeration and freezing equipment provided in the embodiment of the present application. Figure 4 ;

[0036] Figure 5 is with Figure 4 The circuit structure corresponding to the structure shown is shown in FIG. Figure 1 ;

[0037] Figure 6 is with Figure 4 The circuit structure corresponding to the structure shown is shown in FIG. Figure 2 . DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0039] It should be noted that, when an element is described as being “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0040] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0041] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of the refrigeration and freezing equipment provided in the embodiment of the present application. Figure 1 As shown, the refrigeration and freezing equipment 1000 includes a control circuit 100 , a temperature control switch 200 and a heater 300 . The control circuit 100 includes a signal output branch 10 and a controller 20 .

[0042] The first end of the temperature control switch 200 is connected to the first end of the AC power supply 2000 and the first end of the signal output branch 10, respectively; the second end of the temperature control switch 200 is connected to the first end of the heater 300 and the second end of the signal output branch 10, respectively; the second end of the heater 300 is connected to the second end of the AC power supply 2000; and the third end of the signal output branch 10 is connected to the controller 20. In a specific embodiment, the AC power supply 200 is a mains supply.

[0043] Specifically, the temperature control switch 200 is configured to close in response to the heating temperature of the heater 300 being less than the first preset temperature, so as to output the short-circuit signal branch 10. The temperature control switch 200 is also configured to open in response to the heating temperature being greater than or equal to the first preset temperature, so as to stop the short-circuit signal output branch 10. Among them, the temperature control switch 200 refers to a series of automatic control elements that produce a conduction or disconnection action by physically deforming inside the switch according to the temperature change of the working environment, thereby producing certain special effects. The temperature control switch 200 may also be called a thermostat, a temperature protector or a temperature controller. In a specific embodiment, the heater 300 is used to realize the defrosting function. The heater 300 uses an electric heating element and can be heated when frosting to prevent the influence of frosting on the refrigeration and freezing equipment.

[0044] The signal output branch 10 is configured to output a first level signal to the controller 20 when it is short-circuited, so that the controller 20 determines that the heating temperature is less than the first preset temperature. The signal output branch 10 is also configured to output a second level signal to the controller 20 when it is not short-circuited, so that the controller 20 determines that the heating temperature is greater than or equal to the first preset temperature. Among them, the first preset temperature is a pre-set temperature value, which can be set based on the actual application scenario, and the embodiment of the present application does not impose specific restrictions on this. The first level signal and the second level signal are different signals. For example, when the first level signal is a high level signal, the second level signal is a low level signal; when the first level signal is a low level signal, the second level signal is a high level signal.

[0045] The controller 20 may be a microcontroller unit (MCU) or a digital signal processing (DSP) controller, etc.

[0046] In practical applications, when the heating temperature of the heater 300 is less than the first preset temperature, the temperature control switch 200 remains closed and short-circuits the signal output branch 10. At this time, the signal output branch 10 outputs a first level signal to the controller 20, and the controller 20 determines that the heating temperature is less than the first preset temperature based on the first level signal. When the heating temperature of the heater 300 is greater than or equal to the first preset temperature, the temperature control switch 200 is disconnected and no longer short-circuits the signal output branch 10. At this time, the signal output branch 10 outputs a second level signal to the controller 20, and the controller 20 determines that the heating temperature is greater than or equal to the first preset temperature based on the second level signal. Thus, the characteristic that the temperature control switch 200 automatically disconnects based on the temperature is cleverly utilized to realize the determination process of the heating temperature, and there is no need to add a circuit for real-time determination of the heating temperature as in the related art. In other words, relative to the related art, the present application can reduce the circuit for heating the temperature, such as reducing the circuit implemented by the NTC resistor, thereby reducing the cost.

[0047] In one embodiment, if Figure 2 As shown, the refrigeration and freezing equipment 1000 also includes a compressor 400, and the control circuit 100 also includes a switch branch 30 connected between the AC power supply 2000 and the signal output branch 10, a voltage reduction branch 40 for reducing the voltage, a rectification branch 50 for rectifying, and a voltage stabilizing branch 60 for generating a stable voltage.

[0048] Among them, the first end of the compressor 400 is respectively connected to the first end of the switch branch 30 and the first end of the step-down branch 40, the second end of the step-down branch 40 is connected to the first end of the rectifier branch 50, the second end of the rectifier branch 50 is connected to the first end of the voltage stabilizing branch 60, the second end of the voltage stabilizing branch 60 is connected to the third end of the rectifier branch 50, the fourth end of the rectifier branch 50 is respectively connected to the second end of the switch branch 30, the first end of the signal output branch 10 and the first end of the temperature control switch 200, the second end of the compressor 400 is connected to the second end of the AC power supply 2000, the third end of the switch branch 30 is connected to the first end of the AC power supply 2000, and the fourth end of the switch branch 30 is connected to the controller 20.

[0049] Specifically, the switch branch 30 is configured to short-circuit its first end and the third end in response to the first control signal output by the controller 20, so as to power the compressor 400 based on the AC power supply 2000. The switch branch 30 is also configured to short-circuit its second end and the third end in response to the second control signal output by the controller 20, so as to power the heater 300 based on the AC power supply 2000. In a specific embodiment, the first control signal and the second control signal are both level signals, and the first control signal is different from the second control signal, that is, when the first control signal is a high level signal, the second control signal is a low level signal; when the first control signal is a low level signal, the second control signal is a high level signal.

[0050] In this embodiment, when the first control signal output by the controller 20 is sent to the switch branch 30, the first end and the third end of the switch branch 30 are short-circuited. On the one hand, the AC power supply 200 supplies power to the compressor 400 through the switch branch 30; on the other hand, the AC power supply 200 forms a loop through the switch branch 30, the step-down branch 40, the rectifier branch 50, the voltage stabilizing branch 60, the temperature control switch 200 and the heater 300 in sequence to connect the load of the heater 300 to the control circuit 100. Subsequently, when external interference is input into the control circuit 100 through the AC power supply 2000, it will first be absorbed by the heater 200, which is beneficial to increase the anti-interference ability of the control circuit 100.

[0051] When the second control signal output by the controller 20 reaches the switch branch 30, the second end and the third end of the switch branch 30 are short-circuited. On the one hand, the AC power supply 200 supplies power to the heater 200 through the switch branch 30; on the other hand, the AC power supply 200 forms a loop with the compressor 400 through the switch branch 30, the rectifier branch 50, the voltage stabilizing branch 60, the voltage step-down branch 40 in sequence, so as to connect the load of the compressor 400 to the control circuit 100. Subsequently, when external interference is input into the control circuit 100 through the AC power supply 2000, it will be first absorbed by the compressor 400, which is beneficial to increase the anti-interference ability of the control circuit 100.

[0052] In one embodiment, if Figure 3 As shown, the control circuit 100 further includes a zero-crossing detection branch 70 , a first end of the zero-crossing detection branch 70 and a first end of the step-down branch 40 are connected to a first node N1 , and a second end of the zero-crossing detection branch 70 is connected to the controller 20 .

[0053] The zero-crossing detection branch 70 is configured to output a first level signal to the controller 20 when the voltage of the first node N1 is less than or equal to the first preset voltage, so that the controller 20 determines that the AC power supply 2000 has been powered off (the voltage of the corresponding AC power supply 2000 is zero). The zero-crossing detection branch 70 is also configured to output a second level signal to the controller 20 when the voltage of the first node N1 is greater than the first preset voltage, so that the controller 20 determines that the AC power supply 2000 is not powered off (the voltage of the corresponding AC power supply 2000 remains normal, for example, when the AC power supply 2000 is the mains, the AC power supply 2000 is not powered off and the voltage of the corresponding AC power supply 2000 is 220V). Among them, the first preset voltage is a pre-set voltage value, which can be set based on the actual application scenario, and the embodiment of the present application does not make specific restrictions on this.

[0054] In one embodiment, if Figure 4 As shown, the refrigeration and freezing equipment 1000 further includes a first interface J1 , a second interface J2 , a third interface J3 , a fourth interface J4 and a printed circuit board 500 .

[0055] Among them, the first interface J1, the second interface J2, the third interface J3, the fourth interface J4 and the control circuit 100 are all arranged on a printed circuit board 500. A printed circuit board (PCB) 50 is a substrate for supporting and connecting electronic components. It is usually made of insulating material and covered with a conductive layer for arranging and connecting electronic components, such as resistors, capacitors, integrated circuits, etc. The printed circuit board 50 plays an important role in the refrigeration and freezing equipment, such as carrying electronic components, providing electrical connections, and transmitting signals.

[0056] Specifically, the first interface J1 is connected between the second end of the signal output branch 10 and the second end of the temperature control switch 200, the second interface J2 is connected between the first end of the switch branch 30 and the first end of the compressor 400, the third interface J3 is connected between the third end of the switch branch 30 and the first end of the AC power supply 2000, and the fourth interface J4 is connected between the second end of the switch branch 30 and the first end of the temperature control switch 200.

[0057] In the related art, the AC power source is directly connected to the printed circuit board 500. In this case, external interference will directly enter the printed circuit board 500 and interfere with the control circuit 100. In the present application, the heater 300 and the compressor 400 are connected in series to the control circuit 100. When external interference enters, it will be absorbed by the heater 300 or the compressor 400 first, so that the anti-interference ability of the control circuit 100 can be enhanced without increasing the cost.

[0058] Figure 5 An example is shown with Figure 4 A circuit structure corresponding to the structure shown in FIG. Figure 5 As shown, the signal output branch 10 includes a first diode D1 , a first resistor R1 , a second resistor R2 , a third resistor R3 and an optical coupler U1 .

[0059] Among them, the anode of the first diode D1 is connected to the cathode of the light emitter of the optocoupler U1, and is connected to the first end of the heater 300 through the first interface J1, the cathode of the first diode D1 is respectively connected to the first end of the first resistor R1 and the anode of the light emitter of the optocoupler U1, the second end of the first resistor R1 is connected to the second end of the switch branch 30, the second resistor R2 is connected between the anode and the cathode of the first diode D1, the first end of the light receiver of the optocoupler U1 is grounded GND, the second end of the light receiver of the optocoupler U1 is respectively connected to the first end of the third resistor R3 and the controller 20, and the second end of the third resistor R3 is connected to the first power supply V1.

[0060] The first resistor R1 and the second resistor R2 are voltage-dividing resistors, and the third resistor R3 is a pull-up resistor.

[0061] In this embodiment, the switch branch 30 includes a first switch tube Q1, a second switch tube Q2, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a relay K1.

[0062] The first end of the first switch tube Q1 is connected to the controller 20 through the fifth resistor R5, the second end of the first switch tube Q1 is connected to the first end of the first switch tube Q1 through the fourth resistor R4, the second end of the first switch tube Q1 is connected to the first power supply V1, the third end of the first switch tube Q1 is connected to the first end of the second switch tube Q2 through the sixth resistor R6, the first end of the second switch tube Q2 is connected to the second end of the second switch tube Q2 through the seventh resistor R7, the second end of the second switch tube Q2 and the first end of the coil KM of the relay K1 are both connected to the second power supply V2, and the second switch tube Q2 is connected to the first end of the second switch tube Q2 through the sixth resistor R6. The third end of the switch Q2 is connected to the ground GND through the eighth resistor R8, the second end of the coil KM is connected to the ground GND, the first contact S1 of the relay K1 is connected to the first end of the step-down branch 40, the second contact S2 of the relay K1 is connected to the first end of the temperature control switch 200 through the fourth interface J4, and the third contact S3 of the relay K1 is connected to the first end of the AC power supply 2000, wherein the first contact S1 and the third contact S3 of the relay K1 form a pair of normally closed contacts, and the second contact S2 and the third contact S3 of the relay K1 form a pair of normally open contacts.

[0063] Specifically, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6 and the seventh resistor R7 are all voltage-dividing resistors. The eighth resistor R8 is used to prevent the second power source V1 from being short-circuited with the ground GND when the second switch tube Q2 is turned on.

[0064] Among them, in this embodiment, the first switch tube Q1 is a PNP type transistor and the second switch tube Q2 is an NPN type transistor. The base of the PNP type transistor is the first end of the first switch tube Q1, the emitter of the PNP type transistor is the second end of the first switch tube Q1, and the collector of the PNP type transistor is the third end of the first switch tube Q1. The base of the NPN type transistor is the first end of the second switch tube Q2, the emitter of the NPN type transistor is the second end of the second switch tube Q2, and the collector of the NPN type transistor is the third end of the second switch tube Q2.

[0065] In addition, the first switch tube Q1 and the second switch tube Q2 can be any controllable switches, such as insulated gate bipolar transistor (IGBT) devices, integrated gate commutated thyristor (IGCT) devices, gate turn-off thyristor (GTO) devices, silicon controlled rectifier (SCR) devices, junction gate field effect transistor (JFET) devices, MOS controlled thyristor (MCT) devices, etc.

[0066] In this embodiment, the voltage-reducing branch 40 includes a ninth resistor R9 and a first capacitor C1 .

[0067] The ninth resistor R9 and the first capacitor C1 are connected in parallel between the first end of the switch branch 30 and the first end of the rectifier branch 50. The ninth resistor R9 and the first capacitor C1 are used to achieve resistance-capacitance voltage reduction. The magnitude of the voltage reduction is determined by the capacitive reactance of the first capacitor C1. The larger the capacitive reactance, the greater the magnitude of the voltage reduction; the smaller the capacitive reactance, the smaller the magnitude of the voltage reduction.

[0068] In this embodiment, the rectifying branch 50 includes a second diode D2 , a third diode D3 , a fourth diode D4 and a fifth diode D5 .

[0069] Among them, the anode of the second diode D2 is respectively connected to the second end of the step-down branch 40 and the cathode of the third diode D3, the anode of the third diode D3 is respectively connected to the anode of the fifth diode D5 and the second end of the voltage stabilizing branch 60, and outputs the second power supply V2, the cathode of the fourth diode D4 is respectively connected to the cathode of the second diode D2 and the first end of the voltage stabilizing branch 60, and outputs the first power supply V1, and the anode of the fourth diode D4 is respectively connected to the cathode of the fifth diode D5 and the first end of the signal output branch 10.

[0070] Specifically, the second diode D2, the third diode D3, the fourth diode D4 and the fifth diode D5 all implement half-wave rectification.

[0071] In this embodiment, the voltage stabilizing branch 60 includes a first voltage stabilizing diode DW1 , a second voltage stabilizing diode DW2 , a second capacitor C2 , a third capacitor C3 , a fourth capacitor C4 , and a fifth capacitor C5 .

[0072] Among them, the cathode of the first voltage zener diode DW1 is respectively connected to the first end of the second capacitor C2, the first end of the third capacitor C3 and the second end of the rectifier branch 50, and outputs the first power supply V1, the anode of the first voltage zener diode DW1, the second end of the second capacitor C2, the second end of the third capacitor C3, the first end of the fourth capacitor C4, the cathode of the second voltage zener diode DW2 and the second end of the fifth capacitor C5 are all connected to the ground GND, the second end of the fourth capacitor C4 is respectively connected to the anode of the second voltage zener diode DW2, the second end of the fifth capacitor C5 and the third end of the rectifier branch 50, and outputs the second power supply V2.

[0073] Specifically, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 are all used for filtering. When the reverse voltage of the first voltage zener diode DW1 (or the second voltage zener diode DW2) approaches the critical value, the reverse current suddenly increases, and the first voltage zener diode DW1 (or the second voltage zener diode DW2) is broken down. At this critical breakdown point, the reverse resistance of the first voltage zener diode DW1 (or the second voltage zener diode DW2) suddenly drops to a very small value. At this time, although the current changes in a large range, the voltage across the first voltage zener diode DW1 (or the second voltage zener diode DW2) is basically stable near the breakdown voltage, thereby realizing the voltage stabilization function of the first voltage zener diode DW1 (or the second voltage zener diode DW2).

[0074] In this embodiment, the zero-crossing detection branch 70 includes a sixth diode D6 , a tenth resistor R10 , an eleventh resistor R11 , a twelfth resistor R12 , a thirteenth resistor R13 , a fourteenth resistor R14 and a third switch tube Q3 .

[0075] Among them, the anode of the sixth diode D6 is connected to the first node N1, the cathode of the sixth diode D6 is connected to the ground GND through the tenth resistor R10 and the twelfth resistor R12 in sequence, the connection point between the tenth resistor R10 and the twelfth resistor R12 is connected to the first end of the third switch tube Q3 through the eleventh resistor R11, the first end of the third switch tube Q3 is connected to the second end of the third switch tube Q3 through the thirteenth resistor R13, the second end of the third switch tube Q3 is connected to the ground GND, the third end of the third switch tube Q3 is connected to the first power supply V1 through the fourteenth resistor R14, and the third end of the third switch tube Q3 is connected to the controller 20.

[0076] Specifically, the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12, and the thirteenth resistor R13 are voltage-dividing resistors, and the fourteenth resistor R14 is a pull-up resistor.

[0077] When the voltage of the first node N1 is less than or equal to the first preset voltage, the third switch tube Q3 is turned off, and the first power source V1 outputs a first level signal (a high level signal at this time) to the controller 20 through the fourteenth resistor R4, so that the controller 20 determines that the AC power source 2000 has been powered off. When the voltage of the first node N1 is greater than the first preset voltage, the third switch tube Q3 is turned on, and the controller 20 is grounded to GND through the third switch tube Q3, corresponding to inputting a second level signal (a low level signal at this time) to the controller 20, so that the controller 20 determines that the AC power source 2000 has not been powered off.

[0078] In this embodiment, the third switch tube Q3 is an NPN transistor as an example. The base of the NPN transistor is the first end of the third switch tube Q3, the emitter of the NPN transistor is the second end of the third switch tube Q3, and the collector of the NPN transistor is the third end of the third switch tube Q3.

[0079] In addition, the third switch tube Q3 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0080] In this embodiment, the control circuit 100 further includes a fifteenth resistor R15 for current limiting. The fifteenth resistor R15 is connected between the first contact S1 of the relay K1 and the first node N1.

[0081] The following Figure 5 The principle of the circuit structure shown is explained again.

[0082] When the voltage of the AC power source 2000 remains normal, if the controller 20 outputs the first control signal (a low level signal at this time) to the first switch tube Q1, the first switch tube Q1 is turned on. The base of the second switch tube Q2 is connected to the first power source V1 through the first switch tube Q1, and the second switch tube Q2 is turned on. The coil KM of the relay K1 is short-circuited, and the first contact S1 and the third contact S3 are short-circuited.

[0083] On the one hand, the AC power supply 2000 sequentially supplies power to the compressor 400 through the third interface J3, the third contact S3, the first contact S1, and the second interface J2. On the other hand, the AC power supply 2000 sequentially forms a loop with the heater 300 through the third interface J3, the third contact S3, the first contact S1, the fifteenth resistor R15, the voltage-reducing branch 40, the second diode D2, the voltage-stabilizing branch 60, the fifth diode D5, the fourth interface J4, the temperature control switch 200, and the heater 300, so as to connect the load of the heater 300 to the control circuit 100. Then, when external interference is input into the control circuit 100 through the AC power supply 2000, it will be absorbed by the heater 200 first, which is conducive to increasing the anti-interference ability of the control circuit 100.

[0084] If the controller 20 outputs the second control signal (a high level signal at this time) to the first switch tube Q1, the first switch tube Q1 is turned off. The second switch tube Q2 is also turned off. The coil KM of the relay K1 is powered by the second power supply V2, and the second contact S2 and the third contact S3 are short-circuited (such as Figure 6 shown).

[0085] On the one hand, the AC power supply 2000 supplies power to the heater 300 through the third interface J3, the third contact S3, the second contact S2, the fourth interface J4, and the temperature control switch 200 in sequence, and the heater 300 starts to heat, and the heating temperature rises. Before the heating temperature rises to the first preset temperature, the temperature control switch 200 remains closed, at which time the two ends of the light emitter of the optocoupler U1 are short-circuited, and the optocoupler U1 is short-circuited. The light receiver of the optocoupler U1 is also disconnected, and the first power supply V1 outputs a first level signal (a high level signal at this time) to the controller 20 through the third resistor R3, so that the controller 20 determines that the heating temperature is less than the first preset temperature. When the heating temperature reaches the first preset temperature, the temperature control switch 200 is automatically disconnected, at which time the two ends of the light emitter of the optocoupler U1 are no longer short-circuited, and the optocoupler U1 is no longer short-circuited. The light emitter of the optocoupler U1 is powered on, and the light receiver of the optocoupler U1 is also turned on. The controller 20 is grounded through the light receiver of the optocoupler U1, and the second level signal (low level signal at this time) is output to the controller 20, so that the controller 20 determines that the heating temperature is greater than or equal to the first preset temperature. So far, the characteristic that the temperature control switch 200 automatically disconnects based on the temperature is cleverly used to realize the determination process of the heating temperature, and there is no need to add a circuit for real-time determination of the heating temperature as in the related art. In other words, compared with the related art, the present application can reduce the circuit for heating the temperature, such as reducing the circuit implemented by the NTC resistor, thereby reducing the cost.

[0086] On the other hand, the AC power supply 2000 forms a loop with the compressor 400 through the third interface J3, the third contact S3, the second contact S2, the fourth diode D4, the voltage stabilizing branch 60, the third diode D3, the voltage step-down branch 40, the fifteenth resistor R15, and the second interface J2 in sequence, so as to connect the load of the compressor 400 to the control circuit 100. Then, when external interference is input into the control circuit 100 through the AC power supply 2000, it will first be absorbed by the heater 200, which is beneficial to increase the anti-interference ability of the control circuit 100.

[0087] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0088] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Under the idea of ​​the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. It should be understood by ordinary technicians in this field that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A refrigeration and freezing equipment, characterized in that: include: A temperature control switch, a heater and a control circuit, wherein the control circuit includes a signal output branch and a controller; The first end of the temperature control switch is connected to the first end of the AC power supply and the first end of the signal output branch respectively, the second end of the temperature control switch is connected to the first end of the heater and the second end of the signal output branch respectively, the second end of the heater is connected to the second end of the AC power supply, and the third end of the signal output branch is connected to the controller; The temperature control switch is configured to close in response to the heating temperature of the heater being less than a first preset temperature to short-circuit the signal output branch, and is configured to open in response to the heating temperature being greater than or equal to the first preset temperature to stop short-circuiting the signal output branch; The signal output branch is configured to output a first level signal to the controller when short-circuited, so that the controller determines that the heating temperature is less than the first preset temperature, and is configured to output a second level signal to the controller when not short-circuited, so that the controller determines that the heating temperature is greater than or equal to the first preset temperature.

2. The refrigeration and freezing equipment according to claim 1, characterized in that: The refrigeration and freezing equipment further includes a compressor, and the control circuit further includes a switch branch, a voltage reduction branch for reducing voltage, a rectification branch for rectifying, and a voltage stabilization branch for generating a stable voltage; The first end of the compressor is connected to the first end of the switch branch and the first end of the step-down branch respectively, the second end of the step-down branch is connected to the first end of the rectifier branch, the second end of the rectifier branch is connected to the first end of the voltage stabilizing branch, the second end of the voltage stabilizing branch is connected to the third end of the rectifier branch, the fourth end of the rectifier branch is connected to the second end of the switch branch, the first end of the signal output branch and the first end of the temperature control switch respectively, the second end of the compressor is connected to the second end of the AC power supply, the third end of the switch branch is connected to the first end of the AC power supply, and the fourth end of the switch branch is connected to the controller; The switch branch is configured to short-circuit its first end and the third end in response to a first control signal output by the controller to power the compressor based on the AC power supply, and is configured to short-circuit its second end and the third end in response to a second control signal output by the controller to power the heater based on the AC power supply.

3. The refrigeration and freezing equipment according to claim 2, characterized in that: The control circuit further comprises a zero-crossing detection branch, a first end of the zero-crossing detection branch and a first end of the step-down branch are connected to a first node, and a second end of the zero-crossing detection branch is connected to the controller; The zero-crossing detection branch is configured to output the first level signal to the controller when the voltage of the first node is less than or equal to the first preset voltage, so that the controller determines that the AC power supply has been powered off, and is configured to output the second level signal to the controller when the voltage of the first node is greater than the first preset voltage, so that the controller determines that the AC power supply has not been powered off.

4. The refrigeration and freezing equipment according to claim 2 or 3, characterized in that: The refrigeration and freezing equipment also includes a first interface, a second interface, a third interface, a fourth interface and a printed circuit board; The first interface, the second interface, the third interface, the fourth interface and the control circuit are all arranged on the printed circuit board; The first interface is connected between the second end of the signal output branch and the second end of the temperature control switch, the second interface is connected between the first end of the switch branch and the first end of the compressor, the third interface is connected between the third end of the switch branch and the first end of the AC power supply, and the fourth interface is connected between the second end of the switch branch and the first end of the temperature control switch.

5. The refrigeration and freezing equipment according to claim 2, characterized in that: The signal output branch includes a first diode, a first resistor, a second resistor, a third resistor and an optical coupler; The anode of the first diode is respectively connected to the first end of the heater and the cathode of the light emitter of the optocoupler, the cathode of the first diode is respectively connected to the first end of the first resistor and the anode of the light emitter of the optocoupler, the second end of the first resistor is connected to the second end of the switch branch, the second resistor is connected between the anode and the cathode of the first diode, the first end of the light receiver of the optocoupler is grounded, the second end of the light receiver of the optocoupler is respectively connected to the first end of the third resistor and the controller, and the second end of the third resistor is connected to the first power supply.

6. The refrigeration and freezing equipment according to claim 2, characterized in that: The switch branch includes a first switch tube, a second switch tube, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a relay; The first end of the first switch tube is connected to the controller through the fifth resistor, the second end of the first switch tube is connected to the first end of the first switch tube through the fourth resistor, the second end of the first switch tube is connected to the first power supply, the third end of the first switch tube is connected to the first end of the second switch tube through the sixth resistor, the first end of the second switch tube is connected to the second end of the second switch tube through the seventh resistor, the second end of the second switch tube and the first end of the coil of the relay are both connected to the second power supply, the third end of the second switch tube is connected to the ground through the eighth resistor, the second end of the coil is connected to the ground, the first contact of the relay is connected to the first end of the step-down branch, the second contact of the relay is connected to the first end of the temperature control switch, and the third contact of the relay is connected to the first end of the AC power supply, wherein the first contact and the third contact of the relay form a pair of normally closed contacts, and the second contact and the third contact of the relay form a pair of normally open contacts.

7. The refrigeration and freezing equipment according to claim 2, characterized in that: The voltage-reducing branch includes a ninth resistor and a first capacitor; The ninth resistor and the first capacitor are connected in parallel between the first end of the switch branch and the first end of the rectifier branch.

8. The refrigeration and freezing equipment according to claim 2, characterized in that: The rectifying branch includes a second diode, a third diode, a fourth diode and a fifth diode; The anode of the second diode is respectively connected to the second end of the step-down branch and the cathode of the third diode, the anode of the third diode is respectively connected to the anode of the fifth diode and the second end of the voltage stabilizing branch, and outputs the second power supply, the cathode of the fourth diode is respectively connected to the cathode of the second diode and the first end of the voltage stabilizing branch, and outputs the first power supply, and the anode of the fourth diode is respectively connected to the cathode of the fifth diode and the first end of the signal output branch.

9. The refrigeration and freezing equipment according to claim 2, characterized in that: The voltage stabilizing branch includes a first voltage stabilizing diode, a second voltage stabilizing diode, a second capacitor, a third capacitor, a fourth capacitor and a fifth capacitor; The cathode of the first voltage-stabilizing diode is respectively connected to the first end of the second capacitor, the first end of the third capacitor and the second end of the rectifier branch, and outputs a first power supply. The anode of the first voltage-stabilizing diode, the second end of the second capacitor, the second end of the third capacitor, the first end of the fourth capacitor, the cathode of the second voltage-stabilizing diode and the second end of the fifth capacitor are all connected to the ground. The second end of the fourth capacitor is respectively connected to the anode of the second voltage-stabilizing diode, the second end of the fifth capacitor and the third end of the rectifier branch, and outputs a second power supply.

10. The refrigeration and freezing equipment according to claim 3, characterized in that: The zero-crossing detection branch includes a sixth diode, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a third switch tube; The anode of the sixth diode is connected to the first node, the cathode of the sixth diode is connected to the ground through the tenth resistor and the twelfth resistor in sequence, the connection point between the tenth resistor and the twelfth resistor is connected to the first end of the third switch tube through the eleventh resistor, the first end of the third switch tube is connected to the second end of the third switch tube through the thirteenth resistor, the second end of the third switch tube is connected to the ground, the third end of the third switch tube is connected to the first power supply through the fourteenth resistor, and the third end of the third switch tube is connected to the controller.

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