Current detection circuit, overcurrent protection circuit and method thereof, circuit board and air conditioner

Abstract

The invention provides a current detection circuit, an overcurrent protection circuit and method, a circuit board and an air conditioner, the current detection circuit comprises a resistance voltage dividing module and a current transformer, the resistance voltage dividing module comprises a first resistance voltage dividing unit and a second resistance voltage dividing unit, one end of the first resistance voltage dividing unit is connected to a power supply input end, and the other end of the first resistance voltage dividing unit is connected to a power supply output end; the other end is connected to the grounding end through the second resistance voltage dividing unit; one end of the current transformer is connected to a common end between the first resistance voltage-dividing unit and the second resistance voltage-dividing unit, and the other end of the current transformer is connected to a sampling end of the control unit. According to the current detection circuit, a full-wave rectifier diode is omitted, the voltage of the common end between the first resistance voltage dividing unit and the second resistance voltage dividing unit is used as the reference voltage, the output end of the current transformer is connected with the common end, and the other end of the current transformer is connected with the sampling end of the control unit; therefore, the current sampling is not affected by the voltage drop of the diode, the current detection error can be reduced, and the control precision is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a current detection circuit, an overcurrent protection circuit and method thereof, a circuit board and an air conditioner. Background Art

[0002] In the related art, the output of the current transformer with the function of detecting AC power is connected to the control unit after full-wave rectification, and then the control unit performs power control according to the detected current. However, since the output of the current transformer is affected by the voltage drop of the full-wave rectifier diode, errors will occur, making it difficult to achieve precise control. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a current detection circuit, an overcurrent protection circuit and method thereof, a circuit board and an air conditioner, aiming to reduce the current detection error and improve the control accuracy.

[0004] In a first aspect, an embodiment of the present application provides a current detection circuit, comprising:

[0005] A resistor voltage divider module, comprising a first resistor voltage divider unit and a second resistor voltage divider unit, wherein one end of the first resistor voltage divider unit is connected to a power supply input end, and the other end of the first resistor voltage divider unit is connected to a ground end through the second resistor voltage divider unit;

[0006] A current transformer, one end of which is connected to a common end between the first resistor voltage divider unit and the second resistor voltage divider unit, and the other end of which is used to be connected to a sampling end of a control unit.

[0007] According to some embodiments of the present application, the first resistor voltage divider unit includes a first resistor and a second resistor, the second resistor voltage divider unit includes a third resistor and a fourth resistor, one end of the first resistor is connected to the power supply input end, and the other end is connected to the ground end through the second resistor, the third resistor and the fourth resistor in sequence.

[0008] According to some embodiments of the present application, the current detection circuit also includes a fifth resistor and a sixth resistor, one end of the fifth resistor is connected to one end of the current transformer, and the other end is connected to the other end of the current transformer; one end of the sixth resistor is connected to the fifth resistor, and the other end is used to connect to the sampling end of the control unit.

[0009] In a second aspect, an embodiment of the present application provides an overcurrent protection circuit, including a current detection circuit as described in the first aspect above.

[0010] According to some embodiments of the present application, the overcurrent protection circuit further includes a comparison module and a driving module, and the current detection circuit is connected to the driving module through the comparison module.

[0011] According to some embodiments of the present application, the comparison module includes at least one of the following:

[0012] A first comparator, wherein a comparison terminal of the first comparator is connected to a common terminal between the first resistor and the second resistor, and another comparison terminal is used to be connected to a sampling terminal of a control unit, and an output terminal of the first comparator is connected to the driving module;

[0013] A second comparator, wherein one comparison end of the second comparator is connected to the common end between the third resistor and the fourth resistor, the other comparison end is used to be connected to the sampling end of the control unit, and the output end of the second comparator is connected to the driving module.

[0014] According to some embodiments of the present application, the driving module includes a switch unit, the switch unit is connected to the comparison module, and the comparison module is used to control the switch unit to be turned off.

[0015] According to some embodiments of the present application, the switching unit includes a first switching tube, a photocoupler, and a second switching tube, the control end of the first switching tube is connected to the comparison module, the input end or the output end of the first switching tube is connected to the input side of the photocoupler, the output side of the photocoupler is connected to the control end of the second switching tube, and the input end or the output end of the second switching tube is used to connect to a load.

[0016] In a third aspect, an embodiment of the present application provides an overcurrent protection method, which is applied to the overcurrent protection circuit of the second aspect above. When the comparison module includes the first comparator and the second comparator, the overcurrent protection method includes:

[0017] Acquire a positive half-cycle voltage through the first comparator, and acquire a first reference voltage at a common end between the first resistor and the second resistor;

[0018] Obtaining a negative half-cycle voltage through the second comparator, and obtaining a second reference voltage at a common end between the third resistor and the fourth resistor;

[0019] The switching state of the switch unit in the driving module is controlled according to the positive half-cycle voltage and the first reference voltage, and the switching state of the switch unit in the driving module is controlled according to the negative half-cycle voltage and the second reference voltage.

[0020] According to some embodiments of the present application, controlling the switching state of the switch unit in the driving module according to the positive half-cycle voltage and the first reference voltage includes one of the following:

[0021] When the positive half-cycle voltage is greater than the first reference voltage, turning off the switch unit in the driving module;

[0022] When the positive half-cycle voltage is less than or equal to the first reference voltage, the switch unit in the driving module is turned on.

[0023] According to some embodiments of the present application, controlling the switching state of the switch unit in the driving module according to the negative half-cycle voltage and the second reference voltage includes one of the following:

[0024] When the negative half-cycle voltage is less than the second reference voltage, turning off the switch unit in the driving module;

[0025] When the negative half-cycle voltage is greater than or equal to the second reference voltage, the switch unit in the driving module is turned on.

[0026] In a fourth aspect, an embodiment of the present application provides a circuit board, comprising the current detection circuit of the first aspect, or comprising the overcurrent protection circuit of the second aspect.

[0027] In a fifth aspect, an embodiment of the present application provides an air conditioner, comprising the circuit board of the fourth aspect.

[0028] According to the technical solution of the embodiment of the present application, it includes but is not limited to the following technical effects: the current detection circuit of the embodiment of the present application includes a resistor voltage divider module and a current transformer, wherein the resistor voltage divider module includes a first resistor voltage divider unit and a second resistor voltage divider unit, one end of the first resistor voltage divider unit is connected to the power supply input end, and the other end is connected to the ground end through the second resistor voltage divider unit; one end of the current transformer is connected to the common end between the first resistor voltage divider unit and the second resistor voltage divider unit, and the other end is used to connect to the sampling end of the control unit. Since the current detection circuit of the embodiment of the present application cancels the full-wave rectifier diode, the voltage of the common end between the first resistor voltage divider unit and the second resistor voltage divider unit is used as the reference voltage, and one end of the output of the current transformer is connected to the common end, and the other end is connected to the sampling end of the control unit, so that the current sampling will not be affected by the diode voltage drop, thereby reducing the current detection error and improving the accuracy of control.

[0029] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are used to provide further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0031] Figure 1 is a structural schematic diagram of an overcurrent protection circuit provided by an embodiment of the present application;

[0032] Figure 2 is a flowchart of the steps of an overcurrent protection method provided by an embodiment of the present application;

[0033] Figure 3 is a flowchart of the steps of an overcurrent protection method provided by another embodiment of the present application;

[0034] Figure 4 is a flowchart of the steps of an overcurrent protection method provided by another embodiment of the present application;

[0035] Figure 5 is a flowchart of the steps of an overcurrent protection method provided by another embodiment of the present application;

[0036] Figure 6 is a flowchart of the steps of an overcurrent protection method provided by another embodiment of the present application;

[0037] Figure 7 This is a step flow chart of an overcurrent protection method provided in another embodiment of the present application.

[0038] Figure 8 It is a schematic diagram of a control unit for executing an overcurrent protection method provided in one embodiment of the present application. DETAILED DESCRIPTION

[0039] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0040] In the description of the present application, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, 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 device or element referred to 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.

[0041] In the description of this application, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0042] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0043] In some cases, the output of a current transformer with the function of detecting AC is connected to a control unit after full-wave rectification, and the control unit performs power control according to the detected current. However, since the output of the current transformer is affected by the voltage drop of the full-wave rectifier diode, errors will occur, making it difficult to achieve precise control.

[0044] Based on the above situation, the embodiments of the present application propose a current detection circuit, an overcurrent protection circuit and method thereof, a circuit board and an air conditioner, aiming to reduce the current detection error and improve the control accuracy.

[0045] The following further describes various embodiments of the current detection circuit of the present application in conjunction with the accompanying drawings.

[0046] like Figure 1 As shown, Figure 1 1 is a schematic diagram of the structure of an overcurrent protection circuit provided in an embodiment of the present application, wherein the overcurrent protection circuit includes a current detection circuit 100.

[0047] Specifically, the current detection circuit 100 of the embodiment of the present application includes but is not limited to a resistor voltage divider module and a current transformer CT, wherein the resistor voltage divider module includes but is not limited to a first resistor voltage divider unit 110 and a second resistor voltage divider unit 120, one end of the first resistor voltage divider unit 110 is connected to the second resistor voltage divider unit 120, the other end of the first resistor voltage divider unit 110 is connected to the power supply input terminal VDD, and the other end of the second resistor voltage divider unit 120 is connected to the ground terminal GND.

[0048] In addition, the current transformer CT is provided with two ends, one end of which is connected to the common end between the first resistance voltage dividing unit 110 and the second resistance voltage dividing unit 120 , and the other end is connected to the sampling end A / D of the control unit 400 .

[0049] It should be noted that, in the embodiment of the present application, the voltage of the common terminal between the first resistor voltage divider unit 110 and the second resistor voltage divider unit 120 is used as the reference voltage e0, wherein the reference voltage e0 is determined according to the voltage of the power supply input terminal VDD and the resistance values ​​of the first resistor voltage divider unit 110 and the second resistor voltage divider unit 120. Specifically, the reference voltage = the voltage of the power supply input terminal / (the resistance value of the first resistor voltage divider unit + the resistance value of the second resistor voltage divider unit)*the resistance value of the second resistor voltage divider unit. For example, when the resistance value of the first resistor voltage divider unit 110 is equal to the resistance value of the second resistor voltage divider unit 120, the reference voltage e0 is half of the voltage of the power supply input terminal VDD.

[0050] It is worth noting that since the current detection circuit 100 of the embodiment of the present application eliminates the full-wave rectifier diode, the voltage at the common end between the first resistor divider unit 110 and the second resistor divider unit 120 is used as the reference voltage e0, and one end of the output of the current transformer CT is connected to the common end, and the other end is connected to the sampling end A / D of the control unit 400, so that the current sampling will not be affected by the diode voltage drop, thereby reducing the current detection error and improving the control accuracy.

[0051] It is understandable that the above-mentioned current transformer CT is an instrument that converts a large primary current into a small secondary current for measurement based on the principle of electromagnetic induction. The current transformer CT may be composed of a closed iron core and a winding, wherein the primary winding has a small number of turns and is connected in series in the circuit of the current to be measured.

[0052] In one embodiment, if Figure 1 As shown, the first resistor voltage divider unit 110 in the embodiment of the present application includes but is not limited to a first resistor R1 and a second resistor R2, and the second resistor voltage divider unit 120 includes but is not limited to a third resistor R3 and a fourth resistor R4, wherein one end of the first resistor R1 is connected to the power supply input terminal VDD, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the ground terminal GND.

[0053] It should be noted that the embodiment of the present application divides the first resistor voltage-dividing unit 110 into a first resistor R1 and a second resistor R2, so that the voltage at the common end between the first resistor R1 and the second resistor R2 can be used as one of the comparison input voltages of the subsequent comparison module 200; in addition, the embodiment of the present application divides the second resistor voltage-dividing unit 120 into a third resistor R3 and a fourth resistor R4, so that the voltage at the common end between the third resistor R3 and the fourth resistor R4 can be used as another comparison input voltage of the subsequent comparison module 200.

[0054] In one embodiment, if Figure 1 As shown, the current detection circuit 100 of the embodiment of the present application also includes a fifth resistor R5 and a sixth resistor R6, wherein the two ends of the fifth resistor R5 are respectively connected to the two ends of the current transformer CT; one end of the sixth resistor R6 is connected to the fifth resistor R5, and the other end of the sixth resistor R6 is connected to the sampling terminal A / D of the control unit 400.

[0055] It should be noted that the embodiment of the present application provides a fifth resistor R5 and a sixth resistor R6, which can play a role in current limiting and voltage dividing, thereby playing a certain protective role.

[0056] Based on the current detection circuit 100 of each of the above embodiments, various embodiments of the overcurrent protection circuit of the present application are respectively proposed below.

[0057] like Figure 1 As shown, Figure 1 1 is a schematic diagram of the structure of an overcurrent protection circuit provided by an embodiment of the present application; the overcurrent protection circuit of the embodiment of the present application includes but is not limited to the current detection circuit 100 of any of the above embodiments.

[0058] It is worth noting that since the overcurrent protection circuit of the embodiment of the present application includes the current detection circuit 100 of any of the above-mentioned embodiments, the specific implementation methods and technical effects of the overcurrent protection circuit of the embodiment of the present application can refer to the specific implementation methods and technical effects of the current detection circuit 100 of any of the above-mentioned embodiments.

[0059] In one embodiment, if Figure 1 As shown, the overcurrent protection circuit of the embodiment of the present application also includes but is not limited to a comparison module 200 and a driving module 300, wherein one end of the comparison module 200 is connected to the current detection circuit 100, and the other end is connected to the driving module 300.

[0060] Specifically, the comparison module 200 of the embodiment of the present application can convert the current detected by the current detection circuit 100 into a voltage, and compare it with the reference voltage to obtain a comparison result, and then control the driving module 300 according to the comparison result.

[0061] In one embodiment, if Figure 1 As shown, the comparison module 200 in the embodiment of the present application includes but is not limited to a first comparator COMP1, which is provided with two comparison terminals, one of which is connected to the common terminal between the first resistor R1 and the second resistor R2, and the other is connected to the sampling terminal A / D of the control unit 400. In addition, the output terminal of the first comparator COMP1 is connected to the driving module 300.

[0062] Specifically, the first comparator COMP1 of the embodiment of the present application is an AC current positive half-axis overcurrent protection comparator, which can convert the detected positive half-axis AC current into a positive half-cycle voltage. At the same time, the first comparator COMP1 will also detect the voltage at the common end between the first resistor R1 and the second resistor R2, and use the voltage as the first reference voltage; then, the first comparator COMP1 will compare the positive half-cycle voltage with the first reference voltage. If the positive half-cycle voltage is greater than the first reference voltage, it indicates that there is an overcurrent phenomenon. In this case, the embodiment of the present application will control the switch unit 310 in the drive module 300 to be turned off, thereby cutting off the subsequent circuit or load; if the positive half-cycle voltage is less than or equal to the first reference voltage, it indicates that there is no overcurrent phenomenon. In this case, the embodiment of the present application will control the switch unit 310 in the drive module 300 to remain turned on, thereby continuing to supply power to the subsequent circuit or load.

[0063] In one embodiment, if Figure 1 As shown, the comparison module 200 in the embodiment of the present application includes but is not limited to a second comparator COMP2, which is provided with two comparison terminals, one of which is connected to the common terminal between the third resistor R3 and the fourth resistor R4, and the other is connected to the sampling terminal A / D of the control unit 400. In addition, the output terminal of the second comparator COMP2 is connected to the driving module 300.

[0064] Specifically, the second comparator COMP2 of the embodiment of the present application is an AC current negative half-axis overcurrent protection comparator, which can convert the detected negative half-axis AC current into a negative half-cycle voltage. At the same time, the second comparator COMP2 will also detect the voltage at the common end between the third resistor R3 and the fourth resistor R4, and use the voltage as the second reference voltage; then, the second comparator COMP2 will compare the negative half-cycle voltage with the second reference voltage. If the negative half-cycle voltage is less than the second reference voltage, it indicates that there is an overcurrent phenomenon. In this case, the embodiment of the present application will control the switch unit 310 in the drive module 300 to be turned off, thereby cutting off the subsequent circuit or load; if the negative half-cycle voltage is greater than or equal to the second reference voltage, it indicates that there is no overcurrent phenomenon. In this case, the embodiment of the present application will control the switch unit 310 in the drive module 300 to remain turned on, thereby continuing to supply power to the subsequent circuit or load.

[0065] In one embodiment, if Figure 1 As shown, the driving module 300 in the embodiment of the present application includes but is not limited to a switch unit 310, wherein the switch unit 310 is connected to the comparison module 200, and the comparison module 200 is used to control the switch unit 310 to be turned off or on.

[0066] Specifically, when an overcurrent phenomenon occurs, the embodiment of the present application will control the switch unit 310 in the driving module 300 to be turned off, thereby cutting off the subsequent circuit or load; when there is no overcurrent phenomenon, the embodiment of the present application will control the switch unit 310 in the driving module 300 to remain turned on, thereby continuing to supply power to the subsequent circuit or load.

[0067] In one embodiment, if Figure 1 As shown, the switch unit 310 in the embodiment of the present application includes but is not limited to a first switch tube Q1, a photocoupler OC and a second switch tube Q2. The control end of the first switch tube Q1 is connected to the comparison module 200, the input end or the output end of the first switch tube Q1 is connected to the input side of the photocoupler OC, the output side of the photocoupler OC is connected to the control end of the second switch tube Q2, and the input end or the output end of the second switch tube Q2 is connected to the load.

[0068] Specifically, when an overcurrent phenomenon occurs, the comparison module 200 can output a low level to the control end of the first switch tube Q1, thereby turning off the first switch tube Q1 and reducing the current at the input and output ends of the first switch tube Q1, so that no current passes through the input side of the photocoupler OC, and then the output side of the photocoupler OC is turned off, that is, the control end of the second switch tube Q2 can be made low level, so that the second switch tube Q2 can be turned off, thereby cutting off the subsequent circuit or load.

[0069] When there is no overcurrent phenomenon, the comparison module 200 can output a high level to the control end of the first switch tube Q1, thereby turning on the first switch tube Q1 and maintaining the current at the input and output ends of the first switch tube Q1, so that current passes through the input side of the photocoupler OC, and then the output side of the photocoupler OC remains turned on, that is, the control end of the second switch tube Q2 can be a high level, so that the second switch tube Q2 can remain turned on, thereby continuing to supply power to subsequent circuits or loads.

[0070] Based on the overcurrent protection circuits of the above-mentioned embodiments, various embodiments of the overcurrent protection method of the present application are respectively proposed below.

[0071] like Figure 2 As shown, Figure 2 It is a step flow chart of an overcurrent protection method provided by an embodiment of the present application; the overcurrent protection method can be applied to the overcurrent protection circuit of the above embodiment, and the overcurrent protection method includes but is not limited to step S210, step S220 and step S230.

[0072] Step S210, obtaining a positive half-cycle voltage through a first comparator;

[0073] Step S220, obtaining a first reference voltage at a common terminal between the first resistor and the second resistor;

[0074] Step S230: Control the switching state of the switch unit in the driving module according to the positive half-cycle voltage and the first reference voltage.

[0075] In one embodiment, the first comparator of the embodiment of the present application is an AC current positive half-axis overcurrent protection comparator, which can convert the detected positive half-axis AC current into a positive half-cycle voltage. At the same time, the first comparator also detects the voltage at the common end between the first resistor and the second resistor, and uses the voltage as the first reference voltage; then, the first comparator compares the positive half-cycle voltage with the first reference voltage to obtain a comparison result, and then controls the switch unit in the driving module to turn off or remain on according to the comparison result.

[0076] In addition, if Figure 3 As shown, Figure 3 It is a step flow chart of an overcurrent protection method provided by another embodiment of the present application; the overcurrent protection method can be applied to the overcurrent protection circuit of the above embodiment, and the overcurrent protection method includes but is not limited to step S310, step S320 and step S330.

[0077] Step S310, obtaining a negative half-cycle voltage through a second comparator;

[0078] Step S320, obtaining a second reference voltage at a common terminal between the third resistor and the fourth resistor;

[0079] Step S330 , controlling the switching state of the switch unit in the driving module according to the negative half-cycle voltage and the second reference voltage.

[0080] In one embodiment, specifically, the second comparator of the embodiment of the present application is an AC current negative half-axis overcurrent protection comparator, which can convert the detected negative half-axis AC current into a negative half-cycle voltage. At the same time, the second comparator also detects the voltage at the common end between the third resistor and the fourth resistor, and uses the voltage as the second reference voltage; then, the second comparator compares the negative half-cycle voltage with the second reference voltage, obtains a comparison result, and then controls the switch unit in the drive module to be turned off or kept on according to the comparison result.

[0081] It should be noted that the control of the switch state of the switch unit in the driving module according to the positive half-cycle voltage and the first reference voltage in the above step S230 may include but is not limited to: Figure 4 or Figure 5 There are two implementation scenarios, as follows:

[0082] like Figure 4 As shown, Figure 4It is a step flow chart of an overcurrent protection method provided by another embodiment of the present application; regarding the above-mentioned step S230, it may include but is not limited to step S410 and step S420.

[0083] Step S410, determining that the positive half-cycle voltage is greater than a first reference voltage;

[0084] Step S420: Turn off the switch unit in the driving module.

[0085] like Figure 5 As shown, Figure 5 It is a step flow chart of an overcurrent protection method provided by another embodiment of the present application; regarding the above-mentioned step S230, it may include but is not limited to step S510 and step S520.

[0086] Step S510, determining that the positive half-cycle voltage is less than or equal to a first reference voltage;

[0087] Step S520: Turn on the switch unit in the driving module.

[0088] In one embodiment, if the positive half-cycle voltage is greater than the first reference voltage, it indicates that there is an overcurrent phenomenon, and the embodiment of the present application will control the switch unit in the driving module to be turned off, thereby cutting off the subsequent circuit or load; if the positive half-cycle voltage is less than or equal to the first reference voltage, it indicates that there is no overcurrent phenomenon, and the embodiment of the present application will control the switch unit in the driving module to remain turned on, thereby continuing to supply power to the subsequent circuit or load.

[0089] It should be noted that the switching state of the switch unit in the driving module is controlled according to the negative half-cycle voltage and the second reference voltage in the above step S330, which may include but is not limited to: Figure 6 or Figure 7 There are two implementation scenarios, as follows:

[0090] like Figure 6 As shown, Figure 6 It is a step flow chart of an overcurrent protection method provided by another embodiment of the present application; regarding the above-mentioned step S330, it may include but is not limited to step S610 and step S620.

[0091] Step S610, determining that the negative half-cycle voltage is less than the second reference voltage;

[0092] Step S620: Turn off the switch unit in the driving module.

[0093] like Figure 7 As shown, Figure 7 It is a step flow chart of an overcurrent protection method provided by another embodiment of the present application; regarding the above-mentioned step S330, it may include but is not limited to step S710 and step S720.

[0094] Step S710, determining that the negative half-cycle voltage is greater than or equal to the second reference voltage;

[0095] Step S720: Turn on the switch unit in the driving module.

[0096] In one embodiment, if the negative half-cycle voltage is less than the second reference voltage, it indicates that there is an overcurrent phenomenon, and the embodiment of the present application will control the switch unit in the driving module to be turned off, thereby cutting off the subsequent circuit or load; if the negative half-cycle voltage is greater than or equal to the second reference voltage, it indicates that there is no overcurrent phenomenon, and the embodiment of the present application will control the switch unit in the driving module to remain turned on, thereby continuing to supply power to the subsequent circuit or load.

[0097] It is worth noting that since the overcurrent protection method of the embodiment of the present application is applied to the overcurrent protection circuit of any of the above-mentioned embodiments, the specific implementation methods and technical effects of the overcurrent protection method of the embodiment of the present application can refer to the specific implementation methods and technical effects of the overcurrent protection circuit of any of the above-mentioned embodiments.

[0098] Based on the overcurrent protection methods of the above-mentioned various embodiments, overall embodiments of the overcurrent protection method of the present application are respectively proposed below.

[0099] In one embodiment, the embodiment of the present application cancels the full-wave rectifier diode, connects one side of the output of the current transformer to the reference voltage e0 at the common end between the first resistor voltage divider unit and the second resistor voltage divider unit, and the other side to the A / D pin of the control unit, so that the current sampling is not affected by the diode voltage drop, and the accuracy is improved. The first comparator is an AC current positive half-axis overcurrent protection comparator, and the detected positive half-axis AC current is converted into a voltage U1 and compared with e1. When U1>e1, the first comparator outputs a low level, the first switch tube is turned off, and the second switch tube is turned off to achieve overcurrent protection; the second comparator is an AC current negative half-axis overcurrent protection comparator, and the detected negative half-axis AC current is converted into a voltage U2 and compared with e2. When U2<e2, the second comparator outputs a low level, the first switch tube is turned off, and the second switch tube is turned off to achieve overcurrent protection.

[0100] Based on the current detection circuit and the overcurrent protection circuit of each of the above-mentioned embodiments, various embodiments of the circuit board and the air conditioner of the present application are respectively proposed below.

[0101] An embodiment of the present application further provides a circuit board, comprising the current detection circuit of any one of the above embodiments or the overcurrent protection circuit of any one of the above embodiments.

[0102] It is worth noting that since the circuit board of the embodiment of the present application includes the current detection circuit or overcurrent protection circuit of any of the above-mentioned embodiments, the specific implementation manner and technical effects of the circuit board of the embodiment of the present application can refer to the specific implementation manner and technical effects of the current detection circuit or overcurrent protection circuit of any of the above-mentioned embodiments.

[0103] An embodiment of the present application further provides an air conditioner, comprising the circuit board of any one of the above embodiments.

[0104] It is worth noting that since the air conditioner of the embodiment of the present application includes the circuit board of the above-mentioned embodiment, and the circuit board of the above-mentioned embodiment includes the current detection circuit or overcurrent protection circuit of any of the above-mentioned embodiments, the specific implementation manner and technical effects of the air conditioner of the embodiment of the present application can refer to the specific implementation manner and technical effects of the current detection circuit or overcurrent protection circuit of any of the above-mentioned embodiments.

[0105] Based on the overcurrent protection methods of the above-mentioned various embodiments, various embodiments of the control unit, air conditioner and computer-readable storage medium of the present application are respectively proposed below.

[0106] like Figure 8 As shown, Figure 8 4 is a schematic diagram of a control unit for executing an overcurrent protection method provided by an embodiment of the present application. The control unit 400 implemented in the present application includes: a processor 410, a memory 420, and a computer program stored in the memory 420 and executable on the processor 410, wherein: Figure 8 In the figure, a processor 410 and a memory 420 are taken as an example.

[0107] The processor 410 and the memory 420 may be connected via a bus or other means. Figure 8 The example of connecting through bus is taken in the following.

[0108] The memory 420, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer executable programs. In addition, the memory 420 may include a high-speed random access memory, and may also include a non-transitory memory, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 420 may optionally include a memory 420 remotely arranged relative to the processor 410, and these remote memories 420 may be connected to the control unit 400 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0109] Those skilled in the art will understand that Figure 8The device structure shown in the figure does not constitute a limitation on the control unit 400, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0110] exist Figure 8 In the control unit 400 shown in the figure, the processor 410 can be used to call the overcurrent protection program stored in the memory 420, so as to implement the above-mentioned overcurrent protection method. Specifically, the non-transient software program and instructions required to implement the overcurrent protection method of the above-mentioned embodiment are stored in the memory 420, and when executed by the processor 410, the overcurrent protection method of the above-mentioned embodiment is executed. Figures 4 to 7 The method steps in .

[0111] It is worth noting that since the control unit 400 of the embodiment of the present application can execute the overcurrent protection method of any of the above-mentioned embodiments, the specific implementation manner and technical effects of the control unit 400 of the embodiment of the present application can refer to the specific implementation manner and technical effects of the overcurrent protection method of any of the above-mentioned embodiments.

[0112] In addition, an embodiment of the present application further provides an air conditioner, comprising the control unit of the above embodiment.

[0113] It is worth noting that since the air conditioner of the embodiment of the present application includes the control unit of the above embodiment, and the control unit of the above embodiment can execute the overcurrent protection method of any of the above embodiments, the specific implementation methods and technical effects of the air conditioner of the embodiment of the present application can refer to the specific implementation methods and technical effects of the overcurrent protection method of any of the above embodiments.

[0114] In addition, an embodiment of the present application further provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are used to execute the above-described overcurrent protection method. Figures 4 to 7 The method steps in .

[0115] It is worth noting that since the computer-readable storage medium of the embodiment of the present application can execute the overcurrent protection method of any of the above-mentioned embodiments, the specific implementation methods and technical effects of the computer-readable storage medium of the embodiment of the present application can refer to the specific implementation methods and technical effects of the overcurrent protection method of any of the above-mentioned embodiments.

[0116] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed method above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically include computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0117] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the above implementation mode. Technical personnel familiar with the field can also make various equivalent modifications or substitutions under the shared conditions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A current detection circuit, characterized in that: include: A resistor voltage divider module, comprising a first resistor voltage divider unit and a second resistor voltage divider unit, wherein one end of the first resistor voltage divider unit is connected to a power supply input end, and the other end of the first resistor voltage divider unit is connected to a ground end through the second resistor voltage divider unit; A current transformer, one end of which is connected to a common end between the first resistor voltage divider unit and the second resistor voltage divider unit, and the other end of which is used to be connected to a sampling end of a control unit.

2. The current detection circuit according to claim 1, characterized in that: The first resistor voltage divider unit includes a first resistor and a second resistor, the second resistor voltage divider unit includes a third resistor and a fourth resistor, one end of the first resistor is connected to the power supply input end, and the other end is connected to the ground end through the second resistor, the third resistor and the fourth resistor in sequence.

3. The current detection circuit according to claim 1, characterized in that: The current detection circuit also includes a fifth resistor and a sixth resistor, one end of the fifth resistor is connected to one end of the current transformer, and the other end is connected to the other end of the current transformer; one end of the sixth resistor is connected to the fifth resistor, and the other end is used to be connected to the sampling end of the control unit.

4. An overcurrent protection circuit, characterized in that: Comprising the current detection circuit as claimed in claim 2.

5. The overcurrent protection circuit according to claim 4, characterized in that: The overcurrent protection circuit further includes a comparison module and a driving module, and the current detection circuit is connected to the driving module through the comparison module.

6. The overcurrent protection circuit according to claim 5, characterized in that: The comparison module includes at least one of the following: A first comparator, wherein a comparison terminal of the first comparator is connected to a common terminal between the first resistor and the second resistor, and another comparison terminal is used to be connected to a sampling terminal of a control unit, and an output terminal of the first comparator is connected to the driving module; A second comparator, wherein one comparison end of the second comparator is connected to the common end between the third resistor and the fourth resistor, the other comparison end is used to be connected to the sampling end of the control unit, and the output end of the second comparator is connected to the driving module.

7. The overcurrent protection circuit according to claim 5, characterized in that: The driving module includes a switch unit connected to the comparison module, and the comparison module is used to control the switch unit to be turned off.

8. The overcurrent protection circuit according to claim 7, characterized in that: The switch unit includes a first switch tube, a photoelectric coupler and a second switch tube, the control end of the first switch tube is connected to the comparison module, the input end or the output end of the first switch tube is connected to the input side of the photoelectric coupler, the output side of the photoelectric coupler is connected to the control end of the second switch tube, and the input end or the output end of the second switch tube is used to connect to a load.

9. An overcurrent protection method, characterized in that: Applied to the overcurrent protection circuit according to claim 6, when the comparison module includes the first comparator and the second comparator, the overcurrent protection method includes: Acquire a positive half-cycle voltage through the first comparator, and acquire a first reference voltage at a common end between the first resistor and the second resistor; Obtaining a negative half-cycle voltage through the second comparator, and obtaining a second reference voltage at a common end between the third resistor and the fourth resistor; The switching state of the switch unit in the driving module is controlled according to the positive half-cycle voltage and the first reference voltage, and the switching state of the switch unit in the driving module is controlled according to the negative half-cycle voltage and the second reference voltage.

10. The overcurrent protection method according to claim 9, characterized in that: The controlling the switching state of the switch unit in the driving module according to the positive half-cycle voltage and the first reference voltage includes one of the following: When the positive half-cycle voltage is greater than the first reference voltage, turning off the switch unit in the driving module; When the positive half-cycle voltage is less than or equal to the first reference voltage, the switch unit in the driving module is turned on.

11. The overcurrent protection method according to claim 9, characterized in that: The controlling the switching state of the switch unit in the driving module according to the negative half-cycle voltage and the second reference voltage includes one of the following: When the negative half-cycle voltage is less than the second reference voltage, turning off the switch unit in the driving module; When the negative half-cycle voltage is greater than or equal to the second reference voltage, the switch unit in the driving module is turned on.

12. A circuit board, characterized in that: The invention comprises a current detection circuit as described in any one of claims 1 to 3, or an overcurrent protection circuit as described in any one of claims 4 to 8.

13. An air conditioner, characterized in that: Includes the circuit board as claimed in claim 12.

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