Air conditioner

Abstract

The utility model discloses an air conditioner. In the air conditioner, the control end of the switching circuit is connected with the rectifying circuit, and the output end of the switching circuit is connected with the ground end, so that the connection between the second control end of the first relay and the ground end is automatically conducted under the condition that the voltage difference value between the control end and the output end of the switching circuit is greater than the conduction threshold value of the switching circuit; and when the voltage difference value between the control end and the output end of the switching circuit is smaller than the conduction threshold value, the first relay automatically disconnects the connection between the second control end of the first relay and the ground end, so that the first relay conducts the connection between the alternating current input end and the load, and the first relay is switched off when the voltage difference value between the control end and the output end of the switching circuit is smaller than the conduction threshold value. Therefore, a controller does not need to be arranged to carry out sampling calculation and control on the input current of the load, overcurrent protection on the load is realized only through a hardware structure, and the load is prevented from being damaged by overcurrent.

Description

Technical Field

[0001] The embodiments of the present application relate to electronic technology, and relate to but are not limited to an air conditioner. Background Art

[0002] If the live and neutral wires of an air conditioner circuit are short-circuited, prolonged power flow to the shorted area can cause sparks or high temperatures, potentially leading to fire. Furthermore, when abnormal current from a lightning surge is input into the air conditioner's load, components on the load can be damaged if the abnormal current exceeds their rated current. Therefore, it is necessary to detect overcurrent in the load.

[0003] In the prior art, current detection for mainstream variable-frequency air conditioners involves sampling the voltage through a current sampling resistor in the load's input path, amplifying the signal through an operational amplifier, and then sending it to the main control chip for calculation. If the detected current value exceeds the set software overcurrent protection value, the controller will indicate a fault and shut down the system. However, if the main control chip or power supply circuit fails, neither the controller's software-calculated current value nor the hardware overcurrent protection circuit will function properly. The load will continue to be subjected to abnormal current shocks, causing damage to the device. Utility Model Content

[0004] In view of this, the air conditioner provided in the embodiment of the present application can achieve overcurrent protection for the load only through hardware structure, thereby preventing the load from being damaged by overcurrent.

[0005] An embodiment of the present application provides an air conditioner, comprising:

[0006] chassis;

[0007] A circuit board is provided in the housing, and the circuit board includes:

[0008] an AC input terminal configured to receive an AC power signal;

[0009] a rectifier circuit connected to the AC input terminal to rectify a first portion of the AC signal and output a DC signal;

[0010] a switch circuit, wherein a control terminal of the switch circuit is connected to the rectifier circuit, an input terminal of the switch circuit is connected to the rectifier circuit via a first relay, and an output terminal of the switch circuit is connected to a ground terminal, so as to connect the first relay to the ground terminal when a voltage difference between the control terminal of the switch circuit and the output terminal of the switch circuit is greater than or equal to a conduction threshold, and disconnect the first relay from the ground terminal when a voltage difference between the control terminal of the switch circuit and the output terminal of the switch circuit is less than the conduction threshold;

[0011] A first relay, wherein a power supply end of the first relay is connected to the rectifier circuit, a control end of the first relay is connected to the switching circuit, an input end of the first relay is connected to the AC input end, and an output end of the first relay is connected to a load, so as to conduct the connection between the AC input end and the load when the control end and the ground end are disconnected, and output the second part of the AC signal to the load.

[0012] In the above-mentioned air conditioner, the control end of the switching circuit is connected to the rectifier circuit, and the output end of the switching circuit is connected to the ground end. When the voltage difference between the control end and the output end of the switching circuit is greater than the conduction threshold of the switching circuit, the connection between the control end and the ground end of the first relay is automatically turned on, so that the first relay disconnects the connection between the AC input end and the load. When the voltage difference between the control end and the output end of the switching circuit is less than the conduction threshold, the connection between the control end and the ground end of the first relay is automatically disconnected, so that the first relay connects the connection between the AC input end and the load. In this way, there is no need to set up a controller to sample, calculate and control the input current of the load, and overcurrent protection of the load is achieved only through the hardware structure to prevent overcurrent damage to the load.

[0013] In one embodiment, the switching circuit includes a voltage divider sub-circuit and a switching tube, the control end of the switching tube is connected to the rectifier circuit through the voltage divider sub-circuit, the input end of the switching tube is connected to the control end of the first relay, and the output end of the switching circuit and the voltage divider sub-circuit are respectively connected to the ground end, so that after the DC signal is divided by the voltage divider sub-circuit, the switching tube obtains and turns on or off the connection between the first relay and the ground end according to the relationship between the voltage value of the divided DC signal and the conduction threshold corresponding to the switching tube.

[0014] It can be understood that since the voltage output by the rectifier circuit is relatively large, the DC signal can be first divided by a voltage divider sub-circuit, and then the divided DC signal can be transmitted to the control end of the switching tube, so that the switching tube can turn on or off the connection between the first relay and the ground terminal according to the relationship between the divided DC signal and the conduction threshold corresponding to the switching tube.

[0015] In one embodiment, the voltage divider sub-circuit includes a first resistor and a second resistor, one end of the first resistor is connected to the rectifier circuit, the other end of the first resistor is connected to one end of the switching tube and the second resistor respectively, and the other end of the second resistor is connected to the ground terminal, so that the switching tube uses the voltage across the second resistor as the voltage value of the divided DC signal.

[0016] It can be understood that by setting up a voltage divider sub-circuit including a first resistor and a second resistor, the second resistor is connected in parallel between the control end and the output end of the switching tube, so that the switching tube uses the voltage difference between the two ends of the second resistor as the voltage value of the DC signal after voltage division, further realizing the judgment of the DC signal after voltage division by the switching tube, while reducing the device cost.

[0017] In one embodiment, the circuit board also includes a voltage conversion circuit, the input end of the voltage conversion circuit is connected to the AC input end, the coupled output end of the voltage conversion circuit is connected to the rectifier circuit, and the direct output end of the voltage conversion circuit is connected to the first relay, so that the AC signal is converted into an AC voltage signal through the voltage conversion circuit, and then the AC voltage signal is converted into the DC signal through the rectifier circuit.

[0018] It is understandable that by providing a voltage conversion circuit, it is possible to ensure that the voltage in the AC input electrical signal is converted into current, thereby ensuring the parameter stability of the DC electrical signal output by the rectifier circuit.

[0019] In one embodiment, the switching circuit further includes an energy storage element, which is connected in parallel with the switching tube to store part of the charge of the divided DC signal and release the stored charge to maintain the disconnection of the first relay when the first relay disconnects the AC input terminal and the load.

[0020] It can be understood that by setting the energy storage element and the switching tube in parallel, part of the charge of the divided DC signal can be stored, and when the first relay disconnects the connection between the AC input terminal and the load, the stored charge is released, so that the first relay can be maintained for a period of time after being disconnected.

[0021] In one embodiment, when the time duration for the energy storage element to release the stored charge reaches a preset time duration threshold, the first relay switches on the connection between the AC input terminal and the load.

[0022] It can be understood that by setting the first relay to disconnect during the abnormal current protection duration and then close again to form the abnormal current protection duration, it can be ensured that the first relay will not frequently switch the open and close states during the process of continuous abnormal input current, thereby reducing device consumption.

[0023] In one embodiment, the preset time threshold is determined by the capacitance of the energy storage element and the resistance of the second resistor.

[0024] It is understandable that determining the preset time threshold by the capacitance of the energy storage element and the resistance of the second resistor can reduce the difficulty of calculation for technicians.

[0025] In one embodiment, the circuit board further includes a thermistor, which is connected to the first relay and the load, respectively, so that when the connection between the AC input terminal and the load is conducted, the second portion of the AC signal is output to the load through the thermistor.

[0026] It can be understood that by providing a thermistor between the first relay and the load, the standby power consumption of the air conditioner during the soft start period can be reduced.

[0027] In one embodiment, the circuit board further includes a second relay and a control circuit, the second relay being connected to the control circuit, the first relay and the load respectively, the control circuit being connected to the load, and the second relay being connected in parallel with the thermistor so that when the load operates normally according to the second part of the electrical signal, the second relay is controlled to conduct through the control circuit.

[0028] It is understandable that by providing the second relay and the control circuit, the controller can control the second relay to conduct the connection between the first relay and the load when the load is able to work normally, thereby ensuring the subsequent operation of the load.

[0029] In one embodiment, the control circuit includes a switching power supply and a controller, the controller is connected to the switching power supply and the load respectively, and the switching power supply is also connected to the second relay so that when the switching power supply receives the second part of the electrical signal in the AC signal, the controller is powered by the switching power supply and the controller is controlled to turn on or off according to whether the load is working normally.

[0030] It can be understood that by setting up a switching power supply and converting the second part of the electrical signal in the AC signal into the operating voltage of the controller through the switching power supply, it can be ensured that the input current, whether normal current or abnormal current, will not cause damage to the controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and, together with the specification, are used to illustrate the technical solutions of the present application.

[0032] Figure 1 This is one of the structural diagrams of the air conditioner provided in the embodiment of the present application;

[0033] Figure 2 This is one of the structural diagrams of the switch circuit provided in the embodiment of the present application;

[0034] Figure 3 A schematic diagram of the implementation structure of the switch circuit provided in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of the structure of a rectifier circuit provided in an embodiment of the present application;

[0036] Figure 5 A schematic diagram of the implementation structure of the rectifier circuit provided in an embodiment of the present application;

[0037] Figure 6 The second structural diagram of the switch circuit provided in the embodiment of the present application;

[0038] Figure 7 The second structural diagram of the air conditioner provided in the embodiment of the present application;

[0039] Figure 8 The third structural diagram of the air conditioner provided in the embodiment of the present application;

[0040] Figure 9 A schematic diagram of the structure of the control circuit provided in an embodiment of the present application;

[0041] Figure 10 This is a schematic diagram of the implementation structure of the air conditioner provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the specific technical solutions of the present application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application but are not intended to limit the scope of the present application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0044] It should be pointed out that the terms "first\second\third" involved in the embodiments of the present application are used to distinguish similar or different objects, and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

[0045] Figure 1 A schematic diagram of the structure of an air conditioner provided in an embodiment of the present application, the air conditioner may include:

[0046] chassis;

[0047] The circuit board is arranged in the housing and includes:

[0048] The AC input terminal 101 is configured to receive an AC signal;

[0049] The rectifier circuit 102 is connected to the AC input terminal 101 to rectify the first part of the AC signal and output a DC signal;

[0050] a switch circuit 104 having a control terminal connected to the rectifier circuit 102, an input terminal connected to the rectifier circuit 102 via the first relay 103, and an output terminal connected to the ground terminal, configured to connect the first relay 103 to the ground terminal when a voltage difference between the control terminal and the output terminal is greater than or equal to a conduction threshold, and disconnect the first relay 103 from the ground terminal when the voltage difference between the control terminal and the output terminal is less than the conduction threshold;

[0051] The first relay 103 has a power supply end connected to the rectifier circuit 102, a control end connected to the switch circuit 104, an input end connected to the AC input end 101, and an output end connected to the load 105. When the control end and the ground end of the first relay 103 are disconnected, the connection between the AC input end 101 and the load 105 is connected, and the second part of the AC signal is output to the load 105.

[0052] It should be understood that the above-mentioned air conditioner can be an outdoor air conditioner or an indoor air conditioner. The specific setting is made by technical personnel in this field according to actual conditions, and this application does not impose any restrictions.

[0053] During the implementation process, the AC signal is input into the circuit board through the AC input terminal 101. At this time, the AC signal is divided into two parts for transmission. One part is transmitted to the input terminal of the first relay 103, and the other part is transmitted to the rectifier circuit 102. The first part of the AC signal is converted into a DC signal through the rectifier circuit 102, and the DC signal is then transmitted to the switch circuit 104, so that the switch circuit 104 automatically turns on or off the connection between the control terminal and the ground terminal of the first relay 103 according to the voltage difference between the control terminal and the output terminal and the magnitude relationship of the conduction threshold. In the case where the connection between the input and output ends is disconnected, that is, the voltage at the control end of the first relay 103 is not zero, the first relay 103 will turn on the connection between the input end and the output end, so that part of the AC signal at the input end of the first relay 103 is transmitted to the load 105, and in the case where the connection between the control end and the ground end of the first relay 103 is turned on, that is, the voltage at the control end of the first relay 103 is zero, the first relay 103 will disconnect the connection between the input and output ends, so that part of the AC signal at the input end of the first relay 103 cannot be transmitted to the load 105, thereby realizing overcurrent protection for the load 105.

[0054] It should be understood that since the basis for controlling the on or off of the switch circuit 104 is the DC signal converted from the AC signal, the switch circuit 104 can, when the voltage of the AC signal is greater than the threshold, turn on the connection between the control terminal and the ground terminal of the first relay 103, thereby disconnecting the connection between the AC input terminal 101 and the load 105, and when the voltage of the AC signal is less than the threshold, disconnect the connection between the control terminal and the ground terminal of the first relay 103, thereby turning on the connection between the AC input terminal 101 and the load 105, that is, overcurrent protection.

[0055] In summary, when the switch circuit 104 in this embodiment switches on or off the connection between the AC input terminal 101 and the load 105, it does not use a controller to control the switching on or off of the AC input terminal 101 and the load 105. Instead, it directly controls the switching on or off based on the voltage difference between the control terminal and the output terminal and the magnitude relationship between the switching on threshold. The switching on threshold of the switch circuit 104 is related to the hardware structure of the switch circuit 104 itself. When the voltage difference between the control terminal and the output terminal of the switch circuit 104 does not reach the switching on threshold, the switch circuit 104 operates in the off state, and the input terminal and the output terminal of the switch circuit 104 are in a disconnected state. When the voltage difference between the control terminal and the output terminal of the switch circuit 104 reaches the switching on threshold, the switch circuit 104 operates in the on state, and the input terminal and the output terminal of the switch circuit 104 are in a connected state. As a result, the entire overcurrent protection process eliminates the existence of the controller, preventing the controller from being damaged and unable to normally perform the corresponding overcurrent protection measures when an overcurrent occurs in the AC signal.

[0056] In some embodiments, the switching circuit 104 may include a transistor, wherein the base of the transistor serves as the control terminal of the switching circuit 104, the collector of the transistor serves as the input terminal of the switching circuit 104, and the emitter of the transistor serves as the output terminal of the switching circuit 104. Of course, since the conduction threshold between the base and emitter of the transistor is only 0.7V, it is necessary to ensure that the voltage applied between the base and emitter of the transistor is less than 0.7V when the overcurrent protection is not triggered. This can be achieved by providing a voltage divider between the transistor and the rectifier circuit 102, thereby ensuring that the voltage applied between the base and emitter of the transistor is less than 0.7V.

[0057] In the above-mentioned air conditioner, the control end of the switch circuit 104 is connected to the rectifier circuit 102, and the output end of the switch circuit 104 is connected to the ground end. When the voltage difference between the control end and the output end of the switch circuit 104 is greater than the conduction threshold of the switch circuit 104, the connection between the control end and the ground end of the first relay 103 is automatically turned on, so that the first relay 103 disconnects the connection between the AC input end 101 and the load 105. When the voltage difference between the control end and the output end of the switch circuit 104 is less than the conduction threshold, the connection between the control end and the ground end of the first relay 103 is automatically disconnected, so that the first relay 103 connects the connection between the AC input end 101 and the load 105. In this way, there is no need to set up a controller to sample, calculate and control the input current of the load 105. Overcurrent protection of the load 105 is achieved only through a hardware structure to prevent the load 105 from being damaged by overcurrent.

[0058] In one embodiment, Figure 2As shown, the switch circuit 104 includes a voltage divider sub-circuit 1041 and a switch tube 1042. The control end of the switch tube 1042 is connected to the rectifier circuit 102 through the voltage divider sub-circuit 1041, and the input end of the switch tube 1042 is connected to the control end of the first relay 103. The output end of the switch circuit 104 and the voltage divider sub-circuit 1041 are respectively connected to the ground end. After the DC signal is divided by the voltage divider sub-circuit 1041, the switch tube 1042 obtains it and turns on or off the connection between the first relay 103 and the ground end according to the relationship between the voltage value of the divided DC signal and the conduction threshold corresponding to the switch tube 1042.

[0059] It should be understood that after receiving the DC signal, the voltage divider sub-circuit 1041 will first divide the DC signal, so that the voltage transmitted to the switch tube 1042 can meet the conduction condition when the current of the AC signal exceeds the threshold, and will not conduct when the current of the AC signal does not exceed the threshold. For example, taking the switch tube 1042 as a transistor, the conduction voltage drop between the control end and the output end is 0.7V. After the DC signal passes through the voltage divider sub-circuit 1041, if the current of the AC signal is less than the threshold, the voltage difference between the control end and the output end transmitted to the transistor can be made less than 0.7V, that is, the transistor is in the disconnected state. If the current of the AC signal is greater than the threshold, the voltage difference between the control end and the output end transmitted to the transistor can be made greater than 0.7V, that is, the transistor is in the on state.

[0060] In some embodiments, the switch tube 1042 may be a transistor with a switching function such as a triode or a field effect transistor.

[0061] The voltage divider circuit 1041 can adopt common technical means in the prior art, for example, Figure 3 As shown, the voltage divider sub-circuit 1041 includes a first resistor and a second resistor, one end of the first resistor is connected to the rectifier circuit 102, the other end of the first resistor is respectively connected to the switch tube 1042 and one end of the second resistor, and the other end of the second resistor is connected to the ground, so that the switch tube 1042 uses the voltage across the second resistor as the voltage value of the divided DC signal.

[0062] It should be noted that the above embodiment describes a technical solution for voltage division by connecting a first resistor and a second resistor in series. In other embodiments, voltage division can also be achieved by connecting two capacitors in series. For example, the voltage divider sub-circuit 1041 includes a first capacitor and a second capacitor, one end of the first capacitor is connected to the rectifier circuit 102, and the other end of the first capacitor is respectively connected to the switch tube 1042 and one end of the second capacitor, and the other end of the second capacitor is connected to the ground, so that the switch tube 1042 uses the voltage across the second capacitor as the voltage value of the DC signal after voltage division.

[0063] It can be understood that since the voltage output by the rectifier circuit 102 is relatively large, the DC signal can first be divided by the voltage divider sub-circuit 1041, and then the divided DC signal can be transmitted to the control end of the switch tube 1042, so that the switch tube 1042 can turn on or off the connection between the first relay 103 and the ground terminal according to the relationship between the divided DC signal and the conduction threshold corresponding to the switch tube 1042.

[0064] In one embodiment, Figure 4 As shown, the circuit board also includes a voltage conversion circuit 106, the input end of the voltage conversion circuit 106 is connected to the AC input end 101, the coupled output end of the voltage conversion circuit 106 is connected to the rectifier circuit 102, and the direct output end of the voltage conversion circuit 106 is connected to the first relay 103, so that the AC signal is converted into an AC voltage signal through the voltage conversion circuit 106, and then the AC voltage signal is converted into a DC signal through the rectifier circuit 102.

[0065] It should be understood that the voltage conversion circuit 106 includes two transmission paths, one is a direct transmission path from the AC input terminal 101 to the first relay 103, and the other is a coupled transmission path from the AC input terminal 101 to the rectifier circuit 102. Obviously, the voltage signal in the coupled transmission path is obtained by coupling with the electrical signal in the direct transmission path. When the first relay 103 is disconnected, the direct transmission path is in an open-circuit state, and the coupled transmission path cannot couple the AC voltage signal from the AC signal, that is, when the direct transmission path is disconnected, the coupled transmission path is also in a disconnected state. When the first relay 103 is turned on, the direct transmission path is in a conductive state, and the coupled transmission path can couple the AC voltage signal from the AC signal, that is, when the direct transmission path is turned on, the coupled transmission path is also in a conductive state.

[0066] Therefore, the first relay 103 needs to be in a conducting state in the initial state to ensure that the rectifier circuit 102 can obtain an AC voltage signal according to the AC power signal.

[0067] In some embodiments, the rectifier circuit 102 may include a bridge rectifier circuit 102 . The specific structure of the bridge rectifier circuit 102 may adopt a common structure in the prior art, which will not be described in detail here.

[0068] In which, the above-mentioned voltage conversion circuit 106 may include a coil, which is used to convert the current signal in the AC signal into a voltage signal, thereby outputting an AC voltage signal, one end of the coil's energized conductor is connected to the AC input terminal 101, and the other end of the coil's energized conductor is connected to the input terminal of the first relay 103, the first output terminal of the coil is connected to the rectifier circuit 102, and the second output terminal of the coil is connected to the ground terminal.

[0069] For example, Figure 5 As shown, the rectifier circuit 102 includes a bridge rectifier circuit, a first end of the coil is connected to the AC input terminal 101, a second end of the coil is connected to the first relay 103K1, a third end of the coil is connected to the ground terminal, and a fourth end of the coil is connected to the bridge rectifier circuit 102 to output a DC signal through the bridge rectifier circuit 102.

[0070] It is understandable that by providing the voltage conversion circuit 106 , it is possible to ensure that the voltage in the AC input electrical signal is converted into current, thereby ensuring the parameter stability of the DC electrical signal output by the rectifier circuit 102 .

[0071] After the first relay 103 disconnects the AC input terminal 101 and the load 105, the voltage conversion circuit 106 in the rectifier circuit 102 cannot normally obtain the DC signal, which will cause the switch tube 1042 to be in the off state, so that the first relay 103 is instantly restored to the on state. However, the abnormal AC signal generally lasts for a period of time. If the first relay 103 is instantly restored to the on state, it will still cause damage to the load 105. At the same time, the frequent switching of the first relay 103 can easily cause damage to the first relay 103.

[0072] In order to solve the above problem, an energy storage element may be provided in the switch circuit 104, for example, Figure 6 As shown, the switching circuit 104 further includes an energy storage element, which is connected in parallel with the switching tube 1042 to store part of the charge of the divided DC signal and release the stored charge when the first relay 103 disconnects the connection between the AC input terminal 101 and the load 105, thereby maintaining the disconnected state of the first relay 103.

[0073] It should be understood that since an energy storage element is connected in parallel between the control end and the output end of the switch tube 1042, the energy storage element can store part of the charge of the AC signal. When the input voltage of the AC signal is greater than the threshold, the transistor will turn on the connection between the control end and the ground end of the first relay 103, and at the same time, the first relay 103 will disconnect the connection between the AC input end 101 and the load 105. At this time, the energy storage element begins to release the stored charge. During the charge release process, the transistor will remain in the on state until the released charge can no longer maintain the on state of the transistor. At this time, the transistor will be disconnected and the first relay 103 will resume the on state.

[0074] It can be understood that by setting the energy storage element and the switching tube 1042 in parallel, part of the charge of the divided DC signal can be stored, and when the first relay 103 disconnects the connection between the AC input terminal 101 and the load 105, the stored charge is released, thereby enabling the first relay 103 to remain in the disconnected state after disconnection, forming a duration period of abnormal current protection in which the disconnected state is maintained.

[0075] In one embodiment, when the time duration for the energy storage element to release the stored charge reaches a preset time duration threshold, the switch tube 1042 disconnects the connection between the control terminal and the ground terminal.

[0076] The preset time threshold is determined by the capacitance of the energy storage element and the resistance of the second resistor.

[0077] by Figure 6 Taking the structure in as an example, the calculation formula for the preset time threshold Tset_max can be:

[0078] Tset_max=R2*C1*ln(Vcc / Vce);

[0079] Wherein, Vcc is the rectified voltage, Vce is the collector voltage of the transistor, C1 is the capacity of the energy storage element, and R2 is the resistance value of the second resistor.

[0080] It can be understood that by setting the first relay 103 to disconnect during the abnormal current protection duration and then close again to form the abnormal current protection duration, it can be ensured that the first relay 103 will not frequently switch the open and close states during the process of continuous abnormal input current, thereby reducing device consumption.

[0081] In one embodiment, Figure 7 As shown, the circuit board also includes a thermistor 107, which is connected to the first relay 103 and the load 105 respectively, so that when the connection between the AC input terminal 101 and the load 105 is turned on, the second part of the AC signal is output to the load 105 through the thermistor 107.

[0082] It should be understood that after the air conditioner is powered on, it will enter the soft start stage. During the soft start stage, the conduction current of the thermistor 107 is used to supply power to the subsequent load 105. At this time, the thermistor 107 does not enter the high-resistance state, so that the air conditioner is in standby mode, thereby achieving the purpose of reducing standby power consumption.

[0083] In one embodiment, Figure 8As shown, the circuit board also includes a second relay 108 and a control circuit 109. The second relay 108 is connected to the control circuit 109, the first relay 103 and the load 105 respectively. The control circuit 109 is connected to the load 105. The second relay 108 is connected in parallel with the thermistor 107 so that when the load 105 works normally according to the second part of the electrical signal, the second relay 108 is controlled to be turned on through the control circuit 109.

[0084] It is understandable that by setting the second relay 108 and the control circuit 109, the controller can control the second relay 108 to conduct the connection between the first relay 103 and the load 105 when the load 105 can work normally, thereby ensuring the subsequent operation of the load 105.

[0085] In one embodiment, Figure 9 As shown, the control circuit 109 includes a switching power supply 1091 and a controller 1092. The controller 1092 is connected to the switching power supply 1091 and the load 105 respectively. The switching power supply 1091 is also connected to the second relay 108, so that when the switching power supply 1091 receives the second part of the electrical signal in the AC signal, the controller 1092 is powered by the switching power supply 1091, and the controller 1092 controls the second relay 108 to be turned on or off according to whether the load 105 is working normally.

[0086] It can be understood that by setting up a switching power supply 1091, the second part of the electrical signal in the AC signal is converted into the working voltage of the controller 1092 through the switching power supply 1091, which can ensure that the input current, whether normal current or abnormal current, will not cause damage to the controller 1092.

[0087] Figure 10 This is a schematic diagram of the implementation structure of an air conditioner provided in this application. Figure 9As shown, the air conditioner may include a casing and a circuit board. The circuit board is arranged in the casing. The circuit board includes an AC input terminal 101, a rectifier circuit 102, a switch circuit 104, a first relay K1, a voltage conversion circuit 106, a control circuit 109, a second relay K2 and a load 105. The input terminal of the rectifier circuit 102 is connected to the AC input terminal 101, and the output terminal of the rectifier circuit 102 is respectively connected to the control terminal of the switch circuit 104 and the power supply terminal of the first relay K1. The input terminal of the switch circuit 104 is connected to the rectifier circuit 102 through the first relay K1, the output terminal of the switch circuit 104 is connected to the ground terminal, the control terminal of the first relay K1 is connected to the switch circuit 104, the input terminal of the first relay K1 is connected to the AC input terminal 101, the output terminal of the first relay K1 is respectively connected to the control circuit 109 and the load 105, and the control circuit 109 is also connected to the load 105. The voltage conversion circuit 106 includes a coil TR1, and the rectifier circuit 102 includes a bridge rectifier circuit. The first end of the coil TR1 is connected to the AC input terminal 101, the second end of the coil TR1 is connected to the first relay K1, the third end of the coil TR1 is connected to the ground terminal, and the fourth end of the coil TR1 is connected to the first relay K1 via a diode. The fourth end of the coil TR1 is also connected to the switching circuit 104 via the bridge rectifier circuit 102. The switch circuit 104 includes a voltage divider subcircuit 1041, a first capacitor C1, a second capacitor C2, and a transistor V5. The output of the bridge rectifier circuit 102 is connected to one end of the first resistor R1 of the voltage divider subcircuit 1041. The second resistor R2, the first capacitor C1, and the second capacitor C2 of the voltage divider subcircuit 1041 are connected in parallel between the other end of the first resistor R1 and ground. The base of the transistor V5 is connected to the other end of the first resistor R1 via a third resistor R3. The emitter of the transistor V5 is connected to ground. The collector of the transistor V5 is connected to the control end of the first relay K1 via a fifth resistor R5. The power supply end of the second relay K2 is connected to a reference power supply. The control end of the second relay K2 is connected to the control circuit 109. The input end of the second relay K2 is connected to the output end of the first relay K1. The output end of the second relay K2 is connected to the load 105 and the control circuit 109, respectively. The control circuit 109 includes a switching power supply 1091 and a controller 1092. The input of the switching power supply 1091 is connected to the output of the second relay K2. The output of the switching power supply 1091 is connected to the controller 1092. The load 105 is also connected to the controller 1092. The second relay K2 is connected in parallel with the fourth resistor R4.

[0088] The air conditioner in this embodiment may include two implementations:

[0089] Implementation case 1: The current of the AC signal does not exceed the overcurrent protection threshold Iset_max.

[0090] When an AC signal is input through AC input terminal AC_L and passes through coil TR1, it is transmitted to controller 1092. Simultaneously, the current at AC_L is converted into a voltage by coil TR1 and then transmitted to the full-bridge rectifier circuit composed of diodes V1-V4 for rectification. After rectification, the current is divided into two branches: overcurrent detection branch 1 and power supply branch 2. The electrical signal in overcurrent detection branch 1 flows to the voltage divider circuit. Since the AC signal does not exceed the overcurrent protection threshold Iset_max, the voltage Vr2 across the second resistor R2 is less than 0.7V, transistor V5 is in the off state, and relay K1 is in the initial closed state. The rectified voltage can be calculated as VCC = (Iop / Nt) * (R1+R2), where Iop is the current value of the AC signal and Nt is the current-to-voltage conversion ratio of coil TR1.

[0091] The electrical signal in the power supply branch 2 is rectified by the full-bridge rectifier circuit, stabilized and filtered by the second capacitor C2, and then output to the relay K1 to provide power. The voltage at the power supply end of the relay K1 is VCC-0.7V.

[0092] Implementation scenario 2: The current of the AC signal exceeds the overcurrent protection threshold Iset_max.

[0093] When the AC signal exceeds the overcurrent protection threshold Iset_max, the induced output voltage of coil TR1 increases, and the voltage Vr2 across the second resistor R2 is greater than 0.7V, reaching the conduction condition of the transistor V5. The base drive current Ibe of the transistor V5 is equal to (Vr2-Vbe) / R3, where Vbe is the voltage at the control terminal of the transistor V5 and R3 is the resistance value of the third resistor R3. After transistor V5 is turned on, the control terminal of first relay K1 is grounded. At this point, transistor V5's collector current, Ice, equals (Vcc-k1-Vce) / (Rk1+R5), with Ice / Ibe > β. Transistor V5 operates in its saturation region, where Vcc-k1 is the voltage at the power supply terminal of first relay K1, Vce is the collector voltage of transistor V5, Rk1 is the internal resistance of first relay K1, R5 is the resistance of fifth resistor R5, Ice is the collector current of transistor V5, Ibe is the base current of transistor V5, and β is the gain factor of transistor V5. First relay K1 operates, disconnecting AC_L from the load and controller, thereby protecting controller 1092 and load 105 from prolonged abnormal current shocks.

[0094] When the current of the AC signal exceeds the overcurrent protection threshold Iset_max and triggers the overcurrent protection function, the first relay can keep disconnecting AC_L from the load and the controller before the overcurrent protection duration reaches the preset duration threshold Tset_max. The specific value of Tset_max can be changed by adjusting the capacitance of the first capacitor C1 and the resistance of the second resistor R2, that is:

[0095] Tset_max=((R2*R3) / (R2+R3))*C1*ln(Vcc / Vce), where Vcc is the rectified voltage and Vce is the collector voltage of transistor V5.

[0096] After Tset_max time, the charge stored in the first capacitor C1 is released, so that the base voltage of the transistor V5 is lower than Vce, so the transistor V5 operates in the cut-off region, disconnecting the connection between the control terminal and the ground terminal of the first relay K1, so the first relay K1 returns to the initial closed state.

[0097] In addition, after the input current is in a normal state, the AC signal is input to the switching power supply and the load respectively through the fourth resistor R4. When the current of the AC signal exceeds the overcurrent protection threshold Iset_max, the overcurrent protection is triggered again (implementation situation two is re-executed). When there is no overcurrent between the controller 1092 and the load 105, that is, the controller 1092 detects that the return signal of the load 105 is normal, the second relay K2 is closed and the air conditioner works normally.

[0098] It should be understood that "one embodiment" or "an embodiment" or "some embodiments" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments. The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other. For the sake of brevity, they will not be repeated here.

[0099] The term "and / or" in this article is only a description of the association relationship between associated objects, indicating that there can be three relationships. For example, object A and / or object B can mean: object A exists alone, object A and object B exist at the same time, and object B exists alone.

[0100] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0101] The modules described above as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules; they may be located in one place or distributed across multiple network units; some or all of the modules may be selected according to actual needs to achieve the purpose of this embodiment.

[0102] In addition, all functional modules in the embodiments of the present application can be integrated into one processing unit, or each module can be a separate unit, or two or more modules can be integrated into one unit; the above-mentioned integrated modules can be implemented in the form of hardware or in the form of hardware plus software functional units.

[0103] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0104] The above is merely an embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An air conditioner, characterized in that: include: chassis; A circuit board is provided in the housing, and the circuit board includes: an AC input terminal configured to receive an AC power signal; a rectifier circuit connected to the AC input terminal to rectify a first portion of the AC signal and output a DC signal; a switch circuit, wherein a control terminal of the switch circuit is connected to the rectifier circuit, an input terminal of the switch circuit is connected to the rectifier circuit via a first relay, and an output terminal of the switch circuit is connected to a ground terminal, so as to connect the first relay to the ground terminal when a voltage difference between the control terminal of the switch circuit and the output terminal of the switch circuit is greater than or equal to a conduction threshold, and disconnect the first relay from the ground terminal when a voltage difference between the control terminal of the switch circuit and the output terminal of the switch circuit is less than the conduction threshold; A first relay, wherein a power supply end of the first relay is connected to the rectifier circuit, a control end of the first relay is connected to the switching circuit, an input end of the first relay is connected to the AC input end, and an output end of the first relay is connected to a load, so as to conduct the connection between the AC input end and the load when the control end of the first relay and the ground end are disconnected, thereby outputting the second part of the AC signal to the load.

2. The air conditioner according to claim 1, wherein The switching circuit includes a voltage divider sub-circuit and a switching tube. The control end of the switching tube is connected to the rectifier circuit through the voltage divider sub-circuit, the input end of the switching tube is connected to the control end of the first relay, and the output end of the switching circuit and the voltage divider sub-circuit are respectively connected to the ground end. After the DC signal is divided by the voltage divider sub-circuit, the switching tube obtains the DC signal and turns on or off the connection between the first relay and the ground end based on the relationship between the voltage value of the divided DC signal and the conduction threshold corresponding to the switching tube.

3. The air conditioner according to claim 2, wherein: The voltage divider sub-circuit includes a first resistor and a second resistor, one end of the first resistor is connected to the rectifier circuit, the other end of the first resistor is connected to one end of the switching tube and the second resistor respectively, and the other end of the second resistor is connected to the ground terminal, so that the switching tube uses the voltage across the second resistor as the voltage value of the divided DC signal.

4. The air conditioner according to claim 3, wherein: The circuit board also includes a voltage conversion circuit, the input end of the voltage conversion circuit is connected to the AC input end, the coupled output end of the voltage conversion circuit is connected to the rectifier circuit, and the direct output end of the voltage conversion circuit is connected to the first relay, so that the AC signal is converted into an AC voltage signal through the voltage conversion circuit, and then the AC voltage signal is converted into the DC signal through the rectifier circuit.

5. The air conditioner according to claim 4, wherein: The switching circuit also includes an energy storage element, which is connected in parallel with the switching tube to store part of the charge of the divided DC signal and release the stored charge to maintain the disconnection of the first relay when the first relay disconnects the AC input terminal and the load.

6. The air conditioner according to claim 5, wherein: When the time duration for the energy storage element to release the stored charge reaches a preset time duration threshold, the first relay switches on the connection between the AC input terminal and the load.

7. The air conditioner according to claim 6, wherein: The preset time threshold is determined by the capacitance of the energy storage element and the resistance of the second resistor.

8. The air conditioner according to claim 1, wherein: The circuit board also includes a thermistor, which is connected to the first relay and the load respectively, so that when the connection between the AC input terminal and the load is conducted, the second part of the AC signal is output to the load through the thermistor.

9. The air conditioner according to claim 8, wherein The circuit board also includes a second relay and a control circuit. The second relay is respectively connected to the control circuit, the first relay and the load. The control circuit is connected to the load. The second relay is connected in parallel with the thermistor so that when the load operates normally according to the second part of the electrical signal, the second relay is controlled to be turned on by the control circuit.

10. The air conditioner according to claim 9, wherein The control circuit includes a switching power supply and a controller. The controller is connected to the switching power supply and the load, respectively. The switching power supply is also connected to the second relay so that when the switching power supply receives the second part of the electrical signal in the AC power signal, the controller is powered by the switching power supply, and the controller controls the second relay to be turned on or off according to whether the load is working normally.

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