Load protection circuit and air conditioner

Abstract

The embodiment of the utility model provides a load protection circuit and an air conditioner, and the load protection circuit comprises a voltage processing circuit which is used for connecting two electrodes of a direct-current power supply, processing the line sequence voltage of the connected direct-current power supply, outputting a first processing signal, and / or outputting a second processing signal when the voltage of the direct-current power supply exceeds a preset voltage. Outputting a second processing signal; the two input ends of the control circuit are correspondingly connected with the two input ends of the voltage processing circuit respectively, the controlled end of the control circuit is connected to the output end of the voltage processing circuit, and the two output ends of the control circuit are used for being correspondingly connected with the positive electrode and the negative electrode of a load respectively. And connecting the negative electrode of the load with the negative electrode of the direct-current power supply, and disconnecting the direct-current power supply and the load according to the second processing signal. Overvoltage protection can be performed on the load, and adaptive adjustment can be performed when the positive and negative electrodes of the direct current power supply are reversely connected, so that the load can be protected.

Description

Technical Field

[0001] This application belongs to the field of air conditioner technology, and particularly relates to a load protection circuit and an air conditioner. Background Technology

[0002] In the electronic control system of air conditioners, there is often a need for DC power supply. The characteristics of DC power are that the voltage magnitude and direction remain constant. If the DC voltage connected to the circuit is too high, or if the positive and negative electrodes of the power supply are reversed, the components in the circuit will burn out or be damaged, reducing the safety of the load. Utility Model Content

[0003] This application provides a load protection circuit and an air conditioner that can reduce or avoid the risk of accidents caused by excessive DC voltage or reversed positive and negative electrodes.

[0004] In a first aspect, embodiments of this application provide a load protection circuit, including:

[0005] A voltage processing circuit has a first input terminal and a second input terminal for connecting to two electrodes of a DC power supply, the two electrodes having opposite polarities. The voltage processing circuit processes the line sequence voltage of the DC power supply connected to the first input terminal and the second input terminal, and outputs a first processing signal through its output terminal, and / or outputs a second processing signal through its output terminal when the voltage of the DC power supply exceeds a preset voltage.

[0006] A control circuit has a first input terminal connected to the first input terminal of the voltage processing circuit, a second input terminal connected to the second input terminal of the voltage processing circuit, and a controlled terminal connected to the output terminal of the voltage processing circuit. Its first output terminal is used to connect to the positive terminal of the load, and its second output terminal is used to connect to the negative terminal of the load. The control circuit is used to connect the positive terminal of the load to the positive terminal of the DC power supply, connect the negative terminal of the load to the negative terminal of the DC power supply, and disconnect the DC power supply and the load according to the second processing signal.

[0007] Optionally, the voltage processing circuit includes:

[0008] The first processing loop has its input terminal as the first input terminal of the voltage processing circuit, its output terminal as the second input terminal of the voltage processing circuit, and its control terminal connected to the controlled terminal of the control circuit.

[0009] The second processing loop has its input terminal as the second input terminal of the voltage processing circuit, its output terminal as the first input terminal of the voltage processing circuit, and its control terminal connected to the controlled terminal of the control circuit.

[0010] The first processing circuit and the second processing circuit are used to connect the positive electrode of the DC power supply to the first input terminal of the voltage processing circuit, and to output the first processing signal through the first processing circuit when the negative electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit, and / or to output the second processing signal through the first processing circuit when the voltage of the DC power supply exceeds the preset voltage.

[0011] The first processing circuit and the second processing circuit are also used to output the first processing signal through the second processing circuit when the negative electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit and the positive electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit, and / or to output the second processing signal through the second processing circuit when the voltage of the DC power supply exceeds the preset voltage.

[0012] Optionally, the first processing loop includes:

[0013] The first comparison branch has its first input terminal connected to the two electrodes of the DC power supply, its second input terminal connected to the two electrodes of the DC power supply, and its ground terminal being the output terminal of the first processing circuit.

[0014] The first diode has its anode connected to the input terminal of the first processing circuit and its cathode connected to the power supply terminal of the first comparison branch.

[0015] The first switch branch has its controlled terminal connected to the output terminal of the first comparison branch, and its input terminal connected to the positive terminal of the first diode.

[0016] The first controller has its input terminal connected to the output terminal of the first switch branch, its output terminal being the output terminal of the first processing circuit, and its control terminal being used to connect the control circuit and the second processing circuit.

[0017] When the positive electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit and the negative electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit, the first diode is turned on, the first comparison branch outputs a first comparison signal according to the voltage of the DC power supply, the first switching branch is turned on based on the first comparison signal, the first controller outputs a first processing signal to the control circuit and outputs a first control signal to the second processing loop to control the second processing loop to stop working.

[0018] When the voltage of the DC power supply exceeds the preset voltage, the first diode is turned on, the first comparison branch outputs a third comparison signal based on the voltage of the DC power supply, the first switching branch is turned off based on the third comparison signal, and the first controller stops working.

[0019] Optionally, the first comparison branch includes:

[0020] The first pressure divider circuit has its input terminal as the input terminal of the first processing circuit and its output terminal as the output terminal of the first processing circuit.

[0021] The first voltage regulator circuit has its input terminal as the input terminal of the first processing circuit and its output terminal as the output terminal of the first processing circuit.

[0022] An operational amplifier has its non-inverting input connected to the voltage regulation point of the first voltage regulator circuit, its inverting input connected to the voltage dividing point of the first voltage divider circuit, its power supply connected to the negative terminal of the first diode, and its ground terminal being the ground terminal of the first comparator branch.

[0023] Optionally, the first switch branch includes:

[0024] The first transistor has its controlled terminal connected to the output terminal of the first comparator branch, and its input terminal is the input terminal of the first switch branch.

[0025] The first switching transistor has its controlled terminal connected to the output terminal of the first transistor, its input terminal being the input terminal of the first switching branch, and its output terminal connected to the first controller.

[0026] Optionally, the first controller includes:

[0027] The first relay includes a first electromagnetic structure, a first normally closed contact, a first normally open contact, and a second normally open contact. The first end of the first electromagnetic structure is connected to the output end of the first switch branch, and the second end of the first electromagnetic structure is connected to the controlled end of the first switch branch. The first normally closed contact is connected to the second processing circuit, the first normally open contact is connected to the first output end of the control circuit, and the second normally open contact is connected to the second output end of the control circuit.

[0028] The first electromagnetic structure is used to power on the first switch branch when it is turned on, and to control the first normally closed contact to open so that the second processing circuit stops working, and to control the first normally open contact to close and control the second normally open contact to close so that the positive electrode of the DC power supply is connected to the positive electrode of the load and the negative electrode of the DC power supply is connected to the negative electrode of the load.

[0029] Optionally, the second processing loop includes:

[0030] The second comparison branch has its first input terminal connected to the two electrodes of the DC power supply, its second input terminal connected to the two electrodes of the DC power supply, and its ground terminal being the output terminal of the second processing circuit.

[0031] The second diode has its anode connected to the input terminal of the second processing circuit and its cathode connected to the power supply terminal of the second comparison branch.

[0032] The second switch branch has its controlled terminal connected to the output terminal of the second comparison branch, and its input terminal connected to the positive terminal of the second diode.

[0033] The second controller has its input terminal connected to the output terminal of the second switch branch, its output terminal being the output terminal of the second processing circuit, and its control terminal being used to connect the control circuit and the first processing circuit.

[0034] When the negative electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit and the positive electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit, the second diode is turned on, the second comparison branch outputs a second comparison signal according to the voltage of the DC power supply, the second switching branch is turned on based on the second comparison signal, the second controller outputs a second processing signal to the control circuit and outputs a second control signal to the first processing loop to control the first processing loop to stop working;

[0035] When the voltage of the DC power supply exceeds the preset voltage, the second diode is turned on, the second comparison branch outputs a fourth comparison signal based on the voltage of the DC power supply, the second switching branch is turned off based on the fourth comparison signal, and the second controller stops working.

[0036] Optionally, the second controller includes:

[0037] The second relay includes a second electromagnetic structure, a second normally closed contact, a third normally open contact, and a fourth normally open contact. The first end of the second electromagnetic structure is connected to the output end of the second switch branch, and the second end of the second electromagnetic structure is connected to the controlled end of the second switch branch. The second normally closed contact is connected in series between the first end of the first electromagnetic structure and the output end of the first switch branch. The third normally open contact and the fourth normally open contact are respectively connected to the first output end and the second output end of the control circuit.

[0038] The second electromagnetic structure is used to power on the second switch branch when it is turned on, and to control the second normally closed contact to open so that the first processing circuit stops working, and to control the third normally open contact to close and the fourth normally open contact to connect the positive electrode of the DC power supply to the positive electrode of the load, and the negative electrode of the DC power supply to the negative electrode of the load.

[0039] Optionally, the control circuit includes:

[0040] The first line has its input terminal being the first input terminal of the control circuit, its output terminal being the first output terminal of the control circuit, and the first line is connected to the first normally open contact.

[0041] The second line has its input terminal as the second input terminal of the control circuit and its output terminal as the second output terminal of the control circuit, and the second line is connected to the second normally open contact.

[0042] The third line has its input terminal being the first input terminal of the control circuit, its output terminal being the second output terminal of the control circuit, and the third line is connected to the third normally open contact.

[0043] The fourth line has its input terminal being the second input terminal of the control circuit, its output terminal being the first output terminal of the control circuit, and the fourth line is connected to the fourth normally open contact.

[0044] Wherein, the first line and the second line are used to connect the positive electrode of the DC power supply to the positive electrode of the load and the negative electrode of the DC power supply to the negative electrode of the load when the first normally open contact and the second normally open contact are closed.

[0045] The third and fourth lines are used to connect the positive electrode of the DC power supply to the positive electrode of the load and the negative electrode of the DC power supply to the negative electrode of the load when the third and fourth normally open contacts are closed.

[0046] Secondly, embodiments of this application also provide an air conditioner, including a load and a load protection circuit as described in any of the above claims, wherein a first input terminal and a second input terminal of the load protection circuit are used to connect to the two electrodes of a DC power supply, and a first output terminal and a second output terminal of the load protection circuit are respectively connected to the positive and negative terminals of the load.

[0047] In the load protection circuit and air conditioner of this application embodiment, the voltage processing circuit and control circuit work together to not only protect the load from overvoltage, but also to adaptively adjust when the positive and negative electrodes of the DC power supply are reversed, thereby protecting the load and reducing or avoiding the risk of accidents caused by excessive DC voltage or reversed positive and negative electrodes. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0049] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.

[0050] Figure 1 This is a structural block diagram of a load protection circuit provided in an embodiment of this application.

[0051] Figure 2 This is another structural block diagram of the load protection circuit provided in the embodiments of this application.

[0052] Figure 3 Another structural block diagram of the load protection circuit provided in the embodiments of this application.

[0053] Figure 4 The circuit diagram of the voltage processing circuit in the load protection circuit provided in the embodiment of this application.

[0054] Figure 5 The circuit diagram of the control circuit in the load protection circuit provided in the embodiment of this application. Detailed Implementation

[0055] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0056] With rapid economic development, people's living standards have gradually improved, and their demands for comfort have also increased, including the requirement for optimal air temperature. Air conditioner control systems often require DC power; if the DC power is reversed or the DC voltage is too high, the circuit will be burned out. Therefore, DC reverse connection protection and overvoltage protection are extremely important in the control system.

[0057] The characteristic of direct current is that its voltage and direction remain constant. If the voltage of the direct current connected to the circuit is too high or reversed, the components in the circuit will be burned out or damaged due to overvoltage, and may even cause harm to the human body.

[0058] To reduce or avoid the risk of accidents caused by excessive voltage or reversed polarity of the power supply during DC power supply to a load, thereby improving the safety of DC power supply and protecting the load, this application provides a load protection circuit and an air conditioner, which will be described below with reference to the accompanying drawings.

[0059] Please see Figure 1 , Figure 1This is a structural block diagram of a load protection circuit provided in an embodiment of this application. Exemplarily, the load protection circuit 100 includes a voltage processing circuit 110 and a control circuit 120.

[0060] The first and second input terminals of the voltage processing circuit 110 are used to connect to the two electrodes of a DC power supply, respectively. The two electrodes of the DC power supply have opposite polarities, such as a positive electrode and a negative electrode. For ease of explanation, the two electrodes of the DC power supply are represented by A and B, and this should not be interpreted as a limitation on the two electrodes of the DC power supply. Accordingly, the diagram illustrates an example where the first input terminal of the voltage processing circuit 110 is connected to one electrode A of the DC power supply, and the second input terminal of the voltage processing circuit 110 is connected to the other electrode B of the DC power supply.

[0061] The voltage processing circuit 110 processes the line sequence voltage of the DC power supply connected to its first and second input terminals and outputs a first processing signal through its output terminal; for example, when the two electrodes of the DC power supply are reversed, it performs the switching processing of the positive and negative electrodes.

[0062] And / or, the voltage processing circuit 110 is used to output a second processing signal through its output terminal when the voltage of the DC power supply exceeds a preset voltage.

[0063] The first input terminal of the control circuit 120 is connected to the first input terminal of the voltage processing circuit 110, the second input terminal of the control circuit 120 is connected to the second input terminal of the voltage processing circuit 110, the controlled terminal of the control circuit 120 is connected to the output terminal of the voltage processing circuit 110, the first output terminal of the control circuit 120 is used to connect to the positive terminal of the load, and the second output terminal of the control circuit 120 is used to connect to the negative terminal of the load.

[0064] The control circuit 120 is used to connect the positive terminal of the load to the positive terminal of the DC power supply according to the first processing signal, connect the negative terminal of the load to the negative terminal of the DC power supply, and disconnect the DC power supply and the load according to the second processing signal.

[0065] The load can be an electrical component within an air conditioner, such as a display panel or sensor circuit. Of course, the load protection circuit 100 can also be applied to other electronic devices, such as refrigerators, washing machines, induction cookers, and microwave ovens. Accordingly, the load can be any electrical component within these other electronic devices; no limitation is made here. Since some circuits in an air conditioner require DC power input, the load protection circuit 100 of this embodiment can be used in products with DC power input. Preventing the power input of other products from using this load protection circuit 100 can greatly improve the safety and stability of the product. Therefore, the load protection circuit 100 of this embodiment has high practical value.

[0066] It should be noted that there is a risk of reversing the two electrodes of a DC power supply, that is, the positive electrode of the DC power supply is connected to the negative electrode of the load, and the negative electrode of the DC power supply is connected to the positive electrode of the load. However, in the embodiment of this application, regardless of whether the two electrodes of the DC power supply are reversed, the voltage processing circuit 110 and the control circuit 120 can work together to reverse the voltage at both ends of the DC power supply so that the load always receives a positive voltage. In other words, the positive electrode of the DC power supply is connected to the positive electrode of the load, and the negative electrode of the DC power supply is connected to the negative electrode of the load, reducing or avoiding damage to the subsequent circuits due to the reversed polarity of the DC power supply.

[0067] Furthermore, in this embodiment of the application, in addition to the above-mentioned reverse connection protection, the input of the DC power supply can be cut off when the voltage of the input DC power supply is too high, or the input terminal of the DC power supply can be isolated from the load to prevent the input voltage from being too high and damaging the subsequent circuit.

[0068] In the load protection circuit 100 provided in this application embodiment, the voltage processing circuit 110 and the control circuit 120 work together to not only protect the load from overvoltage, but also to adaptively adjust when the positive and negative electrodes of the DC power supply are reversed, thereby protecting the load and reducing or avoiding the risk of accidents caused by excessive DC voltage or reversed positive and negative electrodes.

[0069] Please see Figure 2 , Figure 2 This is another structural block diagram of the load protection circuit provided in the embodiments of this application. Exemplarily, the voltage processing circuit 110 includes a first processing loop 112 and a second processing loop 114.

[0070] The input terminal of the first processing circuit 112 is the first input terminal of the voltage processing circuit 110, the output terminal of the first processing circuit 112 is the second input terminal of the voltage processing circuit 110, and the control terminal of the first processing circuit 112 is connected to the controlled terminal of the control circuit 120.

[0071] The input terminal of the second processing circuit 114 is the second input terminal of the voltage processing circuit 110, the output terminal of the second processing circuit 114 is the first input terminal of the voltage processing circuit 110, and the control terminal of the second processing circuit 114 is connected to the controlled terminal of the control circuit 120.

[0072] For example, the first processing circuit 112 and the second processing circuit 114 are used to output a first processing signal through the first processing circuit 112 when the positive electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit 110 and the negative electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit 110; and / or output a second processing signal through the first processing circuit 112 when the voltage of the DC power supply exceeds a preset voltage.

[0073] For example, the first processing circuit 112 and the second processing circuit 114 are also used to output a first processing signal through the second processing circuit 114 when the negative electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit 110 and the positive electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit 110, and / or output a second processing signal through the second processing circuit 114 when the voltage of the DC power supply exceeds a preset voltage.

[0074] It should be noted that the first processing circuit 112 and the second processing circuit 114 are used alternately. For example, when the two electrodes of the DC power supply are connected in the correct direction, the first processing circuit 112 is used to transmit electrical signals. During this process, the second processing circuit 114 can also be controlled to stop working to save energy. When the two electrodes of the DC power supply are connected in reverse, the second processing circuit 114 is used to transmit electrical signals. Correspondingly, during this process, the first processing circuit 112 can be controlled to stop working, which also saves energy.

[0075] When the first processing circuit 112 is working, the second processing circuit 114 can be controlled to stop working. When the second processing circuit 114 is working, the first processing circuit 112 can be controlled to work. This can be achieved through circuit interlocking. The structure of the first processing circuit 112 and the second processing circuit 114 will be described below.

[0076] Please see Figures 3 to 5 , Figure 3 This is another structural block diagram of the load protection circuit provided in the embodiments of this application. Figure 4 This is a circuit diagram of the voltage processing circuit in the load protection circuit provided in the embodiments of this application. Figure 5 This is a circuit diagram of the control circuit in the load protection circuit provided in an embodiment of this application. For example, the first processing loop 112 includes a first comparison branch 1120, a first diode D1, a first switch branch 1122, and a first controller 1124.

[0077] The first input terminal of the first comparison branch 1120 is connected to the two electrodes of the DC power supply, and the second input terminal of the first comparison branch 1120 is connected to the two electrodes of the DC power supply. Its ground terminal is the output terminal of the first processing circuit 112.

[0078] The positive terminal of the first diode D1 is the input terminal of the first processing circuit 112, and the negative terminal of the first diode D1 is connected to the power supply terminal of the first comparison branch 1120.

[0079] The controlled terminal of the first switch branch 1122 is connected to the output terminal of the first comparison branch 1120, and the input terminal of the first switch branch 1122 is connected to the positive terminal of the first diode D1.

[0080] The input terminal of the first controller 1124 is connected to the output terminal of the first switch branch 1122. The output terminal of the first controller 1124 is the output terminal of the first processing loop 112. The control terminal of the first controller 1124 is used to connect the control circuit 120 and the second processing loop 114.

[0081] The working process of the first processing circuit 112 is as follows: when the positive electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit 110 and the negative electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit 110, the first diode D1 is turned on, the first comparison branch 1120 outputs the first comparison signal according to the voltage of the DC power supply, the first switch branch 1122 is turned on based on the first comparison signal, the first controller 1124 outputs the first processing signal to the control circuit 120 and outputs the first control signal to the second processing circuit 114 to control the second processing circuit 114 to stop working.

[0082] When the voltage of the DC power supply exceeds the preset voltage, the first diode D1 is turned on, the first comparison branch 1120 outputs the third comparison signal according to the voltage of the DC power supply, the first switch branch 1122 is turned off based on the third comparison signal, and the first controller 1124 stops working.

[0083] For example, the first comparison branch 1120 includes a first voltage divider circuit, a first voltage regulator circuit, and a first operational amplifier IC1.

[0084] The input terminal of the first voltage divider circuit is the input terminal of the first processing circuit 112, and the output terminal of the first voltage divider circuit is the output terminal of the first processing circuit 112. For example, the first voltage divider circuit includes a first resistor R1 and a second resistor R2. One end of the first resistor R1 is the input terminal of the first processing circuit 112, and the other end of the first resistor R1 is the voltage division point of the first voltage divider circuit. One end of the second resistor R2 is the voltage division point of the first voltage divider circuit, and the other end of the second resistor R2 is the output terminal of the first processing circuit 112.

[0085] The input terminal of the first voltage regulator circuit is the input terminal of the first processing circuit 112, and the output terminal of the first voltage regulator circuit is the output terminal of the first processing circuit 112. For example, the first voltage regulator circuit includes a third resistor R3 and a first Zener diode DZ1. One end of the third resistor R3 is the input terminal of the first processing circuit 112, and the other end of the third resistor R3 is the voltage regulation point of the first voltage regulator circuit. The cathode of the first Zener diode DZ1 is the voltage regulation point of the first voltage regulator circuit, and the anode of the first Zener diode DZ1 is the output terminal of the first processing circuit 112.

[0086] The non-inverting input terminal of the first operational amplifier IC1 is connected to the voltage regulation point of the first voltage regulator circuit, the inverting input terminal of the first operational amplifier IC1 is connected to the voltage dividing point of the first voltage divider circuit, the power supply terminal of the first operational amplifier IC1 is connected to the negative terminal of the first diode D1, and the ground terminal of the first operational amplifier IC1 is the ground terminal of the first comparator branch 1120.

[0087] For example, the first switching branch 1122 includes a first transistor Q1 and a first switching transistor S1. The controlled terminal of the first transistor Q1 is connected to the output terminal of the first comparator branch 1120, and the input terminal of the first transistor Q1 is the input terminal of the first switching branch 1122. The controlled terminal of the first switching transistor S1 is connected to the output terminal of the first transistor Q1, and the input terminal of the first switching transistor S1 is the input terminal of the first switching branch 1122. The output terminal of the first switching transistor S1 is connected to the first controller 1124.

[0088] In this context, the controlled terminal, input terminal, and output terminal of the first transistor Q1 can be understood as the base, collector, and emitter, respectively.

[0089] The first switch S1 can be an NMOS transistor, and the controlled terminal, input terminal and output terminal of the first switch S1 can correspond to the gate, drain and source of the NMOS transistor, respectively.

[0090] For example, the first switch branch 1122 further includes a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6. One end of the fourth resistor R4 is connected to the output terminal of the first operational amplifier IC1, and the other end of the fourth resistor R4 is connected to the controlled terminal of the first transistor Q1. The fourth resistor R4 is the base current-limiting resistor of the first transistor Q1. One end of the fifth resistor R5 is connected to the other end of the fourth resistor R4, and the other end of the fifth resistor R5 is connected to the ground terminal of the first operational amplifier IC1. One end of the sixth resistor R6 is connected to the power supply terminal of the first operational amplifier IC1, and the other end of the sixth resistor R6 is connected to the input terminal of the first transistor Q1. The sixth resistor R6 is the collector current-limiting resistor of the first transistor Q1.

[0091] For example, the first controller 1124 includes a first relay, which includes a first electromagnetic coil KA, a first normally closed contact KA0, a first normally open contact KA1, and a second normally open contact KA2. The first end of the first electromagnetic coil KA is connected to the output terminal of the first switching branch 1122, and the second end of the first electromagnetic coil KA is connected to the controlled terminal of the first switching branch 1122. The first normally closed contact KA0 is connected to the second processing circuit 114, the first normally open contact KA1 is connected to the first output terminal of the control circuit 120, and the second normally open contact KA2 is connected to the second output terminal of the control circuit 120.

[0092] The first electromagnetic coil KA is used to power on the first switch branch 1122 when it is turned on, and to control the first normally closed contact KA0 to open, so that the second processing circuit 114 stops working, and to control the first normally open contact KA1 to close and the second normally open contact KA2 to close, so that the positive electrode of the DC power supply is connected to the positive electrode of the load and the negative electrode of the DC power supply is connected to the negative electrode of the load.

[0093] It should be noted that the electromagnetic coil of a relay is the core component of the relay. For example, a relay can be composed of an iron core, a coil, and an armature. When the coil is energized, it generates a magnetic field, which magnetizes the iron core and attracts the armature, causing the contacts to close or open. This means that normally closed contacts open while normally open contacts close.

[0094] Please continue reading. Figures 3 to 5 For example, the second processing circuit 114 includes a second comparison branch 1140, a second diode D2, a second switch branch 1142, and a second controller 1144.

[0095] The first input terminal of the second comparison branch 1140 is connected to the two electrodes of the DC power supply, and the second input terminal of the second comparison branch 1140 is connected to the two electrodes of the DC power supply. Its ground terminal is the output terminal of the second processing circuit 114.

[0096] The positive terminal of the second diode D2 is the input terminal of the second processing circuit 114, and the negative terminal of the second diode D2 is connected to the power supply terminal of the second comparison branch 1140.

[0097] The controlled terminal of the second switch branch 1142 is connected to the output terminal of the second comparison branch 1140, and the input terminal of the second switch branch 1142 is connected to the positive terminal of the second diode D2.

[0098] The input terminal of the second controller 1144 is connected to the output terminal of the second switch branch 1142. The output terminal of the second controller 1144 is the output terminal of the second processing loop 114. The control terminal of the second controller 1144 is used to connect the control circuit 120 and the first processing loop 112.

[0099] The operation of the second processing circuit 114 is as follows: When the negative electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit 110 and the positive electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit 110, the second diode D2 is turned on. The second comparison branch 1140 outputs a second comparison signal according to the voltage of the DC power supply. The second switch branch 1142 is turned on based on the second comparison signal. The second controller 1144 outputs a second processing signal to the control circuit 120 and outputs a second control signal to the first processing circuit 112 to control the first processing circuit 112 to stop working.

[0100] When the voltage of the DC power supply exceeds the preset voltage, the second diode D2 is turned on, the second comparison branch 1140 outputs the fourth comparison signal according to the voltage of the DC power supply, the second switch branch 1142 is turned off based on the fourth comparison signal, and the second controller 1144 stops working.

[0101] For example, the second comparison branch 1140 includes a second voltage divider, a second voltage regulator, and a second operational amplifier IC2.

[0102] The input terminal of the second voltage divider circuit is the input terminal of the second processing circuit 114, and the output terminal of the second voltage divider circuit is the output terminal of the second processing circuit 114. For example, the second voltage divider circuit includes a seventh resistor R7 and an eighth resistor R8. One end of the seventh resistor R7 is the input terminal of the second processing circuit 114, and the other end of the seventh resistor R7 is the voltage division point of the second voltage divider circuit. One end of the eighth resistor R8 is the voltage division point of the second voltage divider circuit, and the other end of the eighth resistor R8 is the output terminal of the second processing circuit 114.

[0103] The input terminal of the second voltage regulator circuit is the input terminal of the second processing circuit 114, and the output terminal of the second voltage regulator circuit is also the output terminal of the second processing circuit 114. For example, the second voltage regulator circuit includes a ninth resistor R9 and a second Zener diode DZ2. One end of the ninth resistor R9 is the input terminal of the second processing circuit 114, and the other end of the ninth resistor R9 is the voltage regulation point of the second voltage regulator circuit. The cathode of the second Zener diode DZ2 is the voltage regulation point of the second voltage regulator circuit, and the anode of the second Zener diode DZ2 is the output terminal of the second processing circuit 114.

[0104] The non-inverting input of the second operational amplifier IC2 is connected to the voltage regulation point of the second voltage regulator circuit, the inverting input of the second operational amplifier IC2 is connected to the voltage dividing point of the second voltage divider circuit, the power supply terminal of the second operational amplifier IC2 is connected to the negative terminal of the second diode D2, and the ground terminal of the second operational amplifier IC2 is the ground terminal of the second comparator branch 1140.

[0105] For example, the second switching branch 1142 includes a second transistor Q2 and a second switch S2. The controlled terminal of the second transistor Q2 is connected to the output terminal of the second comparator branch 1140, and the input terminal of the second transistor Q2 is the input terminal of the second switching branch 1142. The controlled terminal of the second switch S2 is connected to the output terminal of the second transistor Q2, and the input terminal of the second switch S2 is the input terminal of the second switching branch 1142. The output terminal of the second switch S2 is connected to the second controller 1144.

[0106] In this context, the controlled terminal, input terminal, and output terminal of the second transistor Q2 can be understood as the base, collector, and emitter, respectively.

[0107] The second switch S2 can be a PMOS transistor, and the controlled terminal, input terminal and output terminal of the second switch S2 can correspond to the gate, drain and source of the PMOS transistor, respectively.

[0108] For example, the second switching branch 1142 further includes a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12. One end of the tenth resistor R10 is connected to the output terminal of the second operational amplifier IC2, and the other end of the tenth resistor R10 is connected to the controlled terminal of the second transistor Q2. The tenth resistor R10 is the base current-limiting resistor of the second transistor Q2. One end of the eleventh resistor R11 is connected to the other end of the tenth resistor R10, and the other end of the eleventh resistor R11 is connected to the ground terminal of the second operational amplifier IC2. One end of the twelfth resistor R12 is connected to the power supply terminal of the second operational amplifier IC2, and the other end of the twelfth resistor R12 is connected to the input terminal of the second transistor Q2. The twelfth resistor R12 is the collector current-limiting resistor of the second transistor Q2.

[0109] For example, the second controller 1144 includes a second relay, which includes a second electromagnetic coil KB, a second normally closed contact KB0, a third normally open contact KB1, and a fourth normally open contact KB2. The first end of the second electromagnetic coil KB is connected to the output terminal of the second switching branch 1142, and the second end of the second electromagnetic coil KB is connected to the controlled terminal of the second switching branch 1142. The second normally closed contact KB0 is connected to the second processing circuit 114, such as being connected in series between the first end of the first electromagnetic coil KA and the output terminal of the first switching branch 1122. The third normally open contact KB1 is connected to the first output terminal of the control circuit 120, and the fourth normally open contact KB2 is connected to the second output terminal of the control circuit 120.

[0110] The second electromagnetic coil KB is used to power on the second switch branch 1142 when it is turned on, and to control the second normally closed contact KB0 to open, so that the first processing circuit 112 stops working, and to control the third normally open contact KB1 to close and the fourth normally open contact KB2 to close, so that the positive electrode of the DC power supply is connected to the positive electrode of the load and the negative electrode of the DC power supply is connected to the negative electrode of the load.

[0111] It should be noted that the electromagnetic coil of a relay is the core component of the relay. For example, a relay can be composed of an iron core, a coil, and an armature. When the coil is energized, it generates a magnetic field, which magnetizes the iron core and attracts the armature, causing the contacts to close or open. This means that normally closed contacts open while normally open contacts close.

[0112] For example, the operation of the first processing loop 112 and the second processing loop 114 can be as follows:

[0113] In the first scenario, when terminal A of the DC power supply is the positive electrode and terminal B is the negative electrode, and the voltage of the DC power supply does not exceed the preset voltage, the first diode D1 conducts. The first resistor R1 and the second resistor R2 form a voltage divider circuit, which divides the DC power supply voltage and supplies it to the inverting input terminal of the first operational amplifier IC1. At this time, the potential at the non-inverting input terminal of the first operational amplifier IC1 is greater than the potential at the inverting input terminal of the first operational amplifier IC1, so the output of the first operational amplifier IC1 is high. At this time, the Vds and Vgs of the NMOS transistor are greater than 0, and the NMOS transistor conducts. The first electromagnetic coil KA is energized, the first normally closed contact KA0 opens, that is, the second processing circuit 114 stops working, and the first normally open contact KA1 and the second normally open contact KA2 are both closed. At this time, the second diode D2 in the second processing circuit 114 is cut off, the second operational amplifier IC2 is not energized, and since the Vds of the PMOS transistor is 0, the PMOS transistor does not meet the conduction condition at this time. Because the first electromagnetic coil KA is energized, the first normally closed contact KA0 opens, and the second electromagnetic coil KB is de-energized, achieving an interlocking effect. At this time, the voltage input to the load terminals is the voltage with the input DC power supply line sequence not reversed, and the load voltage is positive at the top and negative at the bottom.

[0114] In the second scenario, when terminal A of the DC power supply is the negative electrode and terminal B is the positive electrode, and the voltage of the DC power supply does not exceed the preset voltage, the Vds value of the PMOS transistor in the second processing circuit 114 is negative, satisfying one of its conduction conditions. The second operational amplifier IC2 outputs a high level, and the second transistor Q2 conducts. At this time, the Vgs of the PMOS transistor is less than 0, and Vds is less than 0, so the PMOS transistor is in the conducting state. The second electromagnetic coil KB is energized, the second normally closed contact KB0 opens, and the third normally open contact KB1 and the fourth normally open contact KB2 are both closed. At this time, the first diode D1 in the first processing circuit 112 is cut off, and the first operational amplifier IC1 is not energized. Since the Vds of the NMOS transistor is negative, the NMOS transistor does not meet the conduction condition. Furthermore, because the second electromagnetic coil KB is conducting, the second normally closed contact KB0 opens, and the first electromagnetic coil KA is not energized, achieving an interlocking effect. At this time, the voltage input to the load terminals is the voltage with the input DC power supply line sequence reversed, and the load voltage is positive at the top and negative at the bottom.

[0115] In the third case, when terminal A of the DC power supply is the positive electrode and terminal B is the negative electrode, and the voltage of the DC power supply exceeds the preset voltage, the non-inverting input of the first operational amplifier IC1 in the first processing circuit 112 is fixed, and the voltage of the inverting input of the first operational amplifier IC1 is higher than the voltage of the non-inverting input. The first operational amplifier IC1 outputs a low level, so the first transistor Q1 is not turned on, the Vgs of the NMOS transistor has no voltage, and the drain and source of the NMOS transistor are not connected. At this time, the first electromagnetic coil KA is not energized, so the first normally open contact KA1 and the second normally open contact KA2 are not closed, so the load is not energized, thereby protecting the load.

[0116] In the fourth case, when terminal A of the DC power supply is the negative electrode and terminal B is the positive electrode, and the voltage of the DC power supply exceeds the preset voltage, the voltage at the non-inverting input terminal of the second operational amplifier IC2 in the second processing circuit 114 is a fixed value, and the voltage at the inverting input terminal of the second operational amplifier IC2 is higher than the voltage at its non-inverting input terminal. The second operational amplifier IC2 outputs a low level, which makes the second transistor Q2 not conduct, and the PMOS transistor has no voltage at Vgs. The drain and source of the PMOS transistor are not conducting. At this time, the second electromagnetic coil KB is not energized, so the third normally open contact KB1 and the fourth normally open contact KB2 are not closed, so the load is not energized, thereby protecting the load.

[0117] For example, please continue reading Figure 5 As shown, the control circuit 120 includes a first line 121, a second line 122, a third line 123, and a fourth line 124.

[0118] The input terminal of the first line 121 is the first input terminal of the control circuit 120, the output terminal of the first line 121 is the first output terminal of the control circuit 120, and the first line 121 is connected to the first normally open contact KA1.

[0119] The input terminal of the second line 122 is the second input terminal of the control circuit 120, the output terminal of the second line 122 is the second output terminal of the control circuit 120, and the second line 122 is connected to the second normally open contact KA2.

[0120] The input terminal of the third line 123 is the first input terminal of the control circuit 120, the output terminal of the third line 123 is the second output terminal of the control circuit 120, and the third line 123 is connected to the third normally open contact KB1.

[0121] The input terminal of the fourth line 124 is the second input terminal of the control circuit 120, the output terminal of the fourth line 124 is the first output terminal of the control circuit 120, and the fourth line 124 is connected to the fourth normally open contact KB2.

[0122] The first line 121 and the second line 122 are used to connect the positive electrode of the DC power supply to the positive electrode of the load and the negative electrode of the DC power supply to the negative electrode of the load when the first normally open contact KA1 and the second normally open contact KA2 are closed.

[0123] The third line 123 and the fourth line 124 are used to connect the positive electrode of the DC power supply to the positive electrode of the load and the negative electrode of the DC power supply to the negative electrode of the load when the third normally open contact KB1 and the fourth normally open contact KB2 are closed.

[0124] This application also provides an air conditioner, which includes a load and the aforementioned load protection circuit. The first and second input terminals of the load protection circuit are used to connect to the two electrodes of a DC power supply. The first and second output terminals of the load protection circuit are respectively connected to the positive and negative terminals of the load. The structure and working principle of the load protection circuit are as described in the above embodiments. Since this air conditioner adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated further here.

[0125] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0126] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0127] The load protection circuit and air conditioner provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A load protection circuit, characterized in that, include: A voltage processing circuit has a first input terminal and a second input terminal for connecting to two electrodes of a DC power supply, the two electrodes having opposite polarities. The voltage processing circuit processes the line sequence voltage of the DC power supply connected to the first input terminal and the second input terminal, and outputs a first processing signal through its output terminal, and / or outputs a second processing signal through its output terminal when the voltage of the DC power supply exceeds a preset voltage. A control circuit has a first input terminal connected to the first input terminal of the voltage processing circuit, a second input terminal connected to the second input terminal of the voltage processing circuit, and a controlled terminal connected to the output terminal of the voltage processing circuit. Its first output terminal is used to connect to the positive terminal of the load, and its second output terminal is used to connect to the negative terminal of the load. The control circuit is used to connect the positive terminal of the load to the positive terminal of the DC power supply, connect the negative terminal of the load to the negative terminal of the DC power supply, and disconnect the DC power supply and the load according to the second processing signal.

2. The load protection circuit according to claim 1, characterized in that, The voltage processing circuit includes: The first processing loop has its input terminal as the first input terminal of the voltage processing circuit, its output terminal as the second input terminal of the voltage processing circuit, and its control terminal connected to the controlled terminal of the control circuit. The second processing loop has its input terminal as the second input terminal of the voltage processing circuit, its output terminal as the first input terminal of the voltage processing circuit, and its control terminal connected to the controlled terminal of the control circuit. The first processing circuit and the second processing circuit are used to connect the positive electrode of the DC power supply to the first input terminal of the voltage processing circuit, and to output the first processing signal through the first processing circuit when the negative electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit, and / or to output the second processing signal through the first processing circuit when the voltage of the DC power supply exceeds the preset voltage. The first processing circuit and the second processing circuit are also used to output the first processing signal through the second processing circuit when the negative electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit and the positive electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit, and / or to output the second processing signal through the second processing circuit when the voltage of the DC power supply exceeds the preset voltage.

3. The load protection circuit according to claim 2, characterized in that, The first processing loop includes: The first comparison branch has its first input terminal connected to the two electrodes of the DC power supply, its second input terminal connected to the two electrodes of the DC power supply, and its ground terminal being the output terminal of the first processing circuit. The first diode has its anode connected to the input terminal of the first processing circuit and its cathode connected to the power supply terminal of the first comparison branch. The first switch branch has its controlled terminal connected to the output terminal of the first comparison branch, and its input terminal connected to the positive terminal of the first diode. The first controller has its input terminal connected to the output terminal of the first switch branch, its output terminal being the output terminal of the first processing circuit, and its control terminal being used to connect the control circuit and the second processing circuit. When the positive electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit and the negative electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit, the first diode is turned on, the first comparison branch outputs a first comparison signal according to the voltage of the DC power supply, the first switching branch is turned on based on the first comparison signal, the first controller outputs a first processing signal to the control circuit and outputs a first control signal to the second processing loop to control the second processing loop to stop working. When the voltage of the DC power supply exceeds the preset voltage, the first diode is turned on, the first comparison branch outputs a third comparison signal based on the voltage of the DC power supply, the first switching branch is turned off based on the third comparison signal, and the first controller stops working.

4. The load protection circuit according to claim 3, characterized in that, The first comparison branch includes: The first pressure divider circuit has its input terminal as the input terminal of the first processing circuit and its output terminal as the output terminal of the first processing circuit. The first voltage regulator circuit has its input terminal as the input terminal of the first processing circuit and its output terminal as the output terminal of the first processing circuit. An operational amplifier has its non-inverting input connected to the voltage regulation point of the first voltage regulator circuit, its inverting input connected to the voltage dividing point of the first voltage divider circuit, its power supply connected to the negative terminal of the first diode, and its ground terminal being the ground terminal of the first comparator branch.

5. The load protection circuit according to claim 3, characterized in that, The first switch branch includes: The first transistor has its controlled terminal connected to the output terminal of the first comparator branch, and its input terminal is the input terminal of the first switch branch. The first switching transistor has its controlled terminal connected to the output terminal of the first transistor, its input terminal being the input terminal of the first switching branch, and its output terminal connected to the first controller.

6. The load protection circuit according to claim 3, characterized in that, The first controller includes: The first relay includes a first electromagnetic structure, a first normally closed contact, a first normally open contact, and a second normally open contact. The first end of the first electromagnetic structure is connected to the output end of the first switch branch, and the second end of the first electromagnetic structure is connected to the controlled end of the first switch branch. The first normally closed contact is connected to the second processing circuit, the first normally open contact is connected to the first output end of the control circuit, and the second normally open contact is connected to the second output end of the control circuit. The first electromagnetic structure is used to power on the first switch branch when it is turned on, and to control the first normally closed contact to open so that the second processing circuit stops working, and to control the first normally open contact to close and control the second normally open contact to close so that the positive electrode of the DC power supply is connected to the positive electrode of the load and the negative electrode of the DC power supply is connected to the negative electrode of the load.

7. The load protection circuit according to claim 6, characterized in that, The second processing loop includes: The second comparison branch has its first input terminal connected to the two electrodes of the DC power supply, its second input terminal connected to the two electrodes of the DC power supply, and its ground terminal being the output terminal of the second processing circuit. The second diode has its anode connected to the input terminal of the second processing circuit and its cathode connected to the power supply terminal of the second comparison branch. The second switch branch has its controlled terminal connected to the output terminal of the second comparison branch, and its input terminal connected to the positive terminal of the second diode. The second controller has its input terminal connected to the output terminal of the second switch branch, its output terminal being the output terminal of the second processing circuit, and its control terminal being used to connect the control circuit and the first processing circuit. When the negative electrode of the DC power supply is connected to the first input terminal of the voltage processing circuit and the positive electrode of the DC power supply is connected to the second input terminal of the voltage processing circuit, the second diode is turned on, the second comparison branch outputs a second comparison signal according to the voltage of the DC power supply, the second switching branch is turned on based on the second comparison signal, the second controller outputs a second processing signal to the control circuit and outputs a second control signal to the first processing loop to control the first processing loop to stop working; When the voltage of the DC power supply exceeds the preset voltage, the second diode is turned on, the second comparison branch outputs a fourth comparison signal based on the voltage of the DC power supply, the second switching branch is turned off based on the fourth comparison signal, and the second controller stops working.

8. The load protection circuit according to claim 7, characterized in that, The second controller includes: The second relay includes a second electromagnetic structure, a second normally closed contact, a third normally open contact, and a fourth normally open contact. The first end of the second electromagnetic structure is connected to the output end of the second switch branch, and the second end of the second electromagnetic structure is connected to the controlled end of the second switch branch. The second normally closed contact is connected in series between the first end of the first electromagnetic structure and the output end of the first switch branch. The third normally open contact and the fourth normally open contact are respectively connected to the first output end and the second output end of the control circuit. The second electromagnetic structure is used to power on the second switch branch when it is turned on, and to control the second normally closed contact to open so that the first processing circuit stops working, and to control the third normally open contact to close and the fourth normally open contact to connect the positive electrode of the DC power supply to the positive electrode of the load, and the negative electrode of the DC power supply to the negative electrode of the load.

9. The load protection circuit according to claim 8, characterized in that, The control circuit includes: The first line has its input terminal being the first input terminal of the control circuit, its output terminal being the first output terminal of the control circuit, and the first line is connected to the first normally open contact. The second line has its input terminal as the second input terminal of the control circuit and its output terminal as the second output terminal of the control circuit, and the second line is connected to the second normally open contact. The third line has its input terminal being the first input terminal of the control circuit, its output terminal being the second output terminal of the control circuit, and the third line is connected to the third normally open contact. The fourth line has its input terminal being the second input terminal of the control circuit, its output terminal being the first output terminal of the control circuit, and the fourth line is connected to the fourth normally open contact. Wherein, the first line and the second line are used to connect the positive electrode of the DC power supply to the positive electrode of the load and the negative electrode of the DC power supply to the negative electrode of the load when the first normally open contact and the second normally open contact are closed. The third and fourth lines are used to connect the positive electrode of the DC power supply to the positive electrode of the load and the negative electrode of the DC power supply to the negative electrode of the load when the third and fourth normally open contacts are closed.

10. An air conditioner, characterized in that, The device includes a load and a load protection circuit as described in any one of claims 1 to 9, wherein the first input terminal and the second input terminal of the load protection circuit are used to connect to the two electrodes of a DC power supply, and the first output terminal and the second output terminal of the load protection circuit are respectively connected to the positive and negative terminals of the load.

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