Null line and live line communication circuit of air conditioner and control method thereof

Abstract

The invention provides a null line and live line communication circuit of an air conditioner and a control method thereof, and the null line and live line communication circuit comprises a power supply loop which comprises a first power interface and a second power interface and is provided with a communication power supply point; the communication loop comprises a communication power supply point and a communication line interface, and the communication line interface is connected with the communication power supply point through the PTC thermistor, the first three-terminal controller and the second three-terminal controller in sequence; the power supply loop is used for supplying power to the communication loop; the PTC thermistor is provided with a voltage detection port, and whether wiring of the null line and live line communication circuit is abnormal or not is judged through a voltage value of the voltage detection port; and controlling the second three-terminal controller to be disconnected under the condition that the wiring of the zero-live wire communication circuit is abnormal. According to the invention, the technical problems of circuit burnout or component explosion, high failure rate and poor safety caused by the fact that 220V AC is input into the indoor unit of the air conditioner generally under the condition that the circuit of the air conditioner is wrongly connected and the circuit burnout or the component explosion is caused by power-on are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to a zero-live line communication circuit of an air conditioner and a control method of the zero-live line communication circuit. Background Art

[0002] Most air conditioners consist of an indoor unit and an outdoor unit. The indoor unit and the outdoor unit need to communicate with each other to achieve complex functions. For example, a variable frequency air conditioner needs to change the operating frequency of the compressor of the outdoor unit according to different working conditions, which requires frequent communication between the indoor unit and the outdoor unit. In order to ensure the reliability of communication between the indoor unit and the outdoor unit, the current indoor and outdoor unit communication circuit of the air conditioner generally adopts the zero-live line communication method, and realizes the data exchange between the indoor and outdoor units by converting the zero-live line voltage, thereby controlling the operation of the air conditioner.

[0003] However, in actual use, there is a problem: due to the universal requirements for the controller wiring ports, the specifications of the controller's live port, neutral port, and communication port are consistent, but there are situations where the air conditioner's lines are connected incorrectly due to accidents or errors (such as the communication line and the neutral line N or the live line L are plugged in reverse). Generally, the air conditioner indoor unit inputs 220V AC, which will cause the circuit to burn out or components to explode when powered on, resulting in a high failure rate and poor safety. Summary of the invention

[0004] The present invention solves the technical problem that when the air conditioner circuit is connected incorrectly (such as the communication line and the neutral line N or the live line L are plugged in reverse), the air conditioner indoor unit generally inputs 220V AC, which may cause the circuit to burn or the components to explode when powered on, resulting in a high failure rate and poor safety.

[0005] To solve the above problems, the present invention provides a zero-live communication circuit of an air conditioner, comprising: a power supply loop, the power supply loop comprises a first power supply interface and a second power supply interface, and a communication power supply point is arranged on the power supply loop; a communication loop, the communication loop comprises a communication power supply point and a communication line interface, and the communication line interface is connected in sequence through a PTC thermistor, a first three-terminal controller, a second three-terminal controller and a communication power supply point, the control end of the first three-terminal controller is connected to the communication loop, and the controlled end of the second three-terminal controller is connected to the communication loop; wherein, the power supply loop is used to supply power to the communication loop; a voltage detection port is arranged on the PTC thermistor, and the voltage value of the voltage detection port is used to judge whether there is an abnormality in the wiring of the zero-live communication circuit; when there is an abnormality in the wiring of the zero-live communication circuit, the second three-terminal controller is controlled to remain disconnected.

[0006] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the zero-live communication circuit in this application takes the indoor side of the air conditioner as an example, and the zero-live communication circuit on the outdoor side is the same as that on the indoor side. The power supply loop is powered by the communication loop. When the wiring is normal, the communication line interface is connected to the communication line RS, the first power interface is connected to the live line L, and the second power interface is connected to the neutral line N. When the wiring of the zero-live communication circuit is normal, during the power-on communication process, the current flow of the power supply loop is from the live line interface to the neutral line interface, and the input voltage of the communication loop is clamped to ; The current flow direction of the communication loop is: communication power supply point → second three-terminal controller → first three-terminal controller → PTC thermistor → communication line interface. In this case, the PTC thermistor works normally and the communication loop on the indoor side remains connected. The first three-terminal controller is used to convert the change of the loop current on the communication loop of the indoor and outdoor unit communication into a communication control signal acceptable to the main control chip of the indoor unit of the air conditioner; the second three-terminal controller is used to generate a change in the loop current on the communication loop of the indoor and outdoor unit communication by the communication control signal sent by the main control chip of the indoor unit of the air conditioner. Specifically, the communication loop is controlled by the on-off control of the second three-terminal controller, thereby controlling the communication of the indoor and outdoor units. When the line of the air conditioner is not connected incorrectly, the second three-terminal controller is controlled to be in a connectable state, and the communication loop on the indoor side is connected; when there is a wiring error in the air conditioner (such as the communication line and the neutral line N or the live line L are plugged in reverse), the second three-terminal controller is controlled to remain disconnected, and the communication loop on the indoor side is disconnected, which can realize the hardware circuit protection after power-on due to wiring errors and avoid burning of components in the circuit. The PTC thermistor is equipped with a voltage detection port, which can be used to determine whether the wiring of the zero-live communication circuit is normal through the voltage value at the voltage detection port. Specifically, the PTC thermistor is equipped with a temperature sensor for temperature detection. The detection value of the temperature sensor is specifically reflected in voltage, which can be reflected through the voltage value at the voltage detection port. Through software logic identification and control, the communication loop is disconnected in time after a wiring error, realizing software monitoring double insurance. At the same time, under normal wiring conditions, the communication loop is cut off in time through CPU software control to reduce standby power consumption.

[0007] In one example of the present invention, the communication loop also includes: a first rectifier diode, which is connected in series to the communication loop, and the positive electrode of the first rectifier diode is connected to the communication power supply point, and the negative electrode of the first rectifier diode is connected to the communication line interface; a fourth resistor, which is connected in series to the communication loop, and the fourth resistor is arranged between the first rectifier diode and the PTC thermistor; wherein the negative electrode of the control end of the first three-terminal controller is connected in sequence through the first rectifier diode, the fourth resistor and the PTC thermistor.

[0008] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the first rectifier diode is connected in series to the communication loop as an isolation unit, and the positive electrode of the first rectifier diode is connected to the communication power supply point, and the negative electrode is connected to the communication line interface, so that the current of the communication loop can only flow from the communication power supply point to the communication line interface. The fourth resistor is a power current limiting resistor, which is used to reduce the voltage of the current passing through the fourth resistor.

[0009] In one embodiment of the present invention, the zero-live line communication circuit also includes: a first branch, the first branch is provided with a first end and a second end, and the first end is connected to the power supply loop, the first end is connected to the second power supply interface, and the second end is connected to the communication loop between the fourth resistor and the first rectifier diode.

[0010] Compared with the prior art, the technical effect achieved by adopting this technical solution is: when the live wire L and the communication wire RS are connected in reverse, during the power-on communication process, the current flows in the first loop: the second power interface → the first end → the first branch → the second end → the fourth resistor → the PTC thermistor → the communication line interface, so that the input voltage of the first end is clamped to , to prevent large current from burning the second three-terminal controller, the first three-terminal controller, the first rectifier diode, etc. along the second circuit. The current flow direction of the second circuit is: first terminal → communication power supply point → second three-terminal controller → first three-terminal controller → first rectifier diode → fourth resistor → PTC thermistor → communication line interface; with the support of PTC thermistor, the fourth resistor can be effectively prevented from overheating and damage. In this case, the voltage of the communication power supply point is too low, and the voltage value of the voltage detection port is also much smaller than ; Therefore, during the power-on process, the CPU detects the voltage value of the voltage detection port ,pass and The size relationship is used to determine the wiring condition of the zero-live communication circuit; if , it can be determined that the live wire L on the indoor side of the air conditioner is connected reversely with the communication wire RS. According to the normal communication fault logic, the indoor and outdoor units can shut down the second three-terminal controller through the CPU to cut off the second circuit. The CPU will remind the user of the communication fault information in the form of code, sound or APP push. The user should turn off the power in time to check the line problem. The zero and live wires are on the negative half axis of the sine wave, and the current flows from the zero wire N to the live wire L.

[0011] In one example of the present invention, the first branch also includes: a third voltage regulator diode and a third rectifier diode, which are connected in series to the first branch in sequence, and the anode of the third voltage regulator diode is connected to the second end, and the anode of the third rectifier diode is connected to the first end.

[0012] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the third voltage-stabilizing diode is used to form a first circuit when the live wire L and the communication wire RS are connected reversely, so as to provide a communication voltage for the second circuit; the third rectifier diode is connected in series to the first branch as an isolation unit, and the positive electrode of the third rectifier diode is connected to the first end, and the negative electrode is connected to the second end, so that the current of the first branch can only flow from the first end to the second end.

[0013] In one example of the present invention, the power supply loop also includes: an eighth resistor, a second rectifier diode and a voltage stabilizing element, which are connected in series in the power supply loop in sequence, and the eighth resistor is connected to the first power supply interface, the positive electrode of the second rectifier diode is connected to the eighth resistor, and the positive electrode of the voltage stabilizing element is connected to the second power supply interface.

[0014] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the eighth resistor is a power current limiting resistor, which is used to reduce the voltage of the current passing through the eighth resistor; the positive electrode of the second rectifier diode is connected to the first power interface to ensure that the current flows from the first power interface to the second power interface; the first voltage stabilizing diode and the second voltage stabilizing diode constitute a voltage stabilizing element to provide communication voltage for the communication loop.

[0015] In an embodiment of the present invention, the power supply loop further includes: a seventh resistor, and the seventh resistor is connected in parallel to two ends of the voltage stabilizing element.

[0016] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the seventh resistor is a parallel resistor of the voltage stabilizing element, which is used for current diversion to avoid overload of the voltage stabilizing element.

[0017] In one embodiment of the present invention, the zero-live line communication circuit further includes: a communication check terminal connected to the controlled terminal of the first three-terminal controller; and a communication sending terminal connected to the control terminal of the second three-terminal controller.

[0018] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the communication verification end is used to receive the communication control signal sent by the zero-live communication circuit; the communication sending end is used to send the communication control signal to the zero-live communication circuit.

[0019] In one example of the present invention, the zero-live line communication circuit also includes: a first resistor and a second resistor, the first resistor is connected to the communication verification end and the controlled end of the first three-terminal controller, one end of the second resistor is grounded, and the other end of the second resistor is connected to the controlled end of the first three-terminal controller; a fifth resistor, a sixth resistor and a first driving transistor, the base of the first driving transistor is connected to the communication sending end, the collector of the first driving transistor is connected to the control end of the second three-terminal controller, the emitter of the first driving transistor is grounded, and the fifth resistor is connected between the base of the first driving transistor and the communication sending end, and the sixth resistor is connected between the collector of the first driving transistor and the control end of the second three-terminal controller.

[0020] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the first resistor and the second resistor are current limiting resistors; the fifth resistor and the sixth resistor are current limiting resistors; and the first driving transistor is used to ensure that the second three-terminal controller is saturated and turned on.

[0021] In an embodiment of the present invention, both the first three-terminal controller and the second three-terminal controller are optocouplers.

[0022] Compared with the prior art, the technical effect achieved by adopting this technical solution is that the first three-terminal controller and the second three-terminal controller can also use controllable elements such as photoelectric relays and photoelectric MOS tubes.

[0023] In a specific embodiment, the present invention also provides a control method for a zero-live wire communication circuit, which is applied to a zero-live wire communication circuit as in any embodiment of the present invention, and the control method includes: judging whether there is an abnormality in the wiring of the zero-live wire communication circuit through the voltage value of the voltage detection port; when it is detected that there is an abnormality in the wiring of the zero-live wire communication circuit, controlling the second three-terminal controller to remain in a disconnected state; and / or when it is detected that there is no abnormality in the wiring of the zero-live wire communication circuit, controlling the second three-terminal controller to be in a connectable state.

[0024] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the control method of the zero-live line communication circuit in this embodiment has all the beneficial effects of the zero-live line communication circuit in any embodiment of the present invention, which will not be repeated here.

[0025] After adopting the technical solution of the present invention, the following technical effects can be achieved: (1) When there is a wiring error in the air conditioner (such as the communication line and the neutral line N or the live line L are plugged in reverse), the second three-terminal controller is controlled to remain disconnected, and the communication loop on the indoor side is disconnected, which can realize the hardware circuit protection after power-on due to wiring errors and avoid burning of components in the circuit; (2) The PTC thermistor is equipped with a voltage detection port, which can be used to determine whether the wiring of the zero-live communication circuit is normal through the voltage value at the voltage detection port. Through software logic identification control, the communication circuit is disconnected in time after the wiring error, realizing software monitoring double insurance; (3) Under normal wiring conditions, the CPU software control can be used to cut off the communication loop in a timely manner to reduce standby power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A circuit diagram of a zero-live wire communication circuit of an air conditioner provided by Embodiment 1 of the present invention when the circuit is normally connected; Figure 2 It is a circuit diagram of a zero-live communication circuit of an air conditioner in the prior art; Figure 3 A circuit diagram of a zero-live communication circuit of an air conditioner provided in Embodiment 1 of the present invention when the neutral line N and the communication line RS are connected incorrectly; Figure 4 A circuit diagram of a zero-live communication circuit of an air conditioner provided in Embodiment 1 of the present invention when the live wire L and the communication wire RS are connected incorrectly.

[0027] Description of reference numerals: 110, first power interface; 120, second power interface; 210, communication power supply point; 220, communication line interface; 201, voltage detection port; 101, first end; 102, second end; 310, communication verification end; 320, communication sending end. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] [Example 1] See also Figure 1 The present invention provides a zero-live communication circuit for an air conditioner, combined with Figure 2-Figure 4The zero-live communication circuit includes: a power supply loop, the power supply loop includes a first power supply interface 110 and a second power supply interface 120, and a communication power supply point 210 is provided on the power supply loop; a communication loop, the communication loop includes a communication power supply point 210 and a communication line interface 220, and the communication line interface 220 is connected in sequence through a PTC thermistor, a first three-terminal controller, a second three-terminal controller and a communication power supply point 210, the control end of the first three-terminal controller is connected to the communication loop, and the controlled end of the second three-terminal controller is connected to the communication loop; wherein, the power supply loop is used to supply power to the communication loop; a voltage detection port 201 is provided on the PTC thermistor, and whether there is an abnormality in the wiring of the zero-live communication circuit is judged by the voltage value of the voltage detection port 201; when there is an abnormality in the wiring of the zero-live communication circuit, the second three-terminal controller is controlled to remain disconnected.

[0030] In a specific embodiment, the zero-live communication circuit in the present application takes the indoor side of the air conditioner as an example, and the zero-live communication circuit on the outdoor side is the same as that on the indoor side. The zero-live communication circuit specifically includes a power supply loop and a communication loop. The power supply loop supplies power to the communication loop. The first power interface 110 is the live interface of the indoor unit of the air conditioner, and the second power interface 120 is the neutral interface of the indoor unit of the air conditioner. A communication power supply point 210 and a communication line interface 220 are provided on the communication loop. The communication line interface 220 is the communication line interface of the indoor unit of the air conditioner, and a communication loop is formed between the communication power supply point 210 and the communication line interface 220. When the wiring is normal, the communication line interface 220 is connected to the communication line RS, the first power interface 110 is connected to the live line L, and the second power interface 120 is connected to the neutral line N. When the wiring of the zero-live communication circuit is normal, during the power-on communication process, the current flow direction of the power supply loop is the live interface → the neutral interface, and the C pin of the second three-terminal controller obtains a voltage value of The input voltage of the communication loop is clamped to ; The current flow direction of the communication loop is: communication power supply point 210 → second three-terminal controller → first three-terminal controller → PTC thermistor → communication line interface 220. In this case, the PTC thermistor works normally and the communication loop on the indoor unit side remains connected. The control end of the first three-terminal controller is connected to the communication loop, and the controlled end of the first three-terminal controller is connected to the internal and external communication sending end 320 of the indoor unit of the air conditioner. The first three-terminal controller is used to convert the change of the loop current on the communication loop of the indoor and outdoor unit communication into a communication control signal acceptable to the main control chip of the indoor unit of the air conditioner; the controlled end of the second three-terminal controller is connected to the communication loop, and the control end of the second three-terminal controller is connected to the internal and external communication verification end 310 of the indoor unit of the air conditioner. The second three-terminal controller is used to generate a change in the loop current on the communication loop of the indoor and outdoor unit communication with the communication control signal sent by the main control chip of the indoor unit of the air conditioner. The zero-live communication circuit of the present invention is connected only when the wiring of the first power interface 110, the second power interface 120 and the communication line interface 220 are normal (that is, the lines are not connected incorrectly), the voltage value at the communication power supply point 210 is within the normal range, and the communication loop remains connected.

[0031] Specifically, a second three-terminal controller is connected in series on the communication loop, and the communication loop is controlled by the on-off of the second three-terminal controller, so as to control the communication between the indoor and outdoor units. When the line of the air conditioner is not connected incorrectly, the second three-terminal controller is controlled to be in a connectable state, and the communication loop on the indoor unit side is connected; when there is a wiring error in the air conditioner (such as the communication line and the neutral line N or the live line L are plugged in reverse), the second three-terminal controller is controlled to remain disconnected, and the communication loop on the indoor unit side is disconnected, which can realize the hardware circuit protection after the wiring error is powered on to avoid the burning of components in the circuit. The PTC thermistor is provided with a voltage detection port 201, which can detect whether the wiring of the zero-live communication circuit is normal through the voltage value at the voltage detection port 201. Specifically, the PTC thermistor is provided with a temperature sensor for temperature detection, and the detection amount of the temperature sensor is specifically reflected in voltage, which can be reflected through the voltage value at the voltage detection port 201. Through software logic identification control, the communication loop is disconnected in time after the wiring error, and the software monitoring double insurance is realized. At the same time, under the condition of normal wiring, the communication loop is cut off in time through CPU software control to reduce standby power consumption.

[0032] Preferably, The preferred value is 54V; the zero-live communication circuit on the outdoor side of the air conditioner is the same as that on the indoor side. Only when the communication loops on the indoor and outdoor sides are both in the connected state can the communication between the indoor and outdoor sides be realized.

[0033] Furthermore, the communication loop also includes: a first rectifier diode and a fourth resistor, the first rectifier diode is connected in series to the communication loop, and the positive electrode of the first rectifier diode is connected to the communication power supply point 210, and the negative electrode of the first rectifier diode is connected to the communication line interface 220; the fourth resistor is connected in series to the communication loop, and the fourth resistor is arranged between the first rectifier diode and the PTC thermistor; wherein the negative electrode of the control end of the first three-terminal controller is connected in sequence through the first rectifier diode, the fourth resistor and the PTC thermistor.

[0034] Specifically, D1 is a first rectifier diode, which is connected in series to the communication loop as an isolation unit, and the positive electrode of the first rectifier diode is connected to the communication power supply point 210, and the negative electrode is connected to the communication line interface 220, so that the current of the communication loop can only flow from the communication power supply point 210 to the communication line interface 220. R4 is a fourth resistor, which is a power current limiting resistor and is used to reduce the voltage of the current passing through R4.

[0035] Preferably, when the wiring of the zero-live communication circuit is normal, during the power-on communication process, the input voltage of the communication loop is clamped to The current flow direction of the communication loop is communication power supply point 210→second three-terminal controller→first three-terminal controller→first rectifier diode→fourth resistor→PTC thermistor→communication line interface 220, and the communication loop on the indoor side is connected.

[0036] When the neutral line N and the communication line RS are connected in reverse, see Figure 1 During the power-on communication process, the current flows from the live wire L to the neutral wire N: the first power interface 110 to the second three-terminal controller to the first three-terminal controller to the first rectifier diode to the fourth resistor to the PTC thermistor to the communication line interface 220. At this time, the PTC thermistor heats up rapidly and immediately becomes a high-resistance state, causing the loop current to drop sharply, thus avoiding damage to the loop components due to high voltage and high current. During the power-on process, the CPU detects the voltage value of the voltage detection port 201. ,pass and The size relationship is used to determine the wiring condition of the zero-live communication circuit; if , it can be determined that the neutral line N and the communication line RS on the air conditioner side are connected in reverse, the CPU controls the communication sending terminal 320 to output a low level to shut down the second three-terminal controller, disconnect the communication loop, and the software algorithm performs hard isolation to achieve double protection. At the same time, a signal is sent to remind the user that the line is connected in reverse and needs to be adjusted (the reminder signal can be an LED code display, a buzzer, an APP push, etc.). Among them, It is the reference threshold voltage detected by the voltage detection port 201 during normal wiring. The preferred value of k is 2. The 2 times reference threshold voltage is used to reduce the errors of software algorithms and hardware parameters. The actual value of wrong wiring will be much greater than 2 times.

[0037] Furthermore, the zero-live line communication circuit also includes: a first branch, the first branch is provided with a first end 101 and a second end 102, and the first end 101 is connected to the power supply loop, the first end 101 is connected to the second power supply interface 120, and the second end 102 is connected to the communication loop between the fourth resistor and the first rectifier diode.

[0038] Specifically, when the live wire L and the communication wire RS are connected in reverse, see Figure 1 During the power-on communication process, the current flows in the first loop: the second power interface 120 → the first terminal 101 → the first branch → the second terminal 102 → the fourth resistor → the PTC thermistor → the communication line interface 220, so that the input voltage of the first terminal 101 is clamped to , to prevent large current from burning the second three-terminal controller, the first three-terminal controller, the first rectifier diode, etc. along the second circuit. The current flow direction of the second circuit is: the first terminal 101→communication power supply point 210→the second three-terminal controller→the first three-terminal controller→the first rectifier diode→the fourth resistor→the PTC thermistor→the communication line interface 220; with the support of the PTC thermistor, the fourth resistor can be effectively prevented from being overheated and damaged. In this case, the voltage of the communication power supply point 210 is too low, and the voltage value of the voltage detection port is also much lower than; therefore, during the power-on process, the CPU detects the voltage value of the voltage detection port 201 ,pass and The size relationship is used to determine the wiring condition of the zero-live communication circuit; if , it can be determined that the live wire L on the indoor side of the air conditioner is connected reversely with the communication wire RS. According to the normal communication fault logic, the indoor and outdoor units can shut down the second three-terminal controller by pulling down the indoor unit communication TX port through the CPU, and cut off the second circuit. The CPU will remind the user of the communication fault information in the form of code, sound or APP push. The user should turn off the power in time to check the line problem. The zero and live wires are on the negative half axis of the sine wave, and the current flows from the zero wire N to the live wire L.

[0039] Preferably, The preferred value is 8.2V.

[0040] Furthermore, the first branch also includes: a third voltage regulator diode and a third rectifier diode, which are connected in series to the first branch in sequence, and the anode of the third voltage regulator diode is connected to the second end 102, and the anode of the third rectifier diode is connected to the first end 101.

[0041] Specifically, ZD3 is a third voltage-stabilizing diode, which is used to form a first circuit when the live wire L and the communication wire RS are connected reversely, and provide communication voltage for the second circuit; D3 is a third rectifier diode, which is connected in series to the first branch as an isolation unit, and the positive electrode of the third rectifier diode is connected to the first end 101, and the negative electrode is connected to the second end 102, so that the current of the first branch can only flow from the first end 101 to the second end 102.

[0042] Furthermore, the power supply loop also includes: an eighth resistor, a second rectifier diode and a voltage stabilizing element, which are connected in series in the power supply loop in sequence, and the eighth resistor is connected to the first power interface 110, the positive electrode of the second rectifier diode is connected to the eighth resistor, and the positive electrode of the voltage stabilizing element is connected to the second power interface 120.

[0043] Specifically, R8 is the eighth resistor, R8 is a power current limiting resistor, and is used to reduce the voltage of the current passing through R8; D2 is the second rectifier diode, and the positive pole of D2 is connected to the first power interface 110 to ensure that the current flows from the first power interface 110 to the second power interface 120.

[0044] Preferably, the voltage stabilizing element comprises: a first voltage stabilizing diode and a second voltage stabilizing diode connected in series; ZD1 is the first voltage stabilizing diode, and ZD2 is the second voltage stabilizing diode, and the communication voltage is provided to the communication loop through the voltage stabilizing element.

[0045] Furthermore, the power supply loop also includes: a seventh resistor, which is connected in parallel to both ends of the voltage stabilizing element.

[0046] Specifically, R7 is the seventh resistor, and R7 is a parallel resistor of the voltage stabilizing element, which is used for current diversion to avoid overload of the voltage stabilizing element.

[0047] Preferably, the communication loop also includes: a third resistor, the third resistor is connected in parallel to the two ends of the control end of the first three-terminal controller, R3 is the third resistor, R3 is the parallel resistor of the first three-terminal controller, and is used to absorb leakage current to prevent the first three-terminal controller from being misconnected.

[0048] Furthermore, the zero-live communication circuit also includes: a communication check terminal 310, which is connected to the controlled terminal of the first three-terminal controller; and a communication sending terminal 320, which is connected to the control terminal of the second three-terminal controller.

[0049] Specifically, the communication check terminal 310 is a communication RX terminal, and the communication check terminal 310 is used to receive a communication control signal sent by the zero-live communication circuit; the communication sending terminal 320 is a communication TX terminal, and the communication sending terminal 320 is used to send a communication control signal to the zero-live communication circuit.

[0050] Furthermore, the zero-live line communication circuit also includes: a first resistor and a second resistor, the first resistor is connected to the communication verification terminal 310 and the controlled terminal of the first three-terminal controller, one end of the second resistor is grounded, and the other end of the second resistor is connected to the controlled terminal of the first three-terminal controller; a fifth resistor, a sixth resistor and a first driving transistor, the base of the first driving transistor is connected to the communication sending terminal 320, the collector of the first driving transistor is connected to the control terminal of the second three-terminal controller, the emitter of the first driving transistor is grounded, and the fifth resistor is connected between the base of the first driving transistor and the communication sending terminal 320, and the sixth resistor is connected between the collector of the first driving transistor and the control terminal of the second three-terminal controller.

[0051] Specifically, R1 is the first resistor, R2 is the second resistor, the communication verification terminal 310 is connected to the E port of the first three-terminal controller, and the C port of the first three-terminal controller is connected to a 3.3V voltage; R1 is connected between the communication verification terminal 310 and the E port of the first three-terminal controller, and R2 is connected between the E port of the first three-terminal controller and the ground; R1 and R2 are current limiting resistors. R5 is the fifth resistor, R6 is the sixth resistor, Q1 is the first driving transistor, the communication sending terminal 320 is connected to the K port of the second three-terminal controller, and the A port of the second three-terminal controller is connected to a 3.3V voltage; R5, Q1 and R6 are between the communication sending terminal 320 and the K port of the second three-terminal controller, the base of Q1 is connected to the communication sending terminal 320, R5 is connected between the base of Q1 and the communication sending terminal 320, the emitter of Q1 is grounded, the collector of Q1 is connected to the K port of the second three-terminal controller, and R6 is connected between the collector of Q1 and the K port of the second three-terminal controller; R5 and R6 are current limiting resistors; Q1 is the first driving transistor, ensuring that the second three-terminal controller is saturated and turned on.

[0052] Furthermore, both the first three-terminal controller and the second three-terminal controller are optocouplers.

[0053] Specifically, the first three-terminal controller is an optocoupler O1, which is used to convert the transformation of the loop current on the communication loop of the indoor and outdoor unit communication into a communication control signal acceptable to the indoor unit main control chip. Controllable components such as photoelectric relays and photoelectric MOS tubes can also be selected; the second three-terminal controller is an optocoupler O2, which is used to convert the communication control signal sent by the indoor unit main control chip into a change in the loop current on the communication loop of the indoor and outdoor unit communication. Controllable components such as photoelectric relays and photoelectric MOS tubes can also be selected.

[0054] In a specific embodiment, in the prior art, see Figure 2 , the zero-live communication circuit is usually divided into the following three parts (the indoor side is taken as an example, the outdoor side is similarly omitted): Power conversion circuit: AC power (AC220V) is first stepped down by power resistor R8, then half-wave rectified by diode D2, and then stabilized by voltage stabilizing diodes ZD1 and ZD2, and finally converted into a stable DC voltage (DC54V-Zener diode breakdown voltage 27V as an example), that is, the communication power supply voltage of the external unit is 54V (the voltage can be selected according to the communication reliability test results), and the communication interface and the neutral line interface form a PWM voltage between 0-54V-0 to ensure reliable transmission of information between the internal and external units; Communication connection circuit: The internal and external units are connected through the communication interface (that is, the communication line interface 220), and the loop power is provided for the external unit after the diode D1 rectifies and stabilizes the voltage and the R4 power resistor limits the current; Information transmission circuit: After power-on, the indoor information controls the opening and closing of Q1 through the R5 current limiting resistor, and controls the optocoupler O2 to be in a saturated on or off state through the R6 voltage divider resistor. On the one hand, the optocoupler O1 transmits the indoor unit signal to the outdoor unit side through the RS port, and on the other hand, the R1 and R2 current limiting resistors perform self-transmission and self-reception verification to ensure the accuracy of the data sent by the indoor unit.

[0055] In this application, see Figure 1 ,exist Figure 2 Based on the circuit, a new zero-live communication circuit solution is designed: adding diode D3, voltage regulator ZD3 (taking 7.5V voltage regulation as an example), and PTC thermistor to achieve the purpose of loop detection and control of the zero-live communication circuit. The specific measures and principles are as follows: 1. The neutral line N and the communication line RS are connected in reverse, such as Figure 3 As shown, the second power interface 120 is the communication line interface of the air conditioner indoor unit, and the communication line interface 220 is the neutral line interface of the air conditioner indoor unit. During the power-on communication process, the current flows from the live line interface → R8 → D2 → O2 → O1 → D1 → R4 → PTC → neutral line interface. At this time, the PTC thermistor heats up rapidly and immediately becomes a high-resistance state, causing the loop current to drop sharply to avoid damage to the loop components due to high voltage and high current. During the power-on process, the CPU detects the voltage at the voltage detection port 201. Voltage (set under normal conditions (i.e. when the PTC is working normally) the voltage flowing through the circuit O2 optocoupler C pin is 54V) the voltage detection port 201 identifies the set reference threshold voltage ),like (The 2 times reference voltage is to reduce the errors of software algorithm and hardware parameters. The actual wrong wiring will be much greater than 2 times). The CPU controls the communication TX end to output a low level to shut down O2 and disconnect the communication loop. The software algorithm performs hard isolation to achieve double protection. At the same time, a signal is sent to remind the user that the line is connected incorrectly and needs to be adjusted (the reminder signal can be LED code display, buzzer beeping, APP push, etc.).

[0056] 2. The live wire and the communication wire are connected in reverse, such as Figure 4As shown, the first power interface 110 is the communication line interface of the indoor unit of the air conditioner, and the communication line interface 220 is the live line interface of the indoor unit of the air conditioner. During the power-on communication process, the current flows from the neutral line interface → D3 → ZD3 → R4 → PTC → live line interface, so that the input voltage of the second circuit is clamped to 8.2V, avoiding large current burning O2, O1, D1, etc. along the second circuit. Secondly, the support of the PTC thermistor can effectively prevent the R4 resistor from being damaged by overheating. In this case, the voltage of the communication line interface 220 is too low. The indoor and outdoor units can pull down the indoor unit communication TX end through the CPU according to the normal communication fault logic to turn off the O2 optical coupler and cut off the second circuit. The CPU will push the communication fault information to the user in the form of code, sound or APP. The user should turn off the power in time to check the line problem. The neutral and live wires are in the negative half axis of the sine wave, and the current flows from the neutral wire N → live wire L.

[0057] 3. Normal wiring schematic diagram, such as Figure 1 As shown, during the power-on communication process, the current of the power supply loop flows from the live wire interface → R8 → D2 → ZD2 → ZD1 → the neutral wire interface, and the C pin of the optocoupler O2 obtains 54V regulated DC power. The current of the communication loop flows from O2 → O1 → D1 → R4 → PTC → the communication interface. By controlling the optocouplers O1 and O2, the voltage between the communication line RS and the neutral line N is switched between 0-54V-0. In this case, if the CPU detects a shutdown signal (the communication between the internal and external units after shutdown has no practical functional significance, and the abnormal signal of the unit can be turned on for detection), the CPU controls the internal unit communication TX end to be pulled down to cut off the O2 optocoupler, cut off the communication loop, and achieve the purpose of reducing power consumption.

[0058] [Example 2] This embodiment further provides a control method for a zero-live line communication circuit, which is applied to the zero-live line communication circuit of the above-mentioned embodiment 1, including: The voltage value of the voltage detection port is used to determine whether there is any abnormality in the wiring of the neutral and live wire communication circuits; When detecting that there is an abnormality in the wiring of the zero-live communication circuit, controlling the second three-terminal controller to remain in a disconnected state; and / or When it is detected that there is no abnormality in the wiring of the zero-live communication circuit, the second three-terminal controller is controlled to be in a connectable state.

[0059] Specifically, this embodiment can achieve the technical effects corresponding to any technical solution in the above-mentioned embodiment 1, which will not be repeated here.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A zero-live communication circuit for an air conditioner, characterized in that: The zero-live communication circuit comprises: A power supply loop, the power supply loop comprising a first power supply interface (110) and a second power supply interface (120), the power supply loop being provided with a communication power supply point (210); A communication loop, the communication loop comprising the communication power supply point (210) and a communication line interface (220), wherein the communication line interface (220) is connected in sequence through a PTC thermistor, a first three-terminal controller, a second three-terminal controller and the communication power supply point (210), a control end of the first three-terminal controller being connected to the communication loop, and a controlled end of the second three-terminal controller being connected to the communication loop; The power supply loop is used to supply power to the communication loop; the PTC thermistor is provided with a voltage detection port (201), and the voltage value of the voltage detection port (201) is used to determine whether there is an abnormality in the wiring of the zero-live communication circuit; when there is an abnormality in the wiring of the zero-live communication circuit, the second three-terminal controller is controlled to remain disconnected.

2. The zero-live wire communication circuit according to claim 1, characterized in that: The communication loop also includes: A first rectifier diode, the first rectifier diode is connected in series to the communication loop, and the anode of the first rectifier diode is connected to the communication power supply point (210), and the cathode of the first rectifier diode is connected to the communication line interface (220); a fourth resistor, the fourth resistor being connected in series to the communication loop and being arranged between the first rectifier diode and the PTC thermistor; Wherein, the cathode of the control terminal of the first three-terminal controller is connected in sequence through the first rectifier diode, the fourth resistor and the PTC thermistor.

3. The zero-live line communication circuit according to claim 2, characterized in that: The zero-live communication circuit also includes: A first branch, wherein the first branch is provided with a first end (101) and a second end (102), and the first end (101) is connected to the power supply loop, the first end (101) is connected to the second power supply interface (120), and the second end (102) is connected to the communication loop between the fourth resistor and the first rectifier diode.

4. The zero-live wire communication circuit according to claim 3, characterized in that: The first branch further includes: A third voltage stabilizing diode and a third rectifier diode are connected in series to the first branch in sequence, and the anode of the third voltage stabilizing diode is connected to the second end (102), and the anode of the third rectifier diode is connected to the first end (101).

5. The zero-live wire communication circuit according to claim 1, characterized in that: The power supply loop also includes: An eighth resistor, a second rectifier diode and a voltage stabilizing element, wherein the eighth resistor, the second rectifier diode and the voltage stabilizing element are sequentially connected in series to the power supply loop, and the eighth resistor is connected to the first power interface (110), the anode of the second rectifier diode is connected to the eighth resistor, and the anode of the voltage stabilizing element is connected to the second power interface (120).

6. The zero-live wire communication circuit according to claim 5, characterized in that: The power supply loop further includes: a seventh resistor, and the seventh resistor is connected in parallel to both ends of the voltage stabilizing element.

7. The zero-live wire communication circuit according to claim 1, characterized in that: The zero-live communication circuit also includes: A communication verification terminal (310), the communication verification terminal (310) being connected to a controlled terminal of the first three-terminal controller; A communication sending end (320), the communication sending end (320) is connected to the control end of the second three-terminal controller.

8. The zero-live line communication circuit according to claim 7, characterized in that: The zero-live communication circuit also includes: a first resistor and a second resistor, the first resistor being connected to the communication verification terminal (310) and the controlled terminal of the first three-terminal controller, one end of the second resistor being grounded, and the other end of the second resistor being connected to the controlled terminal of the first three-terminal controller; A fifth resistor, a sixth resistor and a first driving transistor, wherein the base of the first driving transistor is connected to the communication sending end (320), the collector of the first driving transistor is connected to the control end of the second three-terminal controller, the emitter of the first driving transistor is grounded, and the fifth resistor is connected between the base of the first driving transistor and the communication sending end (320), and the sixth resistor is connected between the collector of the first driving transistor and the control end of the second three-terminal controller.

9. The zero-live wire communication circuit according to claim 1, characterized in that: The first three-terminal controller and the second three-terminal controller are both optocouplers.

10. A control method for a zero-live communication circuit, characterized in that: The control method is applied to the zero-live communication circuit according to any one of claims 1 to 9, and the control method includes: Judging whether there is an abnormality in the connection of the neutral and live wire communication circuit by means of the voltage value of the voltage detection port (201); When detecting that the wiring of the zero-live communication circuit is abnormal, controlling the second three-terminal controller to remain disconnected; and / or When it is detected that there is no abnormality in the wiring of the zero-live communication circuit, the second three-terminal controller is controlled to be in a connectable state.

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