Four-way valve control circuit, control method thereof and air conditioner

Abstract

The present invention discloses a four-way valve control circuit, a control method thereof, and an air conditioner. The four-way valve control circuit includes: an operational amplifier unit for collecting an AC voltage sampling signal; a control unit connected to the output of the operational amplifier unit and configured to determine a zero-crossing moment based on the AC voltage sampling signal and to send a switch control signal based on the zero-crossing moment; and a switch unit, wherein the output of the switch unit is adapted to connect to a power grid and an electromagnetic coil of the four-way valve, and the input of the switch unit is connected to the control unit and configured to execute a switching action based on the switch control signal to control the conduction direction of the four-way valve. The control circuit can meet operating requirements under different input AC voltages, improves the circuit's versatility, and has a simple circuit structure and is easy to implement.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to a four-way valve control circuit and a control method thereof, and an air conditioner. Background Art

[0002] Four-way valves are usually used to switch the refrigerant flow direction of the refrigeration system. For example, during cooling, the four-way valve is used to make the refrigerant flow from the outdoor heat exchanger to the indoor heat exchanger, while during heating, the four-way valve is used to switch the flow direction so that the refrigerant flows from the indoor heat exchanger to the outdoor heat exchanger, thereby realizing the cooling and heating functions of the air conditioner.

[0003] In the related technology, the control circuit of the bistable four-way valve includes a rectifier bridge, a power supply relay, a reversing relay, a current limiting resistor and a related control circuit for driving the above two groups of relays. It converts AC power into DC power through the rectifier bridge, and changes the direction of the current passing through the core iron through the reversing relay. The power supply relay acts as a main switch to control the current on and off of the core iron. However, there are many electrical components in the control circuit and the connection structure is complex, which occupies a large PCB area and has a high cost.

[0004] Furthermore, the current that a four-way valve coil can withstand must be within a reasonable range. Even with the same coil resistance, different voltage inputs will produce different currents. Continuously operating at high currents for extended periods can damage the coil, while too low a current can prevent the coil from generating sufficient electromagnetic force to operate. Existing four-way valve control circuits cannot distinguish between input voltages. When encountering different input voltages, such as 110V and 220V, different four-way valve coils and current-limiting resistors must be designed to ensure coil safety and proper operation of the solenoid valve, resulting in limited circuit versatility. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a four-way valve control circuit that can meet the operating requirements under different input AC voltages, improves the circuit's versatility, and has a simple circuit structure and is easy to implement.

[0006] A second object of the present invention is to provide a control method for a four-way valve control circuit.

[0007] A third object of the present invention is to provide an air conditioner.

[0008] In order to solve the above problems, an embodiment of the first aspect of the present invention provides a four-way valve control circuit, comprising: an operational amplifier unit, the input end of the operational amplifier unit is suitable for connecting to the power grid, for collecting an AC voltage sampling signal; a control unit, the control unit is connected to the output end of the operational amplifier unit, for determining the zero-crossing moment according to the AC voltage sampling signal and sending a switch control signal according to the zero-crossing moment; a switch unit, the output end of the switch unit is suitable for connecting to the power grid and the electromagnetic coil of the four-way valve, the input end of the switch unit is connected to the control unit, for performing a switching action according to the switch control signal to control the conduction direction of the four-way valve; a power supply unit, the power supply unit is suitable for connecting to the power grid, for supplying power to the control unit and the operational amplifier unit.

[0009] According to the four-way valve control circuit of the embodiment of the present invention, an operational amplifier unit is used to collect an AC voltage sampling signal, and a control unit identifies the zero-crossing moment and the effective value of the voltage to output a switch control signal. The switch unit is used as a switch to control the current direction in the electromagnetic coil of the four-way valve, thereby realizing control of the conduction direction of the four-way valve without the need to set up a rectifier bridge, a power relay, a reversing relay and related control circuits, etc., thereby reducing the use of electrical components, and the circuit structure is simple and easy to implement.

[0010] In some embodiments, the operational amplifier unit includes: a first resistor, wherein the first end of the first resistor is suitable for connecting to the live wire of the power grid; an operational amplifier, wherein the positive input end of the operational amplifier is connected to the second end of the first resistor, the power input end of the operational amplifier is connected to the power supply unit, the output end of the operational amplifier is connected to the control unit, and the ground end of the operational amplifier is grounded; a second resistor, wherein the first end of the second resistor is connected to the output end of the operational amplifier; a third resistor, wherein the first end of the third resistor is connected to the negative input end of the operational amplifier and the second end of the second resistor, and the second end of the third resistor is suitable for connecting to the neutral wire of the power grid.

[0011] In some embodiments, the switching unit includes: a solid-state relay, a first end of the solid-state relay is connected to the control unit, a second end of the solid-state relay is grounded, a third end of the solid-state relay is suitable for connecting to the live wire of the power grid, and a fourth end of the solid-state relay is connected to the electromagnetic coil of the four-way valve.

[0012] In some embodiments, it also includes: an energy storage unit, which is connected in parallel with the electromagnetic coil of the four-way valve, and the first end of the energy storage unit is connected to the output end of the switch unit; a current limiting unit, the first end of the current limiting unit is connected to the neutral line of the power grid, and the second end of the current limiting unit is connected to the second end of the energy storage unit.

[0013] In some embodiments, the control unit is further used to determine the effective value of the voltage based on the AC voltage sampling signal, and determine the target conduction time based on the effective value of the voltage, and control the conduction time of the four-way valve based on the target conduction time.

[0014] A second aspect of the present invention provides a method for controlling a four-way valve control circuit, which is used to control the four-way valve control circuit described in the above embodiment. The control method includes: obtaining an AC voltage sampling signal; determining the zero-crossing moment based on the AC voltage sampling signal; and sending a switch control signal based on the zero-crossing moment to control the conduction direction of the four-way valve.

[0015] According to the control method of the four-way valve control circuit of the embodiment of the present invention, the AC voltage sampling signal is used to identify the zero-crossing moment to output the switch control signal, and the switch unit is used as a switch to control the current direction in the electromagnetic coil of the four-way valve, thereby realizing the control of the conduction direction of the four-way valve without setting up a rectifier bridge, power supply relay, reversing relay and related control circuits, etc., reducing the use of electrical components, and the circuit structure is simple and easy to implement.

[0016] In some embodiments, the four-way valve control circuit is used for an air conditioner, and a switch control signal is sent according to the zero-crossing moment to control the conduction direction of the four-way valve, including: obtaining a target operating mode of the air conditioner; sending a switch control signal according to the target operating mode and the zero-crossing moment to control the conduction direction of the four-way valve.

[0017] In some embodiments, the switch control signal includes an on-control signal and an off-control signal, and sending the switch control signal according to the target operating mode and the zero-crossing time to control the conduction direction of the four-way valve includes:

[0018] Determining that the target operating mode is a cooling mode; sending a conduction control signal when the zero-crossing moment is a positive half-cycle zero-crossing moment, so that the conduction direction of the four-way valve is forward conduction; sending a shutoff control signal when the zero-crossing moment is a negative half-cycle zero-crossing moment;

[0019] Alternatively, the target operating mode is determined to be a heating mode; a conduction control signal is sent when the zero-crossing moment is the negative half-cycle zero-crossing moment, so that the conduction direction of the four-way valve is reverse conduction; and a shutdown control signal is sent when the zero-crossing moment is the positive half-cycle zero-crossing moment.

[0020] In some embodiments, before sending a switch control signal according to the target operating mode and the zero-crossing moment to control the conduction direction of the four-way valve, it also includes: obtaining the last operating mode of the air conditioner; stopping the control of the four-way valve when the target operating mode is consistent with the last operating mode, so that the four-way valve maintains the current conduction direction.

[0021] In some embodiments, the control method further includes: determining a voltage effective value based on the AC voltage sampling signal; determining a target on-time based on the voltage effective value; and controlling the on-time of the four-way valve based on the target on-time.

[0022] A third aspect of the present invention provides an air conditioner, comprising: a refrigerant circulation loop, so that the refrigerant circulates in a loop consisting of a compressor, a condenser, an expansion valve, an evaporator and a four-way valve; the four-way valve, the four-way valve including an electromagnetic coil; the four-way valve control circuit described in the above embodiment, the four-way valve control circuit being connected to the electromagnetic coil; at least one processor; a memory communicatively connected to at least one of the processors; wherein the memory stores a computer program executable by at least one of the processors, and when at least one of the processors executes the computer program, the control method of the four-way valve control circuit described in the above embodiment is implemented.

[0023] According to the air conditioner of an embodiment of the present invention, the control method of the four-way valve control circuit provided by the above embodiment is executed by the processor, and the conduction time of the four-way valve can be dynamically adjusted according to the different AC voltages input by the power grid to meet the working requirements under different input AC voltages and improve the versatility of the circuit.

[0024] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0026] Figure 1 It is a schematic diagram of a four-way valve control circuit in the prior art;

[0027] Figure 2 is a schematic diagram of a four-way valve control circuit according to one embodiment of the present invention;

[0028] Figure 3 is a schematic diagram of a four-way valve when it is closed according to one embodiment of the present invention;

[0029] Figure 42 is a schematic diagram of signals when controlling a four-way valve to be forward-conducted according to an embodiment of the present invention;

[0030] Figure 5 is a schematic diagram of a four-way valve control circuit according to another embodiment of the present invention;

[0031] Figure 6 is a schematic diagram of a four-way valve when released according to one embodiment of the present invention;

[0032] Figure 7 A schematic diagram of signals when controlling a four-way valve to conduct in reverse according to an embodiment of the present invention;

[0033] Figure 8 is a structural diagram of an air conditioner according to an embodiment of the present invention;

[0034] Figure 9 is a flow chart of a control method of a four-way valve control circuit according to one embodiment of the present invention;

[0035] Figure 10 is a flow chart of a control method of a four-way valve control circuit according to another embodiment of the present invention;

[0036] Figure 11 is a flow chart of a control method of a four-way valve control circuit according to another embodiment of the present invention;

[0037] Figure 12 FIG. 1 is a structural diagram of an air conditioner according to another embodiment of the present invention.

[0038] Reference numerals:

[0039] Four-way valve control circuit 10; air conditioner 20;

[0040] Operational amplifier unit 1; control unit 2; switch unit 3; power supply unit 4; energy storage unit 5; current limiting unit 6;

[0041] Four-way valve 7; memory 8; processor 9. DETAILED DESCRIPTION

[0042] The embodiments of the present invention will be described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention will be described in detail below.

[0043] In the related art, for the control circuit of the four-way valve, such as Figure 1As shown, relay K11 has one end connected to the live power line L and one end connected to the rectifier bridge V11. The neutral power line N is also connected to the rectifier bridge V11. Relay K12 is a two-group switching relay. Contact 4 is connected to the common cathode output of the rectifier bridge V11, contact 7 is connected to the common anode output of the rectifier bridge V11, contact 3 is connected to the current-limiting resistor R11, and contact 5 is connected to the current-limiting resistor R12. Current-limiting resistors R11 and R12 are respectively connected to the two ends of the four-way valve coil L11. Contacts 6 and 8 are respectively connected to the two ends of the four-way valve coil L11. Relays K11 and K12 are controlled by signals from the control chip. The control chip controls relay K11 via transistor V12. When the control chip outputs a low level, the contacts of relay K11 open; when the control chip outputs a high level, the contacts of relay K11 close. The control chip controls relay K12 via transistor V13. When the control chip provides a low-level control signal, contact 4 of relay K12 connects to contact 3, and contact 7 connects to contact 6. When the control chip provides a high-level control signal, contact 4 of relay K12 connects to contact 5, and contact 7 connects to contact 8. However, the above control circuit has many electrical components and a complex connection structure, occupying a large PCB area and high cost. Furthermore, it cannot distinguish between different input voltages of the power grid. When encountering different input voltages, such as 110V and 220V, different four-way valve coils and current-limiting resistors must be designed to ensure coil safety and proper operation of the solenoid valve, resulting in poor circuit versatility.

[0044] In order to solve the above problems, refer to Figure 1 The four-way valve control circuit provided in the embodiment of the present invention is described. The control circuit can meet the working requirements under different input AC voltages, improve the versatility of the circuit, and has a simple circuit structure and is easy to implement.

[0045] like Figure 2 As shown, the four-way valve control circuit 10 provided in the embodiment of the present invention includes an operational amplifier unit 1 , a control unit 2 , a switch unit 3 and a power supply unit 4 .

[0046] Among them, the input end of the operational amplifier unit 1 is suitable for connecting to the power grid and is used to collect the AC voltage sampling signal; the control unit 2 is connected to the output end of the operational amplifier unit 1, and is used to determine the zero-crossing moment according to the AC voltage sampling signal, and send a switch control signal according to the zero-crossing moment; the output end of the switch unit 3 is suitable for connecting to the power grid and the electromagnetic coil of the four-way valve, and the input end of the switch unit 3 is connected to the control unit, and is used to perform a switching action according to the switch control signal to control the conduction direction of the four-way valve; the power supply unit 4 is suitable for connecting to the power grid and is used to supply power to the control unit 2 and the operational amplifier unit 1.

[0047] In the embodiment, the four-way valve is mainly used in heat pump air conditioners. Structurally, there are four pipes connected. Its function is to change the function of the indoor heat exchanger and the outdoor heat exchanger in the air conditioner by changing the flow direction of the refrigerant in the air-conditioning system, thereby realizing the switching of cooling, heating or defrosting modes.

[0048] like Figure 3 As shown, the four-way valve primarily comprises an electromagnetic coil M, a pilot valve 12, and a main valve 13. The electromagnetic coil M comprises a coil assembly 14 and a permanent magnet 15, while the pilot valve 12 comprises a valve core 16 and a return spring 17. The valve core 16 and the permanent magnet 15 are controlled by changing the direction of the current flowing through the coil assembly 14 to engage and disengage them. The return spring 17 also ensures the valve core 16 remains in its original position after it is released from the permanent magnet 15. Specifically, due to the use of the permanent magnet 15 in the four-way valve, a polarized magnetic flux generated by the permanent magnet exists within the electromagnetic valve body. When the coil assembly 14 generates a working magnetic flux due to the input current signal, this working magnetic flux superimposes with the polarized magnetic flux to enhance the suction force, overcoming the resistance of the return spring 17 and attracting the valve core 16. This, in turn, changes the valve position, resulting in forward conduction of the four-way valve. Even if the input current signal is removed, the valve core 16 remains in the engaged position due to the action of the permanent magnet 15. Obviously, if the signal current is turned on in the original direction at this time, it will have no effect on the valve core 16. If the valve core 16 is released, the current direction in the coil component 14 must be changed. As a result, the working magnetic flux and the polarization magnetic flux cancel each other out, the suction force is reduced, and the valve core 16 returns to its initial position under the elastic force of the return spring 17, making the four-way valve conduct in the reverse direction.

[0049] Furthermore, the four-way valve features high sensitivity, high stability, and a short operating time. Its minimum operating time, or pulse width, is only approximately 50ms. This means the valve consumes energy only during the "momentary" transition between operations, resulting in extremely low power consumption. Furthermore, since the solenoid coil of the four-way valve does not require constant power, the air conditioner does not consume electricity during operation.

[0050] As for the operational amplifier unit 1, it is an amplifier circuit structure with a special coupling circuit and feedback, and its output signal is the result of mathematical operations such as addition, subtraction, differentiation, and integration of the input signal; as for the switch unit 3, when working, if a certain control signal is added to its input end, the switching state of the output end can be controlled.

[0051] Based on the working principle of the above four-way valve, operational amplifier unit 1 and switch unit 3, refer to Figure 1As shown, in the four-way valve control circuit of the embodiment of the present invention, the input end of the power supply unit 4 is connected to the live wire L and the neutral wire N of the power grid to output the voltage required by the back-end load, such as 5V, to power the operational amplifier unit 1 and the control unit 2. In addition, the input end of the operational amplifier unit 1 is also connected to the live wire L and the neutral wire N of the power grid, and the output end of the operational amplifier unit 1 is connected to the control unit 2 to output an AC voltage sampling signal to the control unit 2; the control unit 2 calculates the zero-crossing moment of the AC voltage input from the power grid based on the AC voltage sampling signal; the input end of the switch unit 3 is connected to the control unit 2, and its output end is connected to both the live wire L of the power grid and one end of the electromagnetic coil M of the four-way valve, while the other end of the electromagnetic coil M of the four-way valve is connected to the neutral wire N of the power grid. As a result, a working circuit can be formed between the live wire L, the output end of the switch unit 3, the electromagnetic coil M and the neutral wire N. Thus, based on the above connection method, when the control unit 2 outputs a high-level signal such as 5V, the input end of the switch unit 3 is turned on, thereby controlling the output end of the switch unit 3 to be turned on, and thus the above-mentioned working loop is closed; and when the control unit 2 outputs a low-level signal such as 0V, the input end of the switch unit 3 is cut off, thereby controlling the output end of the switch unit 3 to be disconnected, and thus the above-mentioned working loop is disconnected.

[0052] For example, the four-way valve control circuit 10 is applied to an air conditioner. When the air conditioner starts to power on, the AC voltage input from the power grid passes through the operational amplifier unit 1, and the zero crossing point of the AC voltage is detected to obtain an AC voltage sampling signal input to the control unit 2. That is, the AC voltage sampling signal includes information about the zero crossing moment. The zero crossing moment when the AC voltage changes from negative to positive can be called the positive half-cycle zero crossing moment, and the zero crossing moment when the AC voltage changes from positive to negative can be called the negative half-cycle zero crossing moment. Then, the control unit 2 waits for the control instruction of the four-way valve to determine whether the valve core needs to be attracted or released. For example, when the user controls the air conditioner to execute the cooling mode, the valve core needs to be controlled to be attracted, while when the user controls the air conditioner to execute the heating mode, the valve core needs to be controlled to be released.

[0053] When the control unit 2 determines to control the valve core of the four-way valve to be closed, the control unit 2 detects the AC voltage sampling signal provided by the operational amplifier unit 1, and controls the input end of the switch unit 3 to be turned on based on the zero-crossing moment of the positive half cycle, and turns off the switch unit 3 at the zero-crossing moment of the negative half cycle. As a result, the control unit 2 only sends the positive polarity pulse of the positive half cycle of the AC voltage sine wave to the electromagnetic coil M of the four-way valve through the switch unit 3, so that the electromagnetic coil M of the four-way valve receives the positive polarity pulsating DC power, which prompts the valve core 16 of the four-way valve to move in the closing direction. For example, Figure 2 The figure shows the direction of the current in the electromagnetic coil after the electromagnetic coil M of the four-way valve obtains the pulsating direct current of positive polarity; Figure 3As shown, the valve core 16 of the four-way valve is displaced toward the permanent magnet 14, so that the port a of the four-way valve is connected to the port b, and the port c is connected to the port d; Figure 4 As shown, in the positive half cycle of the AC voltage sampling signal, the valve core 16 of the four-way valve is attracted to the permanent magnet 14, thereby achieving the purpose of controlling the conduction direction of the four-way valve to be forward conduction.

[0054] In addition, the control unit 2 is further configured to determine a voltage effective value according to the AC voltage sampling signal, determine a target on-time according to the voltage effective value, and control the on-time of the four-way valve according to the target on-time.

[0055] Specifically, the AC voltage sampling signal provided by the operational amplifier unit 1 also includes information on the effective value of the voltage. The control unit 2 pre-sets the conduction time of the input terminal of the control switch unit 3 during the positive half-cycle zero-crossing moment according to the different effective values ​​of the voltage detected by the operational amplifier unit 1, as shown in Table 1, to ensure that the electromagnetic coil M can convert sufficient electromagnetic force to move the valve core of the four-way valve into place without being damaged. It can be understood that, when other conditions of the electromagnetic coil M of the four-way valve remain unchanged, the higher the applied voltage of the electromagnetic coil M, the higher the current flowing through the electromagnetic coil M, and thus the greater the electromagnetic force, thereby quickly driving the valve core of the four-way valve to move into place, thereby shortening the required conduction time. At the same time, the shorter the conduction time, the less total power consumption of the electromagnetic coil M of the four-way valve, thereby ensuring the safety of the electromagnetic coil M of the four-way valve. For example, as shown in Table 1, the higher the RMS voltage, the shorter the on-time of the four-way valve. For an RMS voltage of 220 V, the corresponding target on-time is 2.5 seconds, while for an RMS voltage of 110 V, the corresponding target on-time is 6 seconds. After reaching the target on-time, the control action of the four-way valve control circuit 10 is completed. Under the action of the permanent magnet 15, the valve core 16 of the four-way valve remains in the closed position. Therefore, the switch unit 3 remains in the off state, and the electromagnetic coil M of the four-way valve is no longer powered.

[0056] It should be noted that voltages not listed in Table 1 can be linearly interpolated with reference to the voltages listed in Table 1.

[0057] Table 1

[0058] Voltage RMS A On-time A>275V 1.5S 220V<A≤275V 2S 191V<A≤220V 2.5S 164V<A≤191V 3S 137V<A≤164V 3.5S 110V<A≤137V 4S A≤110V 6S

[0059] When the control unit 2 determines to release the valve core of the four-way valve, the control unit 2 detects the AC voltage sampling signal provided by the operational amplifier unit 1, and controls the input end of the switch unit 3 to be turned on based on the zero-crossing moment of the negative half cycle, and turns off the switch unit 3 at the zero-crossing moment of the positive half cycle. As a result, the control unit 2 only sends the negative polarity pulse of the negative half cycle of the AC voltage sine wave to the electromagnetic coil M of the four-way valve through the switch unit 2, so that the electromagnetic coil M of the four-way valve receives a negative polarity pulsating DC power, which prompts the valve core 16 of the four-way valve to move in the release direction. For example, Figure 5 The figure shows the direction of the current in the electromagnetic coil M of the four-way valve after a negative polarity pulsating DC current is obtained; Figure 6 As shown, the valve core 16 of the four-way valve is displaced in the direction away from the permanent magnet 14, so that the port a of the four-way valve is connected to the port d, and the port c is connected to the port b; Figure 7 As shown, the valve core 16 of the four-way valve is released in the negative half cycle of the AC voltage sampling signal, thereby achieving the purpose of controlling the conduction direction of the four-way valve to be reverse conduction.

[0060] At the same time, similar to the principle of forward conduction, negative conduction also requires a certain conduction time before power is discontinued to the solenoid coil M of the four-way valve to ensure that the valve core of the four-way valve can move into position. The target conduction time for negative conduction is determined in the same way as the time required for forward conduction, and will not be further described here. After the target conduction time, the control action of the four-way valve control circuit 10 is completed. Under the action of the return spring 17, the valve core 16 of the four-way valve will remain in the released position. Therefore, the switch unit 3 remains in the off state, and power to the solenoid coil M of the four-way valve is no longer required.

[0061] Thus, the present application utilizes the operational amplifier unit 1 to determine the positive and negative phases of the AC voltage input from the power grid, and sends the determination result as an AC voltage sampling signal to the control unit 2. Thus, when the electromagnetic coil M of the four-way valve needs to be forward-conducted, the control unit 2 controls the switch unit 3 to be turned on at the positive phase of the AC voltage sampling signal, i.e., the positive half-cycle zero-crossing moment, so that the four-way valve is forward-conducted, and not turned on at the negative phase of the AC voltage sampling signal, i.e., the negative half-cycle zero-crossing moment; and, when the electromagnetic coil M of the four-way valve needs to be reverse-conducted, the control unit 2 controls the switch unit 3 to be turned on at the negative phase of the AC voltage sampling signal, i.e., the negative half-cycle zero-crossing moment, so that the four-way valve is reverse-conducted, and not turned on at the positive phase of the AC voltage sampling signal, i.e., the positive half-cycle zero-crossing moment. Thus, there is no need to set up a rectifier bridge, a power relay, a reversing relay, and related control circuits, etc., which reduces the use of electrical components, and the circuit structure is simple and easy to implement. In addition, the present application also uses the AC voltage sampling signal collected by the operational amplifier unit 1 to calculate the effective value of the voltage, and determines the target conduction time based on the effective value of the voltage to control the conduction time of the four-way valve. That is, the conduction time of the four-way valve can be dynamically adjusted according to the different AC voltages input by the power grid to meet the working requirements under different input AC voltages, thereby further ensuring the safety of the four-way valve and the normal operation of the four-way valve, and ensuring the performance of the four-way valve.

[0062] According to the four-way valve control circuit 10 of the embodiment of the present invention, the operational amplifier unit 1 is used to collect the AC voltage sampling signal, and the control unit 2 identifies the zero-crossing moment and the effective value of the voltage to output the switch control signal, and the switch unit 3 is used as a switch to control the current direction in the electromagnetic coil of the four-way valve, so as to realize the control of the conduction direction of the four-way valve without setting up a rectifier bridge, a power relay, a reversing relay and related control circuits, etc., thereby reducing the use of electrical components, and the circuit structure is simple and easy to implement. The control unit 2 also uses the effective value of the voltage to determine the target conduction time. That is to say, the four-way valve control circuit 10 can use the effective value of the voltage to distinguish the AC voltage input from the power grid, so as to ensure the normal operation of the four-way valve. The conduction time of the four-way valve can be dynamically adjusted according to the different AC voltages input from the power grid to meet the working requirements under different input AC voltages, thereby improving the versatility of the circuit.

[0063] In some embodiments, as Figure 2 As shown in FIG5 , the operational amplifier unit 1 includes a first resistor R1 , an operational amplifier N1 , a second resistor R2 and a third resistor R3 .

[0064] The first end of the first resistor R1 is adapted to be connected to the live line L of the power grid; the positive input of the operational amplifier N1 is connected to the second end of the first resistor R1; the power input of the operational amplifier N1 is connected to the power supply unit 4; the output of the operational amplifier N1 is connected to the control unit 2; and the ground of the operational amplifier N1 is grounded; the first end of the second resistor R2 is connected to the output of the operational amplifier N1; the first end of the third resistor R3 is connected to the negative input of the operational amplifier N1 and the second end of the second resistor R2; and the second end of the third resistor R3 is adapted to be connected to the neutral line N of the power grid. Thus, when controlling the four-way valve, the AC voltage input from the power grid enters the positive input of the operational amplifier N1 after being stepped down and current-limited by the first resistor R1; and the AC voltage input from the power grid enters the negative input of the operational amplifier N1 after being stepped down and current-limited by the neutral line N by the third resistor R3. The second resistor R2 is connected between the negative input and output of the operational amplifier N1 and is used, together with the first resistor R1 and the third resistor R3, to determine the amplification or reduction ratio of the operational amplifier N1, thereby acquiring the AC voltage sampling signal.

[0065] Specifically, assuming that the AC voltage between the live wire L and the neutral wire N of the power grid is Vac, and the AC voltage sampling signal output by the operational amplifier N1 is Vad, then Vad=Vac(R2 / R3). In an embodiment, R1 can be designed to be R2.

[0066] In some embodiments, as Figure 2 As shown in FIG5 , the switch unit 3 includes a solid-state relay B1 .

[0067] For example, reference Figure 2 In the embodiment of step 5, solid-state relay B1 is a photocoupler relay. A first end of photocoupler relay B1 is connected to control unit 2, a second end of photocoupler relay B1 is grounded, a third end of photocoupler relay B1 is adapted to be connected to the live wire L of the power grid, and a fourth end of photocoupler relay B1 is connected to the electromagnetic coil M of the four-way valve. Thus, when control unit 2 outputs a high-level signal, the light-emitting diode (LED) of photocoupler relay B1 turns on, thereby controlling the load end of photocoupler relay B1 to conduct, thereby closing the working circuit formed by the live wire L, the load end of photocoupler relay B1, the electromagnetic coil M, and the neutral wire N. When control unit 2 outputs a low-level signal, the light-emitting diode of photocoupler relay B1 turns off, thereby controlling the load end of photocoupler relay B1 to disconnect, thereby breaking the aforementioned working circuit. This allows switch unit 3 to act as a switch to control the direction of current in the electromagnetic coil M of the four-way valve, thereby controlling the conduction direction of the four-way valve.

[0068] Specifically, refer to Figure 2As shown, when the control unit 2 controls the valve core of the four-way valve to be attracted, the control unit 2 controls the light-emitting diode of the optocoupler relay B1 to be turned on based on the zero-crossing moment of the positive half-cycle after detecting the AC voltage sampling signal provided by the operational amplifier N1. That is, the anode A of the light-emitting diode of the optocoupler relay B1 sends a high-level signal such as 5V. Since the anode A of the light-emitting diode receives a voltage of 5V, and the cathode K is connected to the reference ground voltage of 0V, a voltage drop occurs at both ends of the light-emitting diode and a current flows through it; and the light-emitting diode B1 is turned off at the zero-crossing moment of the negative half-cycle. That is, the signal output by the control unit 2 to the anode A of the light-emitting diode of the optocoupler relay B1 is a low-level 0V.

[0069] And, reference Figure 5 As shown, when control unit 2 is controlling the release of the valve core of the four-way valve, it detects the AC voltage sampling signal provided by operational amplifier N1 and, based on the zero-crossing point of the negative half-cycle, controls the conduction of the light-emitting diode (LED) of photocoupler relay B1. This sends a high-level signal to anode A of the LED of photocoupler relay B1. Because anode A of the LED receives a 5V voltage, while cathode K is connected to the reference ground voltage of 0V, a voltage drop occurs across the LED, allowing current to flow. Control unit 2 also turns off photocoupler relay B1 at the zero-crossing point of the positive half-cycle. This means that the signal output by control unit 2 to anode A of the LED of photocoupler relay B1 is a low-level signal of 0V. Thus, through the above process, switch unit 3 acts as a switch to control the direction of current in electromagnetic coil M of the four-way valve, thereby controlling the conduction direction of the four-way valve.

[0070] In some embodiments, as Figure 2 As shown in FIG5 , the four-way valve control circuit 10 further includes an energy storage unit 5 and a current limiting unit 6 .

[0071] Among them, the energy storage unit 5 is connected in parallel with the electromagnetic coil M of the four-way valve, and the first end of the energy storage unit 5 is connected to the output end of the switch unit 3; the first end of the current limiting unit 6 is connected to the neutral line N of the power grid, and the second end of the current limiting unit 6 is connected to the second end of the energy storage unit 5.

[0072] Specifically, refer to Figure 4 or Figure 7 As shown in FIG, since the electromagnetic coil M of the four-way valve only flows with current in one half cycle of the AC voltage and no current flows in the other half cycle, the valve core of the four-way valve may vibrate and become unstable during operation. In order to solve this problem, the present application further provides an energy storage unit 5 in the four-way valve control circuit 10, as shown in FIG. Figure 2 or Figure 5The capacitor C1 shown, the energy storage unit 5, is connected in parallel with the electromagnetic coil M of the four-way valve. The energy storage unit 5 can perform the functions of energy storage and smoothing filtering. That is, the energy storage unit 5 is charged and stored when the positive pulse DC or negative pulse DC is turned on. After the AC voltage reaches its peak, because the voltage across the energy storage unit 5 is higher than the AC voltage, the energy storage unit 5 begins to discharge to power the electromagnetic coil M of the four-way valve. After the load end of the switch unit 3 is turned off, the energy storage unit 5 can still continue to discharge to power the electromagnetic coil M of the four-way valve. As a result, the positive or negative current in the electromagnetic coil M of the four-way valve can still be maintained during the other half cycle of the AC power, thereby ensuring a smoother and more stable switching process.

[0073] In addition, reference Figure 2 or Figure 5 As shown, when the output end of the switch unit 3 is turned on, the live wire L, the output end of the switch unit 3, the electromagnetic coil M and the neutral wire N form a working circuit. However, considering that the resistance of the electromagnetic coil M is small, in order to avoid the problem of damage to the electromagnetic coil due to excessive grid input current, the present application adds a current limiting unit 6 between the electromagnetic coil M and the neutral wire N, as shown in FIG. Figure 2 or Figure 5 The resistor R7 shown hereby serves to limit the current of the electromagnetic coil M.

[0074] A second embodiment of the present invention provides an air conditioner, such as Figure 8 As shown, the air conditioner 20 includes a four-way valve 7 and a four-way valve control circuit 10.

[0075] Air conditioners use a compressor, condenser, expansion valve, and evaporator to perform cooling / heating cycles or dehumidification functions, thereby regulating the indoor environment and improving indoor comfort. The refrigeration cycle involves a series of processes such as compression, condensation, expansion, and evaporation, supplying refrigerant to the conditioned and heat-exchanged air.

[0076] The compressor compresses high-temperature, high-pressure refrigerant gas and discharges the compressed gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, releasing heat into the surrounding environment through the condensation process.

[0077] The expansion valve expands the high-temperature, high-pressure liquid refrigerant condensed in the condenser to a lower-pressure liquid. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves cooling by utilizing the latent heat of evaporation to exchange heat with the material being cooled. Throughout this cycle, the air conditioner regulates the indoor environment.

[0078] The refrigerant circulation loop allows the refrigerant to circulate in a loop consisting of a compressor, condenser, expansion valve, evaporator and four-way valve.

[0079] In the embodiment, the four-way valve 7 includes an electromagnetic coil; the four-way valve control circuit 10 is connected to the electromagnetic coil.

[0080] The air conditioner 20 according to the embodiment of the present invention can meet the working requirements under different input AC voltages by adopting the four-way valve control circuit 10 provided in the above embodiment, thereby improving the versatility of the circuit. The circuit structure is simple and easy to implement.

[0081] A third aspect of the present invention provides a method for controlling a four-way valve control circuit. The method is used to control the four-way valve control circuit provided in the above embodiment. Figure 9 As shown, the control method at least includes steps S1 to S3.

[0082] Step S1: Acquire an AC voltage sampling signal.

[0083] In the examples, reference Figure 2 As shown, the AC voltage output by the power grid enters the operational amplifier unit 1 through the live wire L and the neutral wire N, and is amplified or reduced in proportion by the operational amplifier unit 1 to output an AC voltage sampling signal to be sent to the control unit 2.

[0084] Step S2: determining the zero-crossing time according to the AC voltage sampling signal.

[0085] Step S3: Send a switch control signal according to the zero-crossing time to control the conduction direction of the four-way valve.

[0086] In the examples, reference Figure 2 or Figure 3 As shown, controlling the switch unit 3 to be turned on or off at different zero-crossing moments can effectively change the direction of the current in the electromagnetic coil M, and different current directions will cause the conduction direction of the four-way valve to be different. Therefore, the operational amplifier unit 1 is used to collect the AC voltage sampling signal, and the control unit 2 identifies the zero-crossing moment and the voltage effective value to output the switch control signal, and the switch unit 3 is used as a switch to control the current direction in the electromagnetic coil of the four-way valve. Therefore, when the four-way valve is forward-conducted, the control unit can identify the zero-crossing moment to control the switch unit 3 to be turned on, so as to allow the positive phase current to pass through the electromagnetic coil, so that the four-way valve is forward-conducted and the negative phase is cut off; conversely, when the four-way valve is forward-conducted, the control unit can identify the zero-crossing moment to control the switch unit 3 to be turned on, so as to allow the negative phase current to pass through the electromagnetic coil, so that the four-way valve is reverse-conducted and the positive phase is cut off. Therefore, the conduction direction of the four-way valve can be controlled by the control unit 2 identifying the zero-crossing moment. The circuit structure is simple and the control method is easy to implement.

[0087] According to the control method of the four-way valve control circuit of the embodiment of the present invention, the AC voltage sampling signal is used to identify the zero-crossing moment to output the switch control signal, and the switch unit is used as a switch to control the current direction in the electromagnetic coil of the four-way valve, thereby realizing the control of the conduction direction of the four-way valve without setting up a rectifier bridge, power supply relay, reversing relay and related control circuits, etc., reducing the use of electrical components, and the circuit structure is simple and easy to implement.

[0088] In some embodiments, the above-mentioned four-way valve control circuit is used in an air conditioner. When controlling the four-way valve, the present application determines whether the control action of the four-way valve is an attraction action or a release action by obtaining the target operating mode of the air conditioner, and then sends a switch control signal according to the target operating mode and the zero-crossing time to control the conduction direction of the four-way valve, so as to realize the control of the refrigerant flow direction in the air conditioner and realize the functional switching of the cooling mode, heating mode or defrost mode.

[0089] The target operation mode can be understood as the mode that the air conditioner will operate after starting up.

[0090] In some embodiments, the control method of the present application further includes determining a voltage effective value based on an AC voltage sampling signal; determining a target on-time based on the voltage effective value; and controlling the on-time of the four-way valve based on the target on-time.

[0091] Specifically, with other conditions remaining unchanged for the solenoid coil of a four-way valve, the higher the applied voltage to the solenoid coil, the higher the current flowing through it and the greater the electromagnetic force. This allows the valve core of the four-way valve to be moved into position more quickly, and the required on-time is shortened. Based on the above principle, the corresponding on-time can be pre-set according to different voltage RMS values, as shown in Table 1. Therefore, to ensure the safety and proper operation of the solenoid coil, the on-time of the four-way valve is controlled by the target on-time determined by the voltage RMS value. That is, the voltage RMS value is used to distinguish the AC voltage input from the power grid. This allows the four-way valve to complete the pull-in or release action within the target on-time, ensuring the performance of the four-way valve. Furthermore, the on-time of the four-way valve can be dynamically adjusted according to the different AC voltages input from the power grid to meet the operating requirements under different input AC voltages and improve the versatility of the circuit.

[0092] In some embodiments, the switch control signal includes an on-control signal and an off-control signal.

[0093] If it is determined that the target operating mode is the cooling mode, it means that the control action of the four-way valve is the suction action, and then the following steps are performed.

[0094] The first conduction step is to send a conduction control signal when the zero-crossing moment is the zero-crossing moment of the positive half cycle, so that the conduction direction of the four-way valve is forward conduction; the first closing step is to send a closing control signal when the zero-crossing moment is the zero-crossing moment of the negative half cycle; the first conduction step and the first closing step are repeated until the conduction time of the four-way valve reaches the target conduction time, which indicates that the valve core of the four-way valve has moved into place, that is, under the action of the permanent magnet, the valve core of the four-way valve will still remain in the attracted position, so the switch unit remains in the cut-off state, and there is no need to power the electromagnetic coil of the four-way valve.

[0095] Alternatively, if it is determined that the target operation mode is the heating mode, it means that the control action of the four-way valve is a release action, and then the following steps are performed.

[0096] The second conduction step is to send a conduction control signal when the zero-crossing moment is the negative half-cycle zero-crossing moment, so that the conduction direction of the four-way valve is reverse conduction; the second closing step is to send a closing control signal when the zero-crossing moment is the positive half-cycle zero-crossing moment; the second conduction step and the second closing step are repeated until the conduction time of the four-way valve reaches the target conduction time, which indicates that the valve core of the four-way valve has moved into place, that is, under the action of the reset spring, the valve core of the four-way valve will still remain in the release position, so the switch unit remains in the cut-off state, and there is no need to power the electromagnetic coil of the four-way valve.

[0097] Reference below Figure 10 The control process of the four-way valve is illustrated with an example, and the specific steps are as follows.

[0098] Step S5: determining the effective value of the voltage according to the AC voltage sampling signal.

[0099] Step S6: determining the zero-crossing time according to the AC voltage sampling signal.

[0100] Step S7: determining the target on-time according to the effective value of the voltage.

[0101] Step S8: determining the target operating mode of the air conditioner.

[0102] Step S9: Determine whether to control the four-way valve to be engaged or released according to the target operation mode. If the four-way valve is engaged, execute step S10; if the four-way valve is released, execute step S11.

[0103] Step S10, turning on the solid-state relay when the positive half cycle crosses zero; and turning off the solid-state relay when the negative half cycle crosses zero.

[0104] Step S11 , turning on the solid-state relay when the negative half cycle crosses zero; and turning off the solid-state relay when the positive half cycle crosses zero.

[0105] Step S12: Determine whether the target on-time has been reached. If so, proceed to step S13; if not, proceed to step S10 or step S11.

[0106] Step S13, completing the control action of the electromagnetic coil of a four-way valve and turning off the solid-state relay.

[0107] In some embodiments, before sending a switch control signal according to the target operating mode and the zero-crossing moment to control the conduction direction of the four-way valve, the control method also includes obtaining the last operating mode of the air conditioner; when the target operating mode is consistent with the last operating mode, stopping the control of the four-way valve so that the four-way valve maintains the current conduction direction, thereby eliminating the need to control the conduction direction and conduction duration of the four-way valve, thereby saving energy consumption.

[0108] The last operating mode is the operating mode of the air conditioner when it was last started.

[0109] Specifically, in order to further save the energy consumption of the four-way valve, in the above-mentioned control method, the present application judges the last operating mode and the currently specified operating mode, that is, the target operating mode, so that when the target operating mode is the same as the last operating mode, the valve core of the four-way valve can be controlled not to move, so that the four-way valve maintains the current conduction direction. On the contrary, when the target operating mode is different from the last operating mode, the valve core of the four-way valve needs to move, so that the four-way valve switches the conduction direction.

[0110] For example, if the air conditioner's previous operating mode was cooling mode and the current target operating mode is also cooling mode, it can be determined that the valve core of the four-way valve does not need to be actuated. However, if the current target operating mode is heating mode, it can be determined that the valve core of the four-way valve needs to be actuated. When the valve core of the four-way valve does not need to be actuated, the control unit outputs a low level to the input terminal of the switch unit, the input terminal is cut off, and the output terminal of the switch unit, i.e., the load terminal, is disconnected, thereby causing no current to flow through the solenoid coil of the four-way valve, the solenoid coil to not operate, and the valve core of the four-way valve to remain in its original state. When the valve core of the four-way valve needs to be actuated, it is determined whether the four-way valve needs to be engaged or released based on the target operating mode, and subsequent control actions are then executed.

[0111] In an embodiment, the defrost mode of the air conditioner can be considered as a heating mode.

[0112] Reference below Figure 11 The control process of the four-way valve is illustrated with an example, and the specific steps are as follows.

[0113] Step S14: determining the effective value of the voltage according to the AC voltage sampling signal.

[0114] Step S15: determining the zero-crossing time according to the AC voltage sampling signal.

[0115] Step S16: determining the target on-time according to the effective value of the voltage.

[0116] Step S17: Determine whether the target operating mode of the air conditioner is consistent with the previous operating mode to determine whether the four-way valve needs to be actuated. If they are consistent, execute step S14; if not, execute step S18.

[0117] Step S18: obtaining the target operating mode of the air conditioner.

[0118] Step S19: Determine whether to control the four-way valve to be engaged or released based on the target operation mode. If the four-way valve is engaged, execute step S20; if the four-way valve is released, execute step S21.

[0119] Step S20, turning on the solid-state relay when the positive half cycle crosses zero; turning off the solid-state relay when the negative half cycle crosses zero.

[0120] Step S21 , turning on the solid-state relay when the negative half cycle crosses zero; and turning off the solid-state relay when the positive half cycle crosses zero.

[0121] Step S22: Determine whether the target on-time has been reached. If so, execute step S13; if not, execute step S20 or step S21.

[0122] Step S23, completing the control action of the electromagnetic coil of a four-way valve and turning off the solid-state relay.

[0123] A fourth aspect of the present invention provides an air conditioner, such as Figure 12 As shown, the air conditioner 20 includes at least one processor 9 and a memory 8 communicatively connected to the at least one processor 9 .

[0124] The memory 8 stores a computer program that can be executed by at least one processor 9 , and when the at least one processor 9 executes the computer program, the control method of the four-way valve control circuit provided in the above embodiment is implemented.

[0125] According to the air conditioner 20 of an embodiment of the present invention, the control method of the four-way valve control circuit provided by the above embodiment is executed by the processor 8, and the conduction time of the four-way valve can be dynamically adjusted according to the different AC voltages input by the power grid to meet the working requirements under different input AC voltages and improve the versatility of the circuit.

[0126] In the description of this specification, any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes additional implementations in which functions may be performed in a different order than shown or discussed, including performing functions in a substantially simultaneous manner or in a reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0127] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0128] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0129] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0130] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing module, or each unit may exist physically separately, or two or more units may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or in the form of software functional modules. If the integrated modules are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium.

[0131] The storage medium mentioned above may be a read-only memory, a magnetic disk, or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Persons skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0132] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0133] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A four-way valve control circuit, characterized in that: include: An operational amplifier unit, wherein the input end of the operational amplifier unit is suitable for connecting to a power grid and is used to collect an AC voltage sampling signal; a control unit connected to the output terminal of the operational amplifier unit, configured to determine a zero-crossing moment according to the AC voltage sampling signal, and to send a switch control signal according to the zero-crossing moment; a switch unit, wherein an output end of the switch unit is adapted to be connected to the power grid and the electromagnetic coil of the four-way valve, and an input end of the switch unit is connected to the control unit, and is configured to perform a switching action according to the switch control signal to control the conduction direction of the four-way valve; a power supply unit, adapted to be connected to a power grid and used to supply power to the control unit and the operational amplifier unit; an energy storage unit, wherein the energy storage unit is connected in parallel with the electromagnetic coil of the four-way valve, and a first end of the energy storage unit is connected to an output end of the switch unit; a current limiting unit, wherein a first end of the current limiting unit is connected to the neutral line of the power grid, and a second end of the current limiting unit is connected to the second end of the energy storage unit; The control unit is further configured to determine a voltage effective value based on the AC voltage sampling signal, determine a target on-time based on the voltage effective value, and control the on-time of the four-way valve based on the target on-time.

2. The four-way valve control circuit according to claim 1, characterized in that: The operational amplifier unit comprises: a first resistor, wherein a first end of the first resistor is adapted to be connected to a live wire of the power grid; an operational amplifier, wherein a positive input terminal of the operational amplifier is connected to the second end of the first resistor, a power input terminal of the operational amplifier is connected to the power supply unit, an output terminal of the operational amplifier is connected to the control unit, and a ground terminal of the operational amplifier is grounded; a second resistor, wherein a first end of the second resistor is connected to the output end of the operational amplifier; a third resistor, wherein a first end of the third resistor is connected to the negative input terminal of the operational amplifier and the second end of the second resistor, and a second end of the third resistor is suitable for connecting to a neutral line of the power grid; The switch unit includes: A solid-state relay, wherein a first end of the solid-state relay is connected to the control unit, a second end of the solid-state relay is grounded, a third end of the solid-state relay is suitable for connecting to the live wire of the power grid, and a fourth end of the solid-state relay is connected to the electromagnetic coil of the four-way valve.

3. A control method for a four-way valve control circuit, characterized in that: Used to control the four-way valve control circuit according to claim 1 or 2, the control method includes: Acquire AC voltage sampling signal; Determining a zero-crossing moment according to the AC voltage sampling signal; Sending a switch control signal according to the zero-crossing moment to control the conduction direction of the four-way valve; The control method further includes: Determine the effective value of the voltage according to the AC voltage sampling signal; determining a target on-time according to the effective value of the voltage; The on-time of the four-way valve is controlled according to the target on-time.

4. The control method of the four-way valve control circuit according to claim 3, characterized in that: The four-way valve control circuit is used for an air conditioner, and sends a switch control signal according to the zero-crossing time to control the conduction direction of the four-way valve, including: Obtaining the target operating mode of the air conditioner; A switch control signal is sent according to the target operation mode and the zero-crossing time to control the conduction direction of the four-way valve.

5. The control method of the four-way valve control circuit according to claim 4, characterized in that: The switch control signal includes an on-control signal and an off-control signal. The switch control signal is sent according to the target operation mode and the zero-crossing time to control the conduction direction of the four-way valve, including: Determining that the target operating mode is a cooling mode; When the zero-crossing point is the zero-crossing point of the positive half cycle, a conduction control signal is sent to make the conduction direction of the four-way valve forward conduction; Sending a shutdown control signal when the zero-crossing moment is the negative half-cycle zero-crossing moment; Alternatively, determining that the target operating mode is a heating mode; When the zero-crossing point is the zero-crossing point of the negative half cycle, a conduction control signal is sent to make the conduction direction of the four-way valve reverse conduction; When the zero-crossing moment is the zero-crossing moment of the positive half cycle, a shutdown control signal is sent.

6. The control method of the four-way valve control circuit according to claim 4, characterized in that: Before sending a switch control signal according to the target operation mode and the zero-crossing time to control the conduction direction of the four-way valve, the method further includes: Get the last operating mode of the air conditioner; When the target operation mode is consistent with the previous operation mode, the control of the four-way valve is stopped so that the four-way valve maintains the current conducting direction.

7. An air conditioner, characterized in that: include: The refrigerant circulation loop allows the refrigerant to circulate in the loop consisting of the compressor, condenser, expansion valve, evaporator and four-way valve; The four-way valve includes a solenoid coil; as well as The four-way valve control circuit according to claim 1 or 2, wherein the four-way valve control circuit is connected to the electromagnetic coil; and, at least one processor; a memory communicatively coupled to at least one of the processors; Wherein, the memory stores a computer program that can be executed by at least one of the processors, and when at least one of the processors executes the computer program, the control method of the four-way valve control circuit according to any one of claims 3 to 6 is implemented.

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