Current loop communication circuit and electronic equipment

Abstract

The utility model relates to a current loop communication circuit and electronic equipment. The current loop communication circuit comprises an indoor controller, an outdoor controller, an indoor data transmission module, an outdoor data transmission module, a power grid connection end and a constant current module, the constant-current module is connected with the power grid connecting end and the first end of the indoor data transmission module and is used for providing constant-current power supply for the indoor data transmission module; the indoor data transmission module is connected with the indoor controller and is used for carrying out data transmission with the indoor controller; the outdoor data transmission module is connected with the outdoor controller and is used for carrying out data transmission with the outdoor controller; the first end of the outdoor data transmission module is connected with the second end of the indoor data transmission module, and the second end of the outdoor data transmission module is connected with the power grid connection end. According to the utility model, the loop current can be kept as a constant current, the communication data cannot be abnormal due to line impedance and line voltage drop in the transmission process, and the indoor and outdoor communication quality is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of communication circuits, and more specifically, to a current loop communication circuit and an electronic device. Background Art

[0002] Since there are differences in the power supply voltages in different countries and regions, when an electronic device is used in different countries and regions, the voltage range it can withstand needs to be considered. In the existing power supply of the current loop communication circuit, it is usually to step down the voltage by a resistor and stabilize the voltage by a voltage stabilizing diode to a certain voltage value, such as 24V. However, in the working conditions of high power and low voltage of electrical appliances, when the voltage signal is transmitted over a long distance, communication failures will occur due to the large line impedance and strong electromagnetic interference. Subsequently, the current loop communication circuit cannot perform long-distance communication. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide a current loop communication circuit and an electronic device for the above-mentioned partial technical defects of the prior art.

[0004] The technical solution adopted by the utility model to solve its technical problem is to construct a current loop communication circuit, including: an indoor controller, an outdoor controller, an indoor data transmission module, an outdoor data transmission module, a power grid connection end, and a constant current module;

[0005] The constant current module is connected to the power grid connection end and the first end of the indoor data transmission module, and is used to provide constant current power supply for the indoor data transmission module;

[0006] The indoor data transmission module is connected to the indoor controller and is used to transmit data with the indoor controller;

[0007] The outdoor data transmission module is connected to the outdoor controller and is used to transmit data with the outdoor controller;

[0008] The first end of the outdoor data transmission module is connected to the second end of the indoor data transmission module, and the second end of the outdoor data transmission module is connected to the power grid connection end.

[0009] Preferably, in an embodiment of the current loop communication circuit of the utility model, the constant current module includes a first triode, a second triode, a first resistor, a second resistor, and a first capacitor;

[0010] The collector of the first triode and the first end of the first resistor are connected to the power grid connection end, the base of the first triode is connected to the second end of the first resistor and the collector of the second triode, and the emitter of the first triode is connected to the base of the second triode, the first end of the second resistor, and the first end of the first capacitor;

[0011] The emitter of the second triode is connected to the second end of the second resistor, the second end of the first capacitor, and the first end of the indoor data transmission module.

[0012] Preferably, in an embodiment of the current loop communication circuit of the present invention, the current loop communication circuit further includes a power conditioning module;

[0013] The power conditioning module is connected to the grid connection end and the constant current module for conditioning the power supply input of the constant current module.

[0014] Preferably, in an embodiment of the current loop communication circuit of the present invention, the power conditioning module includes a third resistor, a first diode, a second capacitor, a third capacitor, a fourth resistor, and a zener diode;

[0015] The L end of the grid connection end is connected to the anode of the first diode through the third resistor, and the cathode of the first diode is connected to the first end of the second capacitor, the first end of the third capacitor, the first end of the fourth resistor, the cathode of the zener diode, and the input end of the constant current module;

[0016] The N end of the grid connection end is connected to the second end of the second capacitor, the second end of the third capacitor, the second end of the fourth resistor, and the anode of the zener diode.

[0017] Preferably, in an embodiment of the current loop communication circuit of the present invention, the second end of the outdoor data transmission module is connected to the N end of the grid connection end.

[0018] Preferably, in an embodiment of the current loop communication circuit of the present invention, the indoor data transmission module includes: a first drive switch, a first opto-coupler circuit, a second opto-coupler circuit, a second diode, and a fifth resistor;

[0019] The control end of the first drive switch is connected to the control signal output end of the indoor controller, the first end of the first drive switch is connected to the second end of the first opto-coupler circuit, and the second end of the first drive switch is grounded;

[0020] The first end of the first opto-coupler circuit is connected to a supply voltage, the third end of the first opto-coupler circuit is connected to the output end of the constant current module, the fourth end of the first opto-coupler circuit is connected to the first end of the second opto-coupler circuit, the second end of the second opto-coupler circuit is connected to the anode of the second diode, the cathode of the second diode is connected to the first end of the fifth resistor, and the second end of the fifth resistor serves as the second end of the indoor data transmission module;

[0021] The third terminal of the second optocoupler circuit is connected to a supply voltage, and the fourth terminal of the second optocoupler circuit is connected to the control signal input terminal of the indoor controller.

[0022] Preferably, in an embodiment of the current loop communication circuit of the present invention, the outdoor data transmission module includes: a second drive switch, a third optocoupler circuit, a fourth optocoupler circuit, a third diode, and a sixth resistor;

[0023] The control terminal of the second drive switch is connected to the control signal output terminal of the outdoor controller, the first terminal of the second drive switch is connected to the second terminal of the third optocoupler circuit, and the second terminal of the second drive switch is grounded;

[0024] The first terminal of the third optocoupler circuit is connected to a supply voltage, the third terminal of the third optocoupler circuit is connected to the second terminal of the fourth optocoupler circuit, and the fourth terminal of the third optocoupler circuit serves as the second terminal of the outdoor data transmission module;

[0025] The first terminal of the fourth optocoupler circuit is connected to the cathode of the third diode, the anode of the third diode is connected to the second terminal of the sixth resistor, and the second terminal of the sixth resistor serves as the first terminal of the outdoor data transmission module;

[0026] The third terminal of the fourth optocoupler circuit is connected to a supply voltage, and the fourth terminal of the fourth optocoupler circuit is connected to the control signal input terminal of the outdoor controller.

[0027] Preferably, in an embodiment of the current loop communication circuit of the present invention, the first drive switch includes: a third triode, a seventh resistor, an eighth resistor, a ninth resistor, and a fourth capacitor;

[0028] The first terminal of the seventh resistor is connected to the control signal output terminal of the indoor controller, the second terminal of the seventh resistor is connected to the first terminal of the fourth capacitor, the first terminal of the eighth resistor, and the base of the third triode. The collector of the third triode is connected to the first terminal of the ninth resistor, and the second terminal of the ninth resistor is connected to the second terminal of the first optocoupler circuit; the emitter of the third triode, the second terminal of the fourth capacitor, and the second terminal of the eighth resistor are grounded.

[0029] Preferably, in an embodiment of the current loop communication circuit of the present invention, the second drive switch includes: a fourth triode, a tenth resistor, and an eleventh resistor;

[0030] The base of the fourth triode is connected to the first end of the tenth resistor, the second end of the tenth resistor is connected to the control signal output end of the outdoor controller, the collector of the fourth triode is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is connected to the second end of the third opto-coupler circuit, and the emitter of the fourth triode is grounded.

[0031] The present invention also constructs an electronic device, including the current loop communication circuit as described above.

[0032] Implementing the current loop communication circuit and the electronic device of the present invention has the following beneficial effects: enabling the loop current to remain a constant current, and preventing data anomalies from occurring during the communication data transmission process due to line impedance and line voltage drop, thus ensuring the indoor and outdoor communication quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0034] Figure 1 is a logic block diagram of an embodiment of the current loop communication circuit of the present invention;

[0035] Figure 2 is a circuit schematic diagram of an embodiment of the current loop communication circuit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] For a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the drawings.

[0037] As Figure 1 shown, an embodiment of the current loop communication circuit of the present invention is shown. In Figure 1In an embodiment of the current loop communication circuit of the present utility model shown, the current loop communication circuit includes: an indoor controller 110, an outdoor controller 160, an indoor data transmission module 120, an outdoor data transmission module 150, a power grid connection end 140, and a constant current module 130; the constant current module 130 is connected to the power grid connection end 140 and the first end of the indoor data transmission module 120, and is used to provide constant current power supply for the indoor data transmission module 120; the indoor data transmission module 120 is connected to the indoor controller 110 and is used to perform data transmission with the indoor controller 110; the outdoor data transmission module 150 is connected to the outdoor controller 160 and is used to perform data transmission with the outdoor controller 160; the first end of the outdoor data transmission module 150 is connected to the second end of the indoor data transmission module 120, and the second end of the outdoor data transmission module 150 is connected to the power grid connection end 140. Specifically, the power grid connection end 140 is used to connect to the AC power grid. The power supply input of the power grid connection end 140 provides a constant current output to the indoor data transmission module 120 through the constant current function of the constant current module 130. The indoor data transmission module 120 performs data communication with the indoor controller 110. That is, the indoor data transmission module 120 can generate communication data according to the output of the indoor controller 110 and transmit it to the outdoor data transmission module 150. The indoor data transmission module 120 can also receive the communication data transmitted by the outdoor data transmission module 150 and generate corresponding control data and input it to the indoor controller 110. The outdoor data transmission module 150 performs data communication with the outdoor controller 160. That is, the outdoor data transmission module 150 can generate communication data according to the output of the outdoor controller 160 and transmit it to the indoor data transmission module 120. The outdoor data transmission module 150 can also receive the communication data transmitted by the indoor data transmission module 120 and generate corresponding control data and input it to the outdoor controller 160. Through the above process, data communication between the indoor controller 110 and the outdoor controller 160 is finally achieved. The constant current module 130 ensures that the loop current is in a constant state, converts the communication signal between the outdoor data transmission module 150 and the indoor data transmission module 120 from a voltage signal to a current signal. At the same time, the constant current signal makes the communication data generated by the outdoor data transmission module 150 and the indoor data transmission module 120 not easily affected by external interference during the transmission process, enhances the communication distance, and can improve the communication quality.

[0038] In a specific embodiment, the indoor controller 110 and the outdoor controller 160 can be respectively composed of an MCU chip and its peripheral circuits.

[0039] Optionally, such as Figure 2As shown, the constant current module 130 includes a first triode, a second triode, a first resistor, a second resistor, and a first capacitor; the collector of the first triode and the first end of the first resistor are connected to the grid connection terminal 140, the base of the first triode is connected to the second end of the first resistor and the collector of the second triode, and the emitter of the first triode is connected to the base of the second triode, the first end of the second resistor, and the first end of the first capacitor; the emitter of the second triode is connected to the second end of the second resistor, the second end of the first capacitor, and the first end of the indoor data transmission module 120. In Figure 2 In the specific embodiment shown, the first triode includes triode Q1, the second triode includes triode Q2, the first resistor includes resistor R2, the second resistor includes resistor R4, and the first capacitor includes capacitor C2. Among them, the collector of triode Q1 and the first end of resistor R2 are connected to the grid connection terminal 140, the base of triode Q1 is connected to the emitter of triode Q2 and the second end of resistor R2, the emitter of triode Q1 is connected to the collector of triode Q2, the first end of resistor R4, and the first end of capacitor C2, and the emitter of triode Q2, the second end of resistor R4, and the second end of capacitor C2 are used as the output end of the constant current module 130 and are connected to the first end of the indoor data transmission module 120.

[0040] Optionally, the current loop communication circuit further includes a power conditioning module 170; the power conditioning module 170 is connected to the grid connection terminal 140 and the constant current module 130 for conditioning the power supply input of the constant current module 130. Specifically, the input of the constant current module 130 is conditioned by the power conditioning module 170. That is, the power conditioning module 170 preliminarily conditions the power signal input through the grid connection terminal 140 and then inputs it to the constant current module 130. The signal conditioning process may include but is not limited to filtering, voltage stabilization, etc. of the power supply input.

[0041] Optionally, the power conditioning module 170 includes a third resistor, a first diode, a second capacitor, a third capacitor, a fourth resistor, and a zener diode; the L terminal of the grid connection terminal 140 is connected to the anode of the first diode through the third resistor, and the cathode of the first diode is connected to the first end of the second capacitor, the first end of the third capacitor, the first end of the fourth resistor, the cathode of the zener diode, and the input end of the constant current module 130; the N terminal of the grid connection terminal 140 is connected to the second end of the second capacitor, the second end of the third capacitor, the second end of the fourth resistor, and the anode of the zener diode. Specifically, in Figure 2In the illustrated embodiment, the third resistor includes resistor R1, the first diode includes diode D1, the second capacitor includes capacitor C1, the third capacitor includes capacitor E1, the fourth resistor includes resistor R3, and the zener diode includes zener diode ZD1. Diode D1 is used for input isolation to prevent power backflow. Zener diode ZD1 is used to ensure that the input voltage at the input end of the constant current module 130 is stabilized at a target value, for example, maintained at 48V. Capacitor C1 and capacitor E1 are used for filtering the power input. The power grid connection end 140 includes an AC input, and the L terminal input of the AC input is input to the constant current module 130 after being conditioned by the power conditioning module 170.

[0042] Optionally, the second end of the outdoor data transmission module 150 is connected to the N end of the power grid connection end 140. The second end of the outdoor data transmission module 150 is connected to the N end of the power grid connection end 140, and is connected to the first end of the indoor data transmission module 120 through the N end of the power input to form a communication loop.

[0043] Optionally, the indoor data transmission module 120 includes: a first drive switch, a first opto-coupler circuit, a second opto-coupler circuit, a second diode, and a fifth resistor; the control end of the first drive switch is connected to the control signal output end of the indoor controller 110, the first end of the first drive switch is connected to the second end of the first opto-coupler circuit, and the second end of the first drive switch is grounded; the first end of the first opto-coupler circuit is connected to a supply voltage, the third end of the first opto-coupler circuit is connected to the output end of the constant current module 130, the fourth end of the first opto-coupler circuit is connected to the first end of the second opto-coupler circuit, the second end of the second opto-coupler circuit is connected to the anode of the second diode, the cathode of the second diode is connected to the first end of the fifth resistor, and the second end of the fifth resistor serves as the second end of the indoor data transmission module 120; the third end of the second opto-coupler circuit is connected to a supply voltage, and the fourth end of the second opto-coupler circuit is connected to the control signal input end of the indoor controller 110. Specifically, Figure 2In the illustrated embodiment, the first opto-coupler circuit includes an opto-coupler IC1 and its peripheral circuit, and the second opto-coupler circuit includes an opto-coupler IC3 and its peripheral circuit. Among them, when the indoor controller 110 outputs data, the first drive switch is turned on or off according to the control signal of the indoor controller 110 to control the on or off of the first opto-coupler circuit. The second opto-coupler circuit remains on. The output of the constant current module 130 generates corresponding communication data through the on or off process of the first opto-coupler circuit and is transmitted to the outdoor data transmission module 150 through the second end of the indoor data transmission module 120. When the indoor controller 110 needs to receive data, the first drive switch controls the first opto-coupler circuit to turn on. The data generated by the outdoor data transmission module 150 controls the second opto-coupler circuit to turn on or off through the constant current module 130 to generate corresponding communication data and input it to the control signal input end of the indoor controller 110.

[0044] Optionally, the first drive switch includes: a third triode, a seventh resistor, an eighth resistor, a ninth resistor, and a fourth capacitor; the first end of the seventh resistor is connected to the control signal output end of the indoor controller 110, the second end of the seventh resistor is connected to the first end of the fourth capacitor, the first end of the eighth resistor, and the base of the third triode. The collector of the third triode is connected to the first end of the ninth resistor, and the second end of the ninth resistor is connected to the second end of the first opto-coupler circuit; the emitter of the third triode, the second end of the fourth capacitor, and the second end of the eighth resistor are grounded. Specifically, in Figure 2 the illustrated embodiment, the third triode includes triode Q4, the seventh resistor includes resistor R7, the eighth resistor includes resistor R9, the ninth resistor includes resistor R5, and the fourth capacitor includes capacitor C4. That is, a drive switch is formed by triode Q4 and its peripheral circuit to drive the first opto-coupler circuit to turn on or off through this drive switch.

[0045] Optionally, the outdoor data transmission module 150 includes: a second driving switch, a third optocoupler circuit, a fourth optocoupler circuit, a third diode, and a sixth resistor; the control end of the second driving switch is connected to the control signal output end of the outdoor controller 160, the first end of the second driving switch is connected to the second end of the third optocoupler circuit, and the second end of the second driving switch is grounded; the first end of the third optocoupler circuit is connected to a supply voltage, the third end of the third optocoupler circuit is connected to the second end of the fourth optocoupler circuit, and the fourth end of the third optocoupler circuit serves as the output end of the outdoor data transmission module 150; the first end of the fourth optocoupler circuit is connected to the cathode of the third diode, the anode of the third diode is connected to the second end of the sixth resistor, and the second end of the sixth resistor serves as the first end of the outdoor data transmission module 150; the third end of the fourth optocoupler circuit is connected to a supply voltage, and the fourth end of the fourth optocoupler circuit is connected to the control signal input end of the outdoor controller 160. Specifically, in Figure 2 In the shown embodiment, the third optocoupler circuit includes an optocoupler IC2 and its peripheral circuit, and the fourth optocoupler circuit includes an optocoupler IC4 and its peripheral circuit. Among them, when the outdoor controller 160 outputs data, the second driving switch is turned on or off according to the control signal of the outdoor controller 160 to control the third optocoupler circuit to be turned on or off, the fourth optocoupler circuit remains on, and the output of the constant current module 130 generates corresponding communication data through the on or off process of the third optocoupler circuit and is transmitted to the indoor data transmission module 120 through the output end of the outdoor data transmission module 150. When the outdoor controller 160 needs to receive data, the second driving switch controls the third optocoupler circuit to be turned on, and the data generated by the indoor data transmission module 120 controls the fourth optocoupler circuit to be turned on or off through the constant current module 130 to generate corresponding communication data and input it to the control signal input end of the outdoor controller 160.

[0046] Optionally, the second driving switch includes: a fourth triode, a tenth resistor, and an eleventh resistor; the base of the fourth triode is connected to the first end of the tenth resistor, the second end of the tenth resistor is connected to the control signal output end of the outdoor controller 160, the collector of the fourth triode is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is connected to the second end of the third optocoupler circuit, and the emitter of the fourth triode is grounded. Specifically, in Figure 2 In the shown embodiment, the fourth triode includes a triode Q3, the tenth resistor includes a resistor R8, and the eleventh resistor includes a resistor R6. That is, a driving switch is formed by the triode Q4 and its peripheral circuit to drive the third optocoupler circuit to be turned on or off through this driving switch.

[0047] In addition, the electronic device of the present utility model can be provided with the above current loop communication circuit to achieve long-distance communication between indoors and outdoors. In a specific embodiment, the electronic device can be an air conditioner. The communication process between the indoor unit and the outdoor unit of the air conditioner is achieved through the above current loop communication circuit.

[0048] It can be understood that the above embodiments only express the preferred embodiments of the present utility model, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation to the patent scope of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made to the scope of the claims of the present utility model shall fall within the scope covered by the claims of the present utility model.

Claims

1. A current loop communication circuit, characterized in that: include: Indoor controller, outdoor controller, indoor data transmission module, outdoor data transmission module, grid connection terminal and constant current module; The constant current module is connected to the grid connection end and the first end of the indoor data transmission module, and is used to provide constant current power supply for the indoor data transmission module; The indoor data transmission module is connected to the indoor controller for performing data transmission with the indoor controller; The outdoor data transmission module is connected to the outdoor controller and is used for performing data transmission with the outdoor controller; The first end of the outdoor data transmission module is connected to the second end of the indoor data transmission module, and the second end of the outdoor data transmission module is connected to the grid connection end.

2. The current loop communication circuit according to claim 1, characterized in that: The constant current module includes a first transistor, a second transistor, a first resistor, a second resistor and a first capacitor; The collector of the first transistor and the first end of the first resistor are connected to the grid connection terminal, the base of the first transistor is connected to the second end of the first resistor and the collector of the second transistor, and the emitter of the first transistor is connected to the base of the second transistor, the first end of the second resistor, and the first end of the first capacitor; The emitter of the second transistor is connected to the second end of the second resistor, the second end of the first capacitor and the first end of the indoor data transmission module.

3. The current loop communication circuit according to claim 1, characterized in that: The current loop communication circuit also includes a power conditioning module; The power conditioning module is connected to the grid connection terminal and the constant current module, and is used to condition the power input of the constant current module.

4. The current loop communication circuit according to claim 3, characterized in that: The power conditioning module includes a third resistor, a first diode, a second capacitor, a third capacitor, a fourth resistor and a voltage stabilizing diode; The L end of the grid connection end is connected to the anode of the first diode via the third resistor, and the cathode of the first diode is connected to the first end of the second capacitor, the first end of the third capacitor, the first end of the fourth resistor, the cathode of the voltage regulator diode and the input end of the constant current module; The N-terminal of the grid connection terminal is connected to the second end of the second capacitor, the second end of the third capacitor, the second end of the fourth resistor, and the anode of the voltage-stabilizing diode.

5. The current loop communication circuit according to claim 4, characterized in that: The second end of the outdoor data transmission module is connected to the N end of the grid connection end.

6. The current loop communication circuit according to claim 1, characterized in that: The indoor data transmission module includes: a first driving switch, a first optocoupler circuit, a second optocoupler circuit, a second diode and a fifth resistor; The control end of the first drive switch is connected to the control signal output end of the indoor controller, the first end of the first drive switch is connected to the second end of the first optocoupler circuit, and the second end of the first drive switch is grounded; A first end of the first optocoupler circuit is connected to a power supply voltage, a third end of the first optocoupler circuit is connected to the output end of the constant current module, a fourth end of the first optocoupler circuit is connected to the first end of the second optocoupler circuit, a second end of the second optocoupler circuit is connected to the anode of the second diode, a cathode of the second diode is connected to the first end of the fifth resistor, and a second end of the fifth resistor serves as the second end of the indoor data transmission module; The third end of the second optocoupler circuit is connected to a power supply voltage, and the fourth end of the second optocoupler circuit is connected to the control signal input end of the indoor controller.

7. The current loop communication circuit according to claim 1, characterized in that: The outdoor data transmission module includes: a second drive switch, a third optocoupler circuit, a fourth optocoupler circuit, a third diode and a sixth resistor; The control end of the second drive switch is connected to the control signal output end of the outdoor controller, the first end of the second drive switch is connected to the second end of the third optocoupler circuit, and the second end of the second drive switch is grounded; The first end of the third optocoupler circuit is connected to a power supply voltage, the third end of the third optocoupler circuit is connected to the second end of the fourth optocoupler circuit, and the fourth end of the third optocoupler circuit serves as the second end of the outdoor data transmission module; The first end of the fourth optocoupler circuit is connected to the cathode of the third diode, the anode of the third diode is connected to the second end of the sixth resistor, and the second end of the sixth resistor serves as the first end of the outdoor data transmission module; The third end of the fourth optocoupler circuit is connected to a power supply voltage, and the fourth end of the fourth optocoupler circuit is connected to the control signal input end of the outdoor controller.

8. The current loop communication circuit according to claim 6, characterized in that: The first driving switch includes: a third transistor, a seventh resistor, an eighth resistor, a ninth resistor and a fourth capacitor; The first end of the seventh resistor is connected to the control signal output end of the indoor controller, the second end of the seventh resistor is connected to the first end of the fourth capacitor, the first end of the eighth resistor and the base of the third transistor, the collector of the third transistor is connected to the first end of the ninth resistor, and the second end of the ninth resistor is connected to the second end of the first optocoupler circuit; the emitter of the third transistor, the second end of the fourth capacitor and the second end of the eighth resistor are grounded.

9. The current loop communication circuit according to claim 7, characterized in that: The second driving switch includes: a fourth transistor, a tenth resistor and an eleventh resistor; The base of the fourth transistor is connected to the first end of the tenth resistor, the second end of the tenth resistor is connected to the control signal output end of the outdoor controller, the collector of the fourth transistor is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is connected to the second end of the third optocoupler circuit, and the emitter of the fourth transistor is grounded.

10. An electronic device, characterized in that: The invention comprises the current loop communication circuit as described in any one of claims 1 to 9.

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