CN113741257A - Current loop communication circuit and air conditioning unit - Google Patents
Current loop communication circuit and air conditioning unit Download PDFInfo
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- CN113741257A CN113741257A CN202110976152.5A CN202110976152A CN113741257A CN 113741257 A CN113741257 A CN 113741257A CN 202110976152 A CN202110976152 A CN 202110976152A CN 113741257 A CN113741257 A CN 113741257A
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- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
- G05B19/042—Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
- G05B19/0423—Input/output
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/20—Pc systems
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- G05B2219/25257—Microcontroller
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Abstract
The invention discloses a current loop communication circuit and an air conditioning unit, wherein the method comprises the following steps: the signal input end of the first current loop communication circuit is connected with the processor of the host; the signal input end of the second current loop communication circuit is connected with the signal output end of the first current loop communication circuit through a signal wire, and the signal output end of the second current loop communication circuit is connected with the processor of the slave; and the discharge loop is connected between the zero line and the signal line in series, and parasitic capacitance between the zero line and the signal line is eliminated when the first current loop communication circuit and the second current loop communication circuit communicate. The invention solves the problem of short distance of the communication line caused by parasitic capacitance existing when the communication line and the power line are wired in parallel in the current loop communication circuit in the prior art, eliminates the influence of the parasitic capacitance on the communication signal and reduces the limitation of the length of the connecting line on the current loop communication.
Description
Technical Field
The invention relates to the technical field of electronic power, in particular to a current loop communication circuit and an air conditioning unit.
Background
The communication between the internal machine and the external machine of the current household air conditioner is generally realized by adopting a current loop communication circuit, and the current loop communication is mainly characterized in that the communication circuit and a power supply circuit can share a zero line, the communication between the internal machine and the external machine can be realized only by adding an additional communication line, the connecting line of the whole communication circuit is less, and the cost is low; however, because the current loop communication needs to share the zero line with the power circuit, during actual installation, the communication line and the power line are mostly wired in parallel, the parallel wiring inevitably causes parasitic capacitance between the communication line and the power line, when the connecting line is short, the parasitic capacitance is small, the influence of capacitance charging and discharging on the level of the communication line is small, when the connection is gradually lengthened, the parasitic capacitance is increased, the influence of capacitance charging and discharging on the level of the communication line is increased, and when the connecting line is lengthened to a certain length, the level fluctuation caused by the charging and discharging of the parasitic capacitance interferes with the transmission of the effective level on the communication line, thereby causing communication failure. Based on this, the effective communication distance of the traditional current loop communication is usually shorter, and is generally only 30 m-50 m, which is also the main reason that the current loop communication circuit is rarely used in products requiring long-distance communication.
Aiming at the problem that the communication line distance is short due to parasitic capacitance existing when the communication line and the power line are wired in parallel in the current loop communication circuit in the related technology, no effective solution is provided at present.
Disclosure of Invention
The invention provides a current loop communication circuit and an air conditioning unit, which at least solve the problem that the distance of a communication line is short due to parasitic capacitance when the communication line and a power line are wired in parallel in the current loop communication circuit in the prior art.
To solve the above technical problem, according to an aspect of an embodiment of the present invention, there is provided a current loop communication circuit including: the signal input end of the first current loop communication circuit is connected with the processor of the host; the signal input end of the second current loop communication circuit is connected with the signal output end of the first current loop communication circuit through a signal wire, and the signal output end of the second current loop communication circuit is connected with the processor of the slave; the signal line is a communication line between the master machine and the slave machine; the first current loop communication circuit and the second current loop communication circuit are also connected with a zero line of a host power supply; and the discharge loop is connected between the zero line and the signal line in series, and parasitic capacitance between the zero line and the signal line is eliminated when the first current loop communication circuit and the second current loop communication circuit communicate.
Further, still include: and one end of the power circuit is connected with a live wire of the host power supply, and the other end of the power circuit is connected with the first current loop communication circuit and used for supplying power to the first current loop communication circuit.
Further, the power supply circuit includes: and the anode of the energy storage capacitor is connected with a live wire of the host power supply.
Further, the power supply circuit further includes: one end of the first resistor is connected with the anode of the energy storage capacitor, and the other end of the first resistor is connected with the live wire; the second resistor is connected with the energy storage capacitor in parallel; and the anode of the first diode is connected with the first resistor, and the cathode of the first diode is connected with the anode of the energy storage capacitor.
Further, the power supply circuit further includes: the anode of the second diode is connected with the cathode of the energy storage capacitor, and the cathode of the second diode is connected with the anode of the energy storage capacitor; the anode of the third diode is connected with the cathode of the energy storage capacitor, and the cathode of the third diode is connected with the anode of the energy storage capacitor; wherein the third diode is a clamping diode.
Further, the first current loop communication circuit includes: the collector of the triode of the first optocoupler is connected with the anode of the energy storage capacitor, and the anode and the cathode of the diode of the first optocoupler are both connected with the processor of the host; and the collector and the emitter of the triode of the second optocoupler are connected with the processor of the host, the anode of the diode of the second optocoupler is connected with the emitter of the triode of the first optocoupler, and the cathode of the diode of the second optocoupler is connected with the signal wire.
Further, the first current loop communication circuit further includes: a first end of the third resistor is connected with an anode of a diode of the second optocoupler, and a second end of the third resistor is connected with a cathode of the diode of the second optocoupler; a first connecting point is arranged between the first end of the third resistor and the anode of the diode of the second optocoupler, and the first connecting point is also connected with the emitting electrode of the triode of the first optocoupler; a second connection point is arranged between the second end of the third resistor and the cathode of the diode of the second optocoupler, and the second connection point is also connected with a signal wire; one end of the fourth resistor is connected with the first connecting point, and the other end of the fourth resistor is connected with the signal wire; and a third connection point is arranged between the fourth resistor and the signal line.
Further, the first current loop communication circuit further includes: the anode of the fourth diode is connected with the second connecting point, and the cathode of the fourth diode is connected with the first connecting point; a cathode of the fifth diode is connected with the second connection point, and an anode of the fifth diode is connected with the third connection point; wherein the fifth diode is a clamping diode.
Further, the first current loop communication circuit further includes: one end of the fifth resistor is connected with the third connection point, and the other end of the fifth resistor is connected with the signal wire; and the anode of the sixth diode is connected with the fifth resistor, and the cathode of the sixth diode is connected with the signal line.
Further, the second current loop communication circuit includes: the collector of a triode of the third optocoupler is connected with a signal wire, and the anode and the cathode of a diode of the third optocoupler are both connected with a processor of the slave; and the collector and the emitter of the triode of the fourth optocoupler are both connected with the processor of the slave, the anode of the diode of the fourth optocoupler is connected with the emitter of the triode of the third optocoupler, and the cathode of the diode of the fourth optocoupler is connected with the zero line.
Further, the second current loop communication circuit further includes: a first end of the sixth resistor is connected with a collector of a triode of the third optocoupler, and a second end of the sixth resistor is connected with the signal wire; a fourth connection point is arranged between the first end of the sixth diode and the collector of the triode of the third optocoupler; and the anode of the seventh diode is connected with the signal line, and the cathode of the seventh diode is connected with the second end of the sixth resistor.
Further, the second current loop communication circuit further includes: a first end of the seventh resistor is connected with the fourth connection point, and a second end of the seventh resistor is connected with an emitter of a triode of the third optocoupler; a first end of the eighth resistor is connected with a second end of the seventh resistor, and a second end of the eighth resistor is connected with a cathode of a diode of the fourth optocoupler; and the anode of the eighth diode is connected with the cathode of the diode of the fourth optocoupler, and the cathode of the eighth diode is connected with the anode of the diode of the fourth optocoupler.
Further, the discharge loop includes: a parasitic capacitance; an emitting electrode of a triode of the fifth optocoupler is connected with a zero line, a collector electrode of the triode of the fifth optocoupler is connected with a signal line, and an anode and a cathode of a diode of the fifth optocoupler are both connected with a processor of the host; and the ninth resistor is positioned between the collector of the triode of the fifth optocoupler and the signal wire.
Further, the discharge loop further comprises: parasitic capacitance and ninth diode, the positive pole of ninth diode is connected with the zero line, and the negative pole of ninth diode is connected with the signal line.
Furthermore, the energy storage capacitor, the first optocoupler, the fourth resistor, the fifth resistor, the sixth diode and the parasitic capacitor form a charging loop, and the charging loop is used for charging the parasitic capacitor after discharging.
According to another aspect of the embodiment of the invention, an air conditioning unit is provided, which comprises the current loop communication circuit; the master machine is an outdoor machine, and the slave machine is an indoor machine.
Further, when the host sends a signal to the slave, the slave is used for controlling the third optocoupler to be conducted until the host sends all data; when the host machine sends a high-level signal to the slave machine, the host machine is used for controlling the first optocoupler to be switched on and controlling the fifth optocoupler to be switched off; when the host machine sends a low level signal to the slave machine, the host machine is used for controlling the first optocoupler to be switched off and controlling the fifth optocoupler to be switched on; when the slave machine sends a signal to the host machine, the host machine is used for controlling the first optocoupler to be switched on and controlling the fifth optocoupler to be switched off until the slave machine sends all data; when the slave machine sends a high-level signal to the host machine, the slave machine is used for controlling the conduction of the third optocoupler; when the slave machine sends a low level signal to the host machine, the slave machine is used for controlling the third optocoupler to be disconnected; when the host and the slave do not send signals, the host is used for controlling the first optocoupler to be connected and controlling the fifth optocoupler to be disconnected, and the slave is used for controlling the third optocoupler to be connected.
Further, the outdoor unit is connected with a mains supply and supplies power to the indoor unit; or the indoor unit is connected with a mains supply and supplies power to the outdoor unit.
The current loop communication circuit comprises a first current loop communication circuit and a second current loop communication circuit, and is also provided with a discharge loop which is connected between a zero line and a signal line in series, so that parasitic capacitance between the zero line and the signal line is eliminated when the first current loop communication circuit and the second current loop communication circuit communicate. Through the setting of above-mentioned circuit, eliminated parasitic capacitance to communication signal's influence, reduced the restriction of connecting wire length to the electric current loop communication, effectively solved among the prior art among the electric current loop communication circuit communication line and power cord and walked the line in parallel and have parasitic capacitance, lead to the short problem of communication line distance.
Drawings
FIG. 1 is a schematic diagram of an alternative configuration of a current loop communication circuit according to an embodiment of the present invention;
FIG. 2 is an alternative circuit diagram of a current loop communication circuit according to an embodiment of the present invention;
FIG. 3 is an alternative schematic diagram of an air conditioning unit power supply mode according to an embodiment of the invention; and
fig. 4 is another alternative schematic diagram of the power supply mode of the air conditioning unit according to the embodiment of the invention.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.
Example 1
In a preferred embodiment 1 of the present invention, a current loop communication circuit is provided, and specifically, fig. 1 shows an alternative structural schematic diagram of the current loop communication circuit, as shown in fig. 1, the current loop communication circuit includes:
the signal input end of the first current loop communication circuit is connected with the processor of the host;
the signal input end of the second current loop communication circuit is connected with the signal output end of the first current loop communication circuit through a signal wire, and the signal output end of the second current loop communication circuit is connected with the processor of the slave; the signal line is a communication line between the master machine and the slave machine;
the first current loop communication circuit and the second current loop communication circuit are also connected with a zero line of a host power supply;
and the discharge loop is connected between the zero line and the signal line in series, and parasitic capacitance between the zero line and the signal line is eliminated when the first current loop communication circuit and the second current loop communication circuit communicate.
The current loop communication circuit comprises a first current loop communication circuit and a second current loop communication circuit, and is also provided with a discharge loop which is connected between a zero line and a signal line in series, and when the first current loop communication circuit and the second current loop communication circuit are communicated, parasitic capacitance between the zero line and the signal line is eliminated. Through the setting of above-mentioned circuit, eliminated parasitic capacitance to communication signal's influence, reduced the restriction of connecting wire length to the electric current loop communication, effectively solved among the prior art among the electric current loop communication circuit communication line and power cord and walked the line in parallel and have parasitic capacitance, lead to the short problem of communication line distance.
Fig. 2 shows an alternative circuit diagram of the current loop communication circuit, as shown in fig. 2, in order to supply power to the respective loops, the current loop communication circuit further includes: and one end of the power circuit is connected with a live wire of the host power supply, and the other end of the power circuit is connected with the first current loop communication circuit and used for supplying power to the first current loop communication circuit. The power supply circuit includes: and the positive electrode of the energy storage capacitor C1 and the positive electrode of the energy storage capacitor C1 are connected with the live wire of the host power supply. One end of the first resistor R1 is connected with the positive electrode of the energy storage capacitor C1, and the other end of the first resistor R1 is connected with a live wire; a second resistor R2 connected in parallel with the energy storage capacitor; the first resistor R1 and the second resistor R2 divide the voltage. And the first diode D1 is positioned between the first resistor R1 and the second resistor R2, the anode of the first diode D1 is connected with the first resistor, and the cathode of the first diode D1 is connected with the anode of the energy storage capacitor C1.
Further, the power supply circuit further includes: the second diode D2 is connected in parallel with the energy storage capacitor, the anode of the second diode D2 is connected with the cathode of the energy storage capacitor, and the cathode of the second diode D2 is connected with the anode of the energy storage capacitor and used for protecting the energy storage capacitor and preventing reverse voltage; the third diode D3 is connected with the energy storage capacitor in parallel, the anode of the third diode D3 is connected with the cathode of the energy storage capacitor, and the cathode of the third diode D3 is connected with the anode of the energy storage capacitor; the third diode D3 is a clamping diode, the clamping voltage of the third diode D3 is affected by the divided voltage of the second resistor R2, and under normal conditions, the divided voltage of the second resistor R2 should be less than or equal to the clamping voltage of the third diode D3, otherwise, the clamping voltage action of the third diode D3 cannot be realized.
As shown in fig. 2, the first current loop communication circuit includes: a collector electrode of a triode of the first optocoupler PC10 is connected with an anode of an energy storage capacitor, and an anode and a cathode of a diode of the first optocoupler PC10 are connected with a processor of the host; the collector and the emitter of the triode of the second optocoupler PC11 and the second optocoupler PC11 are connected with a processor of the host, the anode of the diode of the second optocoupler PC11 is connected with the emitter of the triode of the first optocoupler PC10, and the cathode of the diode of the second optocoupler PC11 is connected with a signal line.
The first current loop communication circuit further comprises: a first end of the third resistor R3 is connected with an anode of a diode of the second optocoupler PC11, and a second end of the third resistor R3 is connected with a cathode of a diode of the second optocoupler PC 11; a first connecting point is arranged between the first end of the third resistor R3 and the anode of the diode of the second optocoupler PC11, and the first connecting point is also connected with the emitter of the triode of the first optocoupler PC 10; a second connection point is arranged between the second end of the third resistor R3 and the cathode of the diode of the second optocoupler PC11, and the second connection point is also connected with a signal wire; a fourth resistor R4, one end of which is connected to the first connection point and the other end of which is connected to the signal line; and a third connection point is arranged between the fourth resistor R4 and the signal line. The third resistor R3 is connected with a diode of the second optical coupler PC11 in parallel, and the third resistor R3 is shunted with the second optical coupler PC11 and used for forming a discharge loop with the second optical coupler PC11 after power failure, so that electric energy of the second optical coupler PC11 is released to protect the safety of a circuit; the current flowing from the first optical coupler PC10 is divided into two paths, one path is a third resistor R3 and a second optical coupler PC11, and the other path is a fourth resistor R4.
The first current loop communication circuit further comprises: the anode of the fourth diode D4 is connected with the second connection point, the cathode of the fourth diode D4 is connected with the first connection point, and the fourth diode D3556 is used for protecting the second optocoupler PC11 and preventing reverse breakdown; a fifth diode D5, a cathode of the fifth diode D5 being connected to the second connection point, and an anode of the fifth diode D5 being connected to the third connection point; the fifth diode is a D5 clamping diode, the voltage clamped by the fifth diode D5 exists, the voltage of the diode of the second optical coupler PC11 cannot be directly fluctuated by the voltage on the signal line, and unnecessary conduction of the second optical coupler PC11 is avoided. According to the clamp voltage division scheme, the characteristics that a clamp diode only limits voltage and does not limit current are fully utilized, and on the premise of meeting the circuit voltage division requirement, the current limiting resistance of the whole loop can be reduced, so that the loop current is increased by 1 time, the driving capability of a current loop is improved, and the anti-interference capability of current loop communication is improved.
The first current loop communication circuit further comprises: a fifth resistor R5, one end of which is connected to the third connection point and the other end of which is connected to the signal line; an anode of the sixth diode D6 is connected to the fifth resistor R5, and a cathode of the sixth diode D6 is connected to the signal line, of the sixth diode D6. In addition, the second current loop communication circuit further includes: a first end of a sixth resistor R6, a first end of a sixth resistor R6 is connected with a collector of a triode of the third optocoupler, and a second end of the sixth resistor R6 is connected with the signal wire; a fourth connection point is arranged between the first end of the sixth diode D6 and the collector of the triode of the third optocoupler; an anode of the seventh diode D7, the seventh diode D7 is connected to the signal line, and a cathode of the seventh diode D7 is connected to the second terminal of the sixth resistor R6. The resistor is used for voltage division, and the diode prevents reverse current.
As shown in fig. 2, the second current loop communication circuit includes: a collector electrode of a triode of the third optocoupler PC20 and a collector electrode of a triode of the third optocoupler PC20 are connected with a signal line, and an anode and a cathode of a diode of the third optocoupler PC20 are both connected with a processor of the slave; the collector and the emitter of a triode of the fourth optocoupler PC21 and the fourth optocoupler PC21 are connected with a processor of the slave, the anode of a diode of the fourth optocoupler PC21 is connected with the emitter of the triode of the third optocoupler PC20, and the cathode of the diode of the fourth optocoupler PC21 is connected with a zero line.
In addition, the second current loop communication circuit further includes: a first end of the seventh resistor R7 is connected with the fourth connection point, and a second end of the seventh resistor R7 is connected with an emitter of a triode of the third optocoupler; the first end of the eighth resistor R8 is connected with the second end of the seventh resistor R7, the second end of the eighth resistor R8 is connected with the cathode of a diode of the fourth optocoupler PC21, and the eighth resistor R8 and the second end of the eighth resistor R8 are used for forming a discharge loop with the fourth optocoupler PC21 after power failure, so that electric energy of the fourth optocoupler PC21 is released as soon as possible to protect the safety of a circuit; and an anode of the eighth diode D8, an anode of the eighth diode D8 is connected with a cathode of a diode of the fourth optocoupler PC21, and a cathode of the eighth diode D8 is connected with an anode of a diode of the fourth optocoupler PC21, so that the fourth optocoupler PC21 is protected and reverse breakdown is prevented.
In fig. 2, parasitic capacitances are also labeled; an emitter of a triode of the fifth optocoupler PC12, a triode of the fifth optocoupler PC12 is connected with a zero line, a collector of a triode of the fifth optocoupler PC12 is connected with a signal line, and an anode and a cathode of a diode of the fifth optocoupler PC12 are both connected with a processor of a host; and the ninth resistor R9 is positioned between the collector of the triode of the fifth optocoupler PC12 and the signal wire. The parasitic capacitor, the fifth optocoupler PC12 and the ninth resistor R9 form a discharge loop, and become a first discharge loop.
Furthermore, the discharge loop further comprises: the parasitic capacitance and a ninth diode D9, the anode of the ninth diode D9 is connected with the zero line, the cathode of the ninth diode D9 is connected with the signal line, and the loop is a second discharge loop.
When the host sends a low level signal to the slave, the host control PC10 turns off the PC12 to be connected, the slave control PC20 keeps the connected state unchanged, the main communication loop (a general name of the first current loop communication circuit and the second current loop communication circuit) is turned off, when the parasitic capacitor C4 is influenced by the fluctuation of the voltage of a power line and a live wire, and is in a charging state, the voltage of the S line is higher than that of the N line, the first discharging loop is activated due to the connection of the PC12, the C4 can discharge through the first discharging loop to ensure that the levels of the S line and the N line are basically consistent, and the slave receiving optical coupler PC21 cannot be connected, so that the low level signal transmission from the host to the slave can be realized; when the parasitic capacitor C4 is affected by voltage fluctuation of a power supply line and a live line and is in a discharging state, the voltage of an S line is lower than that of an N line, the second discharging loop is activated, the C4 can discharge through the second discharging loop, the S line and the N line are ensured to be basically consistent in level, the slave receiving optical coupler PC21 cannot be conducted, and low-level signal transmission from the master to the slave can be achieved.
When the master machine sends a high-level signal to the slave machine, the master machine control PC10 is switched on and switched off the PC12, the slave machine control PC20 keeps the on state unchanged, the master communication loop is activated, the first discharging loop and the second discharging loop are both in the off state, and the current flows through the receiving optocoupler PC21 of the slave machine, so that the high-level signal transmission from the master machine to the slave machine can be realized.
In addition, the energy storage capacitor, the first optocoupler PC10, the fourth resistor R4, the fifth resistor R5, the sixth diode D6 and the parasitic capacitor form a charging loop, and the charging loop is used for charging the parasitic capacitor after the parasitic capacitor is discharged.
When the slave machine sends a high level signal to the master machine, the master machine control PC10 is switched on and off the PC12, the slave machine control PC20 is switched on, the first communication loop is activated, the first discharging loop and the second discharging loop are both in a switching-off state, and current flows through the master machine receiving optocoupler PC11, so that the high level signal transmission from the slave machine to the master machine can be realized;
when the slave machine sends a low level signal to the host machine, the host machine control PC10 is connected with the PC12 and is disconnected, the slave machine control PC20 is disconnected, the main communication loop is disconnected, the S line voltage is equal to the power supply voltage of C1, when the parasitic capacitor C4 is affected by the fluctuation of the power supply line live wire voltage and is in a charging state, the S line voltage is raised, the host machine receiving optocoupler PC11 cannot be connected, and the low level transmission from the slave machine to the host machine can be realized; when the parasitic capacitor C4 is affected by the fluctuation of the power line and live line voltage and is in a discharging state, the energy storage capacitor C1 serves as a power supply to charge the parasitic capacitor C2 through the PC10, the R4, the R5 and the D6, no current passes through the slave receiving optocoupler PC21, and low-level signal transmission from the master to the slave can be achieved.
If the ninth diode D9 does not exist, the communication is not affected, but a negative value occurs at the low level of the communication, which is not beneficial to the analysis and processing of data in the test verification process. When the ninth diode D9 does not exist, when the master machine sends a low-level signal to the slave machine, the master machine control PC10 turns off the PC12 to be conducted, the slave machine control PC20 keeps a conducting state unchanged, the master communication loop is turned off, when the parasitic capacitor C4 is influenced by the fluctuation of the voltage of a power supply line and a live line and is in a charging state, the voltage of the S line is higher than that of the N line at the moment, the first discharging loop is activated due to the fact that the PC12 is conducted, the C4 can discharge through the first discharging loop to ensure that the levels of the S line and the N line are basically consistent, the slave machine receiving optical coupler PC21 cannot be conducted, and therefore the low-level signal transmission from the master machine to the slave machine can be achieved; when the parasitic capacitor C4 is affected by the fluctuation of the voltage of the power line and live wire and is in a discharging state, the voltage of the S line is lower than the voltage of the N line, the slave receiving optocoupler PC21 cannot be conducted, and therefore low-level signal transmission from the host to the slave can be achieved. The master high level, the slave high level and the slave low level are the same as the operation mode when the ninth diode D9 is present.
Wherein, the optical coupler can also be replaced by any photoelectric isolation device.
Because the circuit adopts a double-loop control scheme, a high level signal and a low level signal are two independent current loops, and when the high level is transmitted, the influence of the L line voltage fluctuation on the communication level can be almost ignored due to the large loop current; when low level is transmitted, the level of the communication line and the level of the N line are firmly fixed by adopting a discharge loop, so that the level of the communication line is not influenced by the fluctuation of the voltage of the L line any more, the influence of coupling capacitance of a long connecting line on the communication of a current loop is eliminated, and the communication distance is increased from 30m to 100 m.
Example 2
In a preferred embodiment 2 of the present invention, there is provided an air conditioning unit including the current loop communication circuit as in embodiment 1 above; the master machine is an outdoor machine, and the slave machine is an indoor machine.
The current loop communication circuit comprises a first current loop communication circuit and a second current loop communication circuit, and is also provided with a discharge loop which is connected between a zero line and a signal line in series, and when the first current loop communication circuit and the second current loop communication circuit are communicated, parasitic capacitance between the zero line and the signal line is eliminated. Through the setting of above-mentioned circuit, eliminated parasitic capacitance to communication signal's influence, reduced the restriction of connecting wire length to the electric current loop communication, effectively solved among the prior art among the electric current loop communication circuit communication line and power cord and walked the line in parallel and have parasitic capacitance, lead to the short problem of communication line distance.
As described in embodiment 1, when the master sends a signal to the slave, the slave is configured to control the third optocoupler to be turned on until the master sends all data; when the host machine sends a high-level signal to the slave machine, the host machine is used for controlling the first optocoupler to be switched on and controlling the fifth optocoupler to be switched off; when the host machine sends a low level signal to the slave machine, the host machine is used for controlling the first optocoupler to be switched off and controlling the fifth optocoupler to be switched on; when the slave machine sends a signal to the host machine, the host machine is used for controlling the first optocoupler to be switched on and controlling the fifth optocoupler to be switched off until the slave machine sends all data; when the slave machine sends a high-level signal to the host machine, the slave machine is used for controlling the conduction of the third optocoupler; when the slave machine sends a low level signal to the host machine, the slave machine is used for controlling the third optocoupler to be disconnected; when the host and the slave do not send signals, the host is used for controlling the first optocoupler to be connected and controlling the fifth optocoupler to be disconnected, and the slave is used for controlling the third optocoupler to be connected.
A mode that one side supplies power to the other side can be adopted between the indoor unit and the outdoor unit, as shown in fig. 3, the outdoor unit is connected with a mains supply and supplies power to the indoor unit; as shown in fig. 4, the indoor unit is connected to a commercial power supply and supplies power to the outdoor unit.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.
Claims (18)
1. A current loop communication circuit, comprising:
the signal input end of the first current loop communication circuit is connected with a processor of the host;
a signal input end of the second current loop communication circuit is connected with a signal output end of the first current loop communication circuit through a signal line, and a signal output end of the second current loop communication circuit is connected with a processor of a slave; wherein the signal line is a communication line between the master and the slave;
the first current loop communication circuit and the second current loop communication circuit are also connected with a zero line of a host power supply;
and the discharge loop is connected between the zero line and the signal line in series, and parasitic capacitance between the zero line and the signal line is eliminated when the first current loop communication circuit and the second current loop communication circuit communicate with each other.
2. A current loop communication circuit according to claim 1, further comprising:
and one end of the power circuit is connected with the live wire of the host power supply, and the other end of the power circuit is connected with the first current loop communication circuit and used for supplying power to the first current loop communication circuit.
3. A current loop communication circuit according to claim 2, wherein the power circuit comprises:
and the anode of the energy storage capacitor is connected with the live wire of the host power supply.
4. A current loop communication circuit according to claim 3, wherein the power circuit further comprises:
one end of the first resistor is connected with the anode of the energy storage capacitor, and the other end of the first resistor is connected with the live wire;
the second resistor is connected with the energy storage capacitor in parallel;
and the anode of the first diode is connected with the first resistor, and the cathode of the first diode is connected with the anode of the energy storage capacitor.
5. A current loop communication circuit according to claim 3, wherein the power circuit further comprises:
the anode of the second diode is connected with the cathode of the energy storage capacitor, and the cathode of the second diode is connected with the anode of the energy storage capacitor;
the anode of the third diode is connected with the cathode of the energy storage capacitor, and the cathode of the third diode is connected with the anode of the energy storage capacitor; wherein the third diode is a clamping diode.
6. A current loop communication circuit according to claim 3, wherein the first current loop communication circuit comprises:
a collector electrode of a triode of the first optocoupler is connected with the anode of the energy storage capacitor, and an anode and a cathode of a diode of the first optocoupler are both connected with a processor of the host;
and the collector and the emitter of the triode of the second optocoupler are connected with the processor of the host, the anode of the diode of the second optocoupler is connected with the emitter of the triode of the first optocoupler, and the cathode of the diode of the second optocoupler is connected with the signal wire.
7. A current loop communication circuit according to claim 6, wherein the first current loop communication circuit further comprises:
a first end of the third resistor is connected with an anode of a diode of the second optocoupler, and a second end of the third resistor is connected with a cathode of the diode of the second optocoupler; a first connecting point is arranged between the first end of the third resistor and the anode of the diode of the second optocoupler, and the first connecting point is also connected with the emitting electrode of the triode of the first optocoupler; a second connection point is arranged between the second end of the third resistor and the cathode of the diode of the second optocoupler, and the second connection point is also connected with the signal line;
one end of the fourth resistor is connected with the first connecting point, and the other end of the fourth resistor is connected with the signal wire; and a third connection point is arranged between the fourth resistor and the signal wire.
8. A current loop communication circuit according to claim 7, wherein the first current loop communication circuit further comprises:
a fourth diode, an anode of which is connected to the second connection point and a cathode of which is connected to the first connection point;
a fifth diode, a cathode of which is connected to the second connection point and an anode of which is connected to the third connection point; wherein the fifth diode is a clamping diode.
9. A current loop communication circuit according to claim 8, wherein the first current loop communication circuit further comprises:
one end of the fifth resistor is connected with the third connection point, and the other end of the fifth resistor is connected with the signal wire;
and the anode of the sixth diode is connected with the fifth resistor, and the cathode of the sixth diode is connected with the signal line.
10. A current loop communication circuit according to claim 1, wherein the second current loop communication circuit comprises:
a collector of a triode of the third optocoupler is connected with the signal wire, and an anode and a cathode of a diode of the third optocoupler are both connected with a processor of the slave;
and the collector and the emitter of the triode of the fourth optocoupler are both connected with the processor of the slave, the anode of the diode of the fourth optocoupler is connected with the emitter of the triode of the third optocoupler, and the cathode of the diode of the fourth optocoupler is connected with the zero line.
11. A current loop communication circuit according to claim 10, wherein the second current loop communication circuit further comprises:
a first end of the sixth resistor is connected with a collector of a triode of the third optocoupler, and a second end of the sixth resistor is connected with the signal wire; a fourth connection point is arranged between the first end of the sixth diode and the collector of the triode of the third optocoupler;
and the anode of the seventh diode is connected with the signal line, and the cathode of the seventh diode is connected with the second end of the sixth resistor.
12. A current loop communication circuit according to claim 10, wherein the second current loop communication circuit further comprises:
a first end of the seventh resistor is connected with the fourth connection point, and a second end of the seventh resistor is connected with an emitting electrode of a triode of the third optocoupler;
a first end of the eighth resistor is connected with a second end of the seventh resistor, and a second end of the eighth resistor is connected with a cathode of a diode of the fourth optocoupler;
and the anode of the eighth diode is connected with the cathode of the diode of the fourth optical coupler, and the cathode of the eighth diode is connected with the anode of the diode of the fourth optical coupler.
13. A current loop communication circuit according to claim 1, wherein the discharge loop comprises:
the parasitic capacitance;
the emitting electrode of the triode of the fifth optocoupler is connected with the zero line, the collector electrode of the triode of the fifth optocoupler is connected with the signal line, and the anode and the cathode of the diode of the fifth optocoupler are both connected with the processor of the host;
and the ninth resistor is positioned between the collector of the triode of the fifth optocoupler and the signal wire.
14. A current loop communication circuit according to claim 1, wherein the discharge loop further comprises:
the anode of the ninth diode is connected with the zero line, and the cathode of the ninth diode is connected with the signal line.
15. A current loop communication circuit according to claim 9, wherein the energy storage capacitor, the first optocoupler, the fourth resistor, the fifth resistor, the sixth diode and the parasitic capacitor form a charging loop for charging the parasitic capacitor after discharging.
16. An air conditioning assembly comprising a current loop communication circuit according to any of claims 1 to 15; the master machine is an outdoor machine, and the slave machines are indoor machines.
17. Air conditioning assembly according to claim 16,
when the host sends a signal to the slave, the slave is used for controlling the conduction of the third optocoupler until the host sends all data; when the host sends a high-level signal to the slave, the host is used for controlling the first optocoupler to be switched on and controlling the fifth optocoupler to be switched off; when the host sends a low-level signal to the slave, the host is used for controlling the first optocoupler to be switched off and controlling the fifth optocoupler to be switched on;
when the slave machine sends a signal to the host machine, the host machine is used for controlling the first optocoupler to be connected and controlling the fifth optocoupler to be disconnected until the slave machine sends all data; when the slave machine sends a high-level signal to the host machine, the slave machine is used for controlling the conduction of a third optocoupler; when the slave machine sends a low level signal to the host machine, the slave machine is used for controlling the third optocoupler to be disconnected;
when the host and the slave do not send signals, the host is used for controlling the first optocoupler to be switched on and controlling the fifth optocoupler to be switched off, and the slave is used for controlling the third optocoupler to be switched on.
18. Air conditioning assembly according to claim 16,
the outdoor unit is connected with a mains supply and supplies power to the indoor unit; or the indoor unit is connected with a mains supply and supplies power to the outdoor unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110976152.5A CN113741257A (en) | 2021-08-24 | 2021-08-24 | Current loop communication circuit and air conditioning unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110976152.5A CN113741257A (en) | 2021-08-24 | 2021-08-24 | Current loop communication circuit and air conditioning unit |
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| Publication Number | Publication Date |
|---|---|
| CN113741257A true CN113741257A (en) | 2021-12-03 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110976152.5A Pending CN113741257A (en) | 2021-08-24 | 2021-08-24 | Current loop communication circuit and air conditioning unit |
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| Country | Link |
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| CN (1) | CN113741257A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114285439A (en) * | 2021-12-22 | 2022-04-05 | 珠海格力电器股份有限公司 | Current loop communication circuit and air conditioner |
| CN114500125A (en) * | 2022-01-21 | 2022-05-13 | 珠海格力电器股份有限公司 | Power supply and communication assembly, system and communication equipment |
-
2021
- 2021-08-24 CN CN202110976152.5A patent/CN113741257A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114285439A (en) * | 2021-12-22 | 2022-04-05 | 珠海格力电器股份有限公司 | Current loop communication circuit and air conditioner |
| CN114500125A (en) * | 2022-01-21 | 2022-05-13 | 珠海格力电器股份有限公司 | Power supply and communication assembly, system and communication equipment |
| CN114500125B (en) * | 2022-01-21 | 2022-12-16 | 珠海格力电器股份有限公司 | Power supply and communication assembly, system and communication equipment |
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