CN214896272U

CN214896272U - Isolated form RS485 communication circuit and air conditioner of no opto-coupler

Info

Publication number: CN214896272U
Application number: CN202121275024.XU
Authority: CN
Inventors: 王学武; 易红艳; 刘亚洲; 程建军; 周鹏宇; 刘军; 周振威; 张磊; 陈志强
Original assignee: Ningbo Aux Electric Co Ltd; Zhuhai Tuoxin Technology Co Ltd
Current assignee: Ningbo Aux Electric Co Ltd
Priority date: 2021-06-08
Filing date: 2021-06-08
Publication date: 2021-11-26
Anticipated expiration: 2031-06-08

Abstract

The utility model discloses an isolated form RS485 communication circuit and air conditioner of no opto-coupler, include: sending module, enabling module and receiving module, sending module, enabling module and receiving module are connected with RS485 chip IC 1's different pins respectively, sending module, enabling module and receiving module all include NPN type triode, PNP type triode and resistance, the isolated form RS485 communication circuit of no opto-coupler makes through the regulation and control the level of NPN type triode and PNP type triode makes NPN type triode and PNP type triode switch on or end, and then regulates and control sending module, enabling module and receiving module's operating condition, this application isolated form RS485 communication circuit and the air conditioner of no opto-coupler adopt the power isolation scheme of no opto-coupler, can improve the reliability of circuit, reduce the fault rate of circuit.

Description

Isolated form RS485 communication circuit and air conditioner of no opto-coupler

Technical Field

The utility model relates to an air conditioner technical field particularly, the utility model relates to an isolated form RS485 communication circuit of no optical coupling who uses in the air conditioner.

Background

In recent years, with the rapid development of the internet of things, the communication technology is also continuously improved, wherein the 485 communication circuit is used as a main communication technology for communication between devices and is more and more widely applied. In order to ensure that the processor can operate reliably without being interfered by the outside, the power supply of the 485 chip needs to be separated from the power supply of the processor during circuit design.

At present in current 485 communication circuit, as shown in fig. 1, the mode that the power is divided is mainly isolated through the opto-coupler, but because the fault rate of opto-coupler is higher, the reliability is poorer when the scheme that will adopt the opto-coupler to isolate is used for 485 communication circuit.

Chinese patent publication (publication) No. CN212992040U discloses a monitoring device for an air conditioner communication line, which includes a signal input module, a signal output module, an optical coupling isolation circuit and a USB 485 conversion module: wherein, signal input module passes through the RS terminal and connects the air conditioner internal unit, connects the outer machine of air conditioner through the RS1 terminal, and signal output module is 485 processing chips, connects USB and changes 485 modules, and USB changes 485 module connection control computers, and opto-coupler isolating circuit sets up between signal input module and signal output module, and this utility model provides a positive and negative opto-coupler mode need not worry that the signal line connects reversely. However, this background document does not disclose how to improve the reliability of the circuit when the RS485 communication circuit is used.

In view of this, the present invention is especially provided.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an isolated form RS485 communication circuit of no opto-coupler, will again isolated form RS485 communication circuit of no opto-coupler be arranged in the air conditioner to overcome the accident and the phenomenon of 485 communication inefficacy that use among the prior art opto-coupler probably to bring in the air conditioner.

The utility model discloses an isolated form RS485 communication circuit of no opto-coupler, include: the transmitting module, the enabling module and the receiving module are respectively connected with different pins of an RS485 chip IC1, the transmitting module, the enabling module and the receiving module respectively comprise an NPN type triode, a PNP type triode and a resistor, and the isolation type RS485 communication circuit without the optocoupler enables the NPN type triode and the PNP type triode to be connected or disconnected by regulating and controlling the levels of the NPN type triode and the PNP type triode so as to regulate and control the working states of the transmitting module, the enabling module and the receiving module.

The transmitting module, the enabling module and the receiving module are all set to be of a structure comprising an NPN type triode, a PNP type triode and a plurality of resistors, so that the isolating type RS485 communication circuit without the optical coupler can enable the NPN type triode and the PNP type triode to be switched on or switched off by regulating and controlling the levels of the NPN type triode and the PNP type triode, and further regulates and controls the working states of the transmitting module, the enabling module and the receiving module, therefore, the transmitting module, the enabling module and the receiving module are prevented from isolating a power supply in the RS485 communication circuit by adopting the optical coupler, the fault rate of the circuit is reduced, and the reliability of the circuit is improved.

Further, the sending module is connected to an IO port of the processor.

The IO port is used as an input/output interface, and communication between the isolation type RS485 communication circuit without the optocoupler and an external device can be realized.

Further, the sending module includes an NPN transistor Q6, a PNP transistor Q5, and resistors R19, R20, R21, R22, and R23, a base of the NPN transistor Q6 is connected to a TXD pin of the CPU UART through a resistor R22, an emitter of the NPN transistor Q6 is grounded, the TXD pin is grounded through a resistor R23, a collector of the NPN transistor Q6 is connected to the base of the PNP transistor Q5 through a resistor R21, an emitter of the PNP transistor Q5 is connected to the first voltage, the base of the PNP transistor Q5 is pulled up to the first voltage through a resistor R20, a collector of the PNP transistor Q5 is connected to a fourth pin DI of the RS485 chip IC1, and a collector of the PNP transistor Q5 is connected to ground through a resistor R19.

The level of the NPN type triode Q6 and the level of the PNP type triode Q5 can be adjusted through the resistors R19, R20, R21, R22 and R23, so that the levels of the NPN type triode Q6 and the PNP type triode Q5 can be switched between a high level and a low level, and further, the working state of the transmitting module is switched.

Further, when the sending module is at a high level, the NPN transistor Q6 is in a saturated conduction state, and pulls down the base stage of the PNP transistor Q5 to ground, so that the PNP transistor Q5 is in a saturated conduction state, and at this time, the sending port DI of the RS485 chip IC1 is pulled up to a high level through the PNP transistor Q5; when the sending module is at a low level, the NPN transistor Q6 is turned off, so that the base stage of the PNP transistor Q5 is pulled up to a high level by the resistor R20, and at this time, the PNP transistor Q5 is turned off, and the sending port DI of the RS485 chip IC1 is pulled down to a low level by the R19.

By adjusting the level amplitude of the sending module, the switching of the on or off states of the NPN type triode Q6 and the PNP type triode Q5 is realized, and further, the adjustment of the level amplitude of the sending port DI of the RS485 chip IC1 is realized.

Further, the receiving module comprises an NPN type triode Q2, a PNP type triode Q1, a filter capacitor C1 and resistors R2, R3, R4, R5 and R6, the emitting stage of the NPN type triode Q2 is connected with a resistor R6 and a resistor R5, the resistor R6 is connected with a first pin RO of the RS485 chip IC1, the other end of the resistor R5 is connected with the second voltage, the base stage of the NPN type triode Q2 is connected with the second voltage through a resistor R4, the collector of the NPN transistor Q2 is connected to the base of the PNP transistor Q1 through a resistor R3, the base of the PNP transistor Q1 is pulled up to a third voltage through a resistor R2, the emitter of the PNP transistor Q1 is connected to the third voltage, the collector of the PNP transistor Q1 is connected to the RXD pin of the CPU UART through a resistor R1, the RXD pin is simultaneously connected with a filter capacitor C1 and a resistor R124, and the other ends of the filter capacitor C1 and the resistor R124 are grounded.

The filter capacitor C1 and the resistors R2, R3, R4, R5 and R6 can adjust the levels of the NPN transistor Q2 and the PNP transistor Q1, so that the levels of the NPN transistor Q2 and the PNP transistor Q1 can be switched between a high level and a low level, and the operating state of the receiving module is further switched.

Further, when the RO port of the RS485 chip IC1 is at a low level, the NPN transistor Q2 is turned on, so that the PNP transistor Q1 is in saturated conduction, and at this time, the input of the receiving module of the processor IO port is at a high level; when the RO port of the RS485 chip IC1 is at a high level, the NPN transistor Q2 is turned off, so that the base stage of the PNP transistor Q1 is pulled up to a high level by the resistor R2, at this time, the PNP transistor Q1 is turned off, and the input of the receiving module of the processor IO port is at a low level.

By adjusting the level amplitude of the RO port of the RS485 chip IC1, the switching of the on-off states of the NPN type triode Q2 and the PNP type triode Q1 is realized, and further, the level amplitude of the receiving module of the IO port of the processor is adjusted.

Further, the enabling module is connected with an IO port of the processor.

Further, the enabling module includes an NPN transistor Q4, a PNP transistor Q3, and resistors R10, R12, R14, R17, and R18, a base of the NPN transistor Q4 is connected to a DE/RE pin of the CPU UART through a resistor R17, an emitter of the NPN transistor Q4 is grounded, the DE/RE pin is grounded through a resistor R18, a collector of the NPN transistor Q4 is connected to a base of the PNP transistor Q3 through a resistor R12, a base of the PNP transistor Q3 is pulled up to a fourth voltage through a resistor R10, an emitter of the PNP transistor Q3 is connected to the fourth voltage, a collector of the PNP transistor Q3 is connected to the third pin DE and the second pin RE of the RS485 chip IC1, and a collector of the PNP transistor Q3 is connected to ground through a resistor R14.

The level of the NPN type triode Q4 and the level of the PNP type triode Q3 can be adjusted through the resistors R10, R12, R14, R17 and R18, so that the level of the NPN type triode Q4 and the level of the PNP type triode Q3 can be switched between a high level and a low level, and further the working state of the enabling module is switched.

Further, when the enable module is at a high level, the NPN transistor Q4 is in saturation conduction, and pulls down the base stage of the PNP transistor Q3 to ground, so that the PNP transistor Q3 is in saturation conduction, and at this time, the enable port of the RS485 chip IC1 is connected to the ground

And DE is pulled up to high level through the PNP type triode Q3; when the enable module is low, the NPN transistor Q4 is turned off, so that the base of the PNP transistor Q3 is pulled up to high by the resistor R10,at this time, the PNP type triode Q3 is cut off, and the enabling port of the RS485 chip IC1

And DE is pulled down to a low level.

By adjusting the level amplitude of the enabling module, the conversion of the on or off states of the NPN type triode Q4 and the PNP type triode Q3 is realized, and then the enabling port of the RS485 chip IC1 is realized

And adjustment of the level amplitude of DE, i.e., adjustment of the operating state.

An air conditioner comprises the isolation type RS485 communication circuit without the optocoupler.

This application isolated form RS485 communication circuit and air conditioner of no opto-coupler is through inciting somebody to action sending module, enabling module and receiving module all set up to the structure including NPN type triode, PNP type triode and a plurality of resistance, make isolated form RS485 communication circuit of no opto-coupler can be through regulation and control the level of NPN type triode and PNP type triode makes NPN type triode and PNP type triode switch on or end, and then regulate and control sending module, enabling module and receiving module's operating condition has avoided from this sending module, enabling module and receiving module adopt the opto-coupler to keep apart the power among the RS485 communication circuit, have reduced the fault rate of circuit, have improved the reliability of circuit.

Drawings

FIG. 1 is a prior art isolation type RS485 communication circuit;

fig. 2 is the utility model discloses an isolated form RS485 communication circuit of no opto-coupler.

Description of reference numerals:

1. a sending module; 2. an enabling module; 3. and a receiving module.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.

The utility model provides an isolated form RS485 communication circuit of no opto-coupler, include: the optical coupler-free isolation type RS485 communication circuit comprises a sending module 1, an enabling module 2 and a receiving module 3, wherein the sending module 1, the enabling module 2 and the receiving module 3 are respectively connected with different pins of an RS485 chip IC1, the sending module 1, the enabling module 2 and the receiving module 3 respectively comprise an NPN type triode, a PNP type triode and a plurality of resistors, and the NPN type triode and the PNP type triode are switched on or switched off by regulating and controlling the level of the NPN type triode and the PNP type triode so as to regulate and control the working states of the sending module 1, the enabling module 2 and the receiving module 3.

Further, the sending module 1 is connected to an IO port of the processor, and a level amplitude of the sending module 1 is equal to a level amplitude of the processor.

Further, the transmitting module 1 includes an NPN transistor Q6, a PNP transistor Q5, and resistors R19, R20, R21, R22, and R23. The base stage of the NPN transistor Q6 is connected to a TXD pin of the CPU UART through a resistor R22, the emitter stage of the NPN transistor Q6 is grounded, the TXD pin is grounded through a resistor R23, the collector of the NPN transistor Q6 is connected to the base stage of the PNP transistor Q5 through a resistor R21, while the emitter of the PNP transistor Q5 is connected to a first voltage, the base stage of the PNP transistor Q5 is pulled up to the first voltage through a resistor R20, the collector stage of the PNP transistor Q5 is connected to the fourth pin DI of the RS485 chip IC1, and while the collector stage of the PNP transistor Q5 is connected to ground through a resistor R19. Wherein the first voltage may be 485_ 5V.

Further, when the sending module 1 is at a high level, the NPN transistor Q6 is in a saturated conduction state, and pulls down the base stage of the PNP transistor Q5 to ground, so that the PNP transistor Q5 is in a saturated conduction state, and at this time, the sending port DI of the RS485 chip IC1 is pulled up to a high level through the PNP transistor Q5; when the sending module 1 is at a low level, the NPN transistor Q6 is turned off, so that the base stage of the PNP transistor Q5 is pulled up to a high level by R20, and at this time, the PNP transistor Q5 is turned off, and the sending port DI of the RS485 chip IC1 is pulled down to a low level by R19.

Further, the receiving module 3 is connected to a UART port of the processor.

Further, the receiving module 3 includes an NPN transistor Q2, a PNP transistor Q1, a filter capacitor C1, and resistors R2, R3, R4, R5, and R6. An emitter of the NPN-type triode Q2 is connected with a resistor R6 and a resistor R5, the resistor R6 is connected with a first pin RO of the RS485 chip IC1, the other end of the resistor R5 is connected with a second voltage, a base of the NPN-type triode Q2 is connected with the second voltage through a resistor R4, a collector of the NPN-type triode Q2 is connected to a base of the PNP-type triode Q1 through a resistor R3, the base of the PNP-type triode Q1 is pulled up to a third voltage through a resistor R2, the emitter of the PNP-type triode Q1 is connected to the third voltage, a collector of the PNP-type triode Q1 is connected to an RXD pin of the CPU through a resistor R1, the RXD pin is simultaneously connected with a filter capacitor C1 and a resistor R124, and the other ends of the filter capacitor C1 and the resistor R124 are grounded. The second pressure may be 485_ 5V; the third voltage may be 485_ 3.3V.

Further, when the RO port of the RS485 chip IC1 is at a low level, the NPN transistor Q2 is turned on, so that the PNP transistor Q1 is in saturated conduction, and at this time, the input of the receiving module 3 at the IO port of the processor is at a high level; when the RO port of the RS485 chip IC1 is at a high level, the NPN transistor Q2 is turned off, so that the base stage of the PNP transistor Q1 is pulled up to a high level by the resistor R2, at this time, the PNP transistor Q1 is turned off, and the input of the receiving module 3 of the processor IO port is at a low level.

Further, the enabling module 2 is connected to an IO port of the processor, and a level amplitude of the enabling module 2 is equal to a level of the processor.

Further, the enabling module 2 includes an NPN transistor Q4, a PNP transistor Q3, and resistors R10, R12, R14, R17, and R18. The base stage of the NPN type triode Q4 is connected to a DE/RE pin of a CPU UART through a resistor R17, the emitter stage of the NPN type triode Q4 is grounded, the DE/RE pin is grounded through a resistor R18, the collector of the NPN type triode Q4 is connected to the base stage of the PNP type triode Q3 through a resistor R12, meanwhile, the base of the PNP type triode Q3 is pulled up to a fourth voltage through a resistor R10, the emitter stage of the PNP type triode Q3 is connected to the fourth voltage, the collector stage of the PNP type triode Q3 is connected to the third pin DE and the second pin RE of the RS485 chip IC1, and the collector stage of the PNP type triode Q3 is connected to ground through a resistor R14. Wherein the fourth voltage may be 485_ 5V.

Further, when the enable module 2 is at a high level, the NPN transistor Q4 is in saturation conduction, and pulls down the base stage of the PNP transistor Q3 to ground, so that the PNP transistor Q3 is in saturation conduction, and at this time, the enable port of the RS485 chip IC1 is connected to the ground

And DE is pulled up to high level through the PNP type triode Q3; when the enable module 2 is at a low level, the NPN transistor Q4 is turned off, so that the base of the PNP transistor Q3 is pulled up to a high level by the resistor R10, and at this time, the PNP transistor Q3 is turned off, and the enable port of the RS485 chip IC1 is turned off

And DE is pulled down to a low level.

Furthermore, the RS485 chip IC1 has 8 pins, which are a first pin RO and a second pin respectively

A third pin DE, a fourth pin DI, a fifth pin GND, a sixth pin A, a seventh pin B and an eighth pin Vcc, wherein the second pin

And a third pin DE is an enable port of a receiver and a driver of the RS485 chip IC1, specifically, the first pin RO is a receiver output, and the second pin DE is a receiver output

For the receiver output toCan be used as the second pin

When the power is connected to a low level, the RO output of the first pin is effective; when the second pin is

When the first pin RO is connected with a high level, the third pin DE is a driver output enable, when the third pin DE is connected with the high level, the driver output is effective, when the third pin DE is connected with a low level, the driver output is in a high resistance state, the fourth pin DI is a driver input, when the fourth pin DI is in a high level, the low level on the fourth pin DI is forced to be a low level, and the inverted output is a high level; similarly, the high level on the fourth pin DI will force the output to be high level, and the inverted output to be low level; the fifth pin GND is a ground; the sixth pin a is a receiver non-inverting input and a driver non-inverting output, the seventh pin B is a receiver inverting input and a driver inverting output, and the eighth pin Vcc is a positive power supply.

In addition, the application also provides an air conditioner, the air conditioner comprises the isolation type RS485 communication circuit without the optical coupler.

In summary, it is easy to find that: this application isolated form RS485 communication circuit and air conditioner of no opto-coupler is through inciting somebody to action sending module 1, enabling module 2 and receiving module 3 all set up to the structure including NPN type triode, PNP type triode and a plurality of resistance, make isolated form RS485 communication circuit of no opto-coupler can be through regulation and control the level of NPN type triode and PNP type triode makes NPN type triode and PNP type triode switch on or end, and then regulation and control sending module 1, enabling module 2 and receiving module 3's operating condition has been avoided from this sending module 1, enabling module 2 and receiving module 3 adopt the opto-coupler to keep apart the power among the RS485 communication circuit, have reduced the fault rate of circuit, have improved the reliability of circuit.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present invention, and the scope of the present invention is defined by the appended claims.

Claims

1. An isolated RS485 communication circuit without optical couplers comprises: the optical coupling-free isolation type RS485 communication circuit is characterized in that the NPN type triode and the PNP type triode are conducted or cut off by regulating and controlling the levels of the NPN type triode and the PNP type triode, and further the working states of the transmitting module (1), the enabling module (2) and the receiving module (3) are regulated and controlled.

2. The optocoupler-free isolated RS485 communication circuit according to claim 1, wherein the sending module (1) is connected to an IO port of a processor.

3. The optocoupler-free isolated RS485 communication circuit according to claim 1, wherein the transmitting module (1) comprises an NPN transistor Q6, a PNP transistor Q5 and resistors R19, R20, R21, R22 and R23, the base of the NPN transistor Q6 is connected to the TXD pin of the CPU UART through a resistor R22, the emitter of the NPN transistor Q6 is grounded, the TXD pin is grounded through a resistor R23, the collector of the NPN transistor Q6 is connected to the base of the PNP transistor Q5 through a resistor R21, while the emitter of the PNP transistor Q5 is connected to the first voltage, the base of the PNP transistor Q5 is pulled up to the first voltage through a resistor R20, the collector of the PNP Q5 is connected to the fourth pin DI of the RS485 chip IC1, and the collector of the PNP transistor Q5 is connected to ground through a resistor R19.

4. The optocoupler-free isolated RS485 communication circuit according to claim 3, wherein when the transmitting module (1) is at a high level, the NPN transistor Q6 is in saturation conduction, and pulls down the base stage of the PNP transistor Q5 to ground, so that the PNP transistor Q5 is in saturation conduction, and the transmitting port DI of the RS485 chip IC1 is pulled up to a high level through the PNP transistor Q5; when the sending module (1) is at a low level, the NPN type transistor Q6 is turned off, so that the base stage of the PNP type transistor Q5 is pulled up to a high level by the resistor R20, and at this time, the PNP type transistor Q5 is turned off, and the sending port DI of the RS485 chip IC1 is pulled down to a low level by the R19.

5. The optocoupler-less isolated RS485 communication circuit according to claim 1, wherein the receiving module (3) comprises an NPN transistor Q2, a PNP transistor Q1, a filter capacitor C1, and resistors R2, R3, R4, R5, and R6, the emitter of the NPN transistor Q2 is connected to a resistor R6 and a resistor R5, the resistor R6 is connected to the first pin RO of the RS485 chip IC1, the other end of the resistor R5 is connected to the second voltage, the base of the NPN transistor Q2 is connected to the second voltage through a resistor R4, the collector of the PNP transistor Q2 is connected to the base of the PNP transistor Q1 through a resistor R3, the base of the PNP transistor Q1 is pulled up to the third voltage through a resistor R2, the emitter of the PNP transistor Q1 is connected to the third voltage, and the collector of the PNP transistor Q1 is connected to the CPU RXD 1 through a resistor R1, the RXD pin is simultaneously connected with a filter capacitor C1 and a resistor R124, and the other ends of the filter capacitor C1 and the resistor R124 are grounded.

6. The optocoupler-free isolated RS485 communication circuit according to claim 5, wherein when the RO port of the RS485 chip IC1 is at low level, the NPN transistor Q2 is turned on, so that the PNP transistor Q1 is in saturated conduction, and at this time, the input of the receiving module (3) of the IO port of the processor is at high level; when the RO port of the RS485 chip IC1 is at a high level, the NPN type triode Q2 is cut off, so that the base level of the PNP type triode Q1 is pulled up to a high level by the resistor R2, at the moment, the PNP type triode Q1 is cut off, and the input of the receiving module (3) of the IO port of the processor is at a low level.

7. The optocoupler-free isolated RS485 communication circuit according to claim 1, wherein the enabling module (2) is connected to an IO port of a processor.

8. The optocoupler-free isolated RS485 communication circuit of claim 1, the enabling module (2) comprises an NPN type triode Q4, a PNP type triode Q3 and resistors R10, R12, R14, R17 and R18, the base stage of the NPN transistor Q4 is connected to the DE/RE pin of the CPU UART through a resistor R17, the emitter of the NPN transistor Q4 is grounded, the DE/RE pin is grounded through a resistor R18, the collector of the NPN transistor Q4 is connected to the base of the PNP transistor Q3 through a resistor R12, meanwhile, the base of the PNP transistor Q3 is pulled up to a fourth voltage through the resistor R10, the emitter of the PNP type triode Q3 is connected with a fourth voltage, the collector of the PNP type triode Q3 is connected to the third pin DE and the second pin RE of the RS485 chip IC1, and the collector of the PNP type triode Q3 is connected to the ground through a resistor R14.

9. The optocoupler-free isolated RS485 communication circuit of claim 8, wherein when the enable module (2) is high, the NPN transistor Q4 is in saturation conduction and pulls down the base of the PNP transistor Q3 to ground, so that the PNP transistor Q3 is in saturation conduction, and at this time, the enable port of the RS485 chip IC1 is enabled

And DE is pulled up to high level through the PNP type triode Q3; when the enabling module (2) is in a low level, the NPN type triode Q4 is cut off, so that the base level of the PNP type triode Q3 is pulled up to a high level by the resistor R10, at the moment, the PNP type triode Q3 is cut off, and the enabling port of the RS485 chip IC1 is cut off

And DE is pulled down to a low level.

10. An air conditioner, characterized in that, the air conditioner includes the isolation type RS485 communication circuit without optical coupling of any of the above claims 1-9.