High-temperature-resistant level conversion circuit for high-temperature environment

Abstract

According to the high-temperature-resistant level switching circuit for the high-temperature environment, one end of a resistor R6 is connected with a TTL serial port signal sending pin, the other end of the resistor R6 is connected with a base electrode of a triode Q3, and a collector electrode of the triode Q3 is connected to a resistor R2 and a resistor R4; the emitter of the triode Q3 is grounded; the resistor R4 is connected with a base electrode of the triode Q1, a collector electrode of the triode Q1 is respectively connected to the resistor R1, the diode D1, the diode D2 and a first RS485 / RS422 sending pin, and an emitting electrode of the triode Q1 is grounded; one end of the resistor R11 is connected with a TTL serial port signal sending pin, the other end of the resistor R11 is connected with a base electrode of the triode Q5, and a collector electrode of the triode Q5 is respectively connected to the resistor R10, the diode D7, the diode D8 and a second RS485 / RS422 sending pin; the emitter of the triode Q5 is grounded. According to the utility model, a communication circuit is effectively prevented from being damaged by extremely high temperature in a high-temperature environment, and circuit reliability is ensured.

Description

Technical Field

[0001] The utility model relates to a high-temperature resistant level conversion circuit for high-temperature environment, belonging to the technical field of communication circuits. Background Art

[0002] When carbon dioxide first contacts with formation crude oil, it cannot form a miscible phase. However, under the conditions of appropriate pressure, temperature and crude oil components, carbon dioxide can form a miscible front. The supercritical fluid will extract heavier hydrocarbons from the crude oil and continuously concentrate the gas at the displacement front. Thus, carbon dioxide and crude oil become a miscible liquid, forming a single liquid phase, so that the formation crude oil can be effectively displaced to the production well.

[0003] At present, in deep wells for water injection and gas injection enhanced oil recovery, due to the high ambient temperature, when using RS485 / RS422 communication, ordinary chips can no longer meet the requirements. The maximum temperature of the existing RS485 / RS422 chips is 125°C. Extremely high temperatures are likely to damage the communication circuit and cannot meet the use requirements in the high-temperature environment of 150 - 200°C underground. How to prevent the extremely high temperature from damaging the communication circuit in the high-temperature environment has practical application significance. Summary of the Utility Model

[0004] Therefore, the utility model provides a high-temperature resistant level conversion circuit for high-temperature environment to solve the problem that extremely high temperatures are likely to damage the communication circuit in the high-temperature environment.

[0005] To achieve the above object, the utility model provides the following technical solution: A high-temperature resistant level conversion circuit for high-temperature environment, including a circuit for converting TTL at the sending end to RS485 / RS422 and a circuit for converting RS485 / RS422 at the receiving end to TTL;

[0006] The circuit for converting TTL at the sending end to RS485 / RS422 includes resistor R6, triode Q3, resistor R2, resistor R4, triode Q1, resistor R1, diode D1 and diode D2;

[0007] One end of resistor R6 is connected to the TTL serial port signal sending pin, and the other end of resistor R6 is connected to the base of triode Q3. The collector of triode Q3 is respectively connected to resistor R2 and resistor R4; the emitter of triode Q3 is grounded; resistor R4 is connected to the base of triode Q1. The collector of triode Q1 is respectively connected to resistor R1, diode D1, diode D2 and the first RS485 / RS422 sending pin, and the emitter of triode Q1 is grounded;

[0008] The circuit for converting RS485 / RS422 at the receiving end to TTL includes resistor R11, triode Q5, resistor R10, diode D7 and diode D8;

[0009] One end of the resistor R11 is connected to the TTL serial port signal transmitting pin, and the other end of the resistor R11 is connected to the base of the triode Q5. The collector of the triode Q5 is respectively connected to the resistor R10, the diode D7, the diode D8, and the second RS485 / RS422 transmitting pin; the emitter of the triode Q5 is grounded.

[0010] As an optimized solution for the high-temperature-resistant level conversion circuit for high-temperature environments, the circuit for converting the receiving end RS485 / RS422 to TTL further includes a triode Q4, a resistor R3, a resistor R5, a triode Q2, a resistor R7, and a resistor R9;

[0011] The collector of the triode Q4 is respectively connected to the resistor R3 and the resistor R5; the resistor R5 is connected to the base of the triode Q2; the emitter of the triode Q2 is respectively connected to the resistor R7 and the resistor R9. The resistor R7 is connected to the TTL serial port signal receiving pin, and the resistor R9 is grounded.

[0012] As an optimized solution for the high-temperature-resistant level conversion circuit for high-temperature environments, a resistor R8 is connected between the first RS485 / RS422 receiving pin and the base of the triode Q4;

[0013] It further includes diodes D3 and D4; the positive electrode of the diode D3 is connected between the first RS485 / RS422 receiving pin and the resistor R8, and the negative electrode of the diode D4 is connected between the first RS485 / RS422 receiving pin and the resistor R8; the positive electrode of the diode D4 is grounded.

[0014] As an optimized solution for the high-temperature-resistant level conversion circuit for high-temperature environments, it further includes diodes D5 and D6;

[0015] The positive electrode of the diode D5 is connected between the second RS485 / RS422 receiving pin and the emitter of the triode Q4, and the negative electrode of the diode D6 is connected between the second RS485 / RS422 receiving pin and the emitter of the triode Q4; the positive electrode of the diode D6 is grounded.

[0016] As an optimized solution for the high-temperature-resistant level conversion circuit for high-temperature environments, the resistance values of the resistors R2, R3, R4, R5, R6, R8, R9, and R11 are all 10 KΩ.

[0017] As an optimized solution for the high-temperature-resistant level conversion circuit for high-temperature environments, the resistance values of the resistors R1, R7, and R10 are all 1 KΩ.

[0018] As an optimized solution for the high-temperature-resistant level conversion circuit for high-temperature environments, the transistors Q1, Q3, Q4, and Q5 are all NPN transistors.

[0019] As an optimal solution for the high-temperature-resistant level conversion circuit used in high-temperature environments, the triode Q2 is a PNP triode.

[0020] The utility model has the following advantages: It includes a circuit for converting TTL at the sending end to RS485 / RS422 and a circuit for converting RS485 / RS422 at the receiving end to TTL. The circuit for converting TTL at the sending end to RS485 / RS422 includes resistor R6, triode Q3, resistor R2, resistor R4, triode Q1, resistor R1, diode D1, and diode D2. One end of resistor R6 is connected to the TTL serial port signal sending pin, and the other end of resistor R6 is connected to the base of triode Q3. The collector of triode Q3 is respectively connected to resistor R2 and resistor R4. The emitter of triode Q3 is grounded. Resistor R4 is connected to the base of triode Q1. The collector of triode Q1 is respectively connected to resistor R1, diode D1, diode D2, and the first RS485 / RS422 sending pin. The emitter of triode Q1 is grounded. The circuit for converting RS485 / RS422 at the receiving end to TTL includes resistor R11, triode Q5, resistor R10, diode D7, and diode D8. One end of resistor R11 is connected to the TTL serial port signal sending pin, and the other end of resistor R11 is connected to the base of triode Q5. The collector of triode Q5 is respectively connected to resistor R10, diode D7, diode D8, and the second RS485 / RS422 sending pin. The emitter of triode Q5 is grounded. The utility model can also achieve RS485 / RS422 communication in an environment with a high temperature of 150°C - 200°C, and can effectively prevent the extremely high temperature in the high-temperature environment from damaging the communication circuit, ensuring the functional reliability of the communication circuit. Description of the Drawings

[0021] In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only exemplary. For those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained based on the provided drawings.

[0022] The structures, ratios, sizes, etc. depicted in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions under which the present utility model can be implemented. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model.

[0023] Figure 1Schematic diagram of the circuit for converting TTL at the transmitting end to RS485 / RS422 provided in the embodiment of the present utility model;

[0024] Figure 2 Schematic diagram of the circuit for converting RS485 / RS422 at the receiving end to TTL provided in the embodiment of the present utility model. Detailed implementation manners

[0025] The following specific embodiments illustrate the implementation manners of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0026] Refer to Figure 1 and Figure 2 An embodiment of the present utility model provides a high-temperature-resistant level conversion circuit for high-temperature environments, including a circuit for converting TTL at the transmitting end to RS485 / RS422 and a circuit for converting RS485 / RS422 at the receiving end to TTL;

[0027] Among them, the circuit for converting TTL at the transmitting end to RS485 / RS422 includes resistor R6, triode Q3, resistor R2, resistor R4, triode Q1, resistor R1, diode D1 and diode D2;

[0028] Among them, one end of resistor R6 is connected to the TTL serial port signal transmitting pin, the other end of resistor R6 is connected to the base of triode Q3, the collector of triode Q3 is respectively connected to resistor R2 and resistor R4; the emitter of triode Q3 is grounded; resistor R4 is connected to the base of triode Q1, the collector of triode Q1 is respectively connected to resistor R1, diode D1, diode D2 and the first RS485 / RS422 transmitting pin, and the emitter of triode Q1 is grounded;

[0029] Among them, the circuit for converting RS485 / RS422 at the receiving end to TTL includes resistor R11, triode Q5, resistor R10, diode D7 and diode D8;

[0030] Among them, one end of resistor R11 is connected to the TTL serial port signal transmitting pin, the other end of resistor R11 is connected to the base of triode Q5, the collector of triode Q5 is respectively connected to resistor R10, diode D7, diode D8 and the second RS485 / RS422 transmitting pin; the emitter of triode Q5 is grounded.

[0031] In this embodiment, the circuit for converting the receiving end from RS485 / RS422 to TTL further includes a triode Q4, a resistor R3, a resistor R5, a triode Q2, a resistor R7, and a resistor R9. The collector of the triode Q4 is respectively connected to the resistor R3 and the resistor R5. The resistor R5 is connected to the base of the triode Q2. The emitter of the triode Q2 is respectively connected to the resistor R7 and the resistor R9. The resistor R7 is connected to the TTL serial port signal receiving pin, and the resistor R9 is grounded. The resistor R3 is also connected to the 5V voltage pin, and the collector of the triode Q2 is connected to the 5V voltage pin.

[0032] Among them, a resistor R8 is connected between the first RS485 / RS422 receiving pin and the base of the triode Q4. In addition, a diode D3 and a diode D4 are also included. The positive electrode of the diode D3 is connected between the first RS485 / RS422 receiving pin and the resistor R8, and the negative electrode of the diode D3 is connected to the 5V voltage pin. The negative electrode of the diode D4 is connected between the first RS485 / RS422 receiving pin and the resistor R8; the positive electrode of the diode D4 is grounded. In addition, a diode D5 and a diode D6 are also included. The positive electrode of the diode D5 is connected between the second RS485 / RS422 receiving pin and the emitter of the triode Q4, and the negative electrode of the diode D5 is connected to the 5V voltage pin; the negative electrode of the diode D6 is connected between the second RS485 / RS422 receiving pin and the emitter of the triode Q4; the positive electrode of the diode D6 is grounded.

[0033] The principle of this embodiment is as follows:

[0034] When the TTL serial port signal transmitting pin TTL_Tx transmits a logic 1, the signal is converted to a logic 1 at the first RS485 / RS422 transmitting pin through the triode Q3 and the triode Q1, and the signal is converted to a logic 0 at the second RS485 / RS422 transmitting pin through the triode Q5.

[0035] When the TTL serial port signal transmitting pin TTL_Tx transmits a logic 0, the signal is converted to a logic 0 at the first RS485 / RS422 transmitting pin through the triode Q3 and the triode Q1, and the signal is converted to a logic 1 at the second RS485 / RS422 transmitting pin through the triode Q5.

[0036] When the first RS485 / RS422 receiving pin is at logic 1 and the second RS485 / RS422 receiving pin is at logic 0, the signal is output to the TTL serial port signal receiving pin TTL_Rx as logic 1 through the triode Q4 and the triode Q2.

[0037] When the first RS485 / RS422 receiving pin is at logic 0 and the second RS485 / RS422 receiving pin is at logic 1, the signal passes through transistors Q4 and Q2 and is output to the TTL serial port signal receiving pin TTL_Rx as logic 0.

[0038] Among them, diodes D1, D2, D3, D4, D5, D6, D7, and D8 all play a protective role to prevent the signal voltage from being higher than 5V or lower than 0V. When used in an environment with a high temperature of 200 degrees Celsius, the requirement for the RS485 / RS422 received signal differential level to be greater than or equal to 0.2V can be appropriately relaxed. For the circuit of this application, the RS485 / RS422 signal differential level is required to be greater than 0.7V.

[0039] In a possible embodiment, resistors R2, R3, R4, R5, R6, R8, R9, and R11 are 10K resistors, and the model reference is PATT0603E1002BGT1. Resistors R1, R7, and R10 are 1K resistors, and the model reference is PATT0603E1002BGT1. The models of diodes D1, D2, D3, D4, D5, D6, D7, and D8 are reference BAV103. Transistors Q1, Q3, Q4, and Q5 are NPN transistors, and the model reference is ZTX455. Transistor 2 is a PNP transistor, and the model reference is ZTX553.

[0040] In summary, the utility model is provided with a TTL level to RS485 / RS422 sending circuit and an RS485 / RS422 receiving to TTL level receiving circuit. The TTL level to RS485 / RS422 sending circuit includes a TTL serial port signal sending pin, a first RS485 / RS422 sending pin, and a second RS485 / RS422 sending pin; the RS485 / RS422 receiving to TTL level receiving circuit includes a first RS485 / RS422 receiving pin, a second RS485 / RS422 receiving pin, and a TTL serial port signal receiving pin; a first processing circuit is connected between the TTL serial port signal sending pin and the first RS485 / RS422 sending pin, and the first processing circuit is used to convert the communication logic between the TTL serial port signal sending pin and the first RS485 / RS422 sending pin; a second processing circuit is connected between the TTL serial port signal sending pin and the second RS485 / RS422 sending pin, and the second processing circuit is used to convert the communication logic between the TTL serial port signal sending pin and the second RS485 / RS422 sending pin; the first RS485 / RS422 sending pin is connected to the first RS485 / RS422 receiving pin, and a third processing circuit is connected between the first RS485 / RS422 receiving pin and the TTL serial port signal receiving pin, and the third processing circuit is used to convert the communication logic between the first RS485 / RS422 receiving pin and the TTL serial port signal receiving pin; the second RS485 / RS422 sending pin is connected to the second RS485 / RS422 receiving pin, and a third processing circuit is also connected between the second RS485 / RS422 receiving pin and the TTL serial port signal receiving pin, and the third processing circuit is used to convert the communication logic between the second RS485 / RS422 receiving pin and the TTL serial port signal receiving pin. The utility model can also realize the communication of RS485 / RS422 in an environment with a high temperature of 150°C - 200°C, which can effectively prevent the extremely high temperature in the high-temperature environment from damaging the communication circuit and ensure the functional reliability of the communication circuit.

[0041] In the above text, the utility model has been described in a relatively specific and detailed manner through general descriptions and specific embodiments. It should be understood that based on the technical concept of the utility model, several conventional adjustments or further innovations can be made to these specific embodiments; but as long as they do not deviate from the technical concept of the utility model, the technical solutions obtained through these conventional adjustments or further innovations also fall within the protection scope of the claims of the utility model.

Claims

1. A high temperature resistant level conversion circuit for high temperature environment, characterized in that: Including the circuit for converting TTL to RS485 / RS422 at the sending end and the circuit for converting RS485 / RS422 to TTL at the receiving end; The circuit for converting TTL to RS485 / RS422 at the transmitting end includes resistor R6, transistor Q3, resistor R2, resistor R4, transistor Q1, resistor R1, diode D1 and diode D2; One end of the resistor R6 is connected to the TTL serial port signal sending pin, and the other end of the resistor R6 is connected to the base of the transistor Q3, and the collector of the transistor Q3 is connected to the resistor R2 and the resistor R4 respectively; the emitter of the transistor Q3 is grounded; the resistor R4 is connected to the base of the transistor Q1, and the collector of the transistor Q1 is connected to the resistor R1, the diode D1, the diode D2 and the first RS485 / RS422 sending pin respectively, and the emitter of the transistor Q1 is grounded; The circuit for converting RS485 / RS422 to TTL at the receiving end includes resistor R11, transistor Q5, resistor R10, diode D7 and diode D8; One end of the resistor R11 is connected to the TTL serial port signal sending pin, and the other end of the resistor R11 is connected to the base of the transistor Q5. The collector of the transistor Q5 is respectively connected to the resistor R10, the diode D7, the diode D8 and the second RS485 / RS422 sending pin; the emitter of the transistor Q5 is grounded.

2. The high temperature resistant level conversion circuit for high temperature environment according to claim 1, characterized in that: The circuit for converting RS485 / RS422 to TTL at the receiving end also includes transistor Q4, resistor R3, resistor R5, transistor Q2, resistor R7 and resistor R9; The collector of transistor Q4 is connected to resistor R3 and resistor R5 respectively; resistor R5 is connected to the base of transistor Q2; the emitter of transistor Q2 is connected to resistor R7 and resistor R9 respectively, resistor R7 is connected to the TTL serial port signal receiving pin, and resistor R9 is grounded.

3. The high temperature resistant level conversion circuit for high temperature environment according to claim 2, characterized in that: A resistor R8 is connected between the first RS485 / RS422 receiving pin and the base of the transistor Q4; It also includes a diode D3 and a diode D4; the anode of the diode D3 is connected between the first RS485 / RS422 receiving pin and the resistor R8, the cathode of the diode D4 is connected between the first RS485 / RS422 receiving pin and the resistor R8; the anode of the diode D4 is grounded.

4. The high temperature resistant level conversion circuit for high temperature environment according to claim 3, characterized in that: Also includes diode D5 and diode D6; The anode of the diode D5 is connected between the second RS485 / RS422 receiving pin and the emitter of the transistor Q4, the cathode of the diode D6 is connected between the second RS485 / RS422 receiving pin and the emitter of the transistor Q4; the anode of the diode D6 is grounded.

5. The high temperature resistant level conversion circuit for high temperature environment according to claim 4, characterized in that: The resistance values ​​of the resistors R2, R3, R4, R5, R6, R8, R9 and R11 are all 10KΩ.

6. The high temperature resistant level conversion circuit for high temperature environment according to claim 4, characterized in that: The resistance values ​​of the resistors R1, R7 and R10 are all 1KΩ.

7. The high temperature resistant level conversion circuit for high temperature environment according to claim 4, characterized in that: Transistor Q1, transistor Q3, transistor Q4 and transistor Q5 all adopt NPN transistors.

8. The high temperature resistant level conversion circuit for high temperature environment according to claim 7, characterized in that: The transistor Q2 is a PNP transistor.

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