阅读说明：本技术 两线制回路供电数显智能温度控制器和变送器一体化仪表 (Two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument ) 是由 吴鹤春 于 2019-10-10 设计创作，主要内容包括：本发明公开了两线制回路供电数显智能温度控制器和变送器一体化仪表,用于与PLC控制器或DCS系统或电磁阀、接触器等设备连接,实现对温度的监视、远传、控制、报警和设备保护,本发明使温度仪表从低功耗(毫安级)跨入微功耗(微安级),将引起温度仪表的可靠性和稳定性的根本性提高,实现了对温度的就地监视和4-20mA远传、控制和报警,把现场的设备温度信号远传到DCS系统或PLC控制器,完成工业、交通等各种行业的设备的监视、控制、报警与保护；本发明将温度变送器、温控开关、数显功能三合一,实现了变送器的微功耗1-5mA信号模式和电气隔离模式,实现了温度控制器两线制,不再需要单独供电(市面上常见的为三线制温控器),而是通过信号回路供电,做到无条件替代机械式温控器,解决了长期以来机械式温控器不能替代的瓶颈,解决了使用机械式控制器卡涩和漂移带来的保护失灵(误动和拒动),解决了机械式温控器不能监控带来保护系统不可控的安全隐患,从而提高了保护系统的可靠性。(The invention discloses a two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument, which is used for being connected with a PLC (programmable logic controller) or a DCS (distributed control system) or electromagnetic valves, contactors and other equipment to realize monitoring, remote transmission, control, alarming and equipment protection on temperature, and the invention enables the temperature instrument to cross into micro power consumption (microampere level) from low power consumption (milliampere level), so that the reliability and stability of the temperature instrument are fundamentally improved, in-situ monitoring on temperature and 4-20mA remote transmission, control and alarming are realized, and on-site equipment temperature signals are remotely transmitted to the DCS or the PLC to complete monitoring, control, alarming and protection on equipment in various industries such as industry, traffic and the like; the invention integrates the functions of the temperature transmitter, the temperature control switch and the digital display into a whole, realizes the micro-power consumption 1-5mA signal mode and the electrical isolation mode of the transmitter, realizes the two-wire system of the temperature controller, does not need to supply power independently (common three-wire system temperature controllers on the market), supplies power through a signal loop, unconditionally replaces the mechanical temperature controller, solves the bottleneck that the mechanical temperature controller cannot be replaced for a long time, solves the problem of protection failure (misoperation and refusal) caused by unsmooth and drifting of the mechanical controller, solves the problem of uncontrollable potential safety hazard of a protection system caused by the incapability of monitoring the mechanical temperature controller, and improves the reliability of the protection system.)

1. Two-wire system return circuit power supply digital display intelligence temperature controller and changer integration instrument for be connected with PLC controller or DCS system and realize temperature transmitter, temperature detect switch and digital display function, PLC controller or DCS system all is equipped with AI input port, DI input port, its characterized in that: including constant current source, temperature sensor, instrumentation amplifier, AD converter, singlechip, changer, controller, redundant power module, button module, digital display module, constant current source, temperature sensor, instrumentation amplifier, AD converter, singlechip connect gradually, the singlechip passes through the changer with AI input port connects, the singlechip passes through the controller with DI input port connects, changer, controller all pass through redundant power module with the singlechip is connected, the singlechip respectively with button module, digital display module connect.

2. The two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument according to claim 1, characterized in that: the transmitter comprises an electromagnetic isolation chip, a digital/analog (D/A) converter, a voltage-to-input (V/I) converter, a first rectification filtering common-mode circuit, a first linear voltage stabilizer, a transformer driving circuit, an isolation transformer and a second linear voltage stabilizer, the single chip microcomputer sequentially passes through the electromagnetic isolation chip, the D/A converter, the V/I converter and the first rectification filtering common-mode circuit and is connected with an analog-to-digital (AI) input port, the AI input port sequentially passes through the first rectification filtering common-mode circuit, the first linear voltage stabilizer, the transformer driving circuit, the isolation transformer and the second linear voltage stabilizer and is connected with the redundant power supply module, the first linear voltage stabilizer is respectively connected with the D/A converter and the V/I converter, and the second linear voltage stabilizer is connected with the electromagnetic.

3. The two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument according to claim 1, characterized in that: the controller comprises a switch driving circuit, an IGBT switch, a second rectification filter common mode circuit, a buck LDO, a boost LDO and a boost/buck switching circuit, the single chip microcomputer sequentially passes through the switch driving circuit, the IGBT switch and the second rectification filter common mode circuit and is connected with the DI input port, the second rectification filter common mode circuit respectively passes through the buck LDO and the boost LDO and is connected with the boost/buck switching circuit, and the boost/buck switching circuit is connected with the redundant power supply module.

4. The two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument according to claim 1, characterized in that: the constant current source adopts a 50uA micro-power constant current source and is used for providing 50uA power supply current for the temperature sensor.

5. The two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument according to claim 1, characterized in that: the instrumentation amplifier adopts a 50uA micro-power consumption instrumentation amplifier.

6. The two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument according to claim 1, characterized in that: the single chip microcomputer adopts a 50uA working current single chip microcomputer.

7. The two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument according to claim 1, characterized in that: the display module adopts a 10uA micro-power consumption display.

Technical Field

The invention relates to the technical field of intelligent temperature instruments, in particular to a two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument.

Background

The mechanical temperature controller has poor precision for a long time, is jammed and drifts occasionally, causes misoperation and refusal of various equipment protection, and causes accidents and equipment damage. The three-wire system temperature controller needs to be independently powered, the power supply is managed, the power supply reliability is difficult to guarantee, and due to the line voltage drop of long-distance power supply and other reasons, the three-wire system temperature controller does not meet the dry contact requirement of industrial control, so that the condition that the three-wire system temperature controller is industrially occupied by a mechanical temperature controller, particularly an imported mechanical temperature controller, is formed.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument.

The purpose of the invention is realized by the following technical scheme: the invention discloses a two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument which is used for being connected with a PLC (programmable logic controller) or a DCS (distributed control System) to realize the functions of a temperature transmitter, a temperature control switch and a digital display, wherein the PLC or the DCS is provided with an AI input port and a DI input port And the digital display module is connected.

In a preferred embodiment, the transmitter comprises an electromagnetic isolation chip, a D/A converter, a V/I converter, a first rectifying and filtering common-mode circuit, a first linear voltage stabilizer, a transformer driving circuit, an isolation transformer and a second linear voltage stabilizer, the singlechip is connected with the AI input port through the electromagnetic isolation chip, the D/A converter, the V/I converter and the first rectification filtering common-mode circuit in sequence, the AI input port is connected with the redundant power supply module sequentially through the first rectifying and filtering common-mode circuit, the first linear voltage stabilizer, the transformer driving circuit, the isolation transformer and the second linear voltage stabilizer, the first linear voltage stabilizer is respectively connected with the D/A converter and the V/I converter, and the second linear voltage stabilizer is connected with the electromagnetic isolation chip.

In a preferred embodiment, the controller includes a switch driving circuit, an IGBT switch, a second rectification filter common mode circuit, a buck LDO, a boost LDO, and a boost/buck switching circuit, the single chip microcomputer is connected to the DI input port sequentially through the switch driving circuit, the IGBT switch, and the second rectification filter common mode circuit, the second rectification filter common mode circuit is connected to the boost/buck switching circuit through the buck LDO and the boost LDO, and the boost/buck switching circuit is connected to the redundant power supply module.

In a preferred embodiment, the constant current source is a 50uA micro-power consumption constant current source for providing 50uA power supply current for the temperature sensor.

In a preferred embodiment, the instrumentation amplifier is a 50uA micro power consumption instrumentation amplifier.

In a preferred embodiment, the single chip microcomputer adopts a 50uA working current single chip microcomputer.

In a preferred embodiment, the display module adopts a 10uA micro power consumption display.

The invention has the beneficial effects that:

1. the invention integrates the functions of the temperature transmitter, the temperature control switch and the digital display into a whole, realizes the micro-power consumption 1-5mA signal mode and the electrical isolation mode of the transmitter, realizes the two-wire system of the temperature controller, does not need to supply power independently (common three-wire system temperature controllers on the market), supplies power through a signal loop, realizes unconditional replacement of the mechanical temperature controller, solves the bottleneck that the mechanical temperature controller cannot be replaced for a long time, solves the problem of protection failure (misoperation and refusal) caused by unsmooth and drifting of the mechanical controller, solves the possibility of out-of-control protection caused by the incapability of monitoring the mechanical temperature controller, and improves the reliability of a protection system.

2. The invention makes the temperature instrument cross from low power consumption (milliampere level) to micro power consumption (microampere level), which can radically improve the reliability and stability of the temperature instrument, realize in-situ monitoring and 4-20mA remote transmission, control and alarm of temperature, remotely transmit the temperature signal of the equipment on site to a DCS system or a PLC controller, and complete the monitoring, control, alarm and protection of the equipment in various industries such as industry, traffic and the like.

Drawings

The invention is explained in further detail below with reference to the drawing.

Fig. 1 is a frame structure diagram of a two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument according to an embodiment of the present invention.

In the figure:

1. a constant current source; 2. a temperature sensor; 3. an instrumentation amplifier; 4. an A/D converter; 5. a single chip microcomputer; 6. a key module; 7. a display module; 8. a transmitter; 801. an electromagnetic isolation chip; 802. a D/A converter; 803. a V/I converter; 804. a first rectifying and filtering common mode circuit; 805. a first linear regulator; 806. a transformer drive circuit; 807. an isolation transformer; 808. a second linear regulator; 9. a controller; 901. a switch drive circuit; 902. an IGBT switch; 903. a second rectifying and filtering common mode circuit; 904. step-down LDO; 905. a boost LDO; 906. a step-up/step-down switching circuit; 10. a redundant power supply module; 11. an AI input port; 12. DI input port.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The invention will be further described with reference to the drawings and specific examples.

As shown in fig. 1, the two-wire loop power supply digital display intelligent temperature controller and transmitter integrated instrument of the embodiment of the invention is used for being connected with a PLC controller or a DCS system to realize temperature transmitter, temperature control switch and digital display function, the PLC controller or the DCS system is provided with an AI input port 11 and a DI input port 12, the invention comprises a constant current source 1, a temperature sensor 2, an instrument amplifier 3, an a/D converter 4, a single chip microcomputer 5, a transmitter 8, a controller 9, a redundant power supply module 10, a key module 6 and a digital display module 7, the constant current source 1, the temperature sensor 2, the instrument amplifier 3, the a/D converter 4 and the single chip microcomputer 5 are sequentially connected, the single chip microcomputer 5 is connected with the AI input port 11 through the transmitter 8 to achieve temperature transmitter function, the single chip microcomputer 5 is connected with the DI input port 12 through the controller 9 to, the transmitter 8 and the controller 9 are both connected with the singlechip 5 through a redundant power supply module 10, and the singlechip 5 is respectively connected with the key module and the digital display module;

the constant current source 1 adopts a 50uA micro-power constant current source and is used for providing 50uA power supply current for the temperature sensor 2;

the temperature sensor 2 is used for detecting the external temperature to obtain an analog voltage signal and sending the analog voltage signal to the instrument amplifier 3; the power supply current of a conventional temperature sensor is 1mA, the bridge arm resistance of the sensor is 4k, the power consumption is 160mw, and the temperature drift caused by the resistance value change of the diffused silicon bridge arm resistance due to the power consumption is caused by the self-heating of the sensor; the invention adopts the micro-power consumption temperature sensor with the power supply current of 50uA, the power consumption is 0.8mW, the power consumption is greatly reduced, the heating of the sensor is greatly reduced, and the drift caused by the heating of the sensor is overcome.

The instrumentation amplifier 3 adopts a 50uA micro-power-consumption instrumentation amplifier, the power consumption is low, the stability is good, the instrumentation amplifier 3 amplifies the analog voltage signal and sends the analog voltage signal to the A/D converter 4;

the A/D converter 4 is an analog-to-digital converter and is used for converting the analog voltage signal into a digital signal and sending the digital signal to the singlechip 5;

the singlechip 5 adopts a 50uA working current singlechip and is used for receiving a digital signal sent by an A/D converter and receiving a set value input by the key module 5, so that the digital signal is sent to the transmitter 8 to achieve the function of a temperature transmitter; on one hand, an AND logic circuit is arranged in the singlechip 5, and the digital signal is compared with a set value and then sent to the controller 9 to achieve the function of a temperature control switch; simultaneously, the digital signal and the set value are sent to a display module 7 for real-time temperature display and set value display;

in a specific embodiment, the transmitter 8 includes an electromagnetic isolation chip 801, a D/a converter 802, a V/I converter 803, a first rectification and filtering common mode circuit 804, a first linear voltage stabilizer 805, a transformer driving circuit 806, an isolation transformer 807, and a second linear voltage stabilizer 808, the single chip microcomputer 5 is connected with the AI input port 11 through the electromagnetic isolation chip 801, the D/a converter 802, the V/I converter 803, the first rectification and filtering common mode circuit 804 in sequence to realize a temperature transmitter function, the AI input port 11 is connected with the redundant power supply module 10 through the first rectification and filtering common mode circuit 804, the first linear voltage stabilizer 805, the transformer driving circuit 806, the isolation transformer 807, and the second linear voltage stabilizer 808 in sequence to achieve a loop power supply function, the first linear voltage stabilizer 805 is connected with the D/a converter 802 and the V/I converter 803 respectively, the second linear voltage stabilizer 808 is connected with the electromagnetic isolation chip 801;

the single chip microcomputer 5 sends the received digital signal to the electromagnetic isolation chip 801, wherein the electromagnetic isolation chip 801 is in the prior art and sends the digital signal to the D/A converter 802;

the D/a converter 802, i.e. a digital-to-analog converter, is configured to receive a digital signal transmitted by the electromagnetic isolation chip 801, convert the digital signal into an analog voltage signal, and send the analog voltage signal to the V/I converter 803;

the V/I converter 803 is used for converting the analog voltage signal into an analog current signal of 4-20mA, sending the analog current signal to the AI input port 11 through the first rectification filtering common mode circuit 804, and obtaining the analog current signal by the PLC or the DCS system, so as to realize the function of the temperature transmitter;

in the embodiment of the present invention, 24V voltage (24V voltage provided by a PLC controller or DCS system) input from the AI input port 11 is output as 3V voltage through the first rectifying and filtering common mode circuit 804 and the first linear voltage regulator 805, and is used by the transformer driving circuit 806, the first linear voltage regulator 805 is used to provide 3V voltage for the D/a converter 802 and the V/I converter 803, the transformer driving circuit 806 generates 400KHz ac signal and outputs the signal to the primary of the isolation transformer 807, the secondary of the isolation transformer 807 outputs 5V voltage to the redundant power module 10 through the second linear voltage regulator 808, and the second linear voltage regulator 808 is used to provide voltage for the electromagnetic isolation chip 801;

in a specific embodiment, the controller 9 includes a switch driving circuit 901, an IGBT switch 902, a second rectification filter common mode circuit 903, a buck LDO904, a boost LDO905, and a boost/buck switching circuit 906, the single chip microcomputer 5 is connected with the DI input port 12 through the switch driving circuit 901, the IGBT switch 902, and the second rectification filter common mode circuit 903 in sequence to achieve a temperature controlled switch function, the second rectification filter common mode circuit 903 is connected with the boost/buck switching circuit 906 through the buck LDO904 and the boost LDO905, and the boost/buck switching circuit 906 is connected with the redundant power supply module 10 to achieve a loop power supply function;

an AND gate logic circuit is arranged in the singlechip 5, when the temperature value represented by the digital signal is greater than the set value by comparing the set value with the digital signal, the singlechip 5 outputs logic '1' to a switch driving circuit 901, and the switch driving circuit 901 controls an IGBT switch 902 to be closed; when the temperature value represented by the digital signal is less than or equal to the set value, the single chip microcomputer 5 outputs logic "0" to the switch driving circuit 901, and then controls the IGBT switch 902 to be turned off; a closing or opening signal of the IGBT switch 902 passes through the second rectification filtering common mode circuit 903 and is then acquired by the PLC controller or the DCS system through the DI input port 21, thereby realizing the function of the temperature control switch;

it should be noted that, in the embodiment of the present invention, the DI input port 12 may also be replaced with a solenoid valve, a contactor, or other devices, that is, a closing or opening signal of the IGBT switch 902 is obtained by the solenoid valve, the contactor, or other devices through the second rectification filter common mode circuit 903, so as to achieve a function of a temperature control switch.

24-220 VAC/DC (24-220 VAC/DC is provided by a PLC controller or a DCS system) input by the DI input port 12 is processed by the second rectifying and filtering common mode circuit 903 and then provided to the buck LDO904 or the boost LDO905, wherein the buck LDO904 is a buck regulator, and the prior art is adopted; the boost LDO905, i.e., a boost regulator, is a prior art; the boost/buck switching circuit 906 is used for selecting the buck LDO904 or the boost LDO905 to work, and a voltage signal is output as 5V voltage to the redundant power supply module 10 through the boost/buck switching circuit 906;

the voltage provided by the transmitter 8 loop and the voltage provided by the controller 9 loop are both 5V theoretically, but in practice, there is a small amount of loss in the two paths of voltages in the conversion process, the redundant power supply module 10 is used for selecting the one with the higher actual voltage to pass through, the redundant power supply module 10 is in the prior art and comprises two diodes, the anode of one diode is connected with the output end of the second linear voltage stabilizer 808, the anode of the other diode is connected with the output end of the voltage boosting/reducing switching circuit 906, the cathodes of the two diodes are collinear and connected with the single chip microcomputer 5, the redundant power supply module 10 works according to the principle that the one with the higher voltage passes through the two diodes, for example, when the actual voltage provided by the transmitter 8 loop is greater than the actual voltage provided by the controller 9, the voltage provided by the transmitter 8 loop supplies power to the single chip microcomputer 5 through the redundant power supply module 10, the voltage provided by the controller 9 loop is blocked; similarly, when the actual voltage provided by the controller 9 loop is greater than the actual voltage provided by the transmitter 8 loop, the voltage provided by the controller 9 loop supplies power to the singlechip 5 through the redundant power module 10, and the voltage provided by the transmitter 8 loop is blocked;

in summary, the two-wire system digital display intelligent temperature instrument system of the present invention integrates three functions of a temperature transmitter, a temperature control switch and a digital display, and changes the three-wire system of the prior art into a two-wire system, which does not supply power independently, but supplies power through a loop, wherein:

1. the temperature transmitter function is that a temperature analog voltage signal is obtained through the temperature sensor 2, the analog voltage signal is amplified and converted into a digital signal through the instrument amplifier 3 and the A/D converter 4 in sequence and sent to the singlechip 5, then the digital signal is converted into an analog voltage signal through the electromagnetic isolation chip 801, the D/A converter 802, the V/I converter 803 and the first rectification filtering common mode circuit 804 in sequence, the analog voltage signal is converted into an analog current signal, and the analog current signal is output to the AI input port 11, so that the temperature transmitter function is realized;

2. the temperature control switch function is that after the temperature analog voltage signal obtained by the temperature sensor 2 is converted into a digital signal and sent to the single chip microcomputer 5, the single chip microcomputer 5 compares the digital signal with a set value input by the key module 6 through an AND logic circuit arranged inside, and when the temperature value represented by the digital signal is greater than the set value, the IGBT switch 902 is closed; when the temperature value represented by the digital signal is less than or equal to the set value, the IGBT switch 902 is turned off; after passing through the second rectification filtering common mode circuit 903, the on or off signal of the IGBT switch 902 is acquired by the PLC controller or the DCS system through the DI input port 12, thereby realizing the function of the temperature control switch;

3. the digital display function is realized, temperature analog voltage signals acquired by the temperature sensor 2 are converted into digital signals, the digital signals are sent to the singlechip 5, then the digital signals are sent to the display module 7 through the singlechip 5 to be displayed, and meanwhile, set values input by the key module 6 are displayed, in the embodiment of the invention, the display module 7 adopts a 10uA micro-power consumption display;

4. the invention provides a two-wire loop power supply function, the power is supplied by two paths through an AI input port 11 and a DI input port 12, the two paths are respectively converted into 5V voltage, the power is supplied to a single chip microcomputer through a redundant power module 10, the redundant power module 10 selects according to actual voltage provided by the two paths, a high voltage person supplies power to the single chip microcomputer and the system of the invention through the redundant power module 10, and a low voltage person is blocked.

Finally, it should be noted that: the above-mentioned embodiments are only used for illustrating the technical solution of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.