CN2462355Y - Micro power loss optical fiber transmitting multiple parameter transducer - Google Patents

Abstract

The utility model relates to a micro power loss optical fiber transmitting multiple parameter transducer. A differential capacitance diaphragm box measuring head is provided with a connector, is connected with a mounting flange and then through the connector, is connected with a converting component which is connected with a controller through optical fiber. A differential capacitance diaphragm box is composed of two lateral separated diaphragms, the middle of which is an insulating layer. The middle part of the insulating layer is made of a common capacitance polar plate and two lateral fixed capacitance polar plates. The middle of a lead wire is filled with silicone oil, and the lead wire, an isolation diaphragm component, a common capacitance polar plate and a capacitance seat are welded to form three welded rings.

Description

Multi-parameter sensor for micro-power optical fibre transmission

The utility model relates to automation process control and uses the thermal measurement instrument, belongs to little power consumption Optical Fiber Transmission multiparameter variable differential capacitance type differential pressure or pressure, temperature sensor specifically.

A large amount of on-the-spot differential pressure/pressure, temperature measuring instrument that existing automation field uses, one class is a pneumatic instrument, variation with air pressure transmits information measured, one class is to use the electric signal that changes by analog quantity to transmit information measured, and a class is to use the electric signal that changes by digital quantity to transmit information measured.All need to consume the more energy during above-mentioned three class instrumentations, general power supply is the power consumption of 30～40mw, and transmission manner has that pipeline transmission, lead transmit, the radio modulation emission transmits.In order to reach the little power consumption work below the 0.7mw, take light signal to send in-site measurement information with the photoconduction transmitting fiber tow, once there was the patent No. 95223991.4 to introduce the Optical Fiber Transmission luminous power and promoted little power consumption differential pressure pick-up, find to exist more problem in actual applications, particularly it is applied in differential capacitive structure, its common electrode need connect shell, the contacted sensor of the earth and measured medium adopts this patent, circuit can't make measured value stable, under external interference, can cause the blocking of oscillator, the output of sensor no signal, but adopt differential capacitive structure, can't accomplish that common electrode and measured medium and the earth are isolated, therefore adopt this patented technology can't produce product.This patented technology simultaneously, only can transmit the single channel pressure signal an optical-fibre channel, can't transmit signal synthesis such as multiparameter such as temperature, pressure, differential pressures, therefore also can't compensate and correct temperature performance, change in voltage is big in the luminous power change-over circuit of its transmitting terminal in addition, cause and send the data instability, measuring error is increased, poor stability in the demodulator circuit of its receiving end, circuit parameter needs often to adjust, and therefore can't use in the differential capacitive sensor of public electrode ground connection.

The purpose of this utility model provides same optical fiber and carries out the multiparameter information transmission, it is stable to be used for its measured value of the contacted sensor of the earth and measured medium, keep the circuit of transmitting terminal and receiving end stable simultaneously, can adapt to a kind of multi-parameter sensor for micro-power optical fibre transmission of differential capacitive sensor with public electrode ground connection.

For finishing the technical scheme that above-mentioned purpose is taked; Differential capacitor measurement of film thickness head is established web member and is connected with mounting flange, and again by connecting converting member, converting member connects controller by optical fiber, the differential capacitor bellows is by both sides isolation diaphragm assembly, the centre is an insulation course, the centre of insulation course is fixed capacity pole plate and extension line by shared capacitor plate and both sides, middle filling silicon oil, above-mentioned isolation diaphragm assembly, shared capacitor plate, the electric capacity seat is welded into three weld-rings and forms the differential capacitor bellows, differential capacitor measurement of film thickness head is established web member and is connected with the dress flange, and connecting converting member by web member again, converting member connects control box by optical fiber, wherein is provided with by light emitting diode D in the converting member ₂It is elementary to connect transformer B, and next level connects stabilivolt Z ₁～Z ₆, diode D ₃, resistance R ₅～R ₆, capacitor C ₂With electric capacity E ₁～E ₃The light of forming promotes the power supply generative circuit and reaches by differential capacitor C _H, C _LWith thermistor R _TPass through R respectively ₁₀, R ₉And capacitor C ₄Connect integrated package U ₁CD4013 and U ₂The d type flip flop of CD4013 connects reverser U simultaneously ₅CD4069 and U ₆, U ₇The CD4051 analog switch, U ₆And U ₇Other connects oscillatory circuit U ₃CD4069 and timing circuit U ₄CD4069 and R ₁₄, R ₇～R ₈, and C ₃, C ₇Other connects triode T ₃, light emitting diode D ₄, resistance R ₁₃The input coded modulation circuit of forming constitutes, and connects optical fiber, delivers to control box by optical fiber, and above-mentioned control box is interior by resistance R ₁, R ₂And capacitor C ₁Connect integrated package six reverser square-wave oscillator U respectively ₁₄CD4069 passes through R ₃And R ₄Connect triode T ₂And laser diode D ₁The light of forming promotes exciting circuit and reaches by photo-detector D ₅, D ₅Connect R ₁₅And C ₇And triode T ₄, connect integrated package U through amplifying ₄And R ₁₈, C ₈And connection JK flip-flop U ₁₂CD4047, U ₁₂Signal is delivered to XOR gate electricity U ₁₃74LS89 is until CPU ₂, other delivers to CPU ₁Form measuring-signal reception Jie and mediate the reason circuit.

The utility model adopts the differential pressure/pressure transducer of differential capacitance type structure to combine with the Fibre Optical Communication Technology that special benefits is arranged, and can in same optical fiber, adopt width modulation, pulse code, the method that the arteries and veins position sends, the requirement that little power consumption is transmitted and reached to the realization parameter has promotional value, can use up the promotion method to provide the energy for sensor, also available sensors inside is done electric former from charged pool, have very big dirigibility and security, be applicable to inflammable and explosive Medium Measurement and occasion, more can be applicable to the environment of strong electromagnetic radiation, the present invention can abandon complicated controller switching equipment in addition, and carries the lithium battery work that meets the Sefe antiexplosion requirement by in the instrument.

The utility model embodiment is described in detail in conjunction with the accompanying drawings.

Fig. 1 the utility model structural drawing;

Fig. 2 the utility model sensor bellows structural drawing;

Fig. 3 the utility model input coded modulation circuit diagram;

Fig. 4 the utility model light promotes power supply generative circuit figure

Fig. 5 the utility model light promotes exciting circuit figure;

Fig. 6 the utility model measuring-signal receives to be situated between mediates the reason circuit diagram.

According to shown in Figure 1, differential capacitor measurement of film thickness head is established web member and is connected with mounting flange, and again by connecting converting member, converting member connects controller by optical fiber, the differential capacitor bellows as shown in Figure 2, by both sides isolation diaphragm assembly 7, the centre is an insulation course 11, and the centre of insulation course 11 is fixed capacity pole plate 9, extension line 8 its middle filling silicon oils by shared capacitor plate 10 and both sides.According to illustrated in figures 1 and 2, by both sides isolation diaphragm assembly 7, the centre is an insulation course 11, the centre of insulation course 11 by shared capacitor plate 10 and both sides be fixed capacity pole plate 9, extension line 8 in the middle of it filling silicon oils 12, isolation diaphragm assembly 7, shared capacitor plate 10, electric capacity seat 13 be welded into the differential capacitor bellows 1 that three weld-rings 14 are formed, its shared capacitor plate 10 constitutes two capacitors with the fixed capacity pole plate 9 and the middle silicone oil of filling 12 of its both sides, the high-pressure side is capacitor C H, low pressure is surveyed capacitor C L, extraneous tested pressure P ₁, P ₂Act on the spacer of both sides, transmit pressure by silicone oil 12 and act on the shared capacitor plate 10, make shared capacitor plate 10 produce displacement, the electric capacity of CH and CL is changed, can measure P by the electric capacitance change that detects CH and CL ₁With P ₂Difference, differential capacitor is directly contacted with measured medium and the earth by three weld-rings 14, so mode is delivered to input coded modulation circuit with pressure and temperature measurement signal, as shown in Figure 3, U ₁, U ₂(can increase on demand) is the pulse width detection circuit of d type flip flop (CD4013) formation sensor, sensing element C _H, C _L, R _TConstitute the timing element of the RC charging and discharging circuit of d type flip flop, when these component parameters were measured effect of signals and changed, then the RC charging rate of d type flip flop changed.By U ₆Under the effect of output pulse, corresponding d type flip flop output terminal becomes high level, is charged in the RC loop.When the charging level on the C reaches a certain value, because an end in RC loop is continuous with the reset terminal of d type flip flop, therefore, make the d type flip flop upset, output becomes low level.The width of pulse and the parameter correlation of sensing element.The pulse of d type flip flop is by U ₃The time clock that reverser (CD4069) constitutes is as U ₄The count pulse of counter (CD40193), counter can be arranged to scale-of-eight (or 16 systems are decided on d type flip flop quantity) working method on demand, and its output end signal is as U ₆, U ₇The control signal of eight path analoging switch (CD4051) drives corresponding switch motion.Because at analog switch U ₆Public termination high level, so the output switching terminal mouth at gating can produce a positive pulse, its time that continues is depended on the frequency of time clock, this positive pulse will trigger the corresponding D trigger, make the output terminal of this d type flip flop produce the positive pulse that depends on the RC network parameter that connects, its pulsewidth has been represented the size of measured signal.Because U ₇Gating port and U ₆The output port of the d type flip flop of corresponding gating port links to each other, so at U ₇Common port obtain to press counter U ₄Control timing connects the pulse train that each d type flip flop produces, and the start bit of this pulse train can be by counter U ₄Control produces a specific identification pulse, forms coded pulse group (U ₇Function also can be finished with OR circuit).

Through U ₇The coded pulse group of common port output is via U ₈(MC14528) and the 3.5us pulsewidth that constitutes of outward element RC respectively by front and back along two monostalbe triggers that trigger, convert each pulse width signal to two narrow pulse signals, its time interval equals the width of former pulse width signal.Two monostalbe triggers output burst pulse is delivered to OR circuit U ₉(CD4071) input end is at U ₉Output terminal formed coding burst pulse group driving LED light emitting diode D ₄Change light pulse into, be sent to the pulpit secondary instrument through light transmitting fiber 5.

As shown in Figure 4, the light-pulse generator that is transmitted by optical fiber 5 is through D ₃After silicon photocell receives, produce pulsating dc voltage, it is elementary to deliver to step-up transformer B, and level produces higher pulsating dc voltage secondarily, through D ₁Rectification, R ₅, Z ₅, Z ₆, voltage stabilizing, electric capacity E ₁, C ₂, E ₂, E ₃, form direct supply after the filtering for other circuit function.

Promotion exciting circuit in control box 6 as shown in Figure 4, U ₁₄CD4069 is that six reversers constitute square-wave oscillator, exports triode T to through shaping ₁And T ₂The complex pipe driving laser diode D that constitutes ₁, the output light-pulse generator is coupled to optical fiber 5 and is sent to spot sensor.And for example shown in Figure 6, by the light pulse signal of optical fiber 5 transmission through photo-detector D ₅, change electric impulse signal into, deliver to transistor T ₄Base stage, through being amplified in its collector output encoder burst pulse group, deliver to by U ₁₁The monostalbe trigger of the 5us pulsewidth forward position triggering that (CD4027) constitutes with pulse strenching, is delivered to by U ₁₂(CD4047) JK flip-flop is at JK flip-flop U ₁₂Q and Q end just can demodulate coded pulse group signal or its reversed phase signal, these two signals can directly send the INT0 of CPU1, fracture among the INT1 through the counting computing of CPU1 to each pulse width signal, just can be obtained corresponding measured value.Also can be with U ₁₂The Q end signal is delivered to by U ₁₃(74LS86) NOR gate circuit is via the polarity orientation circuit that constitutes with two XOR gate and RC circuit, at U ₁₃Output terminal 6 pin can obtain the single polar signal identical with modulation signal, for computing machine or other circuit application.

Claims (5)

1, a kind of multi-parameter sensor for micro-power optical fibre transmission of forming by differential pressure pick-up, temperature detection sensitive element, light promotion circuit, it is characterized in that differential capacitor measurement of film thickness head (1) establishes that web member (2) is connected with mounting flange (3) and connect converting member (4) by web member again, converting member (4) connects controller (6) by optical fiber (5), wherein is provided with by differential capacitor C in the converting member (4) _H, C _LWith thermistor R _TPass through R respectively ₁₀, R ₉And capacitor C ₄Connect integrated package U ₁CD4013 and U ₂The d type flip flop of CD4013 connects reverser U simultaneously ₅CD4069 and U ₆, U ₇The CD4051 analog switch, U ₆And U ₇Other connects oscillatory circuit U ₃CD4069 and timing circuit U ₄CD40193, and R ₁₄, R ₇～R ₈And C ₃, U ₇Other connects U ₈MC14528 and U ₉CD4071 and R ₁₁～R ₁₂And C ₅～C ₆, its U ₉Connect triode T ₃, light emitting diode D ₄And resistance R ₁₃Form input coded modulation circuit (15), light promotion power supply generative circuit (16); Light is set in the controller (6) to be promoted exciting circuit (17) and measuring-signal and receives to be situated between to mediate and manage circuit (18).

2, multi-parameter sensor for micro-power optical fibre transmission according to claim 1 is characterized in that measuring-signal receives Jie and mediates reason circuit (18) by optical fiber (5) connection photo-detector D ₅, D ₅Connect R ₁₅And C ₇And triode T ₄Connect integrated package U through amplifying ₁₁With and R ₁₈, C ₈And connection JK flip-flop U ₁₂CD4047, U ₁₂Signal is delivered to XOR social connections U ₁₃74LS86 to CPU ₂, other delivers to CPU ₁

3, multi-parameter sensor for micro-power optical fibre transmission according to claim 1, it is characterized in that differential capacitor bellows (1) is by both sides isolation diaphragm assemblies (7), the centre is insulation course (11), the centre of insulation course (11) is that fixed capacity pole plate (9) extension line 8 its middle filling silicon oils (12) are formed by shared capacitor plate (10) and both sides, and isolation diaphragm assembly (7), shared capacitor plate (10), electric capacity seat (13) are welded into three weld-rings (14).

4, require 1 described multi-parameter sensor for micro-power optical fibre transmission according to power, it is characterized in that the light in the converting member promotes power supply generative circuit (16) by light emitting diode D ₂Connect the transformer B utmost point just, secondly the utmost point connects stabilivolt Z ₁～Z ₆, diode D ₃, resistance R ₅And R ₆, capacitor C ₂Electric capacity E ₁～E ₃Form.

5, multi-parameter sensor for micro-power optical fibre transmission according to claim 1 is characterized in that light promotes exciting circuit (17) by R ₁～R ₂And C ₁Connect integrated package six reversers respectively and constitute square-wave oscillator U ₁₄CD4069 passes through R ₃And R ₄Connect triode T ₁T ₂And light emitting diode D ₁Form.

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