CN2103836U

CN2103836U - Electronic gas monitor

Info

Publication number: CN2103836U
Application number: CN 91214897
Authority: CN
Inventors: 张德益
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-08-26
Filing date: 1991-08-26
Publication date: 1992-05-06

Abstract

The utility model discloses an electronic gas monitor, comprising an electrical source, a gas-electricity converting circuit, a sensitivity regulating circuit, a triggering oscillation circuit, a built-in alarm signal circuit, a protection controlling circuit, an initial characteristic compensating circuit, etc. The utility model has the advantages of high speed, simple structure and high sensitivity. False alarm can not be induced for switching on initially or power failure while in use. The electronic gas monitor is applicable for monitoring gas, smoking alarm for a fire at an initial period, and monitoring air pollutions in public occasions.

Description

Electronic gas monitor

The utility model belongs to a kind of by there is the alarm of cigarette or gas effect, more particularly to a kind of electronic gas monitor, it is monitored available for escaping gases such as natural gas, coal gas, liquefied petroleum gas, gasoline, carbon monoxide, hydrogen, alkanes, alcohols, ethers, benzene classes, and the alarm of preceding smog is formed available for the burning such as paper, timber, cotton, rubber, woolen, plastic products, grease, it may also be used for monitoring of public arena air pollution etc..

The fuel gas such as natural gas, coal gas, liquefied petroleum gas, huge numbers of families are just entered with the unique advantage such as its convenient, cleaning, pollution-free, replace the indispensable fuel of the three meals in a day such as honeycomb briquette, firewood charcoal, but, usually because improper use, midway is flame-out, pipeline leakage etc. and cause the accidents such as fire, blast, asphyxia, brought about great losses to the country and people's lives and properties.Chinese patent 90204979.8 discloses a kind of Domestic fuel gas leakage alarm, is mainly made up of gas sensor, electronic component and loudspeaker, and when meeting combustion gas, gas sensor sends alarm signal, by electronic component amplification and oscillating alarming circuit, makes loudspeaker sounding；In the utility model patent, due in gas-power conversion circuit output end and triggering IC₂Between inserted with delay circuit, make device to the sensitivity decrease of fuel gas, late, when adjustable resistance W sets to zero, alarm just loses ability to work for reflection, while fragile probe measurement electrode, in addition, also depositing the deficiencies such as power failure false alarm in use.

The purpose of this utility model be to provide it is a kind of it is first be powered and had a power failure using midway will not report by mistake, fast to the reaction speed of fuel gas, sensitivity is high, electronic gas stable and reliable in work monitors assembling device.

What the utility model was realized in：A kind of electronic gas monitor, including power supply, gas-power conversion circuit for coupling with power supply and closing gas sensor, the signal detection coupled with gas-power conversion circuit and sensitivity adjusting circuit, with signal detection and sensitivity adjusting circuit are joining oscillating circuit is electronically activated, is with being electronically activated in place of warning circuit in the joining machine of oscillating circuit, its feature：

Described gas-power conversion circuit, by gas sensor a QM, a diode D₁, a resistance R₂With an electric capacity C₁₁Composition；Diode D₁Anode connects positive source, negative electrode and connects gas sensor QM measuring electrodes, the operating voltage for further stable gas sensor QM；Resistance R₂One end ground connection, another termination gas sensor QM heating electrodes, for limiting heating electrode cold conditions surge current protection heating electrode；Electric capacity C₁₁Positive termination gas sensor QM measuring electrodes output terminals A, other end ground connection, for filtering out clutter interference and the electric leakage interference of air-sensitive element internal；

Described signal detection and sensitivity adjusting circuit are by a variable resistor W and a diode D₂Composition, the termination gas sensor QM measuring electrodes of variable resistor W mono- output terminals A, another terminating diode D₂Anode, swing arm connect ic chip₃'sEnd, for detecting gas sensor QM gas-electricity conversion signal, while carrying out sensitivity adjustment；Diode D₂Anode connects variable resistor W, minus earth, and ic chip is ensured using forward voltage drop 0.7V characteristic₃Input fundamental voltage during sensitivity minimization, monitor remains to normal work during for ensureing that variable resistor W swing arms are transferred to least significant end；

Described is electronically activated oscillating circuit by an ic chip₃, two resistance R₃、R_4′, two electric capacity C₄、C₅Composition, by ic chip₃V_c、

R, Q ' end and C₅、R₄、C₄、R₃Astatic multivibrator is constituted, and by IC₉Q ends output machine in alarm signal and defense controls circuit trigger signal；Whether this partial circuit, which works, is controlled by two：One is

Whether the voltage levels at end, this voltage is touched fuel gas by gas sensor and is changed, and two be by IC₄、C₈、C₁₀、R₅The gas sensor QM initial characteristics compensation circuit control of composition, could only work when probe contacts to fuel gas and initial characteristic compensation time the two conditions enough；

Warning circuit is by an electric capacity C in described machine₆With loudspeaker y compositions, electric capacity C₆One end is connected on ic chip₃Q ends, another termination loudspeaker y, the loudspeaker other end ground connection, work as IC₃During work, loudspeaker sounding 1000Hz alarms；

The utility model also includes：

One with power supply and the joining initial characteristic compensation circuit of oscillating circuit being electronically activated, by ic chip₄, two electric capacity C₈、C1₁₀With resistance R₅Composition；By ic chip₄R,

End and

End and electric capacity C₈, resistance R₅Delay circuit is constituted, and electric visitor C is met in output end Q₁₀Power supply disturbance is further filtered out, this circuit delay must could export DC voltage for 3~5 minutes to ic chip from being powered at its Q end₃Power supply, the initial characteristic to compensate gas sensor QM；Ic chip₄V_cc、

Termination power positive pole, Q termination ic chips₃V_ccEnd and electric capacity C₁₀Anode, electric capacity C₁₀The other end is grounded；

One with power supply and oscillating circuit joining protector control circuit being electronically activated, by bidirectional triode thyristor a BCR, two electricity visitor C₇、C₉, a resistance R₆And two external connection end B₁、B₂Composition；Bidirectional triode thyristor BCR control poles G passes through electric capacity C₇And ic chip₃Q ends be connected, electric capacity C₉And resistance R₆Bidirectional triode thyristor BCR T is parallel to after being serially connected₁、T₂Two ends, T₁End ground connection, T₂Terminate external connection end B₁, external connection end B₂Connect AC power live wire；The power input and external connection end B of controlled protection electrical equipment (such as electric fan, smoke exhaust ventilator, electromagnet)₂、B₁It is connected, the oscillator signal when being alarmed in machine passes through electric visitor C₇Triggering end G poles to bidirectional triode thyristor BCR turn on BCR, controlled electrical equipment energization work.Electric visitor C₉, resistance R₆For protecting bidirectional triode thyristor BCR.

The utility model has following features：

(1) in gas-power conversion circuit output end and triggering ic chip₃'sOther circuits are not inserted between end, therefore, high to the monitoring sensitivity of combustible gas, reaction speed is fast；

(2) in power supply and triggering ic chip₃V_ccBetween end, initial characteristic compensation circuit is inserted, initial characteristic is both compensate for, and do not influence sensitivity and the reaction speed of monitoring；The compensation time can arbitrarily adjust according to gas sensor, while not influenceing gas sensor condition of work；Make to have a power failure all without false alarm in just energization or use, be conducive to mixing up sensitivity by standard requirement during production, use is easier；

(3) diode D is sealed in after gas sensor and variable resistor W₂, variable resistor W swing arms is transferred to smallest end, IC can be ensured₃'sThere are 0.7V fundamental voltages at end, it is ensured that device normal work；

(4) protector control circuit, bidirectional triode thyristor output voltage is triggered without flip-flop with AC signal, is more beneficial for the inductive loads such as control ventilating fan, magnetic valve, smoke exhaust ventilator；Contactless using controllable silicon, no-spark is produced during break-make, it is to avoid when combustion gas reaches finite concentration.Start protector and produce electric spark, cause burning, blast etc. unexpected；

(5) sensitivity inspection can be set to adjust window, user can enter line sensitivity inspection tune according to product description oneself, be allowed to work in optimum state；

(6) simple in construction, small volume, cost are low.

Fig. 1 is the utility model circuit structure block diagram；

Fig. 2 is the utility model circuit structure diagram.

The utility model is further illustrated by embodiment below in conjunction with the accompanying drawings.

A kind of electronic gas monitor, including：By transformer B, diode D₃~D₅, electric capacity C₁~C₃, resistance R₁, circuit of three-terminal voltage-stabilizing integrated IC₁、IC₂The power supply of composition, by gas sensor QM, diode D₁, electric capacity C₁₁, resistance R₂Gas-power conversion circuit of composition, by variable resistor W, diode D₂The signal detection of composition and sensitivity adjusting circuit, by ic chip₃, resistance R₃、R₄, electric capacity C₄、C₅What is constituted is electronically activated oscillating circuit, by electric capacity C₆, loudspeaker y composition machine in warning circuit, by bidirectional triode thyristor BCR, electric capacity C₇、C₉, resistance R₆, external connection end B₁、B₂The defense controls circuit of composition, by ic chip₄, electric capacity C₈、C₁₀, resistance R₅The initial characteristic compensation circuit of composition；Circuit is equipped with the plastic casing that size is 105 × 75 × 50 in a printing version, and upper panel has nameplate, and the middle part left side is provided with power supply instruction D₃, the right is provided with adjustment of sensitivity window, and loudspeaker playback window is arranged at bottom, and bottom right side is provided with fuel gas detection window etc..

In use, 220V50Hz mains supplies become 9V low tensions through transformer B decompressions, through diode D₄(1A/100V), D₅(1A/100V) rectification, electric capacity C₁(1000 μ f/16V) is filtered, by resistance R₁(2K), light emitting diode D₃(LED) power supply instruction is constituted, by filtered low-voltage DC through circuit of three-terminal voltage-stabilizing integrated IC₁After (model 7809) further voltage stabilizing, all the way through IC₄(model NE555), electric capacity C₈(100f), resistance R₅After (1M) delay, ic chip is supplied₃The V of (model NE555)_ccWorking power is made at end, all the way through diode D₁(2CP10) supplies the working power of gas sensor measuring electrode, another Lu Zaijing ic chips₂(model 7805), electric capacity C₂(100μf)、C₃(0.1 μ f) further voltage stabilizing, filtering, through resistance R₂Gas sensor heating electrode is supplied after (10 Ω) current limliting and makees heating power supply, gas sensor must possess the energy of the two power supplys supply, can just enter promoting the circulation of qi-electricity conversion.

By gas sensor QM, internal resistance and variable resistor W (4.7K), diode D₂(2Cp10) constitutes divider, and exports d. c. voltage signal with variable resistor W swing arms, and sensitivity can be changed by changing swing arm position.Gas-electricity conversion regime is the change of gas sensor internal resistance, variable resistor W swing arm current potentials is changed, and variable resistor W swing arm and ic chip₃'s

End connects, and the potential change of swing arm will directly affect IC₃Whether starting of oscillation, when gas sensor QM monitors certain density combustible gas, internal resistance declines rapidly, and W swing arm voltage will decline and rise with internal resistance, due to W swing arms and IC₃'sEnd is connected, and swing arm voltage is exactly

Terminal voltage, when this voltage rises to Triggered Oscillation IC₃1/3 supply voltage when, by IC₃, resistance R₃(10K)、R₄(100K), electric capacity C₄(4700pf)、 C₅The astatic multivibrator of (0.01 μ f) composition possesses condition of work and starting of oscillation, about 1KC (1000 weeks) audio signal is exported by Q ends, all the way through electric capacity C₆(22 μ f/16), loudspeaker y alarm, all the way through electric capacity C₇(22 μ f) gives the bidirectional triode thyristor BCR trigger signal voltage of G poles one, turns on bidirectional triode thyristor BCR, makes to be connected on output end B₁Such as ventilating fan, magnetic valve it is controlled protection electrical equipment start working, automatic protection is realized, by electric capacity O₉(01 μ f/400V), resistance R₆The objective absorption circuit protection bidirectional triode thyristor BCR of (100 Ω) composition resistance.When gas sensor QM is in clean air, gas sensor QM internal resistances higher about 50K Ω, variable resistor W swing arm voltage are less than Triggered Oscillation IC₃1/3 supply voltage, i.e. 1/3V_cc, (W swing arms directly with

It is connected), oscillating circuit failure of oscillation, loudspeaker y is noiseless, and bidirectional triode thyristor BCR cut-offs, device is in monitoring state.

By ic chip₄(NE555), electric capacity C₈(100 μ f), resistance R₅The initial characteristic compensation circuit of (1M) composition, one end couples with power supply, the other end (Q ends) and IC₃Power end connection, to control Triggered Oscillation IC₃Working power.Known by gas sensor initial characteristic：No matter fuel gas is whether there is, be initially powered 1~3 minute of gas sensor, internal resistance will decline, and then slowly go up in clean air, by 1~3 minute, can just go back up to normal operating conditions.After initial characteristic compensation circuit, the time delay of setting does not arrive, IC₃It can not be worked due to no working power, regardless of gas sensor internal resistance,

The voltage levels at end, device can not all work.When set time delay to when, caused by device is just only changed by gas sensor internal resistance

The control of terminal voltage change.

Claims

1. a kind of electronic gas monitor, couple including power supply, with power supply and gas-power conversion circuit containing gas sensor, couple with gas-power conversion circuit signal detection and sensitivity adjusting circuit, with signal detection and sensitivity adjusting circuit it is joining be electronically activated oscillating circuit, with warning circuit in the joining machine of oscillating circuit is electronically activated, it is characterised in that：

Described gas-power conversion circuit is by a gas sensor (QM), a diode (D₁), a resistance (R₂) and an electric capacity (C₁₁) composition, diode (D₁) anode connects positive source, negative electrode and connect gas sensor (QM) measuring electrode, resistance (R₂) one end is grounded, another termination gas sensor (QM) heats electrode, electric capacity (C₁₁) just terminating gas sensor (QM) measuring electrode output end (A), other end ground connection；

Described signal detection and sensitivity adjusting circuit are made up of a variable resistor (W) and a diode (D2), termination gas sensor (QM) the measuring electrode output ends of variable resistor W mono- (A), another terminating diode (D₂) anode, swing arm meet integrated package (IC₃)

End, diode (D₂) anode connects variable resistor (W), minus earth；

Described is electronically activated oscillating circuit by an integrated package (IC₃), two resistance (R₃)、(R₄), two electric capacity (C₄、C₅) composition, by integrated package (IC₃) (V_c、

R, Q ') hold and (C₅、R₄、C₄、R₃) composition astatic multivibrator, and by (IC₃) Q ends output machine in alarm signal and protector control circuit trigger signal；

Warning circuit is by an electric capacity (C in described machine₆) and loudspeaker (y）Composition, electric capacity (C₆) a termination integrated package (IC₃) Q ends, another termination loudspeaker (y), loudspeaker (y) the other end ground connection；

Also include：

One with power supply and the joining initial characteristic compensation circuit of oscillating circuit being electronically activated, by integrated package (IC₄), two electric capacity (C₈、C₁₀) and a resistance (R₅) composition, by integrated package (IC₄) R,

V_ccEnd and electric capacity (C₈), resistance (R₅) composition delay circuit, integrated package (IC₄) V_cc、

Termination power positive pole, Q termination ic chips₃V_ccEnd and electric capacity (C₁₀) anode, electric capacity (C₁₀) other end ground connection；

One with power supply and the joining protector of oscillating circuit being electronically activated controlling circuit, by a bidirectional triode thyristor (BCR), two electric capacity (C₇、C₉), a resistance (R₆) and two external connection end (B₁、B₂) constitute, bidirectional triode thyristor (BCR) control pole passes through electric capacity (C₇) and integrated (IC₃) Q ends be connected, electric capacity (C₉) and resistance (R₆) be serially connected after be parallel to bidirectional triode thyristor (BCR) (T₁、T₂) two ends, T₁End ground connection, T₂Terminate external connection end B₁, external connection end B₂Connect AC power live wire.