CN209215273U - A kind of portable tri-state gas alarm modular circuit - Google Patents
A kind of portable tri-state gas alarm modular circuit Download PDFInfo
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- CN209215273U CN209215273U CN201821913775.8U CN201821913775U CN209215273U CN 209215273 U CN209215273 U CN 209215273U CN 201821913775 U CN201821913775 U CN 201821913775U CN 209215273 U CN209215273 U CN 209215273U
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Abstract
The utility model discloses a kind of portable tri-state gas alarm modular circuits comprising a firedamp sensor circuit, a reference voltage circuit, a linear amplifier circuit, a hysteresis loop comparator circuit, a multivibrator circuit, a general comparator circuit, a current amplification circuit, a warning circuit.Firedamp sensor circuit and reference voltage circuit form gas surveying electric bridge, and bridge output signal enters amplifier A1 and amplifies, and the 1 foot output of A1 enters the inverting input terminal of general comparator circuit A3；Amplifier A simultaneously, constitutes the hysteresis loop comparator circuit and the multivibrator circuit；The output end of the multivibrator circuit enters the non-inverting input terminal of A3, the reverse side voltage for representing face gas concentration signal is compared by A3 with the square-wave signal for representing gas density critical value range, the output signal of A3 is amplified by T1, and the collector output signal of T1 drives warning circuit sound-light alarm.
Description
Technical field
The utility model relates to a kind of compact, novel functions, easy to carry, the portable tri-states watt that are easily integrated
The technology of this alarm module circuit, especially a kind of " three condition " for being different from traditional gas alarm " two condition " alarm structure
Alarm mode, so this " tri-state " alarm is only more perfect gas alarm structure.
Background technique
In Modern Mining Corporation, gas alarm is one of most important safety equipment, any one meets working condition
Large, medium and small moulded coal mine, if being subject to the execution of detailed rules and regulations according to existing safety equipment, watt at coal mine bottom
This explosion is completely avoidable, but the accident of annual gas explosion still occurs in succession, including some large coal mines.
Main cause is not still very scientific, traditional gas report since the alarm setting threshold value of gas alarm is preset
Alert device is using a fixed threshold value as alarm threshold value voltage, due to the shadow of environment on coalface or gas alarm itself element
It rings, threshold value can change, as long as alarm is likely to will strong sound so gas density one closes on presetting threshold value
Light alarm, but often at this moment the concentration of gas may be also not dangerous, and " false alarm " of long-term " wolf comes " formula causes coalman
The bored and idea of leaving things to chance of people, coal miner usually sinks under water firedamp sensor probe, to avoid gas alarm
Harassing and wrecking, the operation of this blindness of worker are one of the main reason for causing gas explosion frequently to occur.
This tradition gas alarm belongs to " two condition " alarm, lacks a kind of critical state warning, is that worker is caused to detest
The main reason for tired.
Although the importance of gas alarm is indubitable, due to its fancy price, it is impossible to manpower one progress
Configuration, designs a kind of adjustable tri-state portable gas explosion concentration alarm module circuit of gas alarming concentration, the alarm module
It not will call the police when being lower than early warning value for gas density, sound-light alarm when gas density is higher than early warning value, gas density, which is in, faces
Can there was only light alarm when boundary's state, audible alarm will not be generated, in order to avoid induce one to dislike.This critical state is not a point,
But a range of voltage values (corresponding gas density range), all " light " is alarmed within critical range, it will not " sound " alarm.
Whether this range of voltage values is suitable, can be determined by multiple field test come final.
This threshold voltage ranges is different from the hysteresis voltage of Schmitt trigger (or hysteresis loop comparator), and hysteresis voltage is
The difference of rising edge threshold value and failing edge threshold value, the presence of hysteresis voltage only can enable worker more disagreeable, hold because delay can generate
Continuous time longer alarm, and the threshold voltage ranges that we are said belong to one of linear voltage (or rising or falling) range
Point, without break over voltage.
So this " tri-state " alarm is only more perfect gas alarm structure, this structure can derive to other
Mineral environment application, such as the alarm of temperature alarming, water-level alarm, pressure alarm, magnetic force etc..
This tri-state portable gas explosion alarm appliance module can independently become a portable gas explosion alarm appliance and carry,
Also can integrate becomes a kind of mine lamp or miners' cap with tri-state gas alarming function in mine lamp or miners' cap.
Summary of the invention
The technical problem to be solved by the utility model is to provide a kind of compacts, novel functions, easy to carry, easy
The portable tri-state gas alarm modular circuit being integrated, which can integrate becomes one in mine lamp or miners' cap
Kind has the mine lamp or miners' cap of tri-state gas alarming function.
To achieve the above object, the utility model provides a kind of portable tri-state gas alarm modular circuit comprising
One firedamp sensor circuit, a reference voltage circuit, a linear amplifier circuit, hysteresis loop comparator circuit, one
A multivibrator circuit, a general comparator circuit, a current amplification circuit, a warning circuit.The gas passes
Two arms of sensor circuit and reference voltage circuit composition gas surveying electric bridge, gas density increase, and measuring bridge loses
Balance, electric bridge export faint electric signal and amplify into the linear amplifier circuit A1, the gas density letter being amplified
Number from 1 foot of A1 output enter general comparator circuit A3 inverting input terminal；Amplifier A2 passes through resistor network R simultaneously10/R6By
Output end introduces positive feedback to non-inverting input terminal, constitutes the hysteresis loop comparator circuit, forms using by capacitor C1 and resistance R9
Differential circuit and the hysteresis loop comparator circuit constitute the multivibrator circuit；The output of the multivibrator circuit
End generates the square-wave signal for representing gas density critical value range by resistance R10, which enters the general comparison
The non-inverting input terminal of device circuit A3, general comparator A3 will represent reverse side voltage and the representative watt of face gas concentration signal
The square-wave signal of this concentration critical value range is compared, and the output end signal of A3 is put by current-limiting resistance R11 by the electric current
Big device circuit T1 amplification, the collector output signal of T1 drive the warning circuit sound-light alarm.
The reference voltage road is sequentially connected in series group by+12V power supply, resistance R1, zero potentiometer p1, resistance R2, place of working
At the sliding end outputting reference voltage of potentiometer P1 enters the inverting input terminal of amplifier A1 by resistance R3.
The firedamp sensor circuit, by+12V power supply, the compensating end C of firedamp sensor, sensitivity adjustment potentiometer P2,
The test side D of firedamp sensor, place of working are sequentially connected in series composition, and the sliding end output gas density signal of potentiometer P2 enters fortune
Put the non-inverting input terminal of A1.
Detailed description of the invention
Attached drawing 1, attached drawing 2, attached drawing 3, attached drawing 4, attached drawing 5 are used to provide a further understanding of the present invention, and constitute this
A part of application, attached drawing 1 are traditional two condition gas alarm block diagrams.Attached drawing 2 is tri-state gas density alarm principle
Figure.Attached drawing 3 is hysteresis loop comparator " hysteresis loop ".Attached drawing 4 is multivibrator waveform.Attached drawing 5 is gas density report
Alert device tri-state alarm curve distribution figure.
Specific embodiment
In Modern Mining Corporation, gas alarm is one of most important safety equipment, any one meets working condition
Large, medium and small moulded coal mine, if being subject to the execution of detailed rules and regulations according to existing safety equipment, watt at coal mine bottom
This explosion is completely avoidable, but the accident of annual gas explosion still occurs in succession, including some large coal mines.
Main cause is not still very scientific, traditional gas report since the alarm setting threshold value of gas alarm is preset
Alert device is using a fixed threshold value as alarm threshold value voltage, due to the shadow of environment on coalface or gas alarm itself element
It rings, threshold value can change, as long as alarm is likely to will strong sound so gas density one closes on presetting threshold value
Light alarm, but often at this moment the concentration of gas may be also not dangerous, and " false alarm " of long-term " wolf comes " formula causes coalman
The bored and idea of leaving things to chance of people, coal miner usually sinks under water firedamp sensor probe, to avoid gas alarm
Harassing and wrecking, the operation of this blindness of worker are one of the main reason for causing gas explosion frequently to occur.
This tradition gas alarm belongs to " two condition " alarm, lacks a kind of critical state warning, is that worker is caused to detest
The main reason for tired.
Although the importance of gas alarm is indubitable, due to its fancy price, it is impossible to manpower one progress
Configuration, designs a kind of adjustable tri-state portable gas explosion concentration alarm module circuit of gas alarming concentration, the alarm module
It not will call the police when being lower than early warning value for gas density, sound-light alarm when gas density is higher than early warning value, gas density, which is in, faces
Can there was only light alarm when boundary's state, audible alarm will not be generated, in order to avoid induce one to dislike.This critical state is not a point,
But a range of voltage values (corresponding gas density range), all " light " is alarmed within critical range, it will not " sound " alarm.
Whether this range of voltage values is suitable, can be determined by multiple field test come final.
This threshold voltage ranges is different from the hysteresis voltage of Schmitt trigger (or hysteresis loop comparator), and hysteresis voltage is
The difference of rising edge threshold value and failing edge threshold value, the presence of hysteresis voltage only can enable worker more disagreeable, hold because delay can generate
Continuous time longer alarm, and the threshold voltage ranges that we are said belong to one of linear voltage (or rising or falling) range
Point, without break over voltage.
So this " tri-state " alarm is only more perfect gas alarm structure, this structure can derive to other
Mineral environment application, such as the alarm of temperature alarming, water-level alarm, pressure alarm, magnetic force etc..
And this tri-state portable gas explosion alarm appliance module can be independently carry-on as a portable gas explosion alarm appliance
It carries, also can integrate becomes a kind of mine lamp or miners' cap with tri-state gas alarming function in mine lamp or miners' cap.
Traditional gas density alarm work principle
Since traditional gas density alarm equipment alarm sound can enable worker be sick of, but largely use must be with the presence of it for industry
Reasonability.
The circuit structure of traditional gas alarm can be referred to as " two condition " alarm, be passed gas using a comparator
The analog signal voltage of sensor output is compared with a reference voltage, and comparator exports " two-value " signal, is exactly compared
Device output signal only has 0 or 1 two states, and binary signal can be directly fed to microcontroller processing, can also be with driving oscillation electricity
Road generates multi-harmonic-oscillations signal, pushes phonation circuit to implement alarm, as shown in Fig. 1.
Traditional gas alarm is well suited for for Industrial Computer Control, because computer natively only identifies
0 or 1 binary numeration system, the unity logic concept of this " non-to i.e. mistake " for computer long-distance control for the finger that generates
Enable distortion very small but slightly inadequate for general gas alarm, centre lacks a kind of gas density and is in critical
The warning of state.
In critical state gas alarm, there is still a need for alarms, but are different from gas density strong report in the hole
Alert, the alarm for belonging to precarious position must be executed firmly: being reinforced ventilation, even stopped production；As long as critical state alarm causes
Worker's vigilance mitigates everybody be sick of as far as possible.
The adjustable tri-state gas density alarm of gas density
The characteristic that can be changed using electronic component with the variation of the imflammable gas concentration such as gas or methane, its parameter,
An electronic instrument be may make up to detect the gas density state of any range, which is exactly methane transducer or gas
Sensor.
Methane transducer
Methane transducer is to be referred to as, and all methane or the sensor of gas density of can detecte can be known as methane sensing
Device, methane transducer are used for coal mine roadway, getting working face, goaf, return aircourse, electromechanics in safety of coal mines detection system
Continuously monitoring methane concentration makes warning circuit sending sound, light alarm automatically when methane content exceeding preset limit to chamber etc., can coal supply
Mine underground operators, CH_4 detection personnel, underground administrative staff etc. carry use, also make for the fixation of above-mentioned place
With.
The design for convenience, uses carrier catalysis gas sensor MC114 as firedamp sensor element, certainly red
Outer or laser methane sensor can equally be applicable in this and be configured as gas sensitive element.
Tri-state gas density alarm electrical principle
Gas density signal by amplifying circuit, comparator circuit, is ultimately used to one light-emitting lamp of control by the design
Implement alarm with an audible alarm device (active buzzer), LAMP(is red when below preset gas density range) and
Active buzzer AMD does not work；When gas density rises to minimum preset value, LAMP is glittering, implements light alarm, direct current
Buzzer is silent, and preset value here is not a fixed voltage, is a voltage range；When gas density is more than that highest is preset
When value, LAMP and direct current buzzer AMD are all connected, and LAMP is always on, direct current buzzer AMD alarms strongly.
Highest preset value can be set to the corresponding any voltage value of gas density, and minimum preset value can be 0, can also be with
For the corresponding voltage value of some gas density.Alarm mode is the same within this voltage range values, such as above-mentioned, this report
Warning tells that worker's gas density is increasing, but is also less than than relatively hazardous degree.
Circuit attached drawing 2 gives the complete electrical schematic diagram of tri-state gas alarm.
From attached drawing 2, it can be seen that, which includes firedamp sensor circuit, reference voltage circuit, linear amplifier electricity
Road, hysteresis loop comparator circuit, multivibrator circuit, comparator circuit, current amplification circuit, warning circuit.
Firedamp sensor circuit
Firedamp sensor circuit is using carrier catalysis gas sensor MC114 as firedamp sensor element, the catalysis of MC114 type
Element works according to the principle of catalysis incendiary effect, by detecting element and compensating element, and reference voltage generating circuit matched group
At two arms of electric bridge, detecting element resistance is increased when meeting imflammable gas, bridge output voltage variation, the voltage quantities with
Gas concentration increases and increase in direct ratio, compensating element, play reference and temperature and humidity compensation.
As shown in Fig. 2, " D " in figure represents MC114 firedamp sensor detecting element, " C " represents compensating element, resistance
R1、R2, potentiometer P1Constitute reference voltage generating circuit, sensor element " D " and compensating element, " C " and reference circuit pairing
Electric bridge is formed, once electric bridge disequilibrium, exports faint electric signal immediately and is amplified by post-amplifier.
The sampled voltage signal balancing of gas density can pass through the potentiometer P in reference circuit element1Sliding end come
It adjusts；The sensitivity of gas density alarm can be by potentiometer P2It adjusts.
The linear amplifier circuit being made of ideal operational amplificr A1
When face gas concentration changes, gas sampling electric bridge exports faint electric signal, which can pass through
Ideal operational amplificr amplification, A/D conversion, the digital signal of formation can be handled for microcontroller, or display gas density
Or alarm signal is formed by operation again and implements alarm, ideal operational amplificr at this moment is in linear working state.
The electric signal of electric bridge output can certainly be directly over comparator or hysteresis loop comparator output " two-value " signal,
Pierce circuit work is pushed directly on, for loudspeaker sounding alarm, ideal operational amplificr at this moment is in nonlinear operation shape
State.This is also the common circuit structure of traditional gas alarm, and this circuit structure has the various shortcoming mentioned in this paper introduction,
Which is not described herein again.
The circuit structure for designing gas alarm herein is that above two the comprehensive of ideal operational amplificr application embodies, both
The application of linear working method, the application for having nonlinear operation mode again.
If being subject to suitable negative feedback resistor, ideal operational amplifier work between an ideal operational amplifier output and input
Make in Linear Amplifer operating mode；There is no any feedback i.e. in open loop mode of operation, ideal operational amplifier structure between output and input
At comparator circuit；If being subject to positive-feedback circuit between output and input, ideal operational amplifier constitutes hysteresis loop comparator circuit.
In Fig. 2, ideal operational amplifier A1With negative feedback resistor R4, current-limiting resistance R3Constitute an in-phase proportion computing circuit, A1
In linear amplifier mode, voltage amplification factor can be calculated by following formula:
Above formula shows the output of in-phase proportion computing circuit and inputs same phase, and exports and be greater than input.
So by adjusting resistance R3、R4Ratio, thus it is possible to vary ideal operational amplifier A1Voltage amplification factor, as illustrated
Resistance calculations, A1Voltage change can be amplified about 10 times.A will be sent to by being amplified later output voltage3Comparator circuit,
Pass through comparator A3The shutdown thresholding of adjustable gas alarm.
The multivibrator circuit being made of hysteresis loop comparator A2
Hysteresis loop comparator is also known as Schmidt trigger, hysteresis comparator.The characteristics of this comparator is as input signal ui
When being gradually increased or being gradually reduced, threshold value there are two it, and it is unequal, transmission characteristic has the shape of " hysteresis " curve, such as
Shown in attached drawing 3.
Because hysteresis loop comparator has the hysteresis characteristic of voltage, commonly use it to pulse waveform shaper, make waveform rising edge or
Failing edge becomes steep；Sometimes also make voltage amplitude identification with it, it is also the device being in daily use in digital circuit.Originally it is setting
The exponential curve that capacitor charge and discharge is formed is transformed to rectangular wave using hysteresis loop comparator in meter, constitutes a multivibrator electricity
Road.
In Fig. 2, resistance R10/R6For ideal operational amplificr A2Output end and non-inverting input terminal between introduce positive feedback
Network constitutes a hysteresis loop comparator.12V DC power supply passes through resistance R5、R7, in R5、R6、R7Intersection point " R " at be hysteresis ratio
A reference voltage is provided compared with device, due to the introducing of reference voltage, hysteresis loop comparator above in substance forms one and " adds
The threshold voltage of the hysteresis loop comparator of reference voltage ", hysteresis loop comparator can be acquired by following formula:
Wherein UT+For rising edge threshold voltage, UT_For failing edge threshold voltage, UREF≈ 6V, VCC=12V。
In Fig. 2, electrolytic capacitor C1With resistance R9The differential circuit and hysteresis loop comparator of composition together form a multi resonant
Pierce circuit, oscillatory process are summarized as follows:
Before alarm powers on, electrolytic capacitor C1Not having storage energy and left and right terminal potential is all 0, comparator A2Output is
0.Alarm powered on moment, based on the characteristic that capacitance voltage cannot be mutated, capacitor C1Two terminal potentials all rise to about 6V's
Near reference voltage, it is greater than A2The failing edge threshold voltage U of hysteresis loop comparatorT—, it is less than rising edge threshold voltage UT+, 12V power supply
Pass through resistance R5、R9And comparator A2Output end be capacitor C1Reverse charging, capacitor C1Right end voltage UA2-13(comparator A2's
13 foot voltage of input terminal) it gradually decreases, voltage drops to hysteresis loop comparator A2Failing edge threshold voltage UT—, then reduce a nothing
When poor a small amount of, A2Output UA2-14It is high level 12V by low level 0V overturning.
Due to the potential change very little at datum mark " R ", therefore comparator A2Output 12V voltage pass through resistance R9、R7For electricity
Hold C1Positive charge, capacitor C1Right end voltage (i.e. UA2-13Voltage) it gradually rises, work as UA2-13Voltage is increased to hysteresis loop comparator A2
Rising edge threshold voltage UT+, then when increasing a dimensionless, A2Output end level UA2-14It is reversed to by high level 12V low
Level 0V, so far, to capacitor C1Next reverse charging process start again, this process circulation does not stop, constitute multi resonant
Pierce circuit forms multi-harmonic-oscillations waveform as shown in Fig. 4.
The frequency of oscillation of multivibrator is by capacitorC 1, resistanceR 9、R 10、R 6It adjusts, alarms if necessary to light glittering
Words are about adjusted in < 10Hz(because the persistence of vision development of human eye can about continue 0.1s or so), if light alarm is always on
, frequency of oscillation can be high.
It is all directly from hysteresis loop comparator A usually using this oscillator signal2Output end (14 foot) number of winning the confidence, this
It is then from resistance R in design6And R10Node " P " at the number of winning the confidence, the swing of waveform peak-to-peak value is than comparator A here2It is defeated
Source is smaller, and is sent to comparator A3As A3The second input signal (reverse phase end signal) be very ideal.
Comparator circuit A3 and warning circuit
Ideal operational amplifier A3Circuit is in open loop mode of operation, therefore can be used as a comparator and treat, it will be from linear
Amplifier A1Represent the voltage value of gas density and from hysteresis loop comparator A2Square-wave signal compare, output signal will driving report
Alert circuit work.Hysteresis loop comparator A2The square-wave signal of output passes through resistance R10It is whether safe or danger pre- to constitute gas density
Value is set, preset value here is a voltage range, and the peak value and valley of square wave pass through R10Decompression is as highest preset value and most
Low preset value, therefore by adjusting resistance R6、R10Ratio, the preset value range of gas alarm can be arbitrarily adjusted, at this
Within ranges, alarm all alarms " light ", without will start strong acoustic alarm.
As the gas concentration U that firedamp sensor MC114 is detectedA1-1When lower than preset value range, linear amplifier A1It is defeated
Voltage, which is lower than, out comes from A2Square-wave signal valley (minimum preset value, similarly hereinafter), that is, represent gas density straight line (it is assumed that watt
This concentration is gradually increasing, and actual conditions may also be so) it is completely under the square-wave signal voltage for representing preset value, such as Fig. 5
Gas density alarm tri-state alarm curve t≤t1Part, at this moment due to amplifier A3In-phase end applied signal voltage always
Lower than reverse side applied signal voltage, therefore comparator A3Output be always zero.
By transistor T1The current amplification circuit of composition is in by state, and luminous LAMP and direct current active buzzer all do not have
There is electric current to pass through, gas alarm does not have any warning, illustrates that face gas concentration is in a safe condition.R11For T1Ground level limit
Leakage resistance, due to T1It is lower that base-penetrates impedance, if comparator A3It is directly connected to transistor T1, biggish ground level driving current can
It can meeting damage comparison device A3。
The voltage value U representated by the gas density that firedamp sensor detectsA1-1In representing preset value square-wave signal
Peak value (highest preset value) and valley between when, be equivalent to t as shown in Figure 51≤t≤t2Part, at this moment due to amplifier A3's
In-phase end applied signal voltage is greater than the minimum preset threshold voltage of reverse side for a moment, for a moment lower than maximum preset threshold voltage, therefore compares
Compared with device A3Output signal be a square-wave signal, output square wave frequency and hysteresis loop comparator A2Multi-harmonic-oscillations frequency it is identical, but
A3Output square wave amplitude be 12V and with multi-harmonic-oscillations signal inversion.
Gas density is in t1≤t≤t2When, the oscillator signal of comparator output passes through transistor T1Amplify electric current, is formed
DC pulse voltage push gas alarm LAMP it is glittering.
Since the ideal signal of active buzzer work is direct current, although certain active buzzers are in specific exchange letter
It can also work under number, it is only very high to the voltage of AC signal and frequency requirement, therefore at this moment active buzzer AMD is in silence
State illustrates that the gas density of working face is rising but be less than precarious position, but must cause the vigilance of staff, when
It carves and prepares to withdraw working face, or reinforce ventilation, reduce gas density.
The voltage value U representated by the gas density that firedamp sensor detectsA1-1, it is completely in that represent gas density pre-
Set the voltage value U of value square-wave signalA2-12On when, be equivalent to t >=t as shown in Figure 52Part, at this moment due to amplifier A3It is same
Phase end applied signal voltage is consistently greater than reverse side applied signal voltage, therefore comparator A3Output be always high level 12V,
12V voltage passes through resistance R11Transistor T is driven after current limliting1Fully on, gas alarm LAMP is always on, the alert sound of active buzzer
Your writing illustrates that face gas concentration is in the hole, and staff must withdraw scene, guarantees safety.
Production and points for attention
Zero potentiometer P1It needs to cooperate by field test and with standard gas alarm to adjust, in order to improve control
Precision, P1、P2Using double-round potentiometer, the highest and lowest preset value for critical state of alarming can be by resistance R6/R10Adjustment.
In order to change LED flash frequency, replacement C is removed with different capacitances1, the slower speed of biggish value reflection.
Alarm module can integrate in mine lamp, or be integrated in miners' cap, the 12V of alarm module power supply can directly by
Mine lamp power supply, if mine lamp voltage mismatch, can suitably modified control circuit parameter, amplifier LM324 single supply power when, supply
Electric range is 3V ~ 32V.
This tri-state gas alarm is changed the less humanized disadvantage of traditional two condition gas alarm, is taken full advantage of
Three kinds of operating modes specific to operational amplifier: it is linear, compare, hysteresis compares, and provides a kind of brand-new alarm mode, this
Alarm mode can use other mineral environments such as temperature detection, air pressure detection etc. completely.
The shortcomings that this alarm mode is when gas density is in critical state, and LED is glittering, but gas density is in danger
It can not achieve glittering mode when dangerous state, can be only in the mode of being always on.
Claims (3)
1. a kind of portable tri-state gas alarm modular circuit comprising a firedamp sensor circuit, a reference voltage
Circuit, a linear amplifier circuit, a hysteresis loop comparator circuit, a multivibrator circuit, a general comparator
Circuit, a current amplification circuit, a warning circuit；The firedamp sensor circuit and reference voltage circuit composition watt
Two arms of this measuring bridge, when gas density increases, measuring bridge disequilibrium, electric bridge exports faint electric signal and enters institute
It states linear amplifier circuit A1 to amplify, the gas density signal being amplified enters general comparator electricity from the output of 1 foot of A1
The inverting input terminal of road A3；Amplifier A2 passes through resistor network R simultaneously10/R6Positive feedback, structure are introduced from output end to non-inverting input terminal
At the hysteresis loop comparator circuit, the differential circuit and the hysteresis loop comparator circuit structure being made of capacitor C1 and resistance R9 are utilized
At the multivibrator circuit；The output end of the multivibrator circuit represents gas density by resistance R10 generation and faces
The square-wave signal of dividing value range, the square-wave signal enter the non-inverting input terminal of the general comparator circuit A3, general comparator
A3 carries out the reverse side voltage for representing face gas concentration signal with the square-wave signal for representing gas density critical value range
Compare, the output end signal of A3 is amplified by current-limiting resistance R11 by the current amplifier circuit T1, and the collector of T1 exports letter
Number driving warning circuit sound-light alarm.
2. a kind of portable tri-state gas alarm modular circuit according to claim 1, it is characterised in that: the benchmark
Voltage road is sequentially connected in series and is formed by+12V power supply, resistance R1, zero potentiometer p1, resistance R2, place of working, the cunning of potentiometer P1
Moved end outputting reference voltage, the inverting input terminal of amplifier A1 is entered by resistance R3.
3. a kind of portable tri-state gas alarm modular circuit according to claim 1, it is characterised in that: the gas
Sensor circuit, by the detection of+12V power supply, the compensating end C of firedamp sensor, sensitivity adjustment potentiometer P2, firedamp sensor
End D, place of working are sequentially connected in series composition, and the sliding end output gas density signal of potentiometer P2 enters the homophase input of amplifier A1
End.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821913775.8U CN209215273U (en) | 2018-11-20 | 2018-11-20 | A kind of portable tri-state gas alarm modular circuit |
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| CN201821913775.8U CN209215273U (en) | 2018-11-20 | 2018-11-20 | A kind of portable tri-state gas alarm modular circuit |
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| CN209215273U true CN209215273U (en) | 2019-08-06 |
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| CN201821913775.8U Expired - Fee Related CN209215273U (en) | 2018-11-20 | 2018-11-20 | A kind of portable tri-state gas alarm modular circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109580715A (en) * | 2018-11-20 | 2019-04-05 | 山西工程技术学院 | The design and implementation methods of portable tri-state gas alarm module |
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2018
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109580715A (en) * | 2018-11-20 | 2019-04-05 | 山西工程技术学院 | The design and implementation methods of portable tri-state gas alarm module |
| CN109580715B (en) * | 2018-11-20 | 2024-03-12 | 山西工程技术学院 | Portable tri-state gas alarm |
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