CN207601992U - A kind of smoke detector based on photoelectric sensing structure - Google Patents

Abstract

The utility model provides a kind of smoke detector based on photoelectric sensing structure,Its structure design advantages of simple,With extremely strong antijamming capability,It can solve the problems, such as that the wrong report phenomenon under muting sensitivity generates,Greatly improve the alarm accuracy rate of photoelectric smoke alarm,It includes the forward-type light channel structure of 90 ° of scatteringangleθ ＞,Forward-type light channel structure includes infraluminescence pipe two,The detector further includes the backward type light channel structure of 90 ° of scatteringangleθ ＜,Backward type light channel structure includes infraluminescence pipe one,The output terminal of forward-type light channel structure and the emitted light output of backward type light channel structure are received by photoelectric smoke sensor photodiode,Input terminal of the photoelectric smoke sensor photodiode as smoke signal,The output terminal of photoelectric smoke sensor is linked in sequence amplifying circuit,Cpu data processing unit,Warning device,Software algorithm module is packaged in cpu data processing unit.

Description

A kind of smoke detector based on photoelectric sensing structure

Technical field

The utility model is related to smoke detector technical field, specially a kind of smog based on photoelectric sensing structure is visited Survey device.

Background technology

Optical detector of fire smoke is a kind of by utilizing photoelectric sensing principle through data processing to smoke particle scattering properties To monitor the fire-alarm of smog.The optical detector of fire smoke being commonly used mainly uses the forward direction of 90 ° of scatteringangleθ ＞ Formula light channel structure, the background signal of the detector of this structure is weaker, and easy to manufacture therefore is widely adopted, but this spy If black smoke alarm requirement will be reached by surveying device, it is necessary to it is realized by improving the sensitivity of smoke sensor, but when sense cigarette spirit When sensitivity improves, phenomena such as cigarette weak present in environment, dust, moisture, also can clearly be perceived, and send out alarm signal, from And lead to report by mistake the appearance of phenomenon.

Providing in the prior art a kind of reduces photoelectric smoke detection by the way of the compensation of additional temperature sensor The sensitivity of device, but the temperature of the black smoke in the environment is low, the temperature difference is too small, and the temperature sensing of temperature sensor requirement is not achieved During setting value, smoke detector cannot effectively realize alarm, and the ambient temperature in addition to black smoke can also pass temperature Sensor has an impact, it is also possible to cause to report the appearance of phenomenon by mistake.

On the market the optical detector of fire smoke of generally existing single supply power supply operation amplifier circuit as shown in figure 4, its The direct reference point connection ground of input signal, since input signal is small-signal, when the common mode interference signal input of negative polarity, Lead to the ability of the amplifying circuit unrestraint common mode interference signal, so as to further increase the wrong report of the optical detector of fire smoke Rate.Though and negative and positive dual power power supply is used to inhibit to interfere, peripheral circuit and very cumbersome also increase cost.

Utility model content

For single supply in the prior art power supply poor anti jamming capability, easy generation wrong report, cannot effectively realize Alarm, the problems such as double power supply circuit is cumbersome, of high cost, the utility model provides a kind of cigarette based on photoelectric sensing structure Fog detector, structure design advantages of simple is at low cost, have extremely strong antijamming capability, it can be achieved that under muting sensitivity can It by alarm, and can avoid the problem that the wrong report phenomenon under high sensitivity generates, make the alarm accuracy rate of photoelectric smoke alarm It greatly improves.

A kind of smoke detector based on photoelectric sensing structure, including 90 ° of forward-type light channel structures of scatteringangleθ ＞, The forward-type light channel structure includes infraluminescence pipe two, which is characterized in that after the detector further includes 90 ° of scatteringangleθ ＜ To formula light channel structure, the backward type light channel structure include infraluminescence pipe one, the output terminal of the forward-type light channel structure with The light that the output terminal of the backward type light channel structure is sent out is received after being scattered by photoelectric smoke sensor photodiode, institute State input terminal of the photoelectric smoke sensor photodiode as smoke signal, output terminal is linked in sequence amplifying circuit, CPU Data processing equipment, warning device are packaged with software algorithm module in the cpu data processing unit；

The noninverting input mouth 4 that the amplifying circuit includes operational amplifier U1, the operational amplifier U1 connects resistance One end of R1, one end of the other end connection signal input terminal IN of the resistance R1, the port 2 of the operational amplifier U1 connects Ground, the port 3 of the operational amplifier U1 connect direct voltage source VCC, and the output port 5 of the operational amplifier U1 connects respectively One end of signal output port OUT, one end of resistance R3, capacitance C2 are connect, the reverse input end mouth 1 of the operational amplifier U1 divides Not Lian Jie the other end of resistance R3, the other end of capacitance C2, resistance R2 one end, the other end connection capacitance C1 of the resistance R2 One end, the floating ground potential of other end connection of other end connection floating the ground potential Va, the signal input part IN of the capacitance C1 After Va respectively with the other end of the capacitance C1, one end of resistance R4, one end of capacitance C3, resistance R5 one end, the resistance It is grounded after the other end connection of the other end, resistance R5 of the other end connection direct voltage source VCC, the capacitance C3 of R4.

It is further characterized by communication interface of the warning device for buzzer or as alarm signal output；

Using the above structure of the utility model, after using forward-type light channel structure and being compounded with 90 ° of scatteringangleθ ＜ To formula light channel structure, the light that infraluminescence pipe two, infraluminescence pipe one are sent out is sensed after smog scatters by photo-electric smog Device photodiode is received and is generated and the associated electric signal of smoke density.It is responded in this way using preceding backward light path dialogue, black smoke Complementation, through amplifying circuit amplification and cpu data processing unit data are handled, make detector under muting sensitivity Can photoelectric smoke so as to which the black smoke solved the problems, such as under muting sensitivity can realize alarm, be substantially increased with Normal Alarm The alarm accuracy rate of detector, and reduce and report phenomenon by mistake caused by environmental pollution；

Backward type light channel structure has the diffusing reflection of black smoke and greyish white smoke particle response but the rising of smokescope is converted Variable quantity for electric signal is smaller, and forward-type light channel structure is to the variation of the Mie scattering of greyish white smoke particle compared with sensitive electrical signal Measure it is larger, but its reduce sensitivity after black smoke particle cannot be responded, compound two kinds of light paths pass through in cpu data processing unit Software algorithm module just can effectively solve black smoke acquisition under muting sensitivity, realize reliable alarm, the device is without temperature Degree sensor can reduce detector sensitivity, and the environmental problems such as smog weak in this way, dust, moisture are just not easy to cause wrong report It is alert；

Amplifying circuit input signal IN is inputted by the way of being connected with floating ground potential Va, and such operational amplifier U1 is defeated Entering the common mode interference signal at end can be added on the voltage on this floating ground, and the common mode weak signal of negative polarity will be lifted to anode Property, using the common mode inhibition capacity of operational amplifier U1, the inhibition of the common mode interference signal of single supply power supply amplifier is realized, greatly The antijamming capability of the device is improved greatly；Simultaneously because the circuit is powered for single supply, so as to substantially reduce financial cost.

Description of the drawings

Fig. 1 is the flow diagram of the utility model；

Fig. 2 is the forward-type light channel structure of the utility model and the structure diagram of backward type light channel structure；

Fig. 3 is the amplifying circuit circuit diagram of the utility model；

Fig. 4 is the amplifying circuit schematic diagram in common smoke detector on the market at present.

Specific embodiment

As shown in Figure 1 and Figure 2, a kind of smoke detector based on photoelectric sensing structure, before 90 ° of scatteringangleθ ＞ To formula light channel structure 2, forward-type light channel structure includes two 2-1 of infraluminescence pipe, which further includes 90 ° of scatteringangleθ ＜'s Backward type light channel structure 1, backward type light channel structure include one 1-1 of infraluminescence pipe, and the output terminal of forward-type light channel structure 2 is with after The input terminal of photoelectric smoke sensor photodiode 3 is connected respectively to the output terminal of formula light channel structure 1, and photo-electric smog passes Input terminal of the sensor photodiode 3 as smoke signal, output terminal are sequentially connected with amplifying circuit 4, cpu data processing unit 5th, warning device 6 are packaged with software algorithm module 51 in cpu data processing unit 5, and warning device is for buzzer or as alarm The communication interface of signal output；

As shown in figure 3, amplifying circuit includes operational amplifier U1, the noninverting input mouth 4 of operational amplifier U1 connects electricity One end of R1, one end of the other end connection signal input terminal IN of resistance R1 are hindered, the port 2 of operational amplifier U1 is grounded, operation The port 3 of amplifier U1 connects direct voltage source VCC, and the output port 5 of operational amplifier U1 distinguishes connection signal output port OUT, one end of resistance R3, capacitance C2 one end, the reverse input end mouth 1 of operational amplifier U1 connects the another of resistance R3 respectively End, one end of the other end of capacitance C2, resistance R2, one end of the other end connection capacitance C1 of resistance R2, the other end of capacitance C1 After the floating ground potential Va of other end connection of connection floating ground potential Va, signal input part IN respectively with the other end of capacitance C1, resistance One end of R4, one end of capacitance C3, resistance R5 one end, resistance R4 the other end connection direct voltage source VCC, capacitance C3's is another One end, resistance R5 the other end connection after be grounded.

Its concrete operating principle is as described below：The light that one 1-1 of infraluminescence pipe, two 2-1 of infraluminescence pipe are sent out is through cigarette Mist scatters, and backward type light channel structure 1 has the diffusing reflection of black smoke and greyish white smoke particle response, and forward-type light channel structure 2 is to ash The Mie scattering of white cigarette particle is larger compared with the variable quantity of sensitive electrical signal, and black smoke particle cannot be responded, compound two kinds of light paths Smokescope, and pass through photoelectric smoke sensor photodiode 3 and receive and generate and the associated electric signal of smoke density, telecommunications Number amplify through single supply operational amplification circuit 4, direct voltage source VCC is divided through resistance R4, R5, and voltage is generated on resistance R5 The floating ground voltage of floating ground potential Va is formed, capacitance C3 is filter capacitor, this floats ground since common mode interference signal can be added to On voltage, using the superpower common mode inhibition capacity of operational amplifier, it can effectively inhibit interference signal, then will be after inhibition interference signal Signal input cpu data processing unit 5, processing judgement is carried out to signal data through software algorithm module 51, if smokescope Data are more than set normality threshold, and cpu data processing unit 5 signals to warning device 6, buzzer response, if smog Concentration data is less than set normality threshold, and cpu data processing unit 5 sends out normal signal；

Forward-type light channel structure and backward type light channel structure are optics labyrinth structure, improved labyrinth structure such as Fig. 2 Shown, the reflection of backward type light channel structure is very big, this be labyrinth structure design difficult point, mainly the angle-determining of angle of scattering and The volume reflection in labyrinth is excessive and has flooded the scattered quantum value of smog, passes through the multiple design and examination to light path and labyrinth structure It tests, to determine the angle of angle of scattering and weaken volume reflection, by greatly reducing volume reflection, to avoid the scattered quantum of smog has been flooded Value.Using labyrinth structure shown in Fig. 2, detector sensitivity can be made than originally to reduce by more than 50.

Claims (2)

1. a kind of smoke detector based on photoelectric sensing structure, including 90 ° of forward-type light channel structures of scatteringangleθ ＞, institute It states forward-type light channel structure and includes infraluminescence pipe two, which is characterized in that the detector further includes the backward of 90 ° of scatteringangleθ ＜ Formula light channel structure, the backward type light channel structure include infraluminescence pipe one, the output terminal of the forward-type light channel structure and institute It states after the light that the output terminal of backward type light channel structure is sent out is scattered and is received by photoelectric smoke sensor photodiode, it is described Input terminal of the photoelectric smoke sensor photodiode as smoke signal, output terminal are linked in sequence amplifying circuit, CPU numbers According to processing unit, warning device is packaged with software algorithm module in the cpu data processing unit；

The noninverting input mouth 4 that the amplifying circuit includes operational amplifier U1, the operational amplifier U1 connects resistance R1's One end, one end of the other end connection signal input terminal IN of the resistance R1, the port 2 of the operational amplifier U1 are grounded, institute The output port 5 for stating port 3 connection the direct voltage source VCC, the operational amplifier U1 of operational amplifier U1 connects letter respectively Number output port OUT, one end of resistance R3, capacitance C2 one end, the reverse input end mouth 1 of the operational amplifier U1 connects respectively The other end of connecting resistance R3, the other end of capacitance C2, resistance R2 one end, the one of the other end connection capacitance C1 of the resistance R2 End, after the other end of the capacitance C1 connects the floating ground potential Va of other end connection for floating ground potential Va, the signal input part IN Respectively with the other end of the capacitance C1, one end of resistance R4, one end of capacitance C3, resistance R5 one end, the resistance R4's It is grounded after the other end connection of the other end, resistance R5 of the other end connection direct voltage source VCC, the capacitance C3.

A kind of 2. smoke detector based on photoelectric sensing structure according to claim 1, which is characterized in that the alarm Communication interface of the device for buzzer or as alarm signal output.