CN104021642A

CN104021642A - Resistance type fire alarm

Info

Publication number: CN104021642A
Application number: CN201410287413.2A
Authority: CN
Inventors: 李柱勇; 邓立
Original assignee: 李柱勇
Priority date: 2014-06-25
Filing date: 2014-06-25
Publication date: 2014-09-03

Abstract

The invention discloses a resistance type fire alarm. A singlechip AT89S52 is used as a core information processing unit, a temperature is measured by using a temperature sensor DS18B20, a smoke concentration is detected by using an MQ-2 type semiconductor resistance type smoke sensor, an A/D (Analog/Digital) converter circuit AD0832 is used for converting an analog signal sent by the smoke detection circuit into a digital signal, and the digital signal is sent into the singlechip AT89S52; the singlechip AT89S52 is used for processing the digital signal, and determining whether the digital signal is more than or equal to an alarm limit value after filtering and analyzing the digital signal, a buzzer in an alarming circuit starts sending buzzing information and an LED (Light Emitting Diode) display tube displays an exceeding smoke concentration value if the digital signal is more than the alarm limit value, and the resistance type fire alarm is in a normal state if the digital signal is less than the alarm limit value. The resistance type fire alarm disclosed by the invention is small in volume, high in precision, and capable of rapidly making an immediate response to the measured temperature. Meanwhile, an alarm part adopts a manner that an LED displays the temperature and the concentration, and the sound of the buzzer exists, thus the effect of a sound-light alarm is achieved.

Description

A kind of resistance-type fire-alarm

Technical field

The present invention relates to warning device, specifically a kind of resistance-type fire-alarm.

Background technology

Along with the fast development of city and economic construction, fire rapid spread is often one of the property sent out and destructiveness and the most serious disaster of influence power of China, once fire occurs, be easy to occur putting out a fire to save life and property not in time, fire distinguisher lacks, people on the scene is panic and escape the unfavorable factor such as slow, research and development fire alarm system is exactly in order to find incipient fire hidden danger, to stamp out a fire in time, stops it to spread, reduce the loss, ensure property and life security.

China's fire alarm system is because being subject to the restriction of economic development, make it from simple to complexity, the develop rapidly of growing out of nothing, intelligent degree has also obtained large increase, before two more than ten years, at scientific and technological content, usability and the Integrity of product, or social influence degree is all quite low, since reform and opening-up, high buildings and large mansions are flourish like the mushrooms after rain, fire alarm system faces the present situation that supply falls short of demand, is urging on constantly bringing forth new ideas of this industry technology, has therefore obtained significant development.Domestic manufacturers are is more prone to, into large enterprise, company, hotel, hotel research and development automatic fire alarm, adopt concentrated area controlling alarm mode, and this system mode is complexity but also the suitable costliness of cost not only.And in the small fireproof region of other sparse populations, just need to suit measures to local conditions to arrange one and there is practical value and low-cost detection autoalarm.

Summary of the invention

The object of this invention is to provide a kind of resistance-type fire-alarm, can make early warning, reduce and lead to massive losses to the mankind because of fire hazard.

Technical scheme of the present invention is: a kind of resistance-type fire-alarm, it is using AT89S52 single-chip microcomputer as core information processing unit, measure temperature by temperature sensor DS18B20, MQ-2 type semi-conductor electricity resistive smoke transducer detects smokescope, and the simulating signal that A/D change-over circuit AD0832 sends Smoke Detection circuit is sent into AT89S52 single-chip microcomputer after converting digital signal to; AT89S52 single-chip microcomputer, to digital signal processing, determines whether to be more than or equal to alarm limit after Filtering Analysis, the hummer being greater than in warning circuit starts to send the information of piping, and laser-emitting diode shows the smokescope value exceeding, otherwise is normal condition;

Single-chip microcomputer 9 pin of described AT89S52 single-chip minimum system circuit connect reset circuit, by reset button S1 to monolithic processor resetting; Crystal oscillator adopts 12MHZ; 31 pin of single-chip microcomputer meet high level VCC; Described reset circuit adopts key circuit;

1 pin ground connection of described DS18B20 temperature sensor, 2 pin data terminals meet the P3.3 of single-chip microcomputer, and 3 pin meet VCC, and in order to ensure DS18B20 reliable operation, 2 pin will connect the pull-up resistor of 4.7K.

The driving that described warning circuit adopts is triode 9013, and this can make up single-chip microcomputer and have little time lasting shortcoming of supplying because output current is little.

Described laser-emitting diode is selected 4 charactrons of the common anode utmost point, adopts the triode 9015 of 4 positive-negative-positives to drive; In the time of single-chip microcomputer Low level effective, the conducting of four positive-negative-positive triodes, now 4 of charactron each common port 1,4,5 and 12 pin are shown as high level, and after its data terminal input low level, charactron is lit, and the current-limiting resistance size that R12 is triode to R19 is 120 Europe.

The present invention in use, airborne smoke signal is converted into simulating signal by the smoke transducer of resistance-type fire-alarm, and convert the digital signal that single-chip microcomputer can identify to and then send into single-chip microcomputer and detect by modulus conversion chip, single-chip microcomputer completes and gives the alarm to controlling warning circuit after the processing of smog data and concentration.Respectively Pressure, Concentration, Temperature is sent in display screen to detect, and be provided with respectively temperature and the smokescope upper limit and lower limit, and in addition button regulates, and meanwhile, on audible alarm basis, adds charactron demonstration smokescope and temperature.

The present invention selects MQ-2 type semi-conductor electricity resistive sensor to have cheap and durable on hardware, be swift in response, volume urine, in advantages such as installations, adopts AT-89S52 single-chip microcomputer as main information process chip, has reasonably utilized its high speed operation performance and scientific structural design.In order to make the continual and steady work of sensor, need to provide endlessly 5V voltage to it, there is broken string or loose contact in the time that temperature exceedes the bearing value of sensor heater strip time, just can start immediately fault alarm.And that the DS18B20 temperature sensor of selecting has volume is little, precision advantages of higher, can make timely reaction to dut temperature rapidly.And adopting the mode of LED displays temperature and concentration in the part of reporting to the police, the sound of hummer in addition simultaneously, has reached the effect of sound and light alarm.

Brief description of the drawings

Fig. 1 is single-chip minimum system circuit diagram of the present invention;

Fig. 2 is DS18B20 circuit diagram of the present invention;

Fig. 3 is buzzer circuit figure of the present invention;

Fig. 4 is digital pipe display circuit figure of the present invention;

Fig. 5 is key circuit figure of the present invention;

fig. 6 is smoke transducer change-over circuit figure of the present invention.

Embodiment

A kind of resistance-type fire-alarm, it is using AT89S52 single-chip microcomputer as core information processing unit, measure temperature by temperature sensor DS18B20, MQ-2 type semi-conductor electricity resistive smoke transducer detects smokescope, and the simulating signal that A/D change-over circuit AD0832 sends Smoke Detection circuit is sent into AT89S52 single-chip microcomputer after converting digital signal to; AT89S52 single-chip microcomputer, to digital signal processing, determines whether to be more than or equal to alarm limit after Filtering Analysis, the hummer being greater than in warning circuit starts to send the information of piping, and laser-emitting diode shows the smokescope value exceeding, otherwise is normal condition;

Single-chip microcomputer 9 pin of described AT89S52 single-chip minimum system circuit connect reset circuit, by reset button S1 to monolithic processor resetting; Crystal oscillator adopts 12MHZ; 31 pin of single-chip microcomputer meet high level VCC;

The driving that described warning circuit adopts is triode 9013, and this can make up single-chip microcomputer and have little time lasting shortcoming of supplying because output current is little;

key circuitas shown in Figure 6, wherein, S2 is function key, now occurs that by once entering upper temperature limit setting system just establishes temperature, and flickering display, enters the setting of alarm temperature lower limit by twice, detects gas concentration higher limits by three capable of regulatings., S3, S4 is respectively and reduces key and increase key.S5 push button for emergency call.

As shown in Figure 7, smoke transducer MQ-2 is resistance class component, and in the time having smog, MQ-2 internal resistance value changes, thereby causes 6 pin output voltages to change, and by the conversion of ADC0832, voltage analog is changed into digital quantity to single-chip microcomputer.

Claims

1. a resistance-type fire-alarm, it is characterized in that it is using AT89S52 single-chip microcomputer as core information processing unit, measure temperature by temperature sensor DS18B20, MQ-2 type semi-conductor electricity resistive smoke transducer detects smokescope, and the simulating signal that A/D change-over circuit AD0832 sends Smoke Detection circuit is sent into AT89S52 single-chip microcomputer after converting digital signal to; AT89S52 single-chip microcomputer, to digital signal processing, determines whether to be more than or equal to alarm limit after Filtering Analysis, the hummer being greater than in warning circuit starts to send the information of piping, and laser-emitting diode shows the smokescope value exceeding, otherwise is normal condition;

1 pin ground connection of described DS18B20 temperature sensor, 2 pin data terminals meet the P3.3 of single-chip microcomputer, and 3 pin meet VCC, and in order to ensure DS18B20 reliable operation, 2 pin will connect the pull-up resistor of 4.7K;

The driving that described warning circuit adopts is triode 9013;

Described laser-emitting diode is selected 4 charactrons of the common anode utmost point, adopts the triode 9015 of 4 positive-negative-positives to drive.