ABSTRACT
Frequent occurrence of fire accidents in recent years,making a great loss of people, financial,
and material.Previously, the fire alarm and control are very backward, causing huge
losses.Nowadays,fire as well as automatic fire alarm systems have become increasingly demanded
by user.For the analysis of fire accidents,except for eliminate water pressure less,the existing fire
partition should not play a role, is the key to cause significant damage.Now the digital control
system of fire alarm and pre-have played an important role.Therefore, the fire alarm system is very
important.
This paper design a better smoke alarm with smoke sensors and SCD technology as the
core,and combines with other electronic technology.the alarm use MQ-2 combustible gas
sensor-type semiconductor to achieve smoke smoke detection sensors with high sensitivity, fast
response, the advantages of anti-interference ability, and low cost and long service life.AT89S52 is
high speed, low power, super anti-jamming, etc, is the same technology the most widely used, and
the expansion of the circuit is very wide.Not only with the smoke sensor also uses a digital
temperature sensor, the accuracy of this alarm system more perfect.
The fire alarm with AT89C52 microcontroller and MQ-2-type semiconductor resistance type
smoke sensor and digital temperature sensor as the core can realizes sound and light alarm, fault
diagnosis, concentration display, alarm limit settings, delay alarm and so on.It is a simple structure,
stable performance, easy to use, inexpensive, intelligent smoke detectors,which has some practical
value.
【Key words】AT89S52 SCD ADC DS18B20 Alarm
