1. DR. RAJENDRA GODE INSTITUTE OF
TECHNOLOGY & RESEARCH
AMRAVATI
Department of Electronics & Telecommunication
Engineering
Seminar Topic :- Smoke Detection System
Presented by:- Tejaswini R. Sawarkar
Guide:- Prof. R. M. Deshmukh
Branch :- Electronic & Telecommunication
3. What is Smoke Detection System
?
A Mechanical device that is Sensitive to smoke or particular material in the air
that transmits a signal to the measuring instrument
Smoke detector consist of two parts
Sensor
Buzzer
5. Photoelectric Smoke Detector
The photoelectric type detector utilizes light as a detection
mechanism
There are two types of photoelectric smoke detector
light sensing (Scattering)
Light obscuring (Blocking)
6. Light Scattering Smoke
Detector
Light scattering Smoke detector depends on the ability
of small airborne particles to scatter light.
Scattering is due to the absorption, reflection,
refraction, polarization and diffraction.
The light emitted from the light source is not detected
by the photo sensor
When smoke particles enter in the chamber increases,
more light is scattered towards the sensor.
When the concentration of particles reach the
threshold, an alarm sound is produced
8. Light Obscuring Smoke
Detector
A projected beam can use a single light source to and
photo sensor to detect a very large area
Most such detectors use IR-LED or laser diode as a
sensor
Detection of smoke by attenuated light
Uses a separate emitter and detector
11. Ionization Smoke Detector
Have ionization chamber inside the detector
Ionization is very simple two plate chamber with
voltage across along with the radioactive source of
ionization
12. Circuit Operation
The LED will light up the light dependent resistor (LDR) and
Making its resistances very low (as low as 500 ohms). In this
case, transistor Q1 and Q2are off. When there is smoke in the
area, light from LED will be blocked resulting to an increases in
LDR
13. Why Smoke Detector ?
The circuit that is installed in the detector is up to the
standards of the electronics
All learning techniques were implemented in the circuit