1. GROUP MEMBER
NAME ROLL NO.
DEBASISH PAL 14402811013
DEOBRAT CHATTERJEE 14402811015
GOURAV GUPTA 14402811017
SHAIKH SHAMIM HASSAN 14402811045
SUBHABRATA GANGULY 14402811053
1
Room temperature controller using Relay
Presentation on Final Year Project
(Duration : 1 Year)
DATE: 13TH MAY ,2015
UNDER GUIDANCE : PROF. MADHUCHHANDA MAJUMDAR
2. Objective of Project
• Our objective of making this project is for reducing the power consumption.
• It may also be used for automatic monitoring the changes in the
environment.
• In near future, it can also be used in different industries where automatic
monitoring and control of temperature is needed.
3. 3
•A temperature controller is a device used to hold a desired temperature at a specified
value.
•There are two fundamental types of temperature control
•open loop control
•closed loop control
open loop control
closed loop control
4. 4
Types of Temperature sensors:
Thermistors:
Thermistors are thermally sensitive resistors.
Precise change in electrical resistance when subjected to a corresponding change in body
temperature.
PTAT sensor:
A proportional to absolute temperature (PTAT) sensor is capable of reducing a sensing error
resulted from a mismatch between circuit components. The PTAT sensor includes a control
unit, a sensing unit and a calculation units.
AD 590:
AD590 temperature sensor is a current-type device, the current output is proportional to the
absolute temperature.
5. Description of the entire circuit
There are four functional parts:
• Power Supply
• Sensing part
• Comparison part
• Relay
Power supply: We are basically using a Transformer to step down the supply voltage and getting 5
voltage as output.
Sensing Part: We are using AD590 sensor. AD590 is a temperature sensor.
Comparison Part: In Comparison part, there is a Comparison in between the reference voltage or our
standard temperature and output of AD590 sensor or actual temperature.
In the Comparison part: We are basically comparing a voltage with a fixed reference voltage
Relay: A relay will switch one or more poles, each of whose contacts can be thrown by energizing the
coil in two ways:- a) Normally open
b) Normally closed
10. Temperature sensing part
•AD590
AD590 temperature sensor is small, small thermal inertia,
fast response, good stability, high accuracy measurement,
is widely used, often as a general purpose digital
thermocouple temperature measurement and
compensation.
14. RELAY
At first when the non inverting terminal does not exceeds the inverting terminal the o/p of the op-amp in the
comparison part is a negative trigger which means the transistor is not getting triggered .hence he relay is no
not energized and the relay is in normally open condition.
15. Now when the noninverting terminal exceed the inverting terminal the o/p of the op-amp gives a positive trigger to the
transistor .hence the transistor gets activated and the depletion layer between emitter and base gets reduced which
helps the relay to get energized.
16. 6. Application:
Heat Treat/Oven Temperature: controllers are used in ovens and in heat-treating applications within furnaces,
ceramic kilns, boilers, and heat exchangers.
Packaging: In the packaging world, machinery equipped with seal bars, glue applicators, hot melt functions, shrink
wrap tunnels or label applicators must operate at designated temperatures and process time lengths.
Temperature controllers precisely regulate these operations to ensure a high quality product output.
Plastics: Temperature control in the plastics industry is common on portable chillers, hoppers and dryers and
molding and extruding equipment. In extruding equipment, temperature controllers are used to precisely monitor
and control temperatures at different critical points in the production of plastic.
Healthcare: Temperature controllers are used in the healthcare industry to increase the accuracy of temperature
control. Common equipment using temperature controllers includes laboratory and test equipment, autoclaves,
incubators, refrigeration equipment, and crystallization growing chambers and test chambers where specimens
must be kept or tests must be run within specific temperature parameters.
Food & Beverage: Common food processing applications involving temperature controllers include brewing,
blending, sterilization, and cooking and baking ovens. Controllers regulate temperature and/or process time to
ensure optimum performance.
19. Future Plan:
1. Can be used in cold storage to maintain a constant temperature in the room.
2. Can be used in house or apartment in places where the temperature variation is high between day
to night.
3. Can be used within the equipment to lower the heating effect.
4. Can be used in the power station as to protect the equipment from getting heated or getting
damaged.
5. As no microcontroller is used in the circuit, the cost of the circuit is low.
