Question

Temperature controlled

1. INTRODUCTION
1.1 Background of the Study

Answer 1

INTRODUCTION
Temperature is the degree of hotness or coldness of a body or an environment.
Control System: A control system is a device or a set of devices that manages, commands,
directs or regulates the behaviour of other devices or systems.
Thus, a Temperature Controller is a device or set of devices that manages, commands, directs or regulates the behaviour of other devices or systems in order to maintain the degree of hotness or coldness of a body or an environment.
A Temperature Controller keeps the environment at a desired temperature regardless of fluctuations in the exterior weather conditions just like a thermostat but the advantage of having a temperature control system over a thermostat is that it saves energy and money by automatically maintaining different temperatures at different times of the day and night. It is usually a feedback system having a control loop, including sensors, control algorithms and actuators.
Its a thermostat that knows when we need it and when we don’t, thus it acts as a energy saver.
A temperature controller has a small programmable digital logic controller
device, wired to a heating and/or cooling system of about the size of a thermostat.It contains a small circuit board and a memory chip.
After setting the temperature controller to a desired temperature, known as a set point,
the system will utilize the heater and/or air conditioning unit as actuators, to
maintain that setting for the duration programmed.

BACKGROUND
Automatic temperature controller are being used since 18th century and the idea was proposed by Warren S. Johnson.
In the modern scenario,we need temperature controllers due to the abrupt changes in climate due the Green House effect .
The temperature controllers are used in-
HOME: Certain food materials have an acceleration in their decay if their temperature rises or falls below a certain temperature.
INDUSTRIES: Mainly Manufacturing and Pharmaceutical
Industries need to store certain production materials within a
specific temperature range.
MORGUES: In morgues dead bodies have to be preserved at a certain
temperature to prevent them from accelerated decay.
IN JETS AND AIRCRAFTS: The temperature of devices for measurement of weather elements such as temperature, air pressure and humidity should be regulated within the aircraft in order to sustain its weight.

Certain important terminologies related to temperature controller are-
1.Controlled Variable: Factor controlled by the Control System. In
this case, it is the temperature.
2. Sensor: The device or unit that measures/detects the temperature of the
environment at a given time.
3.Actuators/Effectors: The output/controlled element and related devices or units that
are used to affect the temperature of the environment. In this case, it is the alarm unit.
4. Controller:The device which processes the temperature reading from
the sensor and generates results to activate the appropriate effectors. In this
case, it is a microcontroller.
5. Set-point: The reference point for the Controller. It is set by the user. The Controller compares the readings received from the sensor with
the set point in order to determine which actuator is appropriate.
6. Thermostat Function: The process that involves comparing the current temperature
status received by the sensor with the set-point
7. Temperature Breach: Any instance whenever the set-point is compromised.

The Importance of a Temperature Controllers are:-
1. Economic Importance – Temperature Controllers are economically important as
they help in saving energy . It is achieved by making sure that the heating and cooling units are only functioning according to the need.
2. Safety Objective – Electrical Fires have been minimized because these
controllers turn off heating and cooling units when they are not necessarily in
use, thus preserving lives and property.
3. Wastage of Resources Prevention – In Homes and Industries much wastage of
useful resources have been prevented. These Systems efficiently manage the temperature of storage areas, thus keeping stored items at temperatures and extending their value period.