Transcript Design and Simulation of a Temperature

By
Saleh Braki Alrashedi
ID:291103609
Under supervision of
Dr. Abdu Idris
Abstract
The triggering of this device depends on the action of a
thermistor . This is a bar, disc or bread of semiconducting
material with the special property that its electrical
resistance decreases appreciably as its temperature
increases. The variation of its resistance is used to trigger a
circuit to switch on an alarm device whenever the
temperature exceeds a given level. We can arrange for the
alarm to be set off when the green house becomes
overheated, or when a house catches fire. The circuit can
be modified to operate in a reverse manner, so that the
alarm is triggered when the temperature falls below a given
level, making it useful as s frost detector.
Objective of the project
The objective of the project is to design and simulate a
temperature warning device system using the Proteus
software .
Introduction
Temperature measurement in today’s industrial environment encompasses a wide
variety of needs and applications. To meet this wide array of needs the process
controls industry has developed a large number of sensors and devices to
handle this demand. In this experiment you will have an opportunity to
understand the concepts and uses of many of the common transducers, and
actually run an experiment using a selection of these devices. Temperature is a
very critical and widely measured variable for most mechanical engineers.
Many processes must have either a monitored or controlled temperature. This
can range from the simple monitoring of the water temperature of an engine or
load device, or as complex as the temperature of a weld in a laser welding
application. More difficult measurements such as the temperature of smoke
stack gas from a power generating station or blast furnace or the exhaust gas of
a rocket may be need to be monitored. Much more common are the
temperatures of fluids in processes or process support applications, or the
temperature of solid objects such as metal plates, bearings and shafts in a piece
of machinery.
Certification
Certified that the contents and form of research report
entitled “Design and Simulation of a TemperatureOperated Alarm System ”submitted by Salih B. have
been satisfactory for the Partial Fulfillment of the
Requirements for the Degree of Science in Science,
The Majmmah University.
Figure 1: Example of an industrial control relay
commonly used on movable spans
Relay and Contactor Unit The connection of the relay and contactor circuit is
shown in Fig.2
Alarm
system
operation
When the switch is ON then a certain voltage is generated from the variable
resistor to the base of the transistor, a certain collector current accordingly is
generated and applied to the relay. The light emitting dide gives light and at the
same time the relay energizes and switches on the siren circuit to produce loud
sound of a fire brigade siren.
V2
R2
110V
560
RL1
12V
D2
C1
D1
470u
1N4148
BUZ1
LED-RED
V1
BUZZER
15V
L2
50V
R1
10
RV1
Q1
+0.55
10k
mA
43%
R6
1K
+6.32
C2
Volts
470u
BC548
CONCLUSIONS
A simple simulated reliable temperature controller was
designed and tested successfully. Variable resistor is
was used instead of the temperature sensor Cold
junction compensation circuit is provided
THANK YOU