10-04-2017, 08:25 PM
Automatic college bell system
Abstract:
The world over the decades has made considerable advancement in automation; automation is
employed in every sector whether it is home or industry. Here a new and inexpensive design is being
presented. This design finds a tremendous use at primary and secondary school levels as well as in colleges
where the teaching sections can span over eight periods including breaks. The advantage of this design is
that the bell rings at the start of each period without any human intervention to a great degree of accuracy
and hence takes over the manual task of switching on/off the college bell with respect to time. It uses Real
Time Clock (DS1307) which tracks the real time. The scheduled time results are compared with that of a
clock, however, some drift is noticed, which is negligible. The microcontroller AT89S52 is used to control
all the functions, it gets the time through the keypad and stores it in its memory. When this programmed
time equals the real time then the bell is switched on via a relay for a predetermined time. The bell ringing
time can be edited at any time, so that it can be reused again and again at normal class timings as well as at
exam times. Also it can be made password protected so that no unintended person can operate this system
except for the operator. For this a microcontroller has to be programmed using the C language or assembly
language for controlling the circuit.
INTRODUCTION
In today s life, everyone gives importance to time.
Time does not wait for anybody. Everything
should be performed in time & with accuracy.
Now a day s school/college bells are operated
manually. Hence there is a big question of
accuracy. Also there is necessity of manpower and
money. Hence here we have presented a system,
which saves our manpower and money & also
give highest accuracy. A bell is a percussion
instrument used in schools and colleges that
indicates the students when it is time to go to the
class in the morning and when it is time to change
classes during the day. No other instrument can do
such a work. So it is an important instrument in
both primary and secondary schools and even in
the industries and other businesses where the bell
timer plays a critical role throughout the day.
Clock towers can be heard over long distance
which was especially important in the time when
clocks were too expensive for widespread use.
And also due to literacy awareness the number of
colleges, schools and institutions are rapidly
increasing. At present bells for periods in schools
are operated manually. After every class, one
employee is engaged into operating the bell.
Automatic college bell helps us to avoid this. This
design takes over the task of ringing the bell in
colleges as the bell would ring automatically at
the schedule time. It has a Real Time Clock
(DS1307) which tracks over
the real time. When this time equals to the bell
ringing time, then the relay for the bell is switched
on.
Relay:
Relay is electro-mechanical device
which is used to isolate one electrical circuit from
another. It allows a low current control circuit to
make or break an electrically isolated high current
circuit path. Total isolation is provided by the
relay between the triggering source applied to the
terminal and the output. This total isolation is a
feature that makes relay different from other
integrated circuits and is also important in many
digital applications. It is a feature that certain
semiconductor switches (e.g. transistors, diodes
and integrated circuits) cannot provide. In this
circuit a 12V magnetic relay is used. In magnetic
relay, insulated copper wire coil is used to
magnetize and attract the plunger .
Conclusion:
Present day ringing the bell in
colleges or schools are carried out manually. The
main disadvantage of this is that one person has to
be alert for this. At the same time during that time
he could not be engage in another task. To
overcome from this, we have decided to prepare
the circuit which will be operated automatically
and the ringing of bell will start by its own time.
The time input can be edited as per requirements.
This circuit is simple to prepare and easy to
install. We can say that it will be much useful for
colleges or schools or other educational
institutions.