CONSTRUCTION OF AN ELECTRONIC BELL INDICATOR.

ABSTRACT

This research work deals with the design and construction of an automatically triggered bell ringer circuit. Several previous attempts have been developed on intruder alert and motion detection systems, complex systems that operate excellently well. The automatically triggered bell ringer circuit integrates knowledge of these previous models and utilizes more readily available components. It also introduces the use of two sensors, thereby increasing its sensitivity. Major components used in the work are the Force and Light sensors, sensors that depict the concepts of pressure and light resistivity/conductivity respectively, and a laser beam directly projected permanently on the light sensor’s surface. A force exerted on the Force sensor triggers a buzzer alarm and likewise, an obstruction in the path of the laser triggers the buzzer alarm. Once there is pressure exerted on the Force sensor, the resistance tends to infinity, and voltage drops across it bias the diode and transistor and the voltage reaching the buzzer triggers it. Likewise, the resistance of the light sensor tends to infinity when in darkness, and the voltage dropped across it also biases a diode and transistor and triggers the buzzer alarm. The work has been tested and seen to have a higher sensitivity and is much cheaper than its counterparts.

 

 

CHAPTER ONE

INTRODUCTION

1.2  BACKGROUND OF THE STUDY

The problem of lack of efficient means of communication is traced from the punitive age when drums and gongs were the means of sending sound signals that had to appear to defer solutions.  Yet, it has been under continuous modification and improvement.

Whistle, flute, trumpet, and some other sound instruments succeeded the era of the ordinary drum.  They were then seen as a better instrument for communication between two persons or groups of people.  All these were geared towards finding a better and more convenient means of sending sound signals, manually operated mechanical bell signal stroke bell, continuous ring bell, tremble bell and later, electronic bell indicator was sequentially invented as a result of technological improvement.

However, the electronic bell indicator is an electronic device used as a means of communication in large organizations such as big hotels, guest houses, hospitals, etc.

The communication process is between the guest and the receptionist.  For instance, if a guest in room one needs the attention of the receptionist, he will press the button or switch in his room and immediately the bell will ring to alert the receptionist, and the bulb will light in the receptionist’s office to indicate the particular room his/her attention is needed.

1.2     AIMS AND OBJECTIVES

We carried out this research project to improve the weaknesses described in the system above.  The project is all about the design, construction, and operation of an electronic bell indicator system.  It was triggered by the need to have a new system as a better answer to communication problems being faced by guests in big hotels and guest houses.  Therefore, we have compacted the bulky system which has been in use in big hotels to a smaller model thereby making it possible and easy to get for use in smaller complexes.

When the bigger circuit of an electronic bell indicator system is in place, a guest who probably stays on the fourth floor of a hotel needs the attention of the receptionist, all he requires to do is to press the bell push or switch in his room the receptionist at his desk on the ground floor will know that his attention is needed at that particular room of the floor.  He will know this because the bell rings and the indicator bulb of the room number from which the bell was pressed lights on.

• STATEMENT OF PROBLEM

Since each of the sound signal instruments mentioned above discovers an atom of inefficiency in the already improved existing one before it, a chain of technological improvement flows.  Taking an example from the signal stroke bell, as the name implies, this bell was not given enough credit because it could only produce a knock.  The continuous ring bell on the other hand was problematic in the sense that it needed a separate mechanical control.  A tremble bell was, however, designed to balance those mentioned shortcomings.  With the treble bell in service, a need to have the bell ring accompanied by an indicator light arose to further solve the communication problem as narrowed to the bell system.  Indicating the direction of sound signals where there are multidirectional signal sources possible in the bell system because it is a good answer to the communication barrier.

Having this assumption in mind, an electronic bell indicator was designed.  This system has been in use mostly in big hotels.  One of its weaknesses right from the invention is that when the bell button or switch is pressed and released, the bell and the indicator light always goes off immediately.  When this happens, the need of the guest will not be solved because the receptionist will not be able to locate the room where his/her attention is needed.

1.4    JUSTIFICATION OF THE STUDY

More importantly in the electrical system, once the bell button has been released, both the bell and t he lights go off.  This problem has been solved in our design of the electronic bell indicator system.  We constructed it such that when the bell is activated and it rings, the bulb will remain on for some time before it goes off even if the circuit has been deactivated.  The essence of the light remaining on for a few minutes is in case the receptionist is not paying attention to the indicator light, or he/she is somewhere nearby, he would still have enough time to see where his service is needed.  In our construction, the bell goes off first then the light goes off some seconds later.  The reason for this delay is to ensure that the immediate need of the guest will be met.

1.5     LIMITATION OF THE STUDY

In a very big hotel, indicator light systems are wired from each room down to the reception room.  but, for our project, we have chosen an indicator system for four-room as a model.  Unlike the popular electrical system which is bulky, expensive, and unreliable to some extent.  We have designed and constructed an electronic bell indicator that has the advantage of more efficient reliability and compatibility.  This means that the space occupied by the electrical system has been minimized.

However, this development renders this project incapable of use in a very big complex due to the smallness of the circuit and the power output/rating of some of the components that are used.

Multiplying the value and number of some of the components of the circuit and increasing the power input will still solve this problem.  Meanwhile, power failure from the electricity source in use limits the use of the system.

CONSTRUCTION OF AN ELECTRONIC BELL INDICATOR.

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