Design And Construction Of A Nightlight

ABSTRACT

A nightlight is a small light fixture, usually electrical, placed for comfort or convenience in dark areas or areas that may become dark at certain times, such as at night or in an emergency.

People usually use nightlights for the sense of security which having a light on provides, or to relieve fear of the dark, especially in young children. Nightlights are also useful to the general public by revealing the general layout of a room without requiring a major light to be switched on, for avoiding tripping over stairs, obstacles, or pets, or to mark an emergency exit.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRCT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• AIM/OBJECTIVE OF THE PROJECT
• SCOPE OF THE PROJECT
• SCOPE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• LIMITATION OF THE PROJECT
• APPLICATION OF THE PROJECT
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

2.0      LITERATURE REVIEW

2.1      REVIEW OF LIGHT SENSOR

2.2      LDR STRUCTURE AND WORKING

2.3      REVIEW OF THE MAJOR COMPONENTS USED

CHAPTER THREE

3.0      CONSTRUCTION METHODOLOGY

3.1      BLOCK DIAGRAM OF THE SYSTEM

3.2      CIRCUIT DIAGRAM

3.3      CIRCUIT DESCRIPTION

3.4      SYSTEM OPERATION

3.5      COMPONENTS LIST

3.6     DESCRIPTION OF MAJOR COMPONENTS USED

CHAPTER FOUR

4.0       RESULT ANALYSIS

4.1      CONSTRUCTION PROCEDURE AND TESTING

4.2      ASSEMBLING OF SECTIONS

4.3      CONSRUCTION OF THE CASING

4.4      TESTING OF SYSTEM OPERATION

4.5    INSTALLATION OF THE COMPLETED DESIGN

4.6    COST ANALYSIS

CHAPTER FIVE

• CONCLUSIONS
• RECOMMENDATION

5.3     REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

The controlling of home lamps (or security lights) is usually maintained by home occupants on several occasions. This is not only precarious but also sometimes results in wastage of power because of the negligence or unusual circumstances on part of the technician in operating the lights on and off. Not only in case of street lights, even for controlling the home appliances like garden or outdoor lights, we can utilize the automatic night lightening system for automatic switching of the lights based on daylight’s intensity by using a light sensor.

Automatic night lightening system is a  electrical project circuit by which we can switch on and off the electrical load appliances like lights, fans, coolers, air conditioners, street lights, etc., automatically based on the day-light intensity instead of manually operating the switches.

By using this method, manpower can be reduced to a great extent. In case of the street lights/lamp erected on highways it is not an easy task to manually control them, but, if uncontrolled, the chances of power wastage would increase. To get rid of this situation, the implementation of automatic light switch by using a dark/light sensor that switches lights automatically on and off is the best option.

1.1                                                   AIM OF THE PROJECT

The main aim of this work is to learn the designing and to understand the explanation of the automatic night lamp circuit with morning alarm. This can also be used for automatic alarm in the day time.

1.2                                             OBJECTIVE OF THE PROJECT

The objective of this work is to design a device that will trigger lamps when darkness falls on the sensor (LDR). At the end of this work the student involved will be able to:

1. understand how light dependent resistor works
2. connect light dependent resistor unto a circuit

• know operation of an op-amp and the functions of the pins

1.3                                                 SCOPE OF THE PROJECT

An automatic night lightening system is an electronic  circuit consisting of LDR, transistor and Relay as connected in the main circuit, as shown below.

The circuit shown below requires a DC voltage, which can be supplied from a battery or by using a bridge rectifier instead of the battery. The bridge rectifier uses a step-down transformer to step-down the 230v into 12v.

This circuit is to switch ON the light when the LDR is illuminated. The light dependent resistor will have high resistance in darkness and low resistance in the light. The comparator used here has LDR connected to its inverting terminal and potentiometer connected to its non-inverting pin.

When the darkness falls on the Light Dependent Resistor, the comparator compares the voltages at the reference pin that is with the non-inverting pin and the inverting pin of the op-amp. If the voltage at the non-inverting pin is greater than the voltage at the inverting pin the transistor cannot be switched. If the voltage at non-inverting pin is less than the voltage at the inverting pin, the output of the comparator can switch the transistor.

Thus the relay switches and light/ or alarm are switched on when LDR is illuminated as transistor switches.

1.4                                         SIGNIFICANCE OF THE PROJECT

This device is very useful in that it distinguishes daylight and dark hours. This device eliminates the need of switching the Porch lamp or Backyard lamp daily and also helps to switch ON or OFF the premises of the house when the occupants are out of station.

1.5                                           LIMITATION OF THE PROJECT

One of the problems of this device is that any opaque material can trigger the device, such as human shadow, movement of animals or ants across the sensor can trigger the system

1.6                                         APPLICATIONS OF THE PROJECT

• Useful for automatic outdoor lighting or garden lighting at home.
• Useful for automatic switching of street lights.
• Useful for switching the hoardings on and off automatically.
• Useful for self-switching operation of displaying title hoardings of companies.
• Useful as a light detector circuit when the pin of the ic is reconfigured.
• Useful as a dark activated switch.

1.7                                        PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to automatic night lightening system. In this chapter, the background, significance, objective limitation and problem of dark activated alarm were discussed.

Chapter two is on literature review of automatic night lightening system. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.

Exit signs often use tritium in the form of a traser. Homeowners usually place nightlights in bathrooms, kitchens and hallways to avoid turning on the main light fixture, especially late at night, and causing their eyes to adjust to the brighter light.^[1]

Some frequent travelers carry small nightlights for temporary installation in their guestroom and bathroom, to avoid tripping or falls in an unfamiliar nighttime environment. Gerontologists have recommended use of nightlights to prevent falls, which can be life-threatening to the elderly.^[2]

The low cost of nightlights has enabled a proliferation of different decorative designs, some featuring superheros and fantastical designs, while others feature the basic simplicity of a small luminous disc.

Light source and variants

Early electrical nightlights used small incandescent lamps or small neon lamps to provide light, and were much safer than small candles using an open flame. The neon versions consumed very little energy and had a long life, but had a tendency to flicker on and off (reminiscent of a candle), which some users liked and others found annoying. In the 1960s, small nightlights appeared that featured a low-power electroluminescent panel emitting soft green or blue light; similar lights are still available today.^[3]

Some nightlights include a photocell, which enables them to switch off when the ambient light is sufficiently bright. Other designs also feature a built-in passive infrared sensor to detect motion, and only switch on when somebody is passing by in the dark. With the availability of low-cost LEDs, many different variants have become available, featuring different colours, sometimes changing automatically or in a user-controllable way.

Safety hazard

The US Consumer Product Safety Commission reports it receives about 10 reports per year where nightlights close to flammable materials were cited as responsible for fires; they recommend the use of nightlight with bulbs cooler than the four or seven watt incandescent bulbs still used in some older products.^[4]

Potential health issues and benefits

A University of Pennsylvania study indicated that sleeping with the light on or with a nightlight was associated with a greater incidence of nearsightedness in children.^[5] However, a later study at Ohio State University contradicted the earlier conclusion.^[6] Both studies were published in the journal Nature.

Another study has indicated that sleeping with the light on may protect the eyes of diabetics from retinopathy, a condition that can lead to blindness.^[7] However, the initial study is still inconclusive.

The optimal sleeping light condition is said by some to be total darkness.^[8] If a nightlight is used within a sleeping area, it is recommended to choose a dim reddish light to minimize disruptive effects on sleep cycles.^[9][1] In addition, nightlights may be useful in locations other than sleeping areas, such as hallways, bathrooms, or kitchens, to allow late night trips to be made without turning on the full light, while preserving a dark sleeping environment.^[2]

See also

• Lamp shade
• LED lamp
• Light-emitting diode

References

• “National Sleep Foundation”. National Sleep Foundation. Retrieved June 23, 2015.
• · McMurdo, M E; Gaskell, A (1991). “Dark adaptation and falls in the elderly”. Gerontology. 37 (4): 221–4. PMID 1916313.
• · “Electroluminescent Lamps – How They Work & History”. http://www.edisontechcenter.org. Retrieved 2017-02-16.
• · “Fire Hazard with Nightlights”. CPSC Document #5063. US Consumer Product Safety Commission. Retrieved May 12, 2011.
• · “Is Nearsightedness in Children Linked to Night Light Exposure During Sleep Before Age Two?” (PDF). Science NetLinks. American Association for the Advancement of Science. Retrieved March 23, 2009.
• · “Night Lights Don’t Lead To Nearsightedness, Study Suggests”. Science Daily. March 9, 2000. Retrieved March 23, 2009.
• · “Light at Night Protects Diabetics’ Eyes”. WebMD. June 27, 2002. Retrieved March 23, 2009.
• · Rettner, Rachel. “Avoiding Depression: Sleeping in Dark Room May Help”. Live Science. Retrieved 23 June 2015.
• Hyman, Mark (8 November 2013). “How a Light Bulb Can Help You Sleep Better”. The Huffington Post. Retrieved 2017-02-16