Automatic LED emergency Light Mini Project By Darshil shah (IU1241090051) Vatsal shah (IU1241090055) Under the guidance Of Prof. Omkar Pabbati Electronics & Communication Department 5 th Semester Indus Institute of Technology and Engineering INDUS UNIVERSITY
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Automatic LED emergency Light
Mini Project
By
Darshil shah (IU1241090051)
Vatsal shah (IU1241090055)
Under the guidance
Of
Prof. Omkar Pabbati
Electronics & Communication Department
5th Semester
Indus Institute of Technology and Engineering
INDUS UNIVERSITY
Index
S No. Details P. No.
List of Figure 3
List of Table 3
1 Abstract
5
Chapter 1
Block Diagram With Explanation Of Each Block
1.1 Introduction 6
1.2 Block Diagram 6
1.2.1 Functional Block Diagram 7
1.2.2 Flow Diagram 8
1.3 Explanation Of Each Block 8
1.3.1 Power Supply 8
1.3.2 Relay 9
1.3.3 Rechargeable Battery 9
1.3.4 LEDS Chapter 2
Design Details 2.1 Transformer 10
2.2 Relay Circuit 10
2.3 Zener Diode 11
2.4 Capacitor 11
2.5 Diode 12
2.6 LEDS 12
2.7 Rechargeable Battery 12
2.8 Bridge Circuit 13
Chapter 3
Circuit Diagram With Explanation Of Each Block 3.1 Circuit Diagram 14
3.2 Operational Of Circuit Diagram 14
3.3 Circuit Diagram With Operational Details 15
3.3.1 Transformer 15
3.3.2 Bridge Circuit 15
3.3.3 Relay 15
3.3.4 Rechargeable Battery 15
3.4 Simulated Circuit 16
Chapter 4
Features 4.1 Scope 17
4.2 Advantages 17
4.3 Disadvantages 17
4.4 Application 17
4.5 Comparison of LED Lamps with other Lighting Technologies
18
Chapter 5
Simulation 5.1 Eagle PCB Layout 19
5.2 Part List 20
Chapter 6
Result, Future-Scope, References 6.1 Result 21
6,2 Future Scope 21
6.3 Conclusion 21
List of Figures
Figure No. Figure Title Page No.
1.2.1 Functional Block Diagram 7
1.2.2 Flow Diagram 8
2.2 Relay 10
2.2.1 Relay Simulated Circuit 10
2.3 Zener Diode 11
2.4 Capacitor 11
2.5 Diode 12
2.6 LED 12
2.7 Rechargeable Battery 12
2.8 Bridge Circuit 13
3.1 Circuit Diagram 14
3.3.1 Bridge Circuit 15
3.3.2 Relay 15
3.4 Simulated Circuit 16
4.5 Comparison of LED with other Technologies 18
5.1 PCB Layout 19
6.1 Circuit diagram in working condition 21
List of Table
Table No. Table Title Page No.
5.2 Part List 20
4
Acknowledgement
It is our privilege to express our sincerest regards to our project coordinator, Mr. Omkar
Pabbati, for their valuable inputs, able guidance, encouragement, whole-hearted cooperation
throughout the duration of our project.
I also express my sincere thanks to Mr. Subhash Patel for his help.
We deeply express our sincere thanks to our Head of Department Prof. R N Mutagi for
encouraging and allowing us to present the project on the topic “Automatic LED Emergency
Light “.
We take this opportunity to thank all our lecturers who contributed their valuable advice and
helped to complete the project successfully.
Abstract
This report describes the design of an LED emergency light that switches on automatically
when main power fails. Power to the LED is supplied by a battery that keeps charging when
the main power is present. The circuit of the automatic LED light is designed, simulated and
built with hardware. The simulation results and design details are provided. Complete circuit
diagram, which is tested successfully, is given.
6
Ch. – 1 Block Diagram with Explanation of Each Block
1.1 Introduction Growing demand for the saving of electricity. It is based on the principle of providing light when
the power is cut off. This is accomplished by the use of automatic charger which gets charged
when power supply exists. When the battery is fully charged it stops charging. In case of power
failure, the LED glows automatically with the supply provided by the charged battery.
This project is working on two major processes:
1. It turns on automatically when the mains power fails, so you need not search it in the
dark.
2. Its battery starts charging as soon as mains resumes.
This Emergency light is used mostly in village because there is the lack of electricity which is
very required. In industries and as well as in household applications an emergency light is
employed where there is frequent non uniform voltage distribution occurs. Many types of
emergency lights from rechargeable torches to systems like generators are available in
market. All of them require a switch to operate them when frequent power failure occurs.
The present one deals with a model which senses the mains as well as daylight to switch on
the emergency light. There is no need to search the switch in the dark as it switches on/off
automatically. This present one has one on/off switch on operating which the emergency light
glows. In most of the emergency light there exists a drawback. The discharge level of the
battery is not being controlled to a safe level. The batteries get discharged completely and
lose their life rapidly. This is a very serious aspect in order to overcome this cut-off is provided
and there exists a minimum discharge level which ensures the long life of batter.
7
1.2 Block Diagram Functional block diagram and flow diagram are explained below:
1.2.1 Functional Block Diagram
Power supply block is connected with relay and if the supply is off it will turn of LEDs.
When supply is on it charge the battery continuously. Functional Block diagram
describe as below.
FIG. 1.2.1 FUNCTIONAL BLOCK DIAGRAM
Power
Supply
Design
(AC -> DC)
Relay
Turn On
LEDs
Battery
Charge
Supply ON
Supply OFF
8
1.2.2 Flow Diagram:
When AC is on the flow shows that battery will be charge. When AC is off it turn on
the LEDs as shown in the flow diagram.
FIG. 1.2.2 FLOW DIAGRAM
1.3 Explanation Of Each Block:
1.3.1 Power Supply:
For converting 230V AC to 12V AC, 12-0-12V Transformer is used. It steps down the
voltage from 230V to 12V AC. Now, to convert 12V AC to 12V DC we use Bridge
Circuit. There are four 1N4007 Diode is used to get 12V DC output. This is the function
of Power Supply to convert AC to DC.
1.3.2 Relay:
Relay is working as a Switch. There are three terminal NC (Normally Close) and NO
(Normally Open) and Common. Here we connect. NC terminal to the rechargeable
battery and Common terminal is Connects with the LEDs. Now if Power supply is on it
connects with NO terminal and charge the battery and when there is no power supply
NC terminal is connected with the battery and LEDs will be ON.
Battery
Charge
Turn On Lights
NO
YES
NO
YES AC
On
AC
Off
9
1.3.3 Rechargeable Battery:
Li-ION battery is used to give 3.7V as Output and Maximum Voltage of the battery is
4.7 voltage Zener Diode of 4.5V is used to get 4.5V as an input. So that it can be
measured how much time it will take to charge battery.
1.3.4 LEDs:
10 LEDs are connected in parallel to get charge from rechargeable battery when power
supply is cut off. It is on automatically when power supply is off.
10
Ch. – 2 Design Details
2.1 Transformer:
In this circuit the transformer used is of step down type which consumes 230 volts
as input (primary side) and produces output of 12volts. This can be termed as
230votls primary, 12v secondary step down transformer.
2.2 Relay circuit:
Relay is working as a Switch. In the input of Relay 9V DC supply can be given and
at the output if we connect bulb so relay is working as switch and bulb will turn
A bridge circuit is a type of electrical circuit in which two circuit branches (usually
in parallel with each other) are "bridged" by a third branch connected between the
first two branches at some intermediate point along them.
In the circuit of automatic emergency light the bridge circuit is used for convert
12VAC to 12VDC voltage.
FIG. 2.8 Bridge Simulation
14
Ch. – 3 Circuit Diagram with Explanation of Each Block
3.1 Circuit Diagram
Circuit diagram of Automatic LED Emergency light is as below:
FIG. 3.1 Circuit Diagram
3.2 Operation of circuit Diagram
The step down transformer and the diode bridge rectifier steps down and convert the high AC (in the range of 110V or 230V) voltage to low (12V) DC voltage.
The diode D5 prevents the battery charge from flowing back, it acts as a freewheeling diode too.
In the presence of electricity, the relay contact connects the NO (Normally Open) terminal to battery. Thus battery charges during this time.
Use Green LED as the charging indicator which glows when the emergency light battery is charging.
When supply failure occurs, relay connects the NC (Normally Closed) terminal to the battery.
The LED arrays are connected to NC terminal, thus they glow by using the charge stored in the battery.
15
3.3 Circuit Diagram With Operational Details
3.3.1 Transformer:
For Converting High AC voltage to Low AC voltage we used 12-0-12V
Transformer.
3.3.2 Bridge Circuit:
To convert 12V AC to 12 V DC, we use 4 Diode 1N4007. It has High Current
Capability and Low Forward Voltage Drop. The value of capacitor is 470µF. So