Report on ALEL

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 List of Figure List of Table Abstract

1

P. No. 3 3 5

Chapter 1 Block Diagram With Explanation Of Each Block 1.1 1.2 1.2.1 1.2.2 1.3 1.3.1 1.3.2 1.3.3

1.3.4

Introduction Block Diagram Functional Block Diagram Flow Diagram Explanation Of Each Block Power Supply Relay Rechargeable Battery

6 6 7 8 8 8 9 9

LEDS Chapter 2 Design Details

2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8

Transformer Relay Circuit Zener Diode Capacitor Diode LEDS Rechargeable Battery Bridge Circuit

10 10 11 11 12 12 12 13

Chapter 3 Circuit Diagram With Explanation Of Each Block 3.1 3.2 3.3 3.3.1 3.3.2 3.3.3 3.3.4 3.4

Circuit Diagram Operational Of Circuit Diagram Circuit Diagram With Operational Details Transformer Bridge Circuit Relay Rechargeable Battery Simulated Circuit

14 14 15 15 15 15 15 16

Chapter 4 Features 4.1 4.2 4.3 4.4 4.5

Scope Advantages Disadvantages Application Comparison of LED Lamps with other Lighting Technologies

17 17 17 17 18

Chapter 5 Simulation 5.1 5.2

Eagle PCB Layout Part List

19 20

Chapter 6 Result, Future-Scope, References 6.1 6,2 6.3

Result Future Scope Conclusion

21 21 21

List of Figures

Figure No.

Figure Title

Page No.

1.2.1 1.2.2 2.2 2.2.1 2.3 2.4 2.5 2.6 2.7 2.8 3.1 3.3.1 3.3.2 3.4 4.5 5.1 6.1

Functional Block Diagram Flow Diagram Relay Relay Simulated Circuit Zener Diode Capacitor Diode LED Rechargeable Battery Bridge Circuit Circuit Diagram Bridge Circuit Relay Simulated Circuit Comparison of LED with other Technologies PCB Layout Circuit diagram in working condition

7 8 10 10 11 11 12 12 12 13 14 15 15 16 18 19 21

List of Table

Table No. 5.2

Table Title Part List

Page No. 20

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.

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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.

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.

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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.

Supply OFF Power Supply Design (AC -> DC)

Battery Charge

Relay

Turn On LEDs

Supply ON

FIG. 1.2.1 FUNCTIONAL BLOCK DIAGRAM

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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.

YES

AC On

Battery Charge

NO

AC Off

YES Turn On Lights

NO

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.

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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.

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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 On/Off so, we can verify the working of Relay.

FIG.2.2 Relay (Source: http://i.stack.imgur.com/AujXg.png)

Simulated circuit for relay as shown below:

FIG. 2.2.1 Relay Simulation Circuit

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2.3 Zener Diode: It permits current to flow in the forward direction as normal, but will also allow it to flow in the reverse direction when the voltage is above a certain value - the breakdown voltage known as the Zener voltage. The Zener diode specially made to have a reverse voltage breakdown at a specific voltage. For example, a diode with a Zener breakdown voltage of 4.2 V exhibits a voltage drop of very nearly 4.2 V across a wide range of reverse currents.

FIG. 2.3 ZENER DIODE (Source: http://www.completepowerelectronics.com/wp-content/uploads/2013/01/zener-diode.jpg)

2.4 Capacitor: A capacitor is a passive two-terminal electrical component used to store energy electro statically in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors (plates) separated by a dielectric (I.e. insulator). An ideal capacitor is characterized by a single constant value for its capacitance. Capacitance is expressed as the ratio of the electric charge Q on each conductor to the potential difference V between them. The SI unit of capacitance is the farad (F), which is equal to one coulomb per volt (1 C/V). Typical capacitance values range from about 1 pF (10−12 F) to about 1 mF (10−3 F)

FIG.2.4 Capacitor (Source: http://www.diyguitarmods.com/images/electrolyticcap.gif)

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2.5 Diode: Diode is a two-terminal electronic component with asymmetric conductance; it has low (ideally zero) resistance to current in one direction, and high (ideally infinite) resistance in the other.

FIG. 2.5 Diode (Source: http://www.electronix.com/images/diode.jpg?osCsid=6tiv9u6bg2re7slavbljhqqpo6)

2.6 LED: A light-emitting diode (LED) is a two-lead semiconductor light source. It is a basic PN-junction diode, which emits light when activated. When a fitting voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons Here 10 LEDs are connected in parallel to get charge from rechargeable battery when power supply is cut off. And it will on automatically when power supply is off.

FIG. 2.6 LED (Source: http://www.lumenstarled.com/media/catalog/category/single_5mm_LEDS.jpg)

2.7 Rechargeable Battery: Li-ION battery is used to give 3.7V as Output and Maximum Voltage of the battery is 4.7 voltages. 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.

FIG. 2.7 Rechargeable Battery (Source: http://ecx.images-amazon.com/images/I/41u7Hh78sLL._SY300_.jpg)

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2.8 Bridge Circuit: 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

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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.

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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 we get rectified output.

FIG. 3.3.2 Bridge Circuit (Source: http://www.radio-electronics.com/info/circuits/diode-rectifier/diode-rectifier-full-wavebridge-03.gif)

3.3.3 Relay: Relay is working as a Switch. To operate relay we needs 12V DC supply so that we are using 12V Transformer.

FIG. 3.3.3 Relay (Source: http://electronicsclub.info/images/swabc.gif)

3.3.4 Rechargeable Battery: For Rechargeable battery, Nominal Voltage of Li-Ion battery is 3.7 Voltage. Standard capacity is 1950mAh. Charging voltage is 4.2V.Constant current 0.2C5A.

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3.4

Simulated Circuit At the time of simulation, circuit is simulated and diagram is as shown below:

FIG. 3.4 Simulated Circuit

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Ch. – 4 Features  Simple: Simple circuit. Components are easily available and low cost.  Automatic: Automatically switches ON when the mains fails and turns OFF when mains power resumes. Also has its own battery charger which when fully charged stops charging automatically.  Convenient : Makes our lives simpler, convenient to use.  Economical: Energy consumption is very less, proves to be more economic for the consumer.

4.1

Scope Scopes of the Automatic LED Emergency Light are:     

4.2

Longer Lasting battery that works approx. 8 hours Power is available; it senses and switches off the LEDs (lamp) instantly. Easy to use. Uses at office, conference room, exhibition hall lighting Uses at Direction Arrow Board for Bathroom

Advantages The advantage are; it is easy to use, very low cost, save energy more and easy to install anywhere.  Efficiency: more light per watt than incandescent bulbs.  Color: can emit of an intended color without use of color filters.  Size: very small.  On/off time: light up very quickly.  Life time: long useful life time.

4.3

Disadvantages  

4.4

Cost: currently more expensive. Health hazard: cool white LEDs can cause problems to eyes.

Application   

Used as an alternative source at the time of power failure. It is suitable for domestic applications. Used in remote residential areas.

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4.5

Comparison of LED Lamps with other Lighting Technologies: The comparison between LED, Florescent Lamp and incandescent lamp is shown:

(Source: https://www.scribd.com/doc/161102521/Automatic-Led-Emergency-Light-Ppt) FIG 4.5 Comparison of LED with other Technologies

Ch. – 5 Simulation 5.1

Eagle PCB Layout With the use of circuit diagram PCB layout is as below:

FIG. 5.1 PCB Layout

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5.2

Part list

Part Value Orientation

Package Library Position (inch)

C1 D1 R270 D2 D3 D4 R270 D5 D6 R180 D7 JP1 JP2 K2 L1 L2 L3 L4 L5 L6 R1 R2 R180 R3 R180 R4 R180

470u 1N4007

E3, 5-8 rcl DO41-10 diode

(0.3 1.1) (0.45 0.45)

R0

1N4007 1N4007 1N4007

DO41-10 diode DO41-10 diode DO41-10 diode

(0.7 0.45) (0.9 0.45) (1.05 0.45)

R90 R90

1N4004 1N4007

DO41-10 diode DO41-10 diode

(0.9 1.05) (1.3 0.8)

R90

1N5333 3.7V 230V G5L Green Red Red Red Red Red 1k 1k

C1702-15 diode JP1 jumper JP1 jumper G5LE relay LED5MM led LED5MM led LED5MM led LED5MM led LED5MM led LED5MM led 0207/10 resistor 0207/10 resistor

(1.6 0.25) (1.9 0.55) (0.25 0.35) (2.2 1.05) (0.65 1.05) (0.25 1.45) (0.55 1.45) (0.85 1.45) (1.15 1.45) (1.45 1.45) (0.45 0.8) (1.25 1.1)

R0 R0 R18 R0 R90 R90 R90 R90 R90 R90 R0

330

0207/10 resistor (2.05 1.5)

330

0207/10 resistor (1.5 0.65)

Table 5.2 Part List

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Ch. – 6 Result, Future-Scope, References 6.1

Result The output of the LEDs is measured and tested battery backup is approx. 8 Hours. At the input of the battery the measured voltage is 4.5V through Zener Diode. Across Capacitor measured voltage is 12.15V DC and from calculated current is 12.15mA. Across Diode D2 voltage is 13.7V. This circuit can also be extended to a higher output voltage for which the charging voltage and the load are to be chosen accordingly. All the other components involved in the circuit are of same value.

6.1 Circuit Diagram in Working Condition

6.2

Future Scope The emergency light which uses IC is a reliable one comparing to other on IC emergency lights and there is an automatic feature by which itself get glows. This project can be adopted for mass production as cheap and efficient method.

6.3

Conclusion    

The project was concluded to be innovative for the improvement of day today life. Device also adds a new look to the traditional lamps. The cost of implementing this circuit is also very less - an added advantage in using this circuit. Thus the implementation of automatic LED emergency light proves to be a cost effective and compact application in today’s world of technological miniaturization. As of there has been an increase in the use of LEDs for the development of new applications, its promotion would lead to the enhancement of future innovations!

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References          

Jacob Millman & Christos C. Halkias, Electronic Devices & Circuits, McGraw-Hill, 1967 – Textbook http://www.fmlink.com/article.cgi?type=Magazine&pub=Premises%20&%20Facilit ies%20Management&id=30856&mode=source http://www.circuitstoday.com/automatic-led-emergency-light http://www.ucl.ac.uk/estates/maintenance/fire/documents/UCLFire_TN_022.pdf http://en.wikipedia.org/wiki/Emergency_light http://electrotech99.blogspot.in/2012/11/led-based-automatic-rechargeable.html http://www.connectingindustry.com/electricalengineering/the-benefits-ofautomatic-emergency-lighting-testing.aspx https://www.scribd.com/doc/161102521/Automatic-Led-Emergency-Light-Ppt http://www.tridonic.com/pl/download/Emergency_Lighting_Overview_EN.pdf http://www.8051projects.net/files/public/1259220442_20766_FT0_7380969-linefollower-using-at89c51.pdf

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