PROJECT NAME: ALTERNATING LED FLASHER
BY
JEHANGIR KHAN ADIL ZAHOOR SADDAM BAIG
Department of Electrical Engineering
COMSATS Institute of Information Technology, Attock.
ACKNOWLEGEMENT I would like to express my deepest appreciation to all those who provided me the possibility to complate this report . A special gratitude i give to our friend of EE deparment of 5th semester whose contribution in stimulating suggestions and encouragement ,helped me to coordinate me to coordinate my project especially in writing this report.I also appreciated the help of lab encharge to access all the lab component for complation of this project.
ABSTRACT We are using 555 timer ic which is higly stable device for generating oscillation or accurate time delays used in pulse width/modulation,sequential timing,time delay generation,linear ramp generator,precision timing,and pulse generation due to its features such as normally open and normally off output,tempreture stability and adjustable duty cycle in both astable and monostable mode.This 555 timer ic can be configure to three operating modes namely namely;monostable(produces signal),astable(produces
a
a
single
continous
(one square
shot wave
pulse) or
upon
receiving
rectangular
pulses
the as
oscillator),bistable(produces a state of set and reset as with flip flop or schmitt trigger).
When operating in bistable mode,it may be utilized in bounce free latched switches.pulse type waveform processing and rail road track designing.When operating in astble mode it may be utilized in pulse position modulation,security alarm,tone generation,logic clock ,pulse generation,lamp flasher and light emitting diode.when it operates at monostabe mode, it may be utilized in pulse width modulation (pwm),capacitance measurement ,frequency devider,tone switches ,bounce free switches,missing pulse detection and timers.
The alternating flashes produced from the LEDs D1 and D2 can be of different colors if desired, for added pysical features and attraction.The value of capacitance C1 can be change which would change the frequency of oscillation.The flasher circuit using leds can be seen widely in motorcycles and cars for their tail, brake ,turn light application.These leds can also come in different monochromatic colors such as whiter, red and amber.One of the most important use of the flasher circuit is providing a visual indication of a hazardous situation from its warning lights
CHAPTER 1
1.1 INTRODUCTION Our project is about time delay pulses of 555 timer ic which would operate two led one by one.This is done by by using this ic in astable mode.
1.2 AIM AND OBJECTIVES 1.2.1 AIM OF PROJECT The aim of building this circuit is to create a led flasher with alternating sequence from the two leds where the operation is based on the functionalities of a 555 timer integrated circuit.
1.2.2 OBJECTIVES OF PROJECT
Railroad crossing signal for model railroads.
safety blinkers for bicycle,etc.
fun stuff for halloween,like making plastic jack-o-lanterns blink.
festival decorations.
blinkers to locate item in dark
CHAPTER 2
2.1- SELECTION OF COMPONENTS 555 timer ic ( only one ) 1 k ohm resister (only one ) 10 k ohm resister ( only one ) 220 k ohm resister (only two ) 100 micro farad capaciter ( only one ) leds ( two only ) jumper wires ( 5 to 7 ) wiro board 9 volt battery [2].
2.1.1 BREAD BOARD:
Used to connect different parts of circuit.the bread
board,we used was horozontally short.
2.1.2 RESISITER:Used
to resist the flow of current to avoid accessive current to
circuit element like ic,led and capaciter.
2.1.3 CAPACITER:Used to store charges on parallel plates and provide charging and discharging for the implemented circuit.
2.1.4 555 TIMER IC:Used
to generate pulses and used as an oscillator.Usually
used in astable,monostable and bistable mode.
2.1.5 LEDs: Light emitting diode used as detecting the pulses produced by ic and glow when receive signals.
2.1.6 WIRO BOARD:Is same
to bread board but the major difference between
bread board and wiro board is that we have to short the components on wiro board by ourselves and bread board automatically connect the components.
CHAPTER 3
3.1 METHODOLOGY it is 8 pin iintegrated chip. we are using 555 timer ic. so pin 1 is connected to the groung and pin 8 is connected to vcc. pin 4 in connected to pin 8 and pin 2 (trigger ) is connected to pin 6 (threshold ).we are using this astable mode so pin 6 and pin 2 is to be shorted.pin 8 is connected to pin 7 ( discharge ) by 1 k ohm resister.pin 7 is connected to the postive leg of 100 micro farad capaciter and also pin 6 is connected to the positive side of the capaciter by simple wire.negative led of capciter is connected to ground. pin 3 as output pin is connected to unused row and one of led is connected to output by 220 ohm resister having negative led and other leg connected to vcc.also positive side of other led is connected to this pin and negative leg is connected to ground.
3.1.1 BLOCK DAIGRAM
voltage source
capaciter charges .
store
capaciter charges.
9v.
555 timer ic producing time delay pulses.
two led glow one by one.
figure 1: block diagram of the project
loses
all
3.1.2 PROJECT IMPLEMENTATION
Figure 2: alternating led flasher [1].
Figure 3: Alternating led flasher on wiroboard.
3.1.3 WORKING OF BLOCK DAIGRAM:
When the ic receive the voltage from 9 volt battery than 555 timer ic start to operater in asable mode.Capaciter starts, storing the charges.Upto 62.3% of voltage the chapaciter will not stop it storing but after that the more charges hardly be store and it.The output will be high when the capaciter charges and it would be low output when capaciter discharges.so the 555 timer ic would generater the pulses and act as an oscillator so if one of led receive a pulse at a discrete time interval than other led would not receive the timing pulse becouse the ic produces time delay pulses just like when we are dealing with logic clock.So one after one both leds would glow.
CHAPTER 4
4.1 RESULT AND DISCUSSION After complate process both the leds would glow and we can use this in low expindature and we can use it for various type of application like in emergency situation we donot have much time to respond to the people so this would help us out in making understantable the people that we have some major problem like ambulance uses this kind of led flasher.We can use it in functions and parties to make adorable and delicate scenes for respected guest and friend and relatives so they can make some fun and relax thereselves in this very moment.
CONCLUSION This is the simple circuit using 555 timer ic which are producing time delay pulses and so output is designed to operate both the led one by one.This project can be used in emergency situation so that every one can take care of himself.
FUTURE RECOMMENDATION
Function and Parties
Default Detector
Emergency Situation In Construciton Area As A Locater
REFERENCES [1] www.youtube.com/watch?v=gYnd_nMi39g. [2] http://www.instructables.com/id/simple-alternate-LED-flashing-using-555-timer/.
