MINI PROJECT REPORT
JD COLLEGE OF ENGINEERING
IC555 TIMER CIRCUIT
A Project Report On
“IC 555 TIMER CIRCUIT” A REPORT SUBMITTED TO J D COLLEGE OF ENGINEERING AND TECHNOLOGY NAGPUR IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF
“ELECTROTECH-2010”
SUBMITTED BY
PRAKASH CHOWDHARY
SAURABH BHOLE
ANIKET CHAUDHARI ( 5th sem. ETC )
UNDER THE GUIDANCE OF
Mr.
Umale Sir
Department of Electronics Engineering
DEPARTMENT OF ELECTRONICS ENGINEERING J D COLLEGE OF ENGINEERING AND TECHOLOGY, NAGPUR
1
CERTIFICATE
“IC 555 TIM TIMER This This is to cert certif ify y that that the the diss disser erta tati tion on enti entitl tled ed “IC CIRCUIT” which has been duly submitted by the following students of third year (5 th Semester) in recognition towards partial fulfillment for the award of “ ELECTROTECH-2010” In Electronics & Telecommunication Engineering (EC), J D College of Engineering & Technology,Nagpur. Submitted By PRAKASH CHOWDHARY
SAURABH BHOLE
ANIKET CHAUDHARI (ETC 5TH SEM)
___________________________ MR. UMALE SIR, PROJECT GUIDE
__________________________
PROF. MRS. A. A. KHURSHID H.O.D, ELECTRONICS ENGG. DEPARTMENT JDCOE, NAGPUR.
_____________________ PROF. DR. P. B. PATIL PRINCIPAL, JDCOE, NAGPUR
2
DECLARATION
We the students of third year Electronics & Telecommunication Engineering (EC) humbly declare that we have completed the project work as described in this report by our own skill and during summer vacation 2010 as per the instructions and guidance of
Mr.
UMALE.
Further we declare that no part of this project is duplicated from any other literature in contravention of the academic ethics.
PROJECTEES SIGNATURE
Aniket A. Chaudhari
Saurabh S. Bhole
Prakash A. Chowdhar y
_________________________ _________________________ _________________________ _________________________ __________________________ __________________________
ACKNOWLEDGEMENT
“No man is indispensable, but there are certain mortal without whom quality of work suffers. Their guidance becomes indispensable in acquiring quality results”.
With deepest sense of esteem and gratitude, we express my sincere thanks to my project guide Prof.
MR.
UMALE , under whose guidance I was able to learn much
more and to complete successfully my dissertation work most efficiently.
We are thankful to Prof. MRS. A. A. KHURSHID, Head and Prof. Electronics Engineering Engineering Department, Department, for his inspirati inspiration on and encouragement encouragement.. She has immensely immensely helped in providing all opportunities and facilities for the dissertation work.
We could not forget to express my sincere thanks to Prof. Dr. P. B. PATIL, Principal, for providing institutional facilities and giving timely suggestions. . We are also thankful to all the faculty members of department who helped us, directly or indirectly. My thanks are due to all those who have shown keen interest in this work and provided much encouragement.
PROJECTEES
ANIKET CHAUDHARI SAURABH BHOLE PRAKASH CHOWDHARY 4
Introduction
Today’s world is a digital one. Everyone wants the world to be faster. Digital technology is the need of the hour. It has widespread application in various fields. TIMER FLASH is one of the basic application that the digital world is aware of. The 555 Timer IC is an integrated circuit (chip) implem implement enting ing a variet variety y of timer timer and multiv multivibr ibrato atorr appli applicat cation ions. s. The IC was designed by Hans R. Camenzind in 1970 and brought to market in 1971 by Signetics (later acquired by Philips). The original original name was was the SE555 (metal (metal can) / (plastic (plastic DIP) DIP) and the part was described as "The IC Time Machine"., the standard 555 package includes over 20 transistors, 2 diodes and 15 resistors on a silicon chip installed in an 8-pin mini dual-in-line package . The 8-pin 555 timer must be one of the most useful ICs ever made and it is used in many projects. With just a few external components it can be used to build many circuits, not all of them involve timing! The IC555 monolithic timing circuit is a highly stable Controller capable of producing accurate time delays or oscillation.In the time delay mode of operation,The time is precisely controlled by one external resistor and capacitor. For astable operation as an oscillator,The free running frequency and the duty cycle are both accurately controlled with two external Resistors and one capacitor.The circuit may be triggered and reset on falling waveforms, and the output Structure can source or sink up to 200mA.The IC555 is available in plastic and ceramic minidip Package and in a 8-leadmicropackage and in metal Can package version.
Circuit Diagram
Internal Layout of IC 555
Components Required
¶ ¶ ¶ ¶ ¶ ¶ ¶ ¶ ¶
Ic 555 2 Light Emitting Diodes Resistor - 470 Ω Resistor - 470 Ω Variable Resistor (Preset) - 222 KΩ Resistor - 1 KΩ Resistor - 1KΩ Capacitor - 10 µF Capacitor - 100 µF
Data Sheet Timers and signal generators
Order code
Manufacturer code
Description
77-1212
n/a
n/a
82-0336
NE555
NE555 SINGLE TIMER (RC)
82-0338
NE555D
NE555D SINGLE TIMER (SMD) (RC)
Order Codes Part Number
Temperature Range
Package N
0°C, 70°C –40°C, 105°C –55°C, 125°C
NE555 SA 555 SE 555
D
Absolute Maximum Ratings Symbol
Parameter
V cc
Supply Voltage
Toper
Operating fr free ai air temp. range for NE555 SA555 SE555
Tj Tstg
Junction Temperature Storage Temperature Range
Value
Unit
18
V
0 to 70 -40 to 105 -55 to 125
°C
150
°C
-65 to 150
°C
ELECTRICAL CHARACTERISTICS CHARACTERISTICS Tamb = +25oC, VCC = +5V to +15V (unless otherwise specified)
Symbol
Parameter
SE555
SA555-NE555
Min. Type Max. Min.
Type
Max.
Unit
Icc
VCL
Vth
Ith
Supply Current (RL 8) (- note 1) Low State VCC = +5V VCC = +15V High State VCC = 5V Timing Error (monostable) (RA = 2k to 100kW, C = 0.1mF) Initial Accuracy (note 2) Drift with Temperature Drift with Supply Voltage Timing Error (astable) (RA, RB = 1kW to 100kW, C = 0.1mF, VCC = +15V) Initial Accuracy (note 2) Drift with Temperature Drift with Supply Voltage Control Voltage level VCC = +15V VCC = +5V Threshold Voltage VCC = +15V VCC = +5V Threshold Current - (note
3 10 2
5 12
3 10 2
6 15
0.5 30 0.05
2 100 0.2
1 50 0.1
3 0.5
1.5 90 0.15
2.25 150 0.3
mA
% ppm/°C %/V
% ppm/°C %/V
9.6 2.9
10 3.33
10.4 3.8
9 2.6
10 3.33
11 4
V
9.4 2.7
10 3.33
10.6 4
8.8 2.4
10 3.33
11.2 4.2
V
0.1
0.25
0.1
0.25
mA
3) Vtrig
Itrig
Vreset VOL
VOH
Trigger 4.8 Voltage 1.45 VCC = +15V VCC = +5V Trigger Current Current (Vtrig (Vtrig = 0V) Reset Voltage 0.4 - (note 4)
5 1.67
5.2 1.9
0.5
0 .9
0 .7
1
Low Level Output Voltage VCC = +15V, IO(sink) = 10mA IO(sink) = 50mA IO(sink) = 100mA IO(sink) = 200mA VCC = +5V, IO(sink) = 8mA IO(sink) = 5mA High Level Output Voltage VCC = +15V, IO(source) = 200mA IO(source) = 100mA VCC = +5V, IO(s IO(sou ourc rce) e) = 100mA
0.15 0.5 2.2
0.1 0.4 2 2.5 0.1 0.05
13 3
4.5 1.1
5 1.67
5.6 2.2
V
0.5
2. 0
mA
0 .7
1
V
0.25 0.75 2.5
V
0.25 0.2
0.1 0.4 2 2.5 0.3 0.25
12.5 13.3 3.3
12.5 13.3 3.3
0 .4
12.7 5 2.75
Notes : 1. Supply current when output is high is typically 1mA less. 2. Tested at V CC = +5V and V CC = +15V. 3. This will determine the maximum value of R A + RB for +15V operation the max total is R = 20M Ω and for 5V operation, the max total R = 3.5M Ω .
Advantages
0.4 0.35
V
¶ LOW TURN OFF TIME ¶ MAXIMUM OPERATING FREQUENCYGREATERTHAN 500kHz ¶ TIMING FROM MICRO SECONDS TO HOURS ¶ OPERATES IN BOTH ASTABLE AND MONOSTABLE MODES ¶ HIGH OUTPUT CURRENT CAN SOURCE OR SINK 200mA ¶ ADJUSTABLE DUTY CYCLE ¶ TTL COMPATIBLE ¶ TEMPERATURE STABILITY OF 0.005% PER °C
Graphs
Minimum Pulse Width Required for Triggering
Supply Current versus Supply Voltage
Delay Time versus Supply Voltage
Propagation Delay versus Voltage Level of Trigger Value
IC 555 Configurations We all know how versatile the IC 555 is and regarding its wide range r ange of applications.. Basically the IC 555 can be operated in two most commonly applications used modes viz. monostable and astable multivibrator. In the monostable mode the output at pin 3 of the IC goes high in response to an external applied trigger at its pin 2. The output holds this position for a time period determined by the values of its timing components consisting of a resistor and a capacitor. The best example of this mode of operation of the IC can be studied in one of my previous article on a frequency meter . But the most common applicatio application n of this mode of operation is in a 555 timer circuit, circuit, where the IC is used to switch ON a load at its output for the set period of time after which it is automatically switched OFF. In the astable mode configuration the IC continuously produces pulses at its output. These pulses are normally square waves and its frequency can be adjusted again by varying the timing components comprising of a resistor and a capacitor.
Working of Circuit As shown in the figure the IC 555 is configured as a monostable mutivibrator. On pressing the switch S1, a momentary logic high appears at pin 2 of the IC and its output at pin 3 goes high switching ON the relay and the load connected to the relay contacts. The output will sustain the position till its timing capacitor C1 gets fully discharged through the variable resistor VR1. The value of this resistor may be varied to get the desirable time delays. The delay may be calculated using the below given formula: T = 1.1 × (VR1 + R1+R2) × C1
Schematic of a 555 in monostable mode The relationships of the trigger signal, the voltage on C and the pulse width in monostable mode. In the monostable mode, the 555 timer acts as a “one-shot” pulse generator. The pulse begins when the 555 timer receives a trigger signal. The width of the pulse is determined by the time constant of an RC network, which consists of a capacitor (C) and a resistor (R). The pulse ends when the charge on the C equals 2/3 of the supply voltage. The pulse width can be lengthened or shortened to the need of the specific application by adjusting the values of R and C.The pulse width of time t, which is the time it takes to charge C to 2/3 of the supply voltage, is given by T = 1.1 × (VR1 + R1+R2) × C1 where t is in seconds, R is in ohms and C is in farads. See RC circuit for an explanation of this effect.
INDEX Sr.No. 1. 2. 3. 4. 5. 6. 7. 8. 9.
Perticulars
Introduction Components Required Circuit Diagram Circuit Explanation IC 555 Configuration Applications & Future Scope Advantages Data Sheet References
References
http://www.brighthub.com/engineering/electrical/articles/ 68119.aspx#ixzz0mMestoXE
Wikipedia
www.scribd.com
Applications
Monostable Mode In this mode, the 555 ffunctions unctions as a "one-shot".
@ Timers @ Missing pulse detection @ Bounce-free switches @ Touch switches @ Frequency divider @ Capacitance measurement @ Pulse-width modulation (PWM) etc. Astable Mode Free running mode: the 555 can operate as an oscillator
@LED and lamp flashers @ Pulse generation @Logic clocks @Tone generation @ Security alarms @Pulse position modulation etc.
Bistable Mode 555 can operate as a flip-flop, if the DIS pin is not connected and no capacitor is used.
@ bounce-free latched switches
MINIPROJECT IC 555 TIMER CIRCUIT
