SUBMITTED BY EDGEFX TEAM 3 PHASE AUTOMATIC STAR- DELTA STARTER USING RELAYS AND ADJUSTABLE ELECTRONIC TIMERS FOR INDUCTION MOTOR SUBMITTED BY EDGEFX TEAM

ABSTRACT Star/Delta starters are probably the most common reduced voltage starters in the 50Hz industrial motor world (Known as Wye / Delta starters in the 60Hz USA world) They are used in an attempt to reduce the start current applied to the motor during start as a means of reducing the disturbances and interference on the electrical supply.

BLOCK DIAGRAM

HARD WARE EQUIPMENTS POWER SUPPLY BLOCK RELAY INDUCTION MOTOR 555 TIMER BC 547 TRNSISTOR BC 558 IN4007 RECTIFIER DIODE LED RESISTORS & CAPACITORS

555 TIMER The 555 Timer IC is an integrated circuit (chip) implementing a variety of timer and multivibrator applications. The original name was the SE555 (metal can)/NE555 (plastic DIP) and the part was described as "The IC Time Machine". Depending on the manufacturer, the standard 555 package includes over 20 transistors, 2 diodes and 15 resistorson a silicon chip installed in an 8-pin mini dual-in-line package (DIP-8)

PIN DIAGRAM OF 555 The 555 timer IC is a simple 8 pin DIL package IC. It can: be used as a monostable be used as an astable source or sink 100mA use supply voltages of 5v to 15v disrupt the power supply - use a decoupling capacitor!

THREE PHASE INDUCTION MOTOR It consists of the fixed stator or frame, a three-phase winding supplied from the three-phase mains and a turning rotor There is no electrical connection between the stator and the rotor Stator and rotor are made of highly magnetizable core sheet providing low eddy current and hysteresis losses

Stator & Rotor The stator winding consists of three individual windings which overlap one another and are offset by an electrical angle of 120° Synchronous Speed (Ns)= 60; f/p Ns= Synchronous Speed/ minute; F= frequency; P=Pole pair Number; Rotor in induction machines with squirrel-cage rotors consists of a slotted cylindrical rotor core sheet package with aluminum barswhich are joined at the front by rings to form a closed cage

Diagrams

BC547 The BC547 transistor is an NPN Epitaxial Silicon Transistor. The BC547 transistor is a general-purpose transistor in small plastic packages. It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors. Whenever base is high, then current starts flowing through base and emitter and after that only current will pass from collector to emitter  

BC558 The BC557 transistor is an PNP Epitaxial Silicon Transistor The BC557 transistor is a general-purpose transistor in small plastic packages. It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA PNP general-purpose transistors.

The arrow in the PNP transistor symbol is on the emitter leg and points in the direction of the conventional current flow when the device is in forward active mode.

RELAY IT IS A ELECTRO MAGNETIC SWITCH USED TO CONTROL THE ELECTRICAL DEVICES COPPER CORE MAGNETIC FLUX PLAYS MAIN ROLE HERE

BIBILOGRAPHY The 8051 Microcontroller and Embedded systems” by Muhammad Ali Mazidi and Janice Gillispie Mazidi , Pearson Education. ATMEL 89S52 Data Sheets. www.atmel.com www.beyondlogic.org www.wikipedia.org www.howstuffworks.com www.alldatasheets.com

THANK ‘Q’