19-02-2016, 04:55 PM
Abstract
The high growth of the semiconductor industry over the past two decades has put Very Large Scale Integration in demand all over the world. The basics of digital logic theory and techniques are easily understood by the design based on VLSI technology. These are the core fundamentals of the fast, high-speed complex digital circuits.
Introduction
In modern life, elevators have become an integral part of any public or commercial complex. It does not only ease the faster movement between any two floors and provide a way for movement of disabled, but has also become a status symbol. Elevators, as usually been called as “cars” which work on a gearless traction system in which the movement of the elevator is controlled by several steel hoist ropes and a counter-weight. The weight of the car and counterweight provides sufficient traction between the sheaves and the hoist ropes so that the sheaves can grip the hoist ropes and move and hold the car without excessive slipping. The machinery to drive the elevator is located in a machine room usually directly above the elevator hoist way. To feed electricity to the car and receive electrical signals from it, a multi-wire electrical cable connects the machine room to the car.