Seminar on Transformer

A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called mutual induction.
If a load is connected to the secondary, an electric current will flow in the secondary winding and electrical energy will be transferred from the primary circuit through the transformer to the load. In an ideal transformer, the induced voltage in the secondary winding (Vs) is in proportion to the primary voltage (Vp), and is given by the ratio of the number of turns in the secondary (Ns) to the number of turns in the primary (Np) as follows:

                 

By appropriate selection of the ratio of turns, a transformer thus allows an alternating current (AC) voltage to be "stepped up" by making Ns greater than Np, or "stepped down" by making Ns less than Np.
In the vast majority of transformers, the windings are coils wound around a ferromagnetic core, air-core transformers being a notable exception.
Transformers range in size from a thumbnail-sized coupling transformer hidden inside a stage microphone to huge units weighing hundreds of tons used to interconnect portions of power grids. All operate with the same basic principles, although the range of designs is wide. While new technologies have eliminated the need for transformers in some electronic circuits, transformers are still found in nearly all electronic devices designed for household ("mains") voltage. Transformers are essential for high-voltage electric power transmission, which makes long-distance transmission economically practical.

Presentation

100 MVA POWER TRANSFORMER

Transformer Design Differences

DRY CORE TRANSFORMERS (rated under 750 volts)

Ramifications of the New Transformer Efficiency Standards

Transformers

Transformer 2

Seminar on Programmable logic controller

A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines. Unlike general-purpose computers, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or non-volatile memory. A PLC is an example of a hard real time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result.

               

The PLC was invented in response to the needs of the American automotive manufacturing industry. Programmable logic controllers were initially adopted by the automotive industry where software revision replaced the re-wiring of hard-wired control panels when production models changed.
Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was accomplished using hundreds or thousands of relays, cam timers, and drum sequencers and dedicated closed-loop controllers. The process for updating such facilities for the yearly model change-over was very time consuming and expensive, as electricians needed to individually rewire each and every relay.

Presentation

PROGRAMMABLE LOGIC CONTROOLER

PROGRAMMABLE LOGIC CONTROOLER 2

Industrial Programmable Logic Controllers (PLCs)

What is a PLC ?

PLC AND ITS APPLICATION

Programmable Logic Controllers

Project - Wireless hand signal transceiver for soldiers

The project is to build a wireless hand signal transceiver for soldiers that can facilitate communication when the current hand signal system doesn't work, such as too dark in the night or people being too far away from each other to see the real hand signals. The transceiver will be in the shape of a glove to enable convenient use and increase stealth. Short range RF will be used for the wireless communication, gyros/accelerometers will be used to detect different motions to make the transceiver a natural expansion of the current hand signal system, buttons on each finger are used to encode information like meters and numbers, an LCD screen will be installed on the back to display the received messages, and an earphone is used to alert the soldier upon receiving a new message.

 

                          

Reference material on the project

Presentation

Paper

Source: University of Illinois

Author :Xiaoli WANG, Yang XU

Project -Spin Bike Studio Project

The majority of spin studios consist of mechanical bikes with no way for members to compare their performance against their peers. Our goal is to create a cost-effective method for upgrading these bikes without having to completely upgrade their studio with expensive bikes, which do not have network capabilities. Our senior design project involves collaboration with a mechanical engineering design team and a start-up company called Flywheel Concepts. We will design a system that acquires measurements from legacy spin bikes that do not contain an electrical system. Our goal is to use microcontrollers for each bike to collect data such as resistance, power, and rpm. We will wirelessly transmit this data onto a central system, which will be interfaced with a display where members of a spin cycle class can compare their performance with others. In order to test the system, we will design a simulation box that mimics the outputs that we will be receiving from the mechanical engineering team. This will include variable resistance, output power, and rpm. Each bike will have its own seven-segment display that shows the measurements obtained. The central display will be incorporate all of the data from each bike on a user-friendly display on a computer.

Final paper

Design review

Ebook - Digital Signal Processing: A Filtering Approach

This new resource introduces the concepts, equations, and terminology of Digital Signal Processing, and also provides the tools needed to analyze and design digital filters. With emphasis on digital filtering, this book applies the reader's knowledge of AC circuits, trigonometry, algebra, calculus and analog filter design to digital signal processing. This book also assists users in the understanding and use of available digital filtering software to meet design criteria.

 

Download free ebook

Link 1

Seminar on Iris Scanning

Iris recognition is a method of biometric authentication that uses pattern-recognition techniques based on high-resolution images of the irides of an individual's eyes.

Not to be confused with another, less prevalent, ocular-based technology, retina scanning, iris recognition uses camera technology, with subtle infrared illumination reducing specular reflection from the convex cornea, to create images of the detail-rich, intricate structures of the iris. Converted into digital templates, these images provide mathematical representations of the iris that yield unambiguous positive identification of an individual.

Iris recognition efficacy is rarely impeded by glasses or contact lenses. Iris technology has the smallest outlier (those who cannot use/enroll) group of all biometric technologies. Because of its speed of comparison, iris recognition is the only biometric technology well-suited for one-to-many identification. A key advantage of iris recognition is its stability, or template longevity, as, barring trauma, a single enrollment can last a lifetime.

Reference Material

• IRIS Recognition for Person Identification

• Iris Recognition

• IRIS SCANNING

• An Efficient Iris Recognition for Security Purposes

• How Iris Recognition Works

• Tools for Iris Recognition Engines

• Iris Modeling and Synthesis

Earth Simulator

The Earth Simulator (ES), developed by the Japanese government's initiative "Earth Simulator Project", was a highly parallel vector supercomputer system for running global climate models to evaluate the effects of global warming and problems in solid earth geophysics. The system was developed for Japan Aerospace Exploration Agency, Japan Atomic Energy Research Institute, and Japan Marine Science and Technology Center in 1997. Construction started in October 1999, and the site officially opened on March 11, 2002. The project cost 60 billion yen.

Built by NEC, ES was based on their SX-6 architecture. It consisted of 640 nodes with eight vector processors and 16 gibibytes of computer memory at each node, for a total of 5120 processors and 10 terabytes of memory. Two nodes were installed per 1 metre x 1.4 metre x 2 metre cabinet. Each cabinet consumed 20 kW of power. The system had 700 terabytes of disk storage (450 for the system and 250 for the users) and 1.6 petabytes of mass storage in tape drives. It was able to run holistic simulations of global climate in both the atmosphere and the oceans down to a resolution of 10 km. Its performance on the LINPACK benchmark was 35.86 TFLOPS, which was almost five times faster than ASCI White.

Reference material

• Earth Simulator Running 1 Introduction

• The Earth Simulator System

• Software of the Earth Simulator

• The Earth Simulator Project and beyond

• CaseStudy - Brief presentation of Earth Simulation Center

• High Resolution Earth System Modelling - PowerPoint Presentation

video door phone

It is a solution for security and can be used in home automation as well. Video door phone has become a necessity of our life because we love our families and we want to protect them. We require a way to see the visitor and have a conversation before allowing the visitor into the house.

We also wish to keep a watch on children when they are playing in the garden or in the club house.

The high quality video door phone is a state-of-the-art product which comprises of:

• An indoor unit with a monitor
• An outdoor unit with an in-built microphone and camera

The hands-free video door phone enables the person inside the house to see the visitor and have a conversation before entry into the house.

Reference link

• F -701 Standalone Video door phone

• Welcome to MiTEC

• Slide 1

• Color Video Doorphone

• B&W Video Doorphone - Easy Setup Guide

• VIDEO DOORPHONE

• Wireless Video Door Phone

• IP based Video Door Phone

• Video Doorphone System

WI-MAX

WiMAX, meaning Worldwide Interoperability for Microwave Access, is a telecommunications technology that provides wireless transmission of data using a variety of transmission modes, from point-to-multipoint links to portable and fully mobile internet access. The technology provides up to 10 Mbps broadband speed without the need for cables. The technology is based on the IEEE 802.16 standard (also called Broadband Wireless Access). The name "WiMAX" was created by the WiMAX Forum, which was formed in June 2001 to promote conformity and interoperability of the standard. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL".

Reference link

• WiMAX

• MobileAccess WiMAX briefing

• WiMAX – A Business Case

• WiMAX security

• WiMAX Performance

• 802.16/WiMAX

• WiMAX Overview

• Mobile WiMAX

WISENET

WISENET is a wireless sensor network that monitors the environmental conditions such as light, temperature, and humidity. This network is comprised of nodes called "motes" that form an ad-hoc network to transmit this data to a computer that function as a server. The server stores the data in a database where it can later be retrieved and analyzed via a web-based interface. The network works successfully with an implementation of one sensor mote.

Introduction:
The technological drive for smaller devices using less power with greater functionality has created new potential applications in the sensor and data acquisition sectors. Low-power microcontrollers with RF transceivers and various digital and analog sensors allow a wireless, battery-operated network of sensor modules ("motes") to acquire a wide range of data. The TinyOS is a real-time operating system to address the priorities of such a sensor network using low power, hard real-time constraints, and robust communications.

The first goal of WISENET is to create a new hardware platform to take advantage of newer microcontrollers with greater functionality and more features. This involves selecting the hardware, designing the motes, and porting TinyOS. Once the platform is completed and TinyOS was ported to it, the next stage is to use this platform to create a small-scale system of wireless networked sensors.

System Description:
There are two primary subsystems (Data Analysis and Data Acquisition) comprised of three major components (Client, Server, Sensor Mote Network).
Primary Subsystems:
There are two top-level subsystems -
Data Analysis
Data Acquisition.

Data Analysis:
This subsystem is software-only (relative to WISENET). It relied on existing Internet and web (HTTP) infrastructure to provide communications between the Client and Server components. The focus of this subsystem was to selectively present the collected environmental data to the end user in a graphical manner.

Reference link

• WISENET Wireless Sensor Network

• Wireless Sensor Network (WiSeNet)

• WISENET

• The Ultra Low-Power WiseNET System

• WISENet — Joining Worlds

• WISENET

• Wisenet - Wireless Sensor Network

Optical fiber communication

Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information. First developed in the 1970s, fiber-optic communication systems have revolutionized the telecommunications industry and have played a major role in the advent of the Information Age. Because of its advantages over electrical transmission, optical fibers have largely replaced copper wire communications in core networks in the developed world.

The process of communicating using fiber-optics involves the following basic steps: Creating the optical signal involving the use of a transmitter, relaying the signal along the fiber, ensuring that the signal does not become too distorted or weak, receiving the optical signal, and converting it into an electrical signal.

Optical fiber is used by many telecommunications companies to transmit telephone signals, Internet communication, and cable television signals. Due to much lower attenuation and interference, optical fiber has large advantages over existing copper wire in long-distance and high-demand applications. However, infrastructure development within cities was relatively difficult and time-consuming, and fiber-optic systems were complex and expensive to install and operate. Due to these difficulties, fiber-optic communication systems have primarily been installed in long-distance applications, where they can be used to their full transmission capacity, offsetting the increased cost. Since 2000, the prices for fiber-optic communications have dropped considerably. The price for rolling out fiber to the home has currently become more cost-effective than that of rolling out a copper based network. Prices have dropped to $850 per subscriber in the US and lower in countries like The Netherlands, where digging costs are low.

Since 1990, when optical-amplification systems became commercially available, the telecommunications industry has laid a vast network of intercity and transoceanic fiber communication lines. By 2002, an intercontinental network of 250,000 km of submarine communications cable with a capacity of 2.56 Tb/s was completed, and although specific network capacities are privileged information, telecommunications investment reports indicate that network capacity has increased dramatically since 2004.

Reference link

• Optical Fibre Communication SystemsHow Things Work

• The Origins of Fiber Optic Communications

• Transmission Characteristics of Optical Fiber

• Optical fiber communication — An overview

• Receiver design for optical fiber communication systems

• OPTICAL FIBER COMMUNICATION

• OPTICAL FIBER COMMUNICATIONS 1. Introduction: The general system

• Data Communication & Network

Organic light emitting diode (OLED)

Organic light emitting diode (OLED) display technology has been grabbing headlines in recent years. Now one form of OLED displays, LIGHT EMITTING POLYMER (LEP) technology is rapidly emerging as a serious candidate for next generation flat panel displays. LEP technology promises thin, light weight emissive displays with low drive voltage, low power consumption, high contrast, wide viewing angle, and fast switching times.
One of the main attractions of this technology is the compatibility of this technology with plastic-substrates and with a number of printer based fabrication techniques, which offer the possibility of roll-to-roll processing for cost-effective manufacturing.
LEPs are inexpensive and consume much less power than any other flat panel display. Their thin form and flexibility allows devices to be made in any shape. One interesting application of these displays is electronic paper that can be rolled up like newspaper.
Cambridge Display Technology, the UK, is betting that its light weight, ultra thin light emitting polymer displays have the right stuff to finally replace the bulky, space consuming and power-hungry cathode ray tubes (CRTs) used in television screens and computer monitors and become the ubiquitous display medium of the 21st century.

Reference links

• OLED Organic Light Emitting Diode characterisation with ...

• Overview of OLED Display Technology

• Organic Light Emitting Diode (OLED) Displays

• Organic Light Emitting Diodes

• Organic Light-Emitting Diode (OLED).ppt

• Organic Light Emitting Diodes and Displays

• OLED Technology

• http://en.wikipedia.org/wiki/Organic_LED

Augmented Reality

Augmented reality (AR) refers to computer displays that add virtual information to a user's sensory perceptions. Most AR research focuses on "see-through" devices, usually worn on the head that overlay graphics and text on the user's view of his or her surroundings. AR systems track the position and orientation of the user's head so that the overlaid material can be aligned with the user's view of the world.
Consider what AR could make routinely possible. A repairperson viewing a broken piece of equipment could see instructions highlighting the parts that need to be inspected. A surgeon could get the equivalent of x-ray vision by observing live ultrasound scans of internal organs that are overlaid on the patient's body. Soldiers could see the positions of enemy snipers who had been spotted by unmanned reconnaissance planes.
Getting the right information at the right time and the right place is key in all these applications. Personal digital assistants such as the Palm and the Pocket PC can provide timely information using wireless networking and Global Positioning System (GPS) receivers that constantly track the handheld devices. But what makes augmented reality different is how the information is presented: not on a separate display but integrated with the user's perceptions. In augmented reality, the user's view of the world and the computer interface literally become one.

Reference links

• 7 Things You Should Know About Augmented Reality
• Augmented Reality
• Augmented Reality Games
• Spatially Augmented Reality
• Augmented Reality in Medicine
• Augmented and virtual reality
• Augmented reality
• The Augmented Reality Homepage

The Bionic Eye

The entire system runs on a battery pack that's housed with the video processing unit. When the camera captures an image -- of, say, a tree -- the image is in the form of light and dark pixels. It sends this image to the video processor, which converts the tree-shaped pattern of pixels into a series of electrical pulses that represent "light" and "dark." The processor sends these pulses to a radio transmitter on the glasses, which then transmits the pulses in radio form to a receiver implanted underneath the subject's skin. The receiver is directly connected via a wire to the electrode array implanted at the back of the eye, and it sends the pulses down the wire.

When the pulses reach the retinal implant, they excite the electrode array. The array acts as the artificial equivalent of the retina's photoreceptors. The electrodes are stimulated in accordance with the encoded pattern of light and dark that represents the tree, as the retina's photoreceptors would be if they were working (except that the pattern wouldn't be digitally encoded). The electrical signals generated by the stimulated electrodes then travel as neural signals to the visual center of the brain by way of the normal pathways used by healthy eyes -- the optic nerves. In macular degeneration and retinitis pigmentosa, the optical neural pathways aren't damaged. The brain, in turn, interprets these signals as a tree and tells the subject, "You're seeing a tree."

Reference links

• Bionic Eye PhD projects
• The Bionic Eye
• Bionic eye team sees far into future
• The 'Bionic' Eye
• BIONIC EYE
• http://health.howstuffworks.com/bionic-eye1.htm
• Bionic Eye in sight

Optical Communications in Space

In telecommunications, Free Space Optics (FSO) is an optical communication technology that uses light propagating in free space to transmit data between two points. The technology is useful where the physical connections by the means of fibre optic cables are impractical due to high costs or other considerations.Optical communications, in various forms, have been used for thousands of years. The Ancient Greeks polished their shields to send signals during battle. In the modern era, semaphores and wireless solar telegraphs called heliographs were developed, using coded signals to communicate with their recipients.
Free Space Optics are additionally used for communications between spacecraft. The optical links can be implemented using infrared laser light, although low-data-rate communication over short distances is possible using LEDs. Maximum range for terrestrial links is in the order of 2-3 km, but the stability and quality of the link is highly dependent on atmospheric factors such as rain, fog, dust and heat. Amateur radio operators have achieved significantly farther distances (173 miles in at least one occasion) using incoherent sources of light from high-intensity LEDs. However, the low-grade equipment used limited bandwidths to about 4kHz. In outer space, the communication range of free-space optical communication is currently in the order of several thousand kilometers, but has the potential to bridge interplanetary distances of millions of kilometers, using optical telescopes as beam expanders. IrDA is also a very simple form of free-space optical communications.

Reference links related to this topics

• Free-Space Optical Communications for Tactical Applications

• A Brief Overview of Free-Space Optical Communications

• Optical Wireless Communication using Digital Pulse Interval Modulation

• FREE SPACE OPTIC COMMUNICATIONS

• Optical Communications in Space

• Free-Space Optical communication using visible light

• Free Space Optical Communications

• Free-space optical communication

4G Wireless Systems

4G refers to the fourth generation of cellular wireless standards. It is a successor to 3G and 2G standards, with the aim to provide a wide range of data rates up to ultra-broadband (gigabit-speed) Internet access to mobile as well as stationary users. Although 4G is a broad term that has had several different and more vague definitions, this article uses 4G to refer to IMT Advanced (International Mobile Telecommunications Advanced), as defined by ITU-R.

A 4G cellular system must have target peak data rates of up to approximately 100 Mbit/s for high mobility such as mobile access and up to approximately 1 Gbit/s for low mobility such as nomadic/local wireless access, according to the ITU requirements. Scalable bandwidths up to at least 40 MHz should be provided. A 4G system is expected to provide a comprehensive and secure all-IP based solution where facilities such as IP telephony, ultra-broadband Internet access, gaming services and HDTV streamed multimedia may be provided to users.

Reference link

• 4G Wireless Systems
• 4G - Wikipedia, the free encyclopedia
• Wireless Communication Systems
• 4th Generation Mobile Broadband Wireless Systems
• Network Integration of 4G Wireless
• 3G vs. 4G Evolution des modulations
• 4G Wireless Standard

Wireless USB

Wireless USB is a short-range, high-bandwidth wireless radio communication protocol created by the Wireless USB Promoter Group. Wireless USB is sometimes abbreviated as "WUSB", although the USB Implementers Forum discourages this practice and instead prefers to call the technology "Certified Wireless USB" to differentiate it from competitors. Wireless USB is based on the WiMedia Alliance's Ultra-WideBand (UWB) common radio platform, which is capable of sending 480 Mbit/s at distances up to 3 meters and 110 Mbit/s at up to 10 meters. It was designed to operate in the 3.1 to 10.6 GHz frequency range, although local regulatory policies may restrict the legal operating range for any given country.

 

Reference links

• Wireless Universal Serial Bus
• A Potential Future Application -- Wireless USB
• Wireless USB for HomeRF-Lite
• Wireless USB

Interactive Voice Response

nteractive Voice Response (IVR) product, interactive technology that allows a computer to detect voice and keypad inputs. IVR technology is used extensively in telecommunications, but is also being introduced into automobile systems for hands-free operation. Current deployment in automobiles revolves around satellite navigation, audio and mobile phone systems. In telecommunications, IVR allows customers to access a company’s database via a telephone touchtone keypad or by speech recognition, after which they can service their own enquiries by following the instructions. IVR systems can respond with pre-recorded or dynamically generated audio to further direct users on how to proceed. IVR systems can be used to control almost any function where the interface can be broken down into a series of simple menu choices. In telecommunications applications, such as customer support lines, IVR systems generally scale well to handle large call volumes.

It has become common in industries that have recently entered the telecom industry to refer to an Automated Attendant as an IVR. The terms Automated Attendant and IVR are distinct and mean different things to traditional telecom professionals, whereas emerging telephony and VoIP professionals often use the term IVR as a catch-all to signify any kind of telephony menu, even a basic automated attendant. The term VRU, for voice reponse unit, is sometimes used as well.

Reference links

• What is IVR?

• Interactive Voice Response (IVR) Software

• Interactive Voice Response

• Interactive Voice Response (IVR)

• HowStuffWorks "How Interactive Voice Response (IVR) Works"

• Custom IVR - Interactive Voice Response Custom Solutions

• Interactive Voice Response (IVR) systems

• Cisco Unified IP Interactive Voice Response - Products & Services

Mobile Computing

Mobile computing is a generic term describing one's ability to use technology while moving, as opposed to portable computers, which are only practical for use while deployed in a stationary configuration.

Many types of mobile computers have been introduced since the 1990s, including the:

    * Wearable computer
    * Personal digital assistant/Enterprise digital assistant
    * Smartphone
    * Carputer
    * UMPC

 

Links:

• Mobile Computing

• Mobile Computing Networks

• Encryption for Mobile Computing

• Mobile Computing and Wireless Communications

• IBM Research | Mobile Computing

• www.citindia.com/September21_2005.htm

Holographic Versatile Disc

The Holographic Versatile Disc (HVD) is an optical disc technology that, in the future, may hold up to 3.9 terabytes (TB) of information, although the current maximum is 250GB. It employs a technique known as collinear holography, whereby two lasers, one red and one green, are collimated in a single beam. The green laser reads data encoded as laser interference fringes from a holographic layer near the top of the disc while the red laser is used as the reference beam and to read servo information from a regular CD-style aluminum layer near the bottom. Servo information is used to monitor the position of the read head over the disc, similar to the head, track, and sector information on a conventional hard disk drive. On a CD or DVD this servo information is interspersed amongst the data.

A dichroic mirror layer between the holographic data and the servo data reflects the green laser while letting the red laser pass through. This prevents interference from refraction of the green laser off the servo data pits and is an advance over past holographic storage media, which either experienced too much interference, or lacked the servo data entirely, making them incompatible with current CD and DVD drive technology. These discs have the capacity to hold up to 3.9 terabytes (TB) of information. The HVD also has a transfer rate of 1 Gbit/s (125 MB/s). Optware planned to release a 200 GB disc in early June 2006, and Maxell planned one for September 2006 with a capacity of 300 GB and transfer rate of 20 MB/s -- although HVD standards were approved and published on June 28, 2007, neither company has released an HVD as of March, 2009.

Study material links:

• Holographic Versatile Disc System

• Holographic Versatile Disc (HVD™) System

• Collinear Holography

• Holographic Versatile Disc

• Holographic Versatile Disc - Wikipedia, the free encyclopedia

• HowStuffWorks "How Holographic Versatile Discs Work"

• Holographic Versatile Disk (HVD) - Express Computer