temprature sensitive fan

                         A Project  Synopsis on

“Temperature Sensitive Fan"                                        

                

                   ACKNOWLEDGEMENT

We express our deep sense of gratitude to Mr. Z and Z  Project Incharge & Lecturer, Department of Electrical & Electronics Engg., for his fruitful guidance, supervision, constructive criticism and constant encouragement throughout this project.

                                         Lastly, We would like to acknowledge our Department staff and all of our college Colleagues.

                                                                                                                

Date:                                        

                                                                                                     

                        

 

                                CONTENTS

             

·       Aim

·       Feasibility Study

·       Block Diagram

·       Circuit Diagram & Circuit Operation

·       Design Issues

·       Overview Image of Project

·       Advantages

                                                    

                                                 

                                        AIM

                    Automating the on/off state of a fan is useful in many ways - it prevents the waste of energy when it's not hot enough for a fan to be needed; it also makes it possible to monitor environments that are not comfortable, or possible, for humans to monitor, especially for extended periods of time. By connecting a temperature sensor to a PolyBlock in Compare Mode, it's quite simple to turn on a fan when the value from the temperature sensor exceeds a given threshold.        

                 Connecting the necessary components for a Temperature Controlled Fan is straightforward. The idea is that the temperature sensor produces a voltage that is proportional to the temperature in degrees fahrenheit. The voltage is just the temperature divided by 100, so when it's 0 degrees fahrenheit, it outputs 0V, when it's 70 degrees the sensor outputs 0.70V, and so on. The idea is to use the Poly Block to compare the incoming voltage with a reference voltage of its own. This reference voltage can be set by using the trimpot dial on the Poly Block.   

                            Feasibility  Study

                 For this project, we want to activate a fan, so we connect the +V of the Poly Block to one side of the Fan, and the other side to the S1 output. When the Poly Block activates its Greater outputs (the low power O1 and the higher current S1), the fan is switched on and starts to run.

                 By setting the trimpot correctly, the fan can be made to come on at any temperature, and turn off again when the temperature falls below the reference point.

                 This set up assumes that the sensor will be located very close to the PolyBlock. If it is necessary to have the temperature sensor far away from the PolyBlock, consider using the Line Block to extend the signal range.

                 If the selected fan draws more than 2A at the voltage supplied, you may want to consider using the Switch Block, which takes would take a weak logical signal from the O1 output and use it to switch much higher currents (up to around 10A).

                 To connect an AC household fan with a standard power outlet, you could use the AC Switch Block connected to the O1 output, although this is more dangerous since AC voltages are present.

Block Diagram

                                      Circuit Diagram

Circuit operation:

R3-R4 and P1-R1 are wired as a Wheatstone bridge in which R3-R4 generates a fixed two-thirds-supply "reference" voltage, P1-R1 generates a temperature-sensitive "variable" voltage, and Q1 is used as a bridge balance detector.
P1 is adjusted so that the "reference" and "variable" voltages are equal at a temperature just below the required trigger value, and under this condition Q1 Base and Emitter are at equal voltages and Q1 is cut off. When the R1 temperature goes above this "balance" value the P1-R1 voltage falls below the "reference" value, so Q1 becomes forward biased, pulse-charging C1.
This occurs because the whole circuit is supplied by a 100Hz half-wave voltage obtained from mains supply by means of D3-D6 diode bridge without a smoothing capacitor and fixed to 18V by R9 and Zener diode D1. Therefore the 18V supply of the circuit is not true DC but has a rather trapezoidal shape. C1 provides a variable phase-delay pulse-train related to temperature and synchronous with the mains supply "zero voltage" point of each half cycle, thus producing minimal switching RFI from the SCR. Q2 and Q3 form a trigger device, generating a short pulse suitable to drive the SCR.

Design Issues

1) Temperature Sensor :-

     The temperature sensor is a powered sensor, and has three wires - one for   the +5V supply, a 0V or ground supply and a signal.

     Sensors include thermistors Hall-effect sensors, and chip-on-board thermal-controller devices, and each fan comes with a linear ramp control featuring two temperature set points.   

2) Poly Block :-

    Poly Block is used to compare the incoming voltage with a reference voltage of its own. This reference voltage can be set by using the trimpot dial on the Poly Block.

3) Power Supply :-

    A power supply is a device that supplies electrical energy to one or more electric loads.

     Every power supply must obtain the energy it supplies to its load, as well as any energy it consumes while performing that task, from an energy source.

     AC/DC supply :-

      In the past, mains electricity was supplied as DC in some regions, AC in others. Transformers cannot be used for DC, but a simple, cheap unregulated power supply could run directly from either AC or DC mains without using a transformer. The power supply consisted of a rectifier and a filter capacitor. When operating from DC the rectifier was essentially a conductor, having no effect; it was included to allow operation from AC or DC without modification.

                               Overview Image of the Project

                                             Advantages

1) More Powerful Cooling :-

AC Switch Block can be used to control a household fan instead of one of its smaller relatives.

2) Oxygen Flow :-

Substitute a carbon dioxide (or other gas) sensor for the temperature sensor to allow the fan to turn on automatically when there's not enough oxygen in a room.

3) Temperature Monitor :-

Substitute a small alarm for the fan to create an alert that lets you know when the temperature has exceeded (or dropped below) a certain threshold.

                                      Applications

Used as CPU Fan to control the Computer Processor Temperature










THANX GUYS

pervasive computing

Summary: What is pervasive computing all about? What kind of scenarios can we
envisage in the future where pervasive technologies will be put to use? Read more..
"Things that think want to link", Nicholas Negraponte of MIT Media Labs is quoted as saying.
This is the doctrine on which pervasive computing is based!
Talking about pervasive computing raises many questions - Will pervasive computing simulate
the super-intelligent HAL in 2001: A Space Odyssey, written by Arthur C. Clarke? HAL seemed
an affectionate and intelligent fellow at the outset, but then morphed into a sinister and powerful
controlling intelligence with a hidden agenda. Will pervasive computing impinge on our privacy
or be a harbinger of 'convenience and convergence'. And will we have to make a choice or can we
marry the two in a rational manner?
What Pervasive?
Let's take a look at what pervasive computing means and what it portends for human kind in the
next few years. To put it simply it is computation that's freely available everywhere. A scenario
where all devices are networked, human-centric, communicate and interact with each other
without any hiccups; their primary objective being to bestow quality life to the user. What's so
beautiful about pervasive computing is that it is an important part of our lives even now, but in
ways that we don't really notice. Earlier, television used to be a source for entertainment while the
computer was used for work-related functions only. But, today, their functions don't adhere to any
rigid boundaries anymore. What this suggests is that pervasive computing is soon going to be
invisible. The way it interfaces with users will also become intuitive. Progress has continued up
to a point where the greatest innovations transcend our personal notions of personal computing.
Pervasive speak
The underlying premise of pervasive computing is compelling: simplicity of use, and the user
spending time completing the task, not learning the application and how to configure and
troubleshoot it. The user experience is the message that the brands of pervasive computing
devices will promote.
The "authorized access to anytime-anywhere-any device-any network-any data", the 6As model
of pervasive computing propounds a new paradigm in convergence and networking. Apart from
making a user's life more easy and convenient, the global nature of these applications, their 7*24
ubiquitous access on a PC or a Palm/PDA or cell phone of email, Internet and other data makes
them an imperative requirement that will increase revenues, improve customer service and
decrease costs in any application.
Nomadic computing
What pervasive devices do is to connect nomadic users. They can access different locations,
URLs that point to specific content through barcodes, electronic tags, optical recognition methods
and infrared and radio frequency transceivers available on PDAs (personal digital assistants) and
laptops through direct or indirect sensing methods.
Any user can monitor his household utility consumption through reports on how the household
generates electricity. Data are analyzed by time, appliance and weather conditions to discover
trends and generate suggestions about efficiency levels, etc. Even the refrigerator knows when it's
running out of lemonade and sends an alert to a system that can tell the grocer to supply
lemonade. When returning home from work, the user can remotely switch on the air-conditioner
while in his car and create the desired ambience/temperature even before he reaches home. A web
tablet that moves from car to home and office and helps a continuum of devices interact and
communicate effectively helps achieve this.
Old age home residents and babies in a day-care center can be tracked through a radio-frequency
infrared badge that the residents wear. When the button is pressed, an alert is conveyed and the
request is relayed to the concerned people at their respective locations. Even the tossing and
turning of a child can be tracked effectively.
Pervasive and embedded software
In it's essence, pervasive computing uses web technology, portable devices, wireless
communications and nomadic or ubiquitous computing systems. The web and the simple standard
HTTP protocol that it is based on, facilitate this kind of ubiquitous access. This can be
implemented on a variety of devices - PDAs, laptops, information appliances such as digital
cameras and printers. Mobile users get transparent access to resources outside their current
environment.
New environments can be accessed without requiring a global wireless connection like a cell
phone and even without networking with the immediate surroundings. In other words, the
infrastructure needed to interact with local users can be minimized to a great extent. Or even
made invisible!
A pervasive system is unobtrusively embedded in the environment. The emerging technologies
that will prevail in a pervasive environment of the future are wearable computers, smart homes
(that can control temperature gauges, control lighting, program a home theatre system and
indulge in other activities of home automation), speech and gesture recognition sensors, optical
switching devices and imbedded sensors.
For example, a mobile user should be able to print a document at a nearby printer without
necessarily having to contact a global service. All they may need is a local web server that helps
them discover these local resources without having to reconfigure their devices as they move
from place to place.
Lets talk about a few emerging technologies.
Emerging Pervasive (ubiquitous) Technologies
1. Peer-to-Peer (P2P) networking
Napster popularized the application of P2P (peer-to-peer networking) products and now the same
technology has begun to sing a business melody. The basic idea behind it being the sharing of
files and programs and communicating directly with people over the Internet, without having to
rely on a centralized server. What it does is to create private workspaces for sharing files,
exchanging information, creating databases and communication instantly. Companies can now
participate in B2B marketplaces, cut out intermediaries and instead collaborate directly with
suppliers. Peers on desktop PCs can share files directly over a network. Renting computing power
can solve resource problems in smaller companies, thus improving the power of web applications.
2. Nano technology
We've seen science fiction flicks where miniature machines get into the human body and track
cell patterns and behavior like those of cancer cells and exterminate them. Molecule sized
computers can be manufactured to create new materials that can replace steel in all its properties
and even withstand temperatures of 6,500 degree Fahrenheit. It is predicted that these materials
will soon be used to build automobiles and office buildings. 'A la' - an invisible infrastructure!
3. Chips and the Net
Net-ready chips are a low cost method of getting on to the Internet. They follow all the necessary
Internet Protocols and can be embedded in home appliances that can then be easily connected to
the Internet. They function as tags that possess comprehensive information about the object that it
is tagged on to and include details like the date and place it was manufactured.
4. Wireless technology
Wireless Internet connection helps access the Net through cellular phones, Personal Digital
Assistants (PDAs) and Wireless laptops and this technology proposes enormous business
opportunities. The sales force can avail real-time access to inventory records; price lists, order
and customer account status and can book a sale almost instantaneously. Constant communication
with wireless gadgets (that cost many degrees lesser than a laptop) can ensure that there is a
constant feedback loop thus ensuring a new way of reaching customers.
5. The tapestry of distributed computing
Distributed computing is the processing power of thousands of PCs aggregated to create a super
computer. A centralized server subsidizes a large computing task in to smaller bits. It then assigns
those bits to thousands of desktop computers, each of which does a small task and returns the
results to the server. Specialists in content delivery, pharmaceuticals, biotechnology and financial
services will see the use of distributed computing capabilities soon. A classic example of how it is
being used today is in the SETI@home project. This project is about searching for extraterrestrial
using radar arrays that look for intelligent patterns of radio waves among the background
radiation. Thousands of volunteers have downloaded the SETI@home screen saver and when
their machines are sitting idle, they get data from the project and do some data crunching and
send it back for analysis.
6. Voice computing: Tell your computer to switch on!
Voice recognition software will soon allow users to switch on their computers by just talking to
them. Even documents can be edited through voice commands. We'll finally be reaching out to
the frontier where man will be able to talk to all his machines and command them to do as he
wishes.
In effect, we are talking about an e-web or the embedded web where the Internet's role as content
provider and shopping assistant morphs into that of companion and advisor. The embedded web
with its swarm of sensors and appliances (an insect colony with worker bees) places machines at
our beck and call and will take us to the ultimate end in convenience or render all our lives to
become a real-life version of The Truman Show.
IBM's pervasive computing lab:
This is a futuristic playground where IBM tests and shows off technology that connects devices in
a seamless computing environment. The entire lab and all its rooms are a prime example of a web
site. The digital images on display in the picture frames on the living room wall can be controlled
remotely. Intelligent countertops in the kitchen recognize bar code labeled stuff and react
accordingly.
E-web:
Embedded devices in cars, refrigerators, shop floors, hospital rooms extend the Internet's role
beyond content providers and shopping assistants to companion and advisors. The Next-Gen web
will be more interactive with a swarm of specialized devices like sensors, and other appliances,
all with Internet access and the ability to communicate.
Pervasive computing illustrates a world that we are moving towards, quite rapidly. The promise
of 'convenience' implies that islands of technologies will soon converge and simplify life even
further. We will finally be witness to the long promised shift to convergence. Computing will no
longer be a monopolizing activity that shackles us to our desktops. Basically easier computing
that's available everywhere as needed, devices that are going to be easy to use, as simple as
calculators and telephones or ATMs. With an extensive range like mobile commerce to home
automation, and from the well-connected car to the convenience of small devices, pervasive
computing exemplifies a vision beyond the PC. Agreed that some of the technologies behind
these devices are in their infancy or evolutionary stages, so it may just be a question of time
before all that is promised is achieved.

commonwealth games 2010

Delhi 2010 set to become largest Commonwealth Games in history


Date: Fri, 10 Sep 2010

NEW DELHI: Organising Committee Commonwealth Games 2010 Delhi today announced that around 7000 athletes and team officials from 71 nations and territories will make next month’s Games the biggest in the history of the Commonwealth Games. There were approximately 5,800 athletes and team officials in attendance in Melbourne.



“We are delighted to announce that Delhi 2010 is set to become the largest ever Commonwealth Games and are confident that it will be conducted smoothly,” said Organising Committee Commonwealth Games 2010 Delhi Secretary-General Dr. Lalit K. Bhanot. “This number is likely to go up as the Commonwealth Games Federation has a policy for accepting late entries and there are many requests.”



“More importantly, there are many World, Olympic, Commonwealth Games and continental champions among the participants,” he said. “We are sure that the paying spectators and the TV audiences across the world will enjoy watching these athletes perform in the world class facilities created here.



“Of course, we are confident that the athletes in 17 disciplines and four Para Sport events (150 athletes) will like the facilities here and deliver very good performances. They will also enjoy living in the Games Village, built to accommodate 7200 persons, and find that it the best they have experienced in multi-discipline events,” he said.



India will field the biggest contingent of more than 600 athletes and team officials while Bostwana will be the smallest with less than five athletes and officials.



Many nations are sending their largest contingents to a Commonwealth Games outside their home nations.



These include



Australia (550)

England (525)

Canada (400)

New Zealand (325)

Malaysia (325)

Scotland (300)

Wales (240)

With a 220-strong contingent, South Africa will be biggest team from Africa.



India’s neighbours Pakistan and Sri Lanka will send contingents of around 125 each. Australia, Canada, England, New Zealand, Scotland and Wales will keep their record as the only nations to participate in all editions of the Commonwealth Games when they compete in Delhi 2010.



The exact number of athletes will be known only when the Delegation Registration Meetings (DRM) are held between September 16 and October 2, 2010. Until this process is complete, the Organising Committee is not allowed by the Commonwealth Games Federation to reveal the names of the individual athletes

but------behind this aal the thing is happen-----------"CORRUPTION"
 

Congress President Sonia Gandhi on Thursday said those found guilty of corruption in the upcoming Commonwealth Games will be punished once the event is over.



“The Prime Minister is looking into the corruption charges against the Commonwealth Games scheduled in the city from October 3-14 this year,” said Gandhi, at a eeting of the Congress Parliamentary Party (CPP) here today.



“The Commonwealth Games are not related to any political party or individual. It is a national pride and efforts should be made to hold them successfully,” she added.



The Congress has so far avoided backing Commonwealth Games Organising Committee Chairman Suresh Kalmadi, who is also a secretary.



In a report, the Times of India had claimed that it had procured enough evidence to prove that Kalmadi cleared payments due to London-based AM Films without securing a written contract or a proper tender process.



The newspaper report alleges that more emails and faxed documents point to Kalmadi’s involvement.



AM Films and AM Car and Van Hire reportedly received 247,000 pounds. Businessman Ashish Patel and Commonwealth Committee members, however, said that it was done for the 2009 Queen’s Baton ceremony.



“The report quotes an email dated October 24, 2009, on payments and with Kalmadi’s signature on it, saying “why so late…now there is no choice.” Publicly, Kalmadi claimed he didn’t know about the entire dealings with AM Films when the scandal first broke,” The NDTV earlier reported.



Moreover, the Central Vigilance Commission has alleged irregularities in several Commonwealth Games related-works being carried out by civic and construction agencies. (ANI)

Read more: Commonwealth Games Corruption: Guilty won’t be spared says Sonia
Bharat Chronicle http://www.bharatchronicle.com/commonwealth-games-corruption-guilty-wont-be-spared-says-sonia-8541#ixzz0zDN7FgVI