50 Common Interview Questions and Answers

What kind of salary do you need? Are you applying for other jobs? Why should we hire you?

Review these typical interview, questions and think about how you would answer them, Read the questions listed; you’ll also find some strategy suggestions with it.

· Tell me about yourself.

The most often asked question in interviews. You need to have a short statement prepared in your mind. Be careful that it does not sound rehearsed. Limit it to work-related items unless instructed otherwise. Talk about things you have done and jobs you have held that relate to the position you are interviewing for. Start with the item farthest back and work up to the present.

· Why did you leave your last job?

Stay positive regardless of the circumstances. Never refer to a major problem with management and never speak ill of supervisors, co-workers, or the organization. If you do, you will be the one looking bad. Keep smiling and talk about leaving for a positive reason such as an opportunity, a chance to do something special, or other forward-looking reasons.

· What experience do you have in this field?

Speak about specifics that relate to the position you are applying for. If you do not have specific experience, get as close as you can.

· Do you consider yourself successful?

You should always answer yes and briefly explain why. A good explanation is that you have set goals, and you have met some and are on tract to achieve the others.

· What do co-workers say about you?

Be prepared with a quote or two from co-workers. Either a specific statement or a paraphrase will work. “Jill Clark, a co-worker at Smith Company, always said I was the hardest worker she had ever known.” It is as powerful as Jill having said it at the interview herself.

· What do you know about this organization?

This question is one reason to do some research on the organization before the interview. Find out where they have been, and where they are going. What are the current issues, and who are the major players?

· What have you done to improve your knowledge in the last year?

Try to include improvement activities that relate to the job. A wide variety of activities can be mentioned as positive self-improvement. Have some good ones handy to mention.

· Are you applying for other jobs?

Be honest but do not spend a lot of time in this area. Keep the focus on this job and what you can do for this organization. Anything else is a distraction.

· Why do you want to work for this organization?

This may take some thought and certainly should be based on the research you have done on the organization, Sincerity is extremely important here, and will easily be sensed. Relate it to your long-term career goals.

· Do you know anyone who works for us?

Be aware of the policy on relatives working for the organization. This can affect your answer even though they asked about friends not relatives. Be careful to mention a friend only if they are will thought of.

· What kind of salary do you need?

A loaded question. A nasty little game that you will probably lose if you answer first. So, do not answer it. Instead, say something like, “That’s a tough question. Can you tell me the range for this position?” In most cases, the interviewer, taken off guard, will tell you. If not, say that it can depend on the details of the job. Then give a wide range.

· Are you a team player?

You are, of course, a team player, Be sure to have examples ready. Specifics that show you often perform for the good of the team rather than for yourself are good evidence of your team attitude. Do not brag, just say it in a matter-of-fact tone. This is a key point.

· How long would you expect to work for us if hired?

Specifics here are not good. Something like this should work: “I’d like it to be a long time.” Or “As long as we both feel I’m doing a good job.”

· Have you ever had to fire anyone? How did you feel about that?

This is serious. Do not make light of it or in any way seem like you like to fire people. At the same time, you will do it when it is the right thing to do. When it comes to the organization versus the individual who has created a harmful situation, you will protect the organization. Remember firing is not the same as layoff or reduction in force.

· What is your philosophy towards work?

The interviewer is not looking for a long or flowery dissertation here. Do you have strong feelings that the job gets done? Yes. That’s the type of answer that works best here. Short and positive, showing a benefit to the organization.

· If you had enough money to retire right now, would you?

Answer yes if you would, But since you need to work, this is the type of work you prefer. Do not say yes if you do not mean it.

· Have you ever been asked to leave a position?

If you have not, say no. If you have, be honest, brief, and avoid saying negative things about the people or organization involved.

· Explain how you would be an asset to this organization.

You should be anxious for this question. It gives you a chance to highlight your best points as they relate to the position being discussed. Give a little advance thought to this relationship.

· Why should we hire your?

Point out how your assets meet what the organization needs. Do not mention any other candidates to make a comparison.

· Tell me about a suggestion you have made.

Have a good one ready. Be sure and use a suggestion that was accepted and was then considered successful. One related to the type of work applied for is a real plus.

· What irritates you about co-workers?

This a trap question. Think “real hard” but fail to come up with anything that irritates you. A short statement that you seem to get along with folks is great.

· What is your greatest strength?

Numerous answers are good, just stay positive. A few good examples: your ability to prioritize.

· Your problem-solving skills.

· Your ability to work under pressure.

· Your ability to focus on projects.

· Your professional expertise.

· Your leadership skills.

· Your positive attitude.

· Tell me about your dream job.

Stay away from a specific job. You cannot win. If you say the job you are contending for is it, you strain credibility. If you say another job is it, you plant the suspicion that you will be dissatisfied with this position if hired. The best bet is to stay generic and say something like: “A job where I love the work, like the people, can contribute, and can’t wait to get to work.”

· Why do you think you would do well at this job?

Give several reasons and include skills, experience, and interest.

· What are you looking for in a job?

Stay away from a specific job. You cannot win. If you say the job you are contending for is it, you strain credibility. If you say another job is it, you plant the suspicion that you will be dissatisfied with this position if hired. The best bet is to stay generic and say something like: “A job where I love the work, like the people, can contribute, and can’t wait to get to work.”

· What kind of person would you refuse to work with?

Do not be trivial, It would take disloyalty to the organization, violence or lawbreaking to get you to object. Minor objections will label you as a whiner.

· What is more important to you: the money or the work?

Money is always important, but the work is the most important. There is not better answer.

· What would your previous supervisor say your strongest point is?

There are numerous good possibilities:

· Loyalty

· Energy

· Positive attitude

· Leadership

· Team Player

· Expertise

· Initiative

· Patience

· Hard Work

· Creativity

· Problem solver

· Tell me about a problem you had with a supervisor.

Biggest trap of all. This is a test to see if you will speak ill of your boss. If you fall for it and tell about a problem with a former boss, you may well blow the interview right there. Stay positive and develop a poor memory about any trouble with a superior.

· What has disappointed you about a job?

Don’t get trivial or negative. Safe areas are few but can include.

· Not enough of a challenge.

· You were laid off in a reduction.

· Company did not win a contract, which would have given you more responsibility.

· Tell me about your ability to work under pressure.

You may say that you thrive under certain types of pressure. Give an example that relates to the type of position applied for.

· Do your skills match this job or another job more closely?

Probably this one. Do not give fuel to the suspicion that you may want another job more than this one.

· What motivates you to do your best on the job?

This is a personal trait that only you can say, but good examples are:

Ø Challenge

Ø Achievement

Ø Recognition

Are you willing to work overtime? Nights? Weekends?

This is up to you. Be totally honest.

· How would you know you were successful on this job?

Several ways are good measures:

Ø You Set high standards for yourself and meet them.

Ø Your outcomes are a success.

Ø Your boss tells you that you are successful.

· Would you be willing to relocate if required?

You should be clear on this with your family prior to the interview if you think there is a chance it may come up. Do not say yes just to get the job if the real answer is no. This can create a lot of problems later on in your career. Be honest at this point and save yourself future grief.

· Are you willing to put the interests of the organization ahead of your own?

This is a straight loyalty and dedication question. Do not worry about the deep ethical and philosophical implications. Just say yes.

· Describe your management style.

Try to avoid labels. Some of the more common labels, like “progressive”, “Salesman” or “Consensus”, can have several meanings or descriptions depending on which management expert you listen to. The “situational” style is safe, because it says you will manage according to the situation, instead of “one size fits all.”

· What have you learned from mistakes on the job?

Here you have to come up with something or you strain credibility. Make it a small, well-intentioned mistake with a positive lesson learned. An example would be … working too far ahead of colleagues on a project and thus throwing coordination off.

· Do you have any blind spots?

Trick question, if you know about blind spots, they are no longer blind spots. Do not reveal any personal areas of concern here. Let them do their own discovery on your bad points. Do not hand it to them.

· If you were hiring a person for this job, what would you look for?

Be careful to mention traits that are needed and that you have.

· Do you think you are overqualified for this position?

Regardless of your qualifications, state that you are very well qualified for the position.

· How do you propose to compensate for your lack of experience?

First, if you have experience that the interviewer does not know about, bring that up. Then, point out (if true) that you are a hard working quick learner.

· What qualities do you look for in a boss?

Be generic and positive, safe qualities are knowledgeable, a sense of humor, fair, loyal to subordinates, and holder of high standards. All bosses think they have these traits.

· Tell me about a time when you helped resolve a dispute between others.

Pick a specific incident. Concentrate on your problem solving technique and not the dispute you settled.

· What position do you prefer on a team working on a project?

Be honest. If you are comfortable in different roles, point that out.

· Describe your work ethic.

Emphasize benefits to the organization. Things like, “determination to get the job done” and “work hard but enjoy your work” are good.

· What has been your biggest professional disappointment?

Be sure that you refer to something that was beyond your control. Show acceptance and no negative feelings.

· Tell me about the most fun you have had on the job.

Talk about having fun by accomplishing something for the organization.

· Do you have any questions for me?

Always have some questions prepared. Questions involving areas where you will be an asset to the organization are good. “How soon will I be able to be productive?” and “What type of projects will I be able to assist on?” are examples.

WORKING WITH ASSEMBLIES:

WORKING WITH ASSEMBLIES:

NOTE: if you are not familiar with the layout of SolidWorks, then click here to familiarize yourself with the layout

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This tutorial expands on the parts tutorial. Instead of working with parts, we will be working with assemblies. We will also consider moving individual parts in assemblies.

This tutorial will use the toggle press assembly. You can find this in the togglepress.zip file.

• Start SolidWorks and goto file->open
• Find "press.SLDASM" in the toggle press folder and click open:

Viewing the Assembly:

• You can zoom and rotate around the assembly just like you did with a single part using the standard views , rotation tool , or move and zoom tools. For clarification review working with parts:

           

Moving the Assembly:

• Since this is a model of a press, lets make it press!
• Select the move component button on the assembly toolbar. The cursor will change to and you can now move individual parts. Click on green part of the model and drag it up or down. You should see the assembly move. You could also click on the handle and move it up or down to simulate the press in action.
• Another option is to use the rotate component button on the assembly toolbar. This button is normally reserved for parts that are mated concentrically because it is often hard to control. It will work though. It is up to you to decide which tool is the best to use in each circumstance. Move component is usually the safe choice though.

Closed	Open

Extracting Dimensions From the Assembly:

• If we want to determine where the green press is in relation to the base we can use the measure tool.
• Go to the main file menu and use Tools>Measure. The cursor will change to a ruler and a dialog box will appear with the title 'Measure.' Click the base (gray) and then click the green part. The measure tool will then display the distance betwen the two parts (100.00 mm)

• If you move the top base by 50mm and measure again you will get the new distance (150 mm):

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to tutorial index...

INDIA TO END ITS 28 YEARS WAIT FOR WORLD CUP TITLE

Gautam Gambhir and MS Dhoni's stellar partnership paved the way for India to end its 28-year wait for a World Cup title even as Mahela Jayawardene's century and Muttiah Muralitharan's swansong ended in hurt and despair.
Chasing a target of 275, India were pegged on the back foot as early as the second ball of their innings when Lasith Malinga trapped Virender Sehwag plumb in front, and though the Indian opener asked for a referral, it was upheld. Malinga then struck again in the seventh over when he had Mumbai's icon Sachin Tendulkar caught behind in the seventh over. But, the title was sealed when Dhoni hit the first ball of the 49th over for a massive six to put the icing on the cake and send a billion people into raptures.
And, to make things even sweeter for India, Yuvraj Singh was named Man of the Series for his 15 wickets and 362 runs. This win has also completed the career CV of Tendulkar, who didn't contribute to the final as much as he may have liked to, but his innings in the lead-up to the final, not least in the semi-finals against Pakistan, It was also the perfect send-off for coach Gary Kirsten, who has now ended his tenure with the Indian team.
Coming back to the loss of those two early wickets, Gambhir and Kohli got the run chase back on track with a 83-run partnership as the Delhi boys got India right back into the match taking minimal risks and milking the Sri Lankan bowling to the fullest. And, even after Kohli was caught off his own bowling by Dilshan, Dhoni and Gambhir took the chase forward.
Dhoni has not been in the best of forms with the bat in the World Cup, but he potentially played the knock of his career in the final as he remained unbeaten on a 79-ball 91 and shared in a 109-run partnership with Gambhir as they snuffed the fight out of the Sri Lankan attack and broke their spirit with each run they made. And, even though Gambhir was bowled going for a massive hit when on 97, India wasn't denied to be a win and it was fitting that Dhoni and Yuvraj, who have shared in so many monumental partnerships were in the middle, when the mission was finally achieved.
Malinga (2-42) made the early dents, but wasn't able to make any more inroads in his subsequent overs. But, however, the most telling blows was felt by the Sri Lankan spinners, Suraj Randiv and Muralitharan, who bowled 17 overs for 82 runs without taking a wicket; and that's really where Sri Lanka lost the match and plot.
Earlier, Jayawardene scored his 14th one-day international century as his unbeaten 103 helped Sri Lanka set India a target of 275 to win the final of the 2011 World Cup at Mumbai's packed Wankhede Stadium.
Jayawardene was the anchor in Sri Lanka's innings as he scored at more than a ball without taking too many risks and he also strung together important partnerships with his skipper Kumar Sangakkara, Thilan Samaraweera, Nuwan Kulasekara and Thisara Perera to negate the good work done early in their innings by Indian pace spearhead Zaheer Khan, who bowled three maiden overs on the trot at the start of the match.
Sreesanth, who shared the new ball with Zaheer, bowled reasonably well in his first two overs, but Tillakaratne Dilshan it him for a couple of boundaries over midwicket and to the midwicket boundary to break the shackles the left-arm pacer had sprung on the Sri Lankan opening batsmen. In between, Zaheer had Upul Tharanga caught by Virender Sehwag at first slip. Tharanga was all at sea against Zaheer and was beaten on more than one occasion; in fact the Sri Lankan opening batsman was unable to score a single run off the 18 deliveries he faced of Zaheer before he was put out of his misery. Zaheer's first spell figures read 5-3-6-1 and he was the main reason Sri Lanka scored only 31 for 1 in their mandatory power play, their lowest score in this spell of play in the entire tournament. Zaheer's bowling apart, exceptional fielding by Yuvraj Singh and Suresh Raina at point and cover point respectively further shackled the Sri Lankan top-order.
Earlier, Sangakkara won the toss and elected to bat. However, there was some controversy as the toss took place twice as no one including match referee Jeff Crowe had heard Sangakkara's call first time round. India made only one change with S Sreesanth coming in for the injured Ashish Nehra; but Sri Lanka made four changes as Chamara Kapugedera, Thisara Perera, Suraj Randiv and Nuwan Kulasekara replaced Chamara Silva, the injured Angelo Mathews, Ajantha Mendis and Rangana Herath.
Dilshan was kept uncharacteristically quiet thanks to Zaheer and with Munaf Patel also keeping things tight at the other end it was tough going for the Sri Lankan opening batsman and Sangakkara. Dilshan did all the hard work and just when he looked as though he would play yet another big innings in the 2011 World Cup, he was unfortunate to get a glove as the ball lobbed back and ht the stumps as he was out for a 49-ball 33. Dilshan though ended the World Cup on exactly 500 runs, and became only the fifth batsman to score so many runs in the mega-event after Sachin Tendulkar (twice), Matthew Hayden, Ricky Ponting and Jayawardene. Sangakkara and Jayawardene then looked untroubled during their 62-run partnership for the third wicket in just over 11 overs before 'golden arm' Yuvraj Singh had the Sri Lankan captain caught behind by Dhoni for a well-made 48 in 67 balls.
Jayawardene, who continued to look as though he was batting on another pitch, was in full control even as Samaraweera led a charmed life in his 34-ball 21 before he was trapped in front by Yuvraj, who finished the 2011 World Cup with 15 wickets. And, though, Zaheer dismissed Kapugedera with a slower ball soon after, Jayawardene continued on his merry ways and was well supported by Kulasekara and the pair added 66 runs for the sixth wicket in quick time.
Jayawardene got to his half-century off 49 balls and then accelerated thereafter bringing up his ton off 84 deliveries. Sri Lanka also took maximum advantage of the batting power play scoring 63 runs for the loss of only Kulasekara's wicket with Jayawardene getting to his century in the space of three deliveries in the 48th over bowled by Zaheer including back-to-back boundaries. Perera then finished the Sri Lankan innings off in style scoring 16 runs including two boundaries and a six as he finished unbeaten on 22 off only 9 balls.
Zaheer destroyed all his good work in the batting power play as he leaked runs and eventually ended with figures of 10-3-60-2, while Yuvraj (2-49) and Harbhajan (1-50) were amongst the other wicket-takers. Sreesanth (8-0-52-0) disappointed yet again, w

india beat Australia by 5 wkts

is the lot of the cricket reporter's life, especially when there is a big tournament on, to go through days, weeks even, celebrating the mediocre. Someone gets runs against ordinary bowling, and you overdose on the superlatives - it is the World Cup, after all.
And then - very rarely, but just often enough to wake us all up - a champion comes along and shows you what this game is really all about. And what it is not.
Irrespective of the outcome of the game, Ricky Ponting's century at the Motera is one for the ages - the kind of knock 'motivational speakers' will want to draw on.
What Australia's batting has lacked through this tournament is the towering tentpole that can hold its edifice up. Once Shane Watson and Brad Haddin are done doing their thing, the rest of the innings has been about the odd cameo, the occasional bravura performance - it wouldn't be unfair to say the porous Australian middle order has begun at number three.
Today, with Watson gone aiming a wild slog sweep at Ashwin to try and break his bonds, Australia needed its best, most experienced batsman to stand up and be counted. And just to up the ante, some joker leaked the news that Cricket Australia had already decided to sack Ponting from the captaincy.
What resulted was a display of grit; an innings as diametrically opposed to, but as valuable, as the century Ponting hit in the 2003 WC final against India. That one was scintillating, arrogant; this was hard manual labor by a batsman fighting, simultaneously, the demons in his mind, the surprises of a wicket baked dusty, a bowling that for once was in no mood to give much away, and a fielding side that, for once, showed some awareness of the value of saving the single.
Through this innings, Ponting was a rock - and the Indian bowlers and other Australian batsmen flowed and eddied around him. He was never entirely comfortable - but equally, barring a brief period at the start of his innings, there was never a time when he was vulnerable. That was when he squared up to Harbhajan Singh, who has had the wood on the Australian skipper since the time they first squared up.
The wicket had turn and just the hint of uncertain bounce; there were fielders close in, and it was set up to be a contest - till Harbhajan backed off. Ponting's problems against off spinners has largely had to do with how he leads with his bat, early in his innings; once Bhajji went around the wicket, the risks were reduced, and Ponting found he could close the bat face down, and just working the spinner away with minimal risk.
At the other end, Brad Haddin played the perfect foil. For someone who came in to the side with the reputation of a berserker, Haddin has matured remarkably in recent outings. Early on, he took on himself the onus of facing Ashwin after seeing his partner struggle against the off spinner who, yet again, opened for India (and it is noticeable that when MS Dhoni switched the bowler to the other end, Watson ended up facing him, got fuddled, tried to break free, and got out).
Once Ponting joined him, Haddin batted with monumental calm, knocking the ball around the park, playing largely in the V to counter spin, and latching on to the odd loose ball with fierce intent. The partnership (70 in 12.5 overs) wasn't electric, but it was very effective in keeping the Indian bowlers pegged.
One critical difference in the Indian side on the day was the entry of Suresh Raina, who teamed up with Virat Kohli and Yuvraj Singh (and Ashwin out on the long boundaries) to finally give the fielding some legs. And this factor was what resulted in the wicket: Haddin, who had single-handedly shamed Munaf Patel in front of his home crowd, was consumed by his own exuberance for once and against Yuvraj, chanced his arm to a ball that was floated, hit off, and spun away. Haddin tried a drive of sorts but failed to account for the spin; the ball went off the toe of the bat, and was dying on him when Raina dived headlong and held. And Yuvraj, feeling his oats, got another one quickly when Clarke played as ugly a slog sweep as you want to see.
That was the cue for the game to turn on a dime. Again. And Zaheer Khan - again - started it with as perfect a set up as you will ever see. Scratch that - as perfect a set up as you have seen, over and over, from the left arm seamer.
He took the ball out, had Michael Hussey fishing, then he produced his now famous knuckle ball - the one that slows down, and shapes in off the deck. Hussey, playing for it to go away, opened a gap as wide as all outdoors; the ball lazily crept through it and onto the stumps, and the batsman's bemused look said it all. The next time he produced a variation was when he held one back on Cameron White - again, the batsman was foxed, and could merely pat it back to the bowler.
David Hussey walked in - and proved that his selection was spot on, with an innings of explosive power that took the onus of run-scoring from his captain, allowing Ponting to continue his calm accumulation. 55 runs at a tick over 7.7 runs between the pair threatened to take the game away from India - but yet again, the game spun around with Ashwin ending Ponting's vigil. That made the difference between a potential 275-plus, and the 260 Australia ended up with.
Rarely has a score made so many people happy. In a note for the team ahead of this game, coach Gary Kirsten had told his wards, 'Do not allow Australia to score over 260.' At the toss, when asked what score he wanted to defend, Ricky Ponting said 260.
As it turned out, Kirsten knew exactly what he was talking of. Though Virender Sehwag, looking a pale shadow of his usual self (there is something seriously wrong with the man, physically - and the most visible symptom is his inability to use his shoulders and wrist to play off his pads, a shot with which he earns his daily bread when he is fully fit and switched on), left early, Sachin Tendulkar looked totally assured and in his shadow, Gautam Gambhir took root, and began to flourish.
Their 50 run association was vital in calming nerves; it ended with the dismissal of Tendulkar, feathering an edge off one of the rare deliveries Shaun Tait got on target. But then followed the best period of play: Virat Kohli and Gautam Gambhir bled Australia in a way I personally haven't seen since Asanka, Aravinda and Arjuna combined in the 1996 final.
Against pace and spin alike, they tapped the ball around the park with almost casual ease, running effortlessly and chipping chunks off the target without looking in the least troubled. It didn't help the bowling side that without exception, their bowlers failed to string a series of good deliveries together. (At the halfway mark, India had taken 14 more singles and twos against Australia's sharp fielding than the Aussies had managed against India).
Just when it looked like India would canter to a one-sided win against the reigning world champions, the home side decided to spice things up a bit. Virat Kohli started it with an incredibly ugly swipe at a David Hussey full toss. Then Gautam Gambhir, who till then had been running as if he had taken lessons from a hamster, totally lost his wits. He has played enough with Yuvraj to realize that the middle order batsman is no longer as fleet of foot as in his heyday, but insisted on calling his partner for incredibly risky singles. Thrice Gambhir looked to run himself out; on the third occasion, after an uncharacteristic miss by Australia on the second try, the batsman succeeded.
When MS Dhoni fell to a superb catch by Michael Clarke at point off a fierce cut, and the score slid from 2/142 in 28 to 5/187 in 37.3, it seemed as if India was set to outdo its earlier collapses.
If, in the end, it cantered to a win with five wickets in hand, credit owes to Yuvraj Singh who, yet again, played a calculating knock that perfectly mixed his trademark punched drives and ferocious pulls with some touch play to work the ball around, and Suresh Raina, in for Yusuf Pathan, taking the likes of Lee and Watson head on as they tried to bounce him out.
What had the potential of being a tense haul to the finish line turned into a thrill a minute ride for the full house at the Motera, with both batsmen opening their shoulders and smashing the ball all around the park. Perhaps the one shot that epitomized both their mood, and the helplessness of the Australians against the sudden counter-attack, came in the 46th over. Lee, bowling around the wicket, speared down an extra quick delivery on length; Raina wound up and smashed the ball effortlessly over the long on fence. As the ball sailed off the bat, you saw, for one moment, Lee stop in his follow through, stare at Raina in disbelief, and drop his head.
16 more runs were needed after that six, but as far as the game was concerned, that shot effectively ended it - and set up what, for fans of both nations, is a dream semi-final between Pakistan and India at Mohali.
The former had ended Australia's 34-game winning streak, the latter had ended its reign as the defending champions.
At the end, you felt for Ponting. He played out of his skin, and way beyond the dictates of form - but he could not find one ally to do for his team with the ball what he had so bravely done with the bat. Australia's batting chinks had been exposed before, but somehow its bowling fault line (the sameness of Johnson, the self-indulgent rubbish dished out by Tait, the fairly ordinary skills of Jason Krejza) had managed to remain hidden till first the Gambhir-Kohli partnership, then the spell of brilliance by Yuvraj and Raina, exposed them cruelly.

Nuclear fallout would not affect New Zealand, expert says

People in New Zealand do not need to worry about radiation poisoning should a quake-damaged nuclear power plant in Japan suffer a catastrophic meltdown, an expert says.
Should there be radioactive fallout from the facilities, it would not affect the southern hemisphere, GNS Science senior scientist Bernard Barry said.
Troubles at the Fukushima Dai-ichi plant in Fukushima province were set in motion when last Friday's magnitude 9 quake and tsunami in Japan's northeast knocked out power, crippling the cooling systems needed to keep nuclear fuel from going into full meltdown even weeks after a reactor shuts down.
There have since been three explosions at the plant, and a fourth reactor has caught fire.
However, even if the reactor cores were to melt and remain within the reactor vessel, consequences for the general population would be minimal, Dr Barry said.
There would be some release of radioactive material in excess of normally acceptable levels but it would be minor compared to the fallout from the Chernobyl, Ukraine, plant in 1986 and not pose a significant public health risk.
"For New Zealanders in Japan, the only significant risk will be to people in the local area if a reactor explosion, with loss of integrity of the reactor containment, did occur. People should follow the instructions of the Japanese authorities regarding evacuation. Moving some distance from the reactor site is the most important risk-minimising procedure.
"Moving 10 times further away will, on average, reduce radiation exposure 100 times," Dr Barry said.
The tsunami had caused the breakdown of emergency cooling, which in turn had the potential to cause core melting and explosions.
Such a potential explosion would not rival that of Chernobyl because nuclear fission stopped days ago, short-lived radioactive fission products had already had time to decay for several days, and containments were in place that would keep fallout inside the plant, or at least minimise external fallout, Dr Barry said.
The Japanese Government today warned anyone nearby to stay indoors to avoid exposure.

Officials say slightly elevated radiation levels have been detected in Tokyo but there is no health threat.

Fukushima nuclear blast

The No 3 nuclear reactor of the Fukushima Daiichi nuclear plant is seen burning after a blast following an earthquake and tsunami in this handout satellite image taken March 14, 2011. The Fukushima nuclear complex, 240 km (150 miles) north of Tokyo, has already seen explosions at two of its reactors on Saturday (reactor No.1) and on Monday (reactor No.3), which sent a huge plume of smoke billowing above the plant, just days after a devastating earthquake and tsunami that killed at least 10,000 people

India orders safety review of nuclear reactors: PM

 India Monday said its nuclear reactors can withstand 'large natural disasters' but has ordered a safety review at nuclear plants following a nuclear fallout in disaster-hit Japan.
Prime Minister Manmohan Singh told the Lok Sabha that the government wanted safety systems at all its nuclear plants studied to ensure they can withstand natural disasters like tsunamis and earthquakes.
'The Department of Atomic Energy (DAE) and its agencies, including the Nuclear Power Corp of India Ltd (NPCIL), have been instructed to undertake an immediate technical review of all safety systems of our nuclear power plants, particularly to (ensure) they would be able to withstand the impact of large disasters such as tsunamis and earthquakes,' he said.
He sought to reassure the house that the government attaches 'the highest importance to nuclear safety'.
The NPCIL, which operates 20 nuclear power reactors, said that Indian nuclear plants maintain the highest levels of safety as per international norms and have withstood major natural disasters in the past.
The DAE and NPCIL are closely monitoring the situation. They are in touch with the World Association of Nuclear Operators, Tokyo Centre, the Japan Atomic Industrial Forum, World Nuclear Association and the International Atomic Energy Agency.
'In-depth review of all such events have been done for all the plants and necessary reinforcement features based on the outcome of these reviews have been incorporated as a laid down procedure.
'The event of Japan will be reviewed in detail in due course as the detailed information becomes available. Resulting out of such a review, any reinforcement as needed in Indian reactors will be implemented,' the NPCIL said in a statement late Sunday.
Manmohan Singh said India operates 20 nuclear plants and 18 of them were indigenous pressurized heavy water reactors and two at Tarapur plant were boiling water reactors of the type being operated in Japan.
'A safety audit of these reactors has been completed recently,' he said in a statement.
Manmohan Singh said the Indian nuclear plants have in the past met their safety standards.
He said that work 'is under way in DAE towards further strengthening of India's national nuclear safety regulatory authority'.
The 20 nuclear power reactors in India have an installed capacity of 4,780 MW, including two Boiling Water Reactors (BWRs). The rest are Pressurised Heavy Water Reactor (PHWRs). Their safety was re-analysed some years back and reviewed by the Atomic Energy Regulatory Board.
Japan has 54 nuclear reactors.
The PHWRs are designed differently than BWRs, and they also have multiple shutdown systems as well as cooling water systems.
The Indian nuclear plants proved their safety during the severe Gujarat earthquake of 2001. The Kakrapar atomic power plant continued to operate safely and supplied much-need energy to affected regions, the statement said.
Similarly, during the 2004 tsunami which hit Tamil Nadu, the Madras Atomic Power Station was safely shut down without any radiological consequences. It was restarted a few days later following regulatory review, it said.
Japan's Fukushima city is home to 10 reactors at two power plants, and explosions have occurred at two of the reactors since Friday's magnitude-9 earthquake and tsunami.
One explosion occurred Saturday and the second Monday after a 6.2 magnitude aftershock.

HC to pronounce judgement in Kasab case on Feb 21

Mumbai, Feb 7 (PTI) The Bombay High Court today said it would deliver its verdict on February 21 on confirmation of death sentence awarded to Pakistani terrorist Ajmal Kasab for his role in the 26/11 terror attacks and also on his appeal against his conviction.

Justices Ranjana Desai and R V More said that they were ready with the judgement even today but because of bulky paper work and heavy compilation they would pronounce the verdict a fortnight later.

On the same day the High Court would also pronounce its judgement on the appeal filed by Maharashtra Government challenging acquittal of co-accused Faheem Ansari and Sabauddin Ahmed in the same case. The trial court had set them free on the ground that evidence against the duo was doubtful.

U.S. in talks over possible Mubarak departure

project

 

 

 

 

 

 

 

                  CONCEPT OF PROJECT WORK

 

 

 

 

 

 

                                      

project work is nothing but doing some technical work under proper guidence. this is done usuallyby the      students and  every work to achieve its final objhectives or goals. This naturally relates to project work also.Before starting any project planning  must be done weather which projet should be selated.How it should performed etc  SO planning must be done either when beginning an enterpriseor to maintain any industry.So planning must be done very carefully as the effiency of our project depends on planning, improper planning will run the project

                   India is the second laregest countary regarding its population. The Govt is unable to provide empolyment forall the educated people,so it is putting more stress on techanical people to start their own industries under what will call "SELFEMPLOYMENT SCHEME " This helps in eradecating unempolyment and inproviding livelihood to educated unempolyment students.Govt is encouraging the enterperneurs by gaining laons to start enterprise. For this bank stared to provide new empolyment oppertunties by giving laons for small scale sectors called industrial develpoment bank of india It hs been enagaged in the folk of promotion from its financing of the small scale secoters from its inception .It sanctions to small scale secoters from its finencing of the small scale sectors have  incersed stedialy overthe year in 1970 to 1975.

If it is rs 1.30 crores at about 16% of total assistance distributed.in 1975 to 1980 its incresed to rs.990 croes to 26% and in 1980-1985. There after it further incerased to rs. 3700 croeses at any individual icannot start his industry without a proper knowledge about the project work as became a necessary "must" to techanical students. For this section reason project work has been inculed in the syallabus. the BTECH courese by the jntu hyderabad universites. this server as a gudencnce if not only individual starts an industry . This project work helpful for an individalfor his  livelihood but also indirectly helpful to the country.

                                  

                                             PROJECT ABSTRACT

We propose to design a device which could be used by automobiles in the highway for the purpose of collision prevention. The main objective of this project is  to avoid collisions between vehicles which results in losses in massive proportions to life and economy. We will be specifically dealing with  accidents  caused  when  a  multitude  of  vehicles  travelling  in  a  linear  manner  collide.  collisions do not terminate with damage to one or two vehicles, rather, an ar ray of cars go smashing into one another.

         

So, we intend to design ultrasonic sensors (transceivers) both at the front and rear of a  vehicle in          order to detect the  range of another  vehicle which is in its immediate  vicinity. The data from the          transceivers along with the velocity of the vehicle and an emergency input from the driver of each vehicle could be used to determine the status of the vehicle. This status, if found alarming will be transmitted backwards to the vehicle immediately behind it. The vehicle which receives this “alert” code, will take steps to slow down and also pass on the same code to the vehicle behind it, and so on  the  code  gets  transmitted  to  all  vehicles  behind  the  troubled  car  which  are  in  range  ultrasonic transceivers 

 

INTRODUCTION

STUDIES AND STATISTICS ON CAUSES OF ACCIDENTS AND ACCIDENT PREVENTION

GENERAL PRINCIPLES IN COLLISION AVOIDANCESYSTEMS

STOPPING DISTANCE AND ASSOCIATED FACTORS

VEHICLE BRAKING CAPABILITY

CALCULATING STOPPING DISTANCE

BLOCK DIAGRAM EXPLANATION

PSOC MIXED SIGNAL  CONTROLLER: CY8C27443

HALL EFFECT SENSOR ALLEGRO A1142

ULTRASONIC TRANSDUCER SQ40 T/R

PSOC RANGE MEASUREMENT

                                                  INTRODUCTION

  

First  of all  it  is very important  that we  understand  the need for  a  collision  prevention  system in automobiles. These are some of the statistics that compelled us to take up a small step towards the prevention of road accidents, particularly Forward Collision

It is well known that driver errors are the main cause, orcontribute to increased severity, of most accidents. Forinstance, the Indiana Tri-level (Treat et al. 1979) founddriver errors to be a cause or severity-increasing factorin 93% of the accidents.

Furthermore,27% of allaccidents (USA 1997) were rear-end collisions. Thisshows the potential of forward collision avoidance (FCA)systems. The crucial part of the algorithm is the decisionmaking, and the conflicting considerations are:

There are 1.2 M fatalities yearly worldwide due to road accidents - 3242 people a day!

According  to  the  World  Health  Organization,  road  accident  fatalities  worldwide  are expected to rise by 67% by the year 2020.

Over 20 million people are injured each year in road accidents

Financial damages of road accidents are ~2% of world GDP.

In the US, in 2010 there were 6 million accidents, costing $230 million; averaging $38,000 per accident – these statistics have been steady in recent years

STUDIES AND STATISTICS ON CAUSES OF ACCIDENTS AND ACCIDENT PREVENTION:

93% of all accidents are due to human factor (Driver inattention cited as the primary cause for accidents).

Nearly 80% of all crashes involve driver inattention within three seconds before the event.

Examples of types of inattention that increase crash risk:

Talking on a cell phone (increases risk by 30%)

Drowsiness  (increases  risk by  400%  and  responsible  for ~23%  of all  crashes and near-crashes)

Reaching for moving objects, like a falling cup (increases risk by 900%)

One  in  every  five  vehicle  accidents  is  caused  by  drowsiness  at  the  wheel,  momentary drowsiness or inattentiveness

Run  off road accidents  account for  nearly  20% of  road  accidents and are responsible  for  60% of all road accident fatalities.

“In a study done at Volkswagen, an analysis of the pre-crash braking behavior shows that in severe accidents about 85% of drivers either did not brake at all or not to the full possible deceleration.”

Rear-end collision accidents account for about 28% of road accidents.

   

           GENERAL PRINCIPLES IN COLLISION AVOIDANCESYSTEMS:

A collision avoidance system operates, generally,in the following manner: a sensor installed at thefront-end of a vehicle constantly scans the roadahead for vehicles or obstacles. When found, thesystem determines whether the vehicle is inimminent danger of crashing, and if so,automatic brakes should be applied .Usually one of these two criteria is used toactivate collision avoidance:

Worst-case criterion: The system assumes thatthe vehicle preceding the CAS-equipped vehiclecould brake at full braking power at any time. Inessence, it operates on a critical headwaydistance," that is, theminimum distancenecessary for the CASequipped vehicle to come to a stop in the event the leading car suddenlybrakes.

Time-to-collision criterion: The systemdetermines whether a collision is likely tohappen at prevailing speeds and distances withina certain time interval. In a  , time-to-collision is defined as the timeduration for the two vehicles to collide if theymaintain theirpresent speed and direction.Collision avoidance maneuvers include one ormore of the following actions:

Headway distance control: The system warns thedriver whenever his/her car isfollowing theleading car too closely. Some systems includeautomatic speed control, i.e., the CAS-equippedcar would automatically reduce its speed in orderto maintain a safe headway with the leadingvehicle

Hazard warning: The system warns the driver ofan object (moving or stationary) within itsprojected path so that the driver has sufficienttime to avoid a crash.

Automatic vehicle control: The system controlsthe vehicle's brakes and steering wheel, andapplies them automatically when it deems itnecessary. In actuality, there are currently nosystems that use automatic steering to preventcollisions, although the technology has beendeveloped and tested experimentally.

                 

                            STOPPING DISTANCE AND ASSOCIATED FACTORS

Many drivers drive in a false belief that if the car in front suddenly started braking, they would react  and brake and end up stopped the same distance apart.

The total stopping distance of a vehicle is made up of 4 components

Human Perception Time:    The human perception time; is how long the driver takes to see the hazard, and the brain realize it is a hazard requiring an immediate reaction.    This perception  time can be as long as ¼ to ½ a second.

Human Reaction Time: Once the brain realizes danger, the human reaction time is how long the body takes to  move  the  foot from  accelerator  to brake pedal. Again this reaction time can vary from ¼ - ¾ of a second.

These  first  2  components  of  stopping  distance  are  human  factors  and  as  such  can  be affected by  tiredness, alcohol, fatigue  and concentration levels. A perception and reaction time of 2 or 3 seconds is possible. 2 seconds at 75 km/hr means the car travels 40 metres before the brakes are applied.

 

Vehicle Reaction Time: Once  the brake pedal is applied there  is the vehicles reaction time which  depends  on  the  brake  pedal  free-play,  hydraulic  properties  of  the  brake  fluid  and  working order of the braking system.

Vehicle Braking Capability: The last factor than determines the total stopping distance is the cars braking capability which depends on factors such as;

      The type of braking system

The Automobile brakes are classified  according to the  different bases, as follows

1.    With respect to application :

(a)    Foot brake

(b)   Hand brake.

      2 .With respect to the numer  of wheels:

(a)   Two wheel brake 

(b)  Four wheel brake.

    3.With respect to the method of braking contact:

           (a) Internal expanding brakes.

           (b)external  contracting brakes

    4. With respect to the method of applying  the braking  force:

            (a) single acting  brakes

             (b) double acting  brakes.

     5 . With respect to the brake gear:

(a)   Mechanical  brakes.

(b)  Power brakes.

     6.  With respect to   the nature of power employed:  

(a)    Vacum brakes

(b)    Air  brakes

(c)      Hydraulic  brakes

(d)     Hydrostatic  brakes

(e)      Electric brakes. 

     

      7.   With respect to power transmission:

             (a) Direct acting brakes

             (b)  Geared brakes.

       8.    With respect to  power unit :

               (a) Cylinder brakes

               (b) diaphragm  brake,

                

              suspension system

The automobile frame and body are mounted on the front and rear axle not directy but some form of spring and shock absorbers.this done danp to raod

Shocks  transmitted  parts to the frame by the  wheels as they roll over the raod.  All these parts perform this function are collectively  called a suspenSion  system .Thus  the  suspension sytem includes springs , shockabsorbers and  their mounting s.The  suspension system of moter vechile is divided into

The rear-end  suspension and front  end suspensio

  Functions of  suspension sytem

1.    To prevent  the raod shocks from being  transmitted  to the  vechile frame

2.    To  preserve the stability of the vechile in pitching or rolling , while in motion

3.    To  safegured  the occupants from raod shocks

4.    To provide good raod  holding while driving ,corning and braking

5.    To maintain proper steering gemontery

      Tyre pressures

The tyre is  designed to be operated at certain pressure to the weiht and characteristics of the vehicle . Every manufarcturer recommends to maintain

The correct tyre pressure. In correct tyre pressure overheating , rapid tyre wear and unsafe steering If the tyre pressure is correct , tyre will have full tread contact with raod surface

    Trye tread and grip

 1.Front  tyre  shows an excessive  wear only on one side of the theard.  Check  camber.  If  it is correct, wear must be ascribed to the habbit of

Negotianing curves  at high speeds

 2. Tyres   shows a wear  particularly remarkable  on the both sides  of 

Tread rater  than  on the centre portion . Tyres   are inflated  at a pressure

Lower than specified . Under  such conditions ,the tread side surfaces are

Supporting most of the laod, while centre portion is deflected upwards

3.Tyres  shows wear on the  tread centre poration . tyres are inflated  at 

Pressure higer than specified. Under such conditions , tread cenral  portion is suppoting most of the  laod 

brake pad material

An automotive brake functions by converting thepedal, brake fluid is effectively pushed against the pistons vehicle’s kinetic energy into heat energy. During brakingof the brake caliper, which in turn forces the brake pads the heat energy is first borne by the two contact surfacesof the brake, namely the brake disc and the brake pad

brake alignment

vehicle weight

The co-efficient of friction of the road surface

wind speed

Wind is simply air in motion. It is produced by the uneven heating of the earth’s surface by energy from the sun.

slope of road

surface smoothness

The braking technique applied by the driver

Brake testing

 When the vechicle moving , it can be stopped by applying by applying  the brakes. It is to be noted here that brake peals cannot be passed instantaneously and the vehicle cannot be stopped instantaneously. First driver thinks, then lift the leg , presses the brake pedal and then the vehicle stop after moving some distance . So it is necessary to note how much time is required to stop the vehicle and how long it will travel after applying the brake . these two factors are directly dependent on the speed of  vehile.

1. stop test. For testing the brakes, this test is usually adopted by mechanic or driver after overhauling the brakes. He moves the vehicle at a speed and suddenly applies the brakes.  Then he checks how much time it has taken to stop and how long it has moved after applying  the brakes . Also he sees the impression of the four tyres on the raod, whether equl or not, and wheater the vehicle is pulling a side  or  not

2.stop watch test; to perform this test,the  vehicle is moved at about 70km/hr.

Then the brakes are applied . The time distance are noted

Let T=time taken to stop the vehicle after applying the brakes

D=distance moved by the vehicle after applying the brakes.

Then,brake efficiency is given by

n=(D-T²)*6.25

3.Brake testers are also used for testing the brakes. they work on the principle

Of decelerometer.  Taply  brake meter is a type of brake tester. This  brake meter is placed on the vehicle floor for testing the brakes. It consists of a round ring with numbers . There is pendulum inside the dial which remain dipped in oil. As soon as the vechile speed decreases which causes the pendulum ring to move. The  number on, the ring gives reading which can be Obtained by an inspection plate

         

                       

                 

                      

                             CALCULATING STOPPING DISTANCE

Assuming  proper  operation  of  the  brakes  on  the  vehicle,  the  minimum  stopping  distance  for  a vehicle is determined by the effective coefficient of friction between the tires and the road, and the driver's reaction time in a braking situation. The friction force of the road must do enough work onthe car to reduce its kinetic energy to zero. If the wheels of the car continue to turn while braking, then static friction is operating, while if the wheels are locked and sliding over the road surface, the braking force is a kinetic friction force only.

To reduce the kinetic energy to zero:

             Work       = - umgd = - (mv₀²)/2       

                    _Friction

so the stopping distance is:

               d=(V₀²)/2ug

For calculating minimum stopping distance, we have provided two modes:

             Dry Weather: The value of u is taken .8

             Wet Weather: The value of u is taken .5

  What is Sensing ?

Collect information about the world

    Sensor - an electrical/mechanical/chemical device that maps an environmental attribute to a  quantitative measurement

Each sensor is based on a transduction principle - conversion of energy from one form to another

          `                   

                                  

                           BLOCK DIAGRAM EXPLANATION

As we can see, the major components required are:

PSoC Mixed-Signal Controller - CY8C27443

Ultrasonic Transducer – SQ40 T & SQ40 R

Hall Effect Sensor – 1142

      

  BLOCK DIAGRAM EXPLANATION

1.   ULTRASONIC TRANSDUCERS (SQ40 T/R)

The ultrasonic transducers are used with a dual purpose. The major and mostly common purpose is that of detecting the range of an obstacle in front of the vehicle. This distance when coupled with the velocity at which it is travelling gives us an idea about the safety of the vehicle.

The ranging works by transmitting a short pulse of sound at a frequency of 40Khz (ultrasonic sound or ultrasound) through the transmitter  SQ40T.  Afterwards the microcontroller listens for an echo through  the r eceiver SQ40R. The time from transmission to echo reception helps to calculate thedistance  from the object. The time from transmission of the pulse to  reception  of the  echo  is the time taken for the sound energy to travel through the air to the object and back again.

Since  the  speed  of  sound  is  constant  through  air  measuring  the  echo  reflection  time  lets  calculate the distance to the object using the DST equation:

                  Distance = (s * t)/2 (in metres)

2.  HALL EFFECT SENSOR FOR VELOCITY

The Hall Effect sensor can sense changes in magnetic field and changes its output accordingly. If a magnet is mounted on any rotating part of a moving vehicle (which is proportional to the velocity), the  change in  output  from  the  sensor  will  indicate  the  rpm  of  the  rotating  part. This  rpm  multiplied by a suitable circumference value will produce distance travelled in a minute. Thus we can have the velocity of the vehicle.

3.USER DISCOMFORT SWITCH

If the user feels any discomfort during the journey, like a possible chest pain, this switch enables him  to  communicate  the  data  to  the  vehicles  behind  him.  This  will  alert  the  other  drivers  likelihood of breaking. This can help save critical reaction time on part of  the  drivers behind the vehicle under scrutiny

4.CLIMATE SELECT SWITCH

The stopping distance of a moving vehicle is given by the formula:

                             d=(V₀²)/2ug

  Here, d is the distance required to bring the vehicle to a halt in metres,

  V₀is the velocity at which it was travelling at the instant just before breaking

 u is the co-efficient of static friction

and g  is the acceleration due to gravity (9.8m/s²)

The co-efficient of static friction has a nominal value of 0.8 provided that the road sur face  is dry and  the  tires  are  in  good  condition.  The  same  value  can  degrade  to  0.5  when  the  road  surface becomes wet or the tires ar e old or in bad condition. So based on the conditions, we have allowed the user to select the appropriate mode in which the stopping distance is to be calculated.

 5.LCD DISPLAYING ESSENTIAL DATA

The LCD display will provide the user with details such as:

1.Real-time distance from a vehicle/obstacle in front of it.

2. The current velocity of the vehicle.

3. The climate selection at present, and

4.The status of the drive, whether it is under alert or not.

6.AUDIO AND VISUAL ALERTS

Audio visual alerts are useful for alerting the driver in case he is not  looking  at the LCD  for thestatus  of  his  drive.  The  audio  alerts  includes  a  buzzer  that  switches  on  at  the  time  of  an  alert. situation, and a bicolour LED which produces yellow colour during normal drive, and red colour at times of alert.

7.PWM SPEED CONTROL

The  PWM  speed  control  is  the  method  used  for  controlling  the  speed  of  the  vehicle,  (for demonstration purposes we use DC motor driven miniature cars). We will be assigning 5 levels of speed to these cars and according to the situation; they will be allowed to either increase the speedor decrease by means of varying the duty cycle of the PWM.

 8.PSoC MIXED SIGNAL  CONTROLLER: CY8C27443

The PSoC Mixed Signal controller is more than just a microcontroller. It is a 28 pin IC with three I/O ports. These ports can be used f or analog or digitals functions. The advantage of PSoC is that it integrates ASIC, FPGA and the usual code controlled functions of a microcontroller into a single         unit

The model can accommodate up to 8 digital blocks and 12 analog blocks within itself

Digital  blocks  include –  PWMs, Counters (8  to 32  bit),  Timers (8  to 32  bit),  UART  8  bit with selectable parity (up to 2), SPI master and slave (up to 2), I2C slave and master (1 available as a System  Resource),  Cyclical  Redundancy  Checker/Generator  (8  to  32  bit) ,  IrDA  (up  to  2)  and Pseudo Random Sequence Generators (8 to 32 bit).

The analog blocks include - Analog-to-digital converters (up to 4, with 6- to 14-bit resolution selectable as Incremental, Delta Sigma, and SAR), Filters (2, 4, 6, and 8 pole band-pass, low-pass, selectable as Incremental, Delta Sigma, and SAR), Filters (2, 4, 6, and 8 pole band-pass, low-pass, with selectable gain to 93x), Comparators (up to 4, with 16 selectable thresholds) , DACs (up to 4, with 6- to 9-bit resolution),  Multiplying DACs (up to 4, with 6- to 9-bit resolution), High current output drivers (four with 30 mA drive as a Core Resource), 1.3V reference (as a System Resource), DTMF dialer, Modulators, Correlators, Peak detectors and a few more.

MORE ON THE MAJOR HARDWARE USED

     

         

               

       PSOC MIXED-SIGNAL CONTROLLER - CY8C27443

PSoC®  (Programmable  System-on-Chip)  is  a  family  of  mixed-signal  arrays  made  by  Cypress Semiconductor,  featuring  a  microcontroller  and  configurable  integrated  analog  and  digital peripherals. PSoC is software configured, mixed-signal array with built-in MCU core. The core is a Cypress proprietary, very-small Harvard architecture machine called the M8C. The M8C is an 8-bit machine with a rich 256 instructions. PSoC has three separate memory spaces: RAM, Flash and IO Registers (which  control and access  the configurable  blocks  and  fixed  functions).  The device  is created using SONOS technology.

PSoC resembles an ASIC in its flexibility and integration: blocks can be assigned a wide range of functions and interconnected on-chip. Unlike an ASIC, there  is no special  manufacturing process required to create the custom configuration - only startup code which is created by Cypress' PSoC

Designer IDE.

PSoC resembles an FPGA in that at power up it must be configured, but this configuration occurs by loading instructions from the built-in Flash memory. Unlike an FPGA, the current generation of PSoC  cannot  have  its  digital  functions  reprogrammed  by  VHDL  or  verilog;  it  can  only  be configured with register settings.

PSoC  most  closely  resembles  a  microcontroller  in  usage,  since  the  programs  written  by  a  user execute  code  to  interact  with  the  user-specified  peripheral  functions  (called  "User  Modules") utilizing  automatically  generated  APIs and  interrupt  routines. PSoC  Designer  IDE  generates  the startup configuration code and  peripheral APIs automatically  based upon the users selections in  a visual-studio-like GUI

            HALL EFFECT SENSOR ALLEGRO A1142

INTRODUCTION

The Hall Effect was discovered  by Dr. Edwin Hall in 1879 while he  was  a doctoral candidate at Johns Hopkins University in Baltimore. Dr. Hall found when a magnet was placed so that its field was perpendicular  to  one  face  of a thin  rectangle of  gold  through which  current was flowing,  a difference in potential appeared at the opposite edges. He found that this voltage was proportional to  the  current  flowing  through  the  conductor,  and  the  flux  density  or  magnetic  induction perpendicular to the conductor

Hall Effect devices when appropriately packaged are immune to dust, dirt, mud, and water. These characteristics make Hall Effect devices better for position sensing than alternative means such as optical and electromechanical sensing. Hall Effect devices used in motion sensing and motion limit. switches  can  offer  enhanced  reliability  in  extreme  environments.  As  there  are  no  moving  parts involved within the sensor or magnet, typical life expectancy is improved compared to traditional electromechanical  switches.  The  sensing  of  wheel rotation is  especially useful  in  anti-lock brake systems. The principles of such systems have been extended and refined  to offer  more  than  anti- skid functions, now providing extended vehicle "handling" enhancements.

APPLICATION

 A Hall Effect sensor is a transducer that varies its output voltage in response to changes in magnetic field  density.  Hall  sensors  are  used  for  proximity  switching,  positioning,  speed  detection,  and current sensing applications.

Hall  sensors  are  commonly  used  to  time  the  speed  of wheels and shafts, such as for internal combustion engine ignition  timing  or  tachometers.  In  the  pictured  wheel carrying  two  equally  spaced  magnets,  the  voltage  from the  sensor  will  peak  twice  for  each  revolution.  This arrangement  is  commonly  used to  regulate  the  speed  of diskette drives

ALLEGRO A1142 DESCRIPTION

The  A1142  device  is  sensitive,  two-wire,  unipolar,  Hall  Effect  switches  that  are  factory  - programmed  at  end-of-line  to  optimize  magnetic  switchpoint  accuracy.  These  devices  use  a patented  high  frequency  chopper  stabilization  technique,  produced  using  the  Allegro  advancedSBiCMOS wafer fabrication process, to achieve magnetic stability and to eliminate offset inherent in single-element devices exposed to harsh application environments.

Commonly found in a number of automotive applications, these switches are utilized to sense seat track  position,  seat  belt  buckle  presence,  hood/trunk  latching,  and  shift  selector  position. A1142has  the  following  output:  the  currents  switch  LOW  in  the  presence  of  a  south-polarity magnetic field of sufficient strength, and switch HIGH otherwise.

 `

         

This shows the output characteristic of the sensor

  

                   ULTRASONIC TRANSDUCER SQ40 T/R

The word Ultrasonic means „above sound , which means above the human hearing range which is approx 300Hz to 14 KHz. Therefore any frequency that is above the human hearing wavelength and below the low frequency RF wavelength may be considered as ultrasonic or „ultrasound  .

Ultrasonic  ranging  is  performed  by transmitting  a  pulse  of  high frequency  sound, then  counting how long it takes for its echo to be detected. Because sound through a given medium (liquid or air) is  a  known  quantity,  it  can  be  considered  a  constant,  the  length  of  time  taken  between  thetransmitted pulse and the received echo can be converted into distance. This is called Time of Flight TOF).

The SQ40 as the name suggests, operates at 40Khz. This is the frequency at which the sensitivity of the ultrasonic receiver is greatest. The transmitter is the one marked SQ40 „ T  and the receiver is the other, which is marked as SQ40 „R . Its operating range is -40 ⁰ C to 85⁰ C

            

Limitations: The Ultrasonic transducer  has two  major limitaions -  narrow beam  angle  and weak received signal strength. The beamwidth is  close  to  55, which means that  only  if  the  obstacle  is almost  right  infront  of  the  transmitter  can the  waves  be  reflected  towards  the  recevier.  A  deviation  of  the  obstacle  will  hinder  the  process  of  range  detection  or  obstacle  detection practical models, multiple transducers will be required for efficient obstacle detection practical models, multiple transducers will be required for efficient obstacle detection The received signal strength is another hindrance towards the comfortable working of the device as the  received    signal  at  the  receiever  is  only  at  about  a  few  millivolts.  This  has  to  be  greatly

amplified and filtered before it can be verified as being a legitimate signal from noise signals.

                  

                      PSoC RANGE MEASUREMENT

There  are  several  ways  to  measure  distance  without  contact.  Some  products  have  infrared  light emitters and receivers that determine an object s distance by implementing the optical triangulation method.  Other  devices  have  laser-based  systems  that  increase  accuracy  and  precision.  For electrically conductive metal objects, the eddy current method is an option, and capacitive sensors that are independent of the metal used in the measured objects can be used.

The PSoC range finder  measures  the amount  of time  it takes  for a  pulse  of sound  to  travel to a particular surface and return. Then, the device calculates the distance based on the estimated speed of  sound.  The  only  required  components  are  a  PSoC  microcontroller,  two  40-kHz  ultrasonic transducers,  two  resistors,  and  two  capacitors.  Similar  circuits  are  typically  complicated  and expensive, consisting of a large number of integrated circuit and passive components.

The  block  diagram  of  range  measurement  module  is  divisible  into  two  parts:  the  transmitting  section  and  receiving  section. Each  section  contains  several  PSoC  blocks.  Using the  PSoC  chip family, all of the digital and analog devices are on-board with the microcontroller.

Several  PSoC  microcontroller  resources  were  used  in  this  module.  The  following  PSoC  digital resources were used: five 8-bit counters, an 8-bit serial transmitter, two 8-bit PWMs, and a digital inverter. The following analog resources: one  programmable gain  amplifier (PGA), two two-pole

pass band filters, a programmable threshold comparator, and a reference multiplexer . In addition, the LCD toolbox software module is also.

This  is a screen shot of the PSoC Designer with the  Device Editor showing  the placement of the PSoC s digital and analog resources. As you can see, a lar ge number of resources are required. All of the digital blocks and several analog blocks are employed. For this application, all of the digital blocks are required.

The software modules include the LCD toolbox user module and a complete set of library routines that allows you to write numbers and strings to a two-line LCD using standard Hitachi  HD44780 commands.

PRINCIPLES

          The transmission section is based on four digital blocks allocated in the DBA00, DBA01, DBA02, and  DBA03  blocks.  An  8-bit  counter  (called  "Time  Base")  provides  a  17,240-Hz  time  base Times New Roman temperature value of 22°C:

                          

                                

where T is equal to the air temperature (°C). So, for a middle value of 22°C:

                              

For a round-trip ping, we have:

                                

And with a 24-MHz MCU clock and period of 12:

                               

An 8-bit  counter (F40kHz)  drives  the  ultrasonic  transmitter and a  digital  inverter  (F40kHz_inv). The  phase  of  the  voltage  applied  to  the  positive  and  negative  terminals  of  the  sensor  has  been shifted 180°, so two times the supply voltage is applied to the sensor.

The 40-kHz  tr ansmission  enables an 8-bit  counter  (called  "Meter")  that  increments  one step per centimeter. The Meter clock input is Time Base (17,240 Hz).

The  ultrasonic  receiver s  positive  terminal  is  connected  to  an  amplification  chain  based  on  a programmable gain amplifier (PGA_1) and two two-pole pass band filters (BPF2_1 and BPF2_2). The first pass band filter is designed for a 40-kHz center frequency and a correspondent gain of 33 dB. The second filter is also designed for a 40-kHz center  frequency, but it has a 10-dB passband gain. Because  of  the  discrete  value  of  the  capacitors integrated  in  the switched-capacitor  analog blocks, the real frequency response is different from the nominal one.

The range detection module has a 40-kHz operating frequency, a range of 25 to 200 cm, and 1-cm resolution. In addition, it requires only a single 5-VDC power supply and draws just 25 mA (23 mA without the LCD).