wireless power transmission ppt as video

here is my presentation on wireless power transmission ppt as a video. 

MATLAB Projects-6

differential amplifier using opamp

differential amplifier using opamp is designed and the opamp is an non-inverting amplifier.this is used to 

make the output as the difference of the two inputs using an opamp

click on the following link to download the matlab file

differentialamplifier

MATLAB Projects-5

instrumentation amplifier

the circuit that is used in the data acquisition, medical instrumentation, current/voltage monitoring etc., is 

instrumentation amplifier and it is built by using the operational amplifier

click on the following link to download the matlab file

instrumentation amplifier

MATLAB Projects- 4

adder using opamp

adder using opamp. this adds the inputs and gives the added one as output.

click on the following link to download the matlab file

adder using opamp

MATLAB Project-3

adder using opamp with negative gain

adder using opamp. this adds the inputs and gives the added one as output. the negative gain here indicates 

the positive output.

click on the following link to download the matlab file


adder using opamp with negative gain

MATLAB Project-2

NON- INVERTING AMPLIFIER

this circuit enables us to amplify the voltage level from one level to other. both the dc and ac can be used as 

supply

click on the following link to download the matlab file

NON INVERTING AMPLIFIER USING MATLAB

MATLAB Projects-1

INVERTING AMPLIFIER

the inverting amplifier using op-amp is implemented in matlab and is copyrighted.

this circuit enables us to amplify the voltage level from one level to other. both the dc and ac can 

 be used as supply.

click on the following link to download the matlab file

inverting amplifier using opamp

Electric shock – What should I do?

What to do if you believe someone has had, or is getting, an electric shock
It may not be immediately clear that someone is getting an electric shock. Smoke won’t be pouring from their ears! If you think someone is suffering from electric shock, approach with extreme caution.

The first step is to separate the person from the source of electricity as quickly as possibly. The best way of doing this is to turn off the supply, for example by unplugging the appliance or by turning the mains off at the fusebox (consumer unit).

If this isn’t possible, then try to remove the source of electricity from the person using a piece of insulating material, such as a length of wood.

NEVER touch the person receiving the electric shock, or you could suffer one too.

After removing the person from the source of electricity, if the person is unconscious call for an ambulance immediately. Only those with the necessary knowledge and skill should carry out first aid.

Where the person is conscious and seems well, it is still advisable to monitor their condition, as the effects of an electric shock may not be immediately obvious. In worst case conditions, an electric shock may lead to a condition known as electroporation, where cells within the body rupture, leading to tissue death. Additional problems might include deep-seated burns, muscle damage and broken bones.

Use an RCD. Using an RCD will help to protect you from dangerous electric shocks. Although not a guarantee of absolute safety, it limits the time current can flow through the body if a person comes into contact with a live source of electricity.

We strongly recommend that anyone using electrical appliances in the garden ensures that they are protected by an RCD, preferably one fitted in the main household fusebox (consumer unit).

Alternatively, a dedicated RCD-protected socket or a plug-in RCD should be used

 SOURCE

Safety tips around the home

You can reduce the risk of electric shock in your home by taking a few precautions, including:

Always hire a licensed electrician for all wiring jobs.

Don’t use extension leads or appliances if the cords are damaged or frayed.

Don’t remove a plug from a power point by pulling on the cord – pull the plug instead.

Keep electrical appliances away from wet areas.

Have safety switches installed by an electrician.

Buy portable power boards with built-in safety switches.

Insert safety plugs into power points not in use to stop children from inserting objects into them.

How to help a victim of electric shock

The first thing you must do is disconnect the power supply. Don’t even touch the victim until you are sure that the power supply is turned off. Be especially careful in wet areas, such as bathrooms, as water conducts electricity. It may be safer to turn off the electricity supply to the building if possible to be absolutely sure.

First aid for electrical shock includes:

Check for a person’s response and breathing. It may be necessary to commence cardiopulmonary resuscitation (CPR).

Call 108 for an ambulance. If you are unsure of resuscitation techniques, the ambulance call-taker will give you easy-to-follow instructions over the telephone, so you can increase the person’s chances of survival until the ambulance arrives.

If their breathing is steady and they are responsive, attend to their injuries. Cool the burns with cool running water for 20 minutes and cover with dressings, if available, that won’t stick. Simple cling wrap found in most kitchens is very suitable to cover burns as long as it is not applied tightly. Never put ointments or oils onto burns. If the person has fallen from a height, try not to move them unnecessarily in case they have spinal injuries. Only move them if there is a chance of further danger from the environment (such as falling objects).

Talk calmly and reassuringly to the person.

SOURCE

Causes of electric shock

Some of the causes of electric shock include:

• Faulty appliances
• Damaged or frayed cords or extension leads
• Electrical appliances coming in contact with water
• Incorrect or deteriorated household wiring
• Downed powerlines
• Lightning strike.
•  

Symptoms of electric shock

The typical symptoms of an electric shock include:

• Unconsciousness
• Difficulties in breathing or no breathing at all
• A weak, erratic pulse or no pulse at all
• Burns, particularly entrance and exit burns (where the electricity entered and left the body)
• Sudden onset of cardiac arrest.

Sometimes victims of electric shock may appear to be unhurt, but they should still be treated as a victim of electric shock. Some injuries and further complications may not yet be obvious. An examination in hospital is important after any electric shock.

electric shock

Electric shock can cause injuries including burns and disturbances to heart rhythm (heart failure) that could be fatal. Always disconnect the power supply before trying to help a victim of electric shock. Be especially careful in wet areas and around downed powerlines. A safety switch can reduce the risk of electric shock in the home.

The human body conducts electricity. If any part of the body receives an electric shock, the electricity will flow through the tissues with little obstruction.

Depending on the length and severity of the shock, injuries can include:

Burns to the skin

Burns to internal tissues

Electrical interference or damage (or both) to the heart, which could cause the heart to stop or beat erratically.

Always disconnect the power supply before trying to help a victim of electric shock.

SAIL previous papers

general awareness paper

previous paper general awareness

important dates for GATE 2014

GATE Online Application Processing System (GOAPS) Website Opens: Enrolment, Application Filling, Application Submission	Monday	2nd September 2013
Last Date for Enrolment (after this only enrolled candidates can fill the application)	Tuesday	1st October 2013
Last date for Submission of Online Application through Website	Thursday	3rd October 2013
Last Date for the receipt of Print-out of the ONLINE Application along with all the supporting documents at the respective Zonal GATE Offices	Thursday	10th October 2013
Last Date for Request for Change in the Choice of City	Wednesday	20th November 2013
Availability of Admit Card on the GOAPS website for printing	Wednesday	18th December, 2013
GATE 2014 Online Examination Forenoon: 9.00 AM to 12.00 Noon Afternoon: 2.00 PM to 5.00 PM	Saturdays and Sundays	Between 1st February and 2nd March 2014
Announcement of Results on the Online Application Website	Friday	28th March 2014 (10:00 Hrs)

New in GATE 2014 

1. Examinations for all the 21 papers will be conducted by an ONLINE Computer Based Test (CBT). 
2. The online examination paper will contain some questions for which numerical answers must be keyed in by the candidate using the virtual keypad. Rest of the questions shall be of Multiple Choice Question (MCQ) type. 
3. GATE 2014 examinations will be held during forenoon and afternoon sessions on alternate weekends (Saturday and Sunday) between 1st February 2014 and 2nd March 2014. Examination for some of the papers in GATE 2014 will be held in multiple sessions. Exact details on complete examination schedule will be notified at a later date. 

Changes in GATE 2013 that will continue to remain in force for GATE 2014

1. Application Process: For GATE 2014, as in GATE 2013, all information related to the candidates’ will be available in a single GATE Online Application Processing System (GOAPS). Candidates have to register/enroll and fill the application via ONLINE mode ONLY by accessing the zonal GATE websites of IISc. and any of the seven IITs. The photograph and signature of the applicant must be uploaded during the online application. The application process becomes complete only when a printout of the filled ONLINE application with the candidate’s signature and a good quality photograph affixed in the appropriate place is received by the respective Zonal GATE offices along with necessary documents, if any, on or before 10th October 2013. Please note that application forms are not available for sale anywhere else. 
2. Downloadable Admit Card: Admit cards will NOT be sent by e-mail/post, they can ONLY be downloaded from the zonal GATE websites from 1st January 2014. The candidate has to bring the printed admit card to the test center along with at least one original (not photocopied / scanned copy) and valid (not expired) photo identification. &It may be noted that one of the following photo identifications is ONLY permitted: Driving license, Passport, PAN Card, Voter ID, Aadhaar UID, College ID, Employee identification card, or a notarized affidavit with Photo, Signature, Date of Birth and Residential Address. The details of this ID proof have to be given while filling the online application. 
3. Numerical Answer Type Questions: The question paper for GATE 2014 will consist of questions of both multiple-choice type and numerical answer type. For multiple choice type questions, candidates have to choose the answer from the given choices. For numerical answer type questions, choices will not be given. Candidates have to enter a number as the answer using a virtual keypad. 

source: http://gate.iitkgp.ac.in/

GATE 2014

GATE (Graduate Aptitude Test in Engineering)

Graduate Aptitude Test in Engineering (GATE) is an all India examination administered and conducted jointly by the Indian Institute of Science and seven Indian Institutes of Technology on behalf of the National Coordination Board - GATE, Department of Higher Education, Ministry of Human Resource Development (MHRD), Government of India.The GATE committee, which comprises of representatives from the administering institutes, is the sole authority for regulating the examination and declaring the results.GATE is  conducted through the constitution of eight zones.

SOURCE: http://gate.iitkgp.ac.in/gate2014/

water level alarm - a mini project of EEE

Circuit diagram:

Parts:

R1_______________1K  1/4W Resistor

R2_____________100K  1/4W Resistor (See Notes)

C1_______________2µ2  50V Electrolytic Capacitor

C2_____________220µF  25V Electrolytic Capacitor (See Notes)

D1______________5 or 10mm. Ultra-bright red LED (See Notes)

D2____________1N5819  40V 1A Schottky-barrier Diode (See Notes)

IC1_____________7555 or TS555CN CMos Timer IC

BZ1____________Piezo sounder (incorporating 3KHz oscillator)

B1_____________1.5V Battery (AAA or AA cell etc.)

Two small crocodile clips

Two pieces of stiff wire of suitable length

Battery socket, etc.

________________________________________

Device purpose:

This circuit will emit an intermittent beep (or will flash a LED) when the water contained into a recipient has reached the desired level. It should be mounted on top of the recipient (e.g. a plastic tank) by means of two crocodile clips, acting also as probes. If a deeper sensing level is needed, the clips can be extended by means of two pieces of stiff wire (see pictures).

Circuit operation:

IC1, a 555 CMos timer chip, is wired as an astable multivibrator whose operating frequency is set by C1, R1 and R2, plus the resistance presented by water across the probes. If the resistance across the probes is zero (i.e. probes shorted), the output frequency will be about 3Hz and the sounder will beep (or the LED will flash) about three times per second.

As water usually presents a certain amount of resistance, the actual oscillation frequency will be lower: less than one beep/flash per second. As probes will be increasingly immersed in water, the resistance across them will decrease and the oscillation frequency of IC1 will increase. This means that a rough aural or visual indication of the level reached by water will be available.

If a LED is chosen as the alert, C2, D1 and D2 must be added to the circuit in order to double the output voltage, thus allowing proper LED operation (see the rightmost part of the schematics).

Interesting features of this circuit are 1.5V supply and ultra-low current consumption: 40µA in stand-by and 0.5mA in operation. This allows a single AAA alkaline cell to last several years and the saving of the power on/off switch.

Notes:

•       If a LED alert is needed instead of the beeper, R2 value must be changed to 10K, the Piezo sounder can be omitted and D1, D2 and C2 must be added, as shown in the rightmost part of the schematics.

•       A common red LED can be used for D1, but ultra-bright types are preferred.

•       Any Schottky-barrier type diode can be used in place of the 1N5819, e.g. the BAT46, rated @ 100V 150mA.

•       Wipe the probes regularly to avoid excessive resistance variations due to partial oxidization.

for details visit :web

super capacitor

here are my publication in electrical-engineering-portal.com

super capacitor 1

super capacitor 2
 

Protection System in Power System

This portion of our website covers almost everything related to protection system in power systemincluding standard lead and device numbers, mode of connections at terminal strips, color codes in multi-core cables, Dos and Don’ts in execution. It also covers principles of various power system protection relays and schemes including special power system protection schemes like differential relays, restricted earth fault protection, directional relays and distance relays etc. The details of transformer protection, generator protection, transmission line protection & protection of capacitor banks are also given. It covers almost everything about protection of power system.

The switchgear testing, instrument transformers like current transformer testing voltage or potential transformer testing and associated protection relay are explained in detail. The close and trip, indication and alarm circuits different of Circuit breakers are also included and explain.

Objective of power system protection

The objective of power system protection is to isolate a faulty section of electrical power system from rest of the live system so that the rest portion can function satisfactorily without any severer damage due to fault current.

Actually circuit breaker isolates the faulty system from rest of the healthy system and this circuit breakers automatically open during fault condition due to its trip signal comes from protection relay. The main philosophy about protection is that no protection of power system can prevent the flow of fault current through the system, it only can prevent the continuation of flowing of fault current by quickly disconnect the short circuit path from the system. For satisfying this quick disconnection the protection relays should have following functional requirements.

Protection system in power system

Let’s have a discussion on basic concept of Protection system in power system and coordination ofprotection relays.

In the picture the basic connection of protection relay has been shown. It is quite simple. The secondary of current transformer is connected to the current coil of relay. And secondary of voltage transformer is connected to the voltage coil of the relay. Whenever any fault occurs in the feeder circuit, proportionate secondary current of the CT will flow through the current coil of the relay due to which mmf of that coil is increased. This increased mmf is sufficient to mechanically close the normally open contact of the relay. This relay contact actually closes and completes the DC trip coil circuit and hence the trip coil is energized. The mmf of the trip coil initiates the mechanical movement of the tripping mechanism of the circuit breaker and ultimately the circuit breaker is tripped to isolate the fault.

The functional requirements of protection relay

Reliability

The most important requisite of protective relay is reliability. They remain inoperative for a long time before a fault occurs; but if a fault occurs, the relays must respond instantly and correctly.

Selectivity

The relay must be operated in only those conditions for which relays are commissioned in the electrical power system. There may be some typical condition during fault for which some relays should not be operated or operated after some definite time delay hence protection relay must be sufficiently capable to select appropriate condition for which it would be operated.

Sensitivity

The relaying equipment must be sufficiently sensitive so that it can be operated reliably when level of fault condition just crosses the predefined limit.

Speed

The protective relays must operate at the required speed. There must be a correct coordination provided in various power system protection relays in such a way that for fault at one portion of the system should not disturb other healthy portion. Fault current may flow through a part of healthy portion since they are electrically connected but relays associated with that healthy portion should not be operated faster than the relays of faulty portion otherwise undesired interruption of healthy system may occur. Again if relay associated with faulty portion is not operated in proper time due to any defect in it or other reason, then only the next relay associated with the healthy portion of the system must be operated to isolate the fault. Hence it should neither be too slow which may result in damage to the equipment nor should it be too fast which may result in undesired operation.

Important Elements for power system protection

Switch gear

Consists of mainly Bulk oil Circuit breaker, Minimum oil Circuit breaker, SF6 Circuit breaker, Air Blast Circuit breaker and Vacuum Circuit breaker etc. Different operating mechanisms such as solenoid, spring, pneumatic, hydraulic etc. are employed in Circuit Breaker. Circuit Breaker is the main part of protection system in power system it automatically isolate the faulty portion of the system by opening its contacts.

Protective gear

Consists of mainly power system protection relays like current relays, voltage relays, impedance relays, power relays, frequency relays, etc. based on operating parameter, definite time relays, inverse time relays, stepped relays etc. as per operating characteristic, logic wise such as differential relays, over fluxing relays etc. During fault the protection relay gives trip signal to the associated circuit breaker for opening its contacts.

Station Battery

All the circuit breakers of electrical power system are DC (Direct Current) operated. Because DC power can be stored in battery and if situation comes when total failure of incoming power occurs, still the circuit breakers can be operated for restoring the situation by the power of storage battery. Hence the battery is another essential item of the power system. Some time it is referred as the heart of the electrical substation. A Substation battery or simply a Station battery containing a number of cells accumulate energy during the period of availability of A.C supply and discharge at the time when relays operate so that relevant circuit breaker is tripped.