Sunday, September 14, 2014

Moto E Price in India - Buy Moto E Online - Motorola free home delivery in stock

moto e


Specifications

Operating system

Android™ 4.4, KitKat®

Processor

Qualcomm® Snapdragon™ 200 with 1.2GHz dual-core A7 CPU
Adreno 302 400MHz single-core GPU

Capacity

4GB standard
MicroSD slot supports up to 32GB expandable memory
1GB RAM

Dimensions and weight

Height: 124.8mm
Width: 64.8mm
Depth: 12.3mm
Weight: 142g

Display

4.3 inches
540 x 960 qHD, 256ppi
Features anti-smudge coating and Corning® Gorilla® Glass 3

Connectivity

MicroUSB, supports USB 2.0
3.5 mm headset jack
Micro SIM

Battery

Built-in rechargeable lithium-ion, 1980mAh
Mixed usage up to 24 hours

Rear camera

5 MP

Video capture and playback

Capture 30fps FWVGA (MP4, H.264, H.263)
Up to 720p playback displayed in qHD resolution

Audio playback

AMR-NB, AMR-WB, AAC, AAC+, eAAC+, MP3, PCM,
FLAC, MIDI, QCELP, EVRC, OGG/Vorbis

Networks



US GSM Model:

GSM/GPRS/EDGE (850, 900, 1800, 1900 MHz)
UMTS/HSPA+ up to 21 Mbps (850, 1700 (AWS), 1900 MHz)
Requires a microSIM card (not included)

Global GSM Model:

GSM/GPRS/EDGE (850, 900, 1800, 1900 MHz)
UMTS/HSPA+ up to 21 Mbps (850, 900, 1900, 2100 MHz)
Requires a microSIM card (not included)

CDMA Model Coming Soon!

CDMA/EVDO Rev A (850, 1900 MHz)
Wi-Fi
802.11 b/g/n, 2.4GHz

Bluetooth® Technology

Version 4.0 LE

Location services

GPS, GLONASS, BeiDou
 

In the box

Moto E in black or white
One-piece charger
Quick start guide

SOURCE:OFFICIAL SITE

BUY NOW:
BLACK : BOOK NOW
WHITE:  BOOK NOW



Saturday, June 28, 2014

universal Zener Diode Tester project

Zener diodes available in the market are specified according to their breakdown voltage as well as tolerance. The tolerance may vary from 5 per cent to 20 per cent. The circuit of a versatile zener diode tester presented here enables you to verify the specified breakdown voltage and tolerance values. In addition, you can check the dynamic impedance of a zener diode. The dynamic impedance characteristics of a zener diode determine as to how well the zener diode regulates its own breakdown voltage. Thus this circuit can be used to compare the dynamic impedance characteristics of zener diodes from a lot and segregate/categorise them accordingly. For full-fledged zener diode testing you
will have to refer to the manufacturer’s datasheet to check zener diode parameters such as zener voltage, power, and current (maximum/nominal) ratings. In addition, temperature coefficient and dynamic impedance have also to be checked if zener diode is to be used for critical functions such as voltage reference for digital voltmeters, control systems, and precision power-supply circuits. However, for a common hobbyist it is not necessary to check zener diodes critically, and only
checking its dynamic impedance characteristic is sufficient. Dynamic impedance implies the degree of change in a zener diode’s voltage with the change in current. Expressed in ohms, it equals the small change in zener voltage divided by the corresponding change in zener current (centered around the test current figure prescribed in datasheets by manufacturers). From datasheets it is observed that test current value is high for low-voltage zener diodes and low for higher-voltage zener diodes. However, the dynamic impedance value will be low for low-voltage zener diodes and vice versa for higher-voltage zener diodes. To test 3.3V to 120V zener diodes by the practical dynamic impedance method, you need to have a variable voltage (0 to above 120V) and current (1 mA to 150mA) supply source. Designing this type of power supply is quite complicated and is prone to damage if excess current is drawn accidentally.
circuit diagram


The zener diode tester circuit presented here has been designed considering the above factors. It is capable of testing zener diodes of breakdown voltage ratings of upto 120V and wattage ratings of
250 mW, 400 mW, 500 mW, and 1W.

The circuit can be deployed in quicktest mode as also in quality-test mode of  you can
perform a rough check of zener diode’s breakdown voltage up to 47 volts. In quality-test mode, you can check dynamic impedance characteristic for zener diodes from 3.3V to 120V. Commonly available step-down transformers X1 and X2 (230V AC primary to 9V AC, 750 mA sec. each) are connected back-to-back as shown in the figure. A bridge rectifier followed by filter capacitor C1 converts the output from X2 transformer to DC. Neon lamp L1 indicates the presence of higher DC voltage (220V approximately) across capacitor C1, which is used to test various zener diode values from 3.3V to 120V.



An advantage of using this high-voltage circuit is that the current gets restricted to a low value. It delivers only 3mA (approx.) when testing zener diodes with higher breakdown values (e.g. 120V
zener diode), but while testing zener diodes of low breakdown values, such as 3.3V, it delivers a current slightly above 20 mA. Such power-supply characteristics suit our requirement, as stated earlier. Since a small current is used for testing of zener diodes, there is no danger of zener diodes getting damaged during testing using the dynamic impedance method. Before using the circuit, check DC voltage across test terminals A and B without connecting any zener diode and then flip toggle switch S2 to quick-test position. DC voltage available across terminals A and B will be around 200V DC. Now put toggle switch to quality-test position. DC voltage can now be adjusted from 6V DC to 200V DC (approx.) with the help of potentiometer VR1. After these preliminary checks, the circuit is ready for operation.
To test zener diode by quick-test method, connect zener diode across terminals A and B and flip switch S1 to ‘on’ position. Note down DC voltage in digital multimeter M2, which is the rough breakdown voltage. In quick-test method you can test zener diode values up to 47 volts safely. For higher-value zener diodes you will have to increase the value of resistor R3 suitably. If zener diode presents a short, digital multimeter M2 will read ‘0’volts To perform quality test on the same
zener diode, turn switch S1 ‘off’and remove zener diode from across terminals Aand B. Now turnswitch S1 ‘on’and adjust potentiometer VR1 to obtain DC voltage (on digital multimeter) across terminals A and B equal to the one found during quick test method. Now keep potentiometer VR2 in mid position and connect zener diode across terminals A and B.
(Note. Before testing zener diode, refer Table I and Table II for the minimum
test current (It min) and maximum test current (It max) required for various zener diode values, depending upon their wattage rating.)Test current is adjusted using potentiometer VR2 and measured using meter M1 (A 0-25mA analogue milliampere meter or a 0-20mA digital multimeter canbe used.)

 Now adjust potentiometer VR2 and note down changes in zener voltage during It min and It max conditions. If the required current is not available, increase DC voltage by adjusting potentiometer
VR1 suitably. While changing test current from It min to It max, the voltage variationacross zener diode should be less than 1 volt for lower-value zener diodes and a few volts for higher-value zener diodes. A voltage variation of more than this value ndicates that zener diode is not properly regulating. When comparing zener diodes of same values, the zeners showing less voltage deviation would regulate better

Tuesday, June 24, 2014

Ohm’s Law and It's Equation,Formula and Limitations

The most basic quantities of electricity are voltage, current and resistance. Ohm's law shows a simple relationship between these three quantities, hence this law can be considered as the most basic law of electrical engineering. This is diamond (priceless) of electrical engineering used to calculate and analyze electrical circuits and quantities related to power, efficiency and impedance.

OHM'S LAW :

GEORG OHM'S:

GEORG OHM

 ABOUT GEORG OHM:

GO TO:GEORG OHM

 

 

 

 STATEMENT: 

"whenever a potential difference or voltage is applied across a resistor of a closed circuit, current starts flowing through it. This current is directly proportional to the voltage applied if temperature and all other factors remain constant"  


Mathematically,


Now putting the constant of proportionality we get,




Transformer defination and Working principle

TRANSFORMER:

what is transformer?

Transformer is a static device which transforms electrical energy from one circuit to another without any direct electrical connection and with the help of mutual induction between two windings and according toFaraday Law's Of Electromagnetic induction . It transforms power from one circuit to another without changing its frequency but may be in different voltage level.

WORKING PRINCIPLE OF A TRASNFORMER:

Transformer works on the principle of mutual induction two coils or Faraday Law's Of Electromagnetic induction.When current in the primary coil is changed the flux linked to the secondary coil also changes. accordingly an EMF is induced in the secondary coil due to Faraday law's of electromagnetic induction.this induced EMF is directly proportional input applied.
  
principle of working

Parts of transformer:

  • Primary Winding of transformer - which produces magnetic flux when it is connected to electrical source.
  • Magnetic Core of transformer - the magnetic flux produced by the primary winding, that will pass through this low reluctance path linked with secondary winding and create a closed magnetic circuit.
  • Secondary Winding of transformer - the flux, produced by primary winding, passes through the core, will link with the secondary winding. This winding also wounds on the same core and gives the desired output of the transformer.

SOURCES:

 Wikipedia and books.

Thursday, June 19, 2014

Nikola Tesla Biography-A Great Legend


nikola tesla,tesla,electrical engineer
Nikola tesla
(10 July 1856 – 7 January 1943) was an inventor, mechanical engineer, electrical engineer, and futurist whose work is integrated into almost all facets of modern life. He is also almost completely absent from US classroom curriculum and history books.
Plaques on buildings around the world — many in New York City — bear his name, however. Statues in the U.S, Canada, Croatia, and Serbia have been made in his honor. During Tesla’s lifetime he received honorary degrees from the world’s most prestigious universities, including Yale, Columbia, and Graz Polytechnic Institute.
In 1960, The Institute Electrotechnical Committee adopted the name “tesla” as the SI unit measuring magnetic field B (also referred to as the magnetic flux density and magnetic induction) at the General Conference on Weights and Measures, in Paris. This honor has been bestowed upon other great inventors such as Hertz (hertz), Ampère (amps), Volta (volts), and Watt (watts).
Tesla appeared on the cover of Time magazine in 1931 in honor of his 75th birthday, with a caption reading, “NIKOLA TESLA – All the world’s his power house”. The cover’s portrait was painted by Princess Lwoff-Parlaghy.
In 1983, the US Post Office honored Tesla with a commemorative stamp.
Upon his death in January 1943, U.S. President and Mrs. Roosevelt expressed their gratitude by issuing a statement regarding his contributions to “science and industry and to this country.” While Vice President Wallace declared, “In Nikola Tesla’s death the common man loses one of his best friends.”And New York City’s Mayor La Guardia read a eulogy on WNYC radio in which he called Tesla “a great American”, and said he was, “one of the most useful and successful men who ever lived.” La Guardia added, “But Tesla is not dead … the real, the important part, of Tesla lives on in his achievement, which was great, almost beyond calculation.”
But Tesla’s work and legacy fell into relative obscurity in the United States after all of his papers and personal effects were enigmatically seized by the FBI the day after his January 1943 death. The FBI reportedly took microfilm of everything, then handed it over to the Office of Alien Property (even though Tesla had been a proud US citizen since age 35), which in turn sent the entire lot to Belgrade under pressure from the then Yugoslavian Ambassador, who happened to be Tesla’s nephew.

Early Life


Nikola Tesla’s birthplace in Smiljan, CroatiaBorn July 10th, 1856, in the remote village of Smiljan — just outside Gospić,  in present day Croatia’s mountainous Northern Dalmatia region — Tesla was a subject of the Austrian Empire by birth (before becoming an American citizen at age 35). His father was an Orthodox minister and his mother was, as described by Tesla, “an inventor of the first order and would, I believe, have achieved great things had she not been so remote from modern life and its multifold opportunities.” After immigrating to the United States, Tesla immediately began working for Thomas Edison, thanks to a recommendation from Charles Batchelorwho ran the Edison Electric Light Company of Europe based in Paris, for which Tesla worked. After a dramatic falling out with Edison, Tesla worked as a day laborer in New York City digging ditches for nearly a year, while still working every evening on his AC induction motor until he finally found a financier in 1884 and formed the Tesla Electric Company on Pearl Street, just blocks from Edison’s power station.

War of the Currents

Nikola Tesla commemorative US postage stamp Telsa was an important contributor to the use of commercial electricity and is best known for developing the modern polyphase alternating current (AC) electrical supply system using an induction motor he invented. His many revolutionary developments in the field of electromagnetism in the late 19th and early 20th centuries were based on the theories of electromagnetic technology discovered by Michael Faraday. Without these leaps forward, more dangerous — often deadly — AC apparatus would have continued to be used. Or, instead, direct current (DC), which was favored by Edison, but unsustainably required a power plant to be located within one mile of its delivery point for the system to operate. This led to what was dubbed the ‘War of the Electric Currents’ which further fueled his rivalry with Edison. During this period Edison was backed by J. Pierpont Morgan and Tesla financed by George Westinghouse.
Edison’s obstinance to AC was partly genuinely concerned that AC was dangerous — as he didn’t have a full understanding of Tesla’s system. But mostly, he didn’t like the newly formed Westinghouse Electric Co. (which had bought Tesla’s patents) taking business way from Edison Electric Company and launched a ruthless smear campaign using his status as a darling of the press to discredit AC. His employees conducted the public electrocution of animals — dogs, cats, a horse, and even an elephant — using the AC current throughout NYC parks and in other cities.
Harold P. Brown, who was funded by Edison and allowed free reign to use his laboratory, developed the Electric Chair for executing prisoners on death row, after covertly licensing the rights to use Tesla’s AC system patents with a Westinghouse dynamo. The first criminal to be executed with electricity in New York State was William Kemmler who had killed his wife with a hatchet. Edison, Brown and other AC critics started dubbing the phrase, “Don’t get ‘Westinghoused.’” when referring to capital punishment as part of the smear campaign.
But Tesla’s polyphase AC system prevailed and Westinghouse Electric won the bid to electrify both the 1893 Chicago World’s Fair and the rushing waters of Niagara Falls, thus ending the ‘War.’ In the process, Edison was ousted from controlling his own electric company, Edison Electric Illuminating Company, upon consolidation with a syndicate of several others which formed the General Electric Company (ironically facilitated by J. P. Morgan).

Tesla’s Inventions, Friends and Personality

Tesla was very well liked and possessed a lot of charisma, even though he also was very eccentric and known to be quite obsessive-compulsive. Franklin Chester wrote in an August 1897 edition of the Citizen that no one could look upon him without feeling his force. Robert Underwood Johnson, editor of Century magazine, became a close friend of Tesla’s and described his personality as one of “distinguished sweetness, sincerity, modesty, refinement, generosity, and force.”He usually worked through the night, and often with observers present, including his good friend Mark Twain, who often visited Tesla’s Houston Street laboratory in the wee hours to watch and participate in experiments. In their off hours, they’d play cards at the Player’s Club.Beyond his other achievements, Tesla’s patents and theoretical work also formed the basis of wireless communication and the radio. He further pioneered some of the first work with X-rays, florescent lighting, radar, and neon, among many other inventions.
From 1899 to 1900 Tesla spent his time researching in Colorado Springs. Among other things, including wirelessly creating artificial lightning from up to 135 feet, he researched ways to transmit power and energy wirelessly over long distances. He transmitted extremely low frequencies through the ground as well as between the Earth’s surface and the Kennelly–Heaviside layer and was granted patents on wireless transceivers that developed standing waves by this method. In his experiments, he made mathematical calculations and computations based on his experiments and discovered that the resonant frequency of the Earth was approximately 8 hertz (Hz). In the 1950s, researchers confirmed that the resonant frequency of the Earth’s ionospheric cavity was in this range.Tesla left Colorado Springs on January 7, 1900. The lab was torn down in 1905 and its contents sold to pay debts, of which he had accumulated many in one year of research. His Colorado experiments prepared Tesla for the establishment of a trans-Atlantic wireless telecommunications facility, and in 1901 with $150,000, the majority financed by J. P. Morgan, Tesla began building the Wardenclyffe Tower facility near Shoreham, Long Island in New York. In June 1902, Tesla’s lab operations were moved out to Wardenclyffe from his Houston Street lab in NYC. After a falling out with Morgan because Marconi beat him to a trans-Atlantic wireless transmission, Morgan pulled funding which made it very difficult for Tesla to get backed by any other financiers. Tesla fell into debt and the tower was dismantled for scrap during World War I.
The New York Times reported Tesla was to be awarded the Nobel Prize in Physics, based on a Reuter’s dispatch from London on November 6, 1915. But it’s rumored he declined the award because it was to be shared with his arch rival Thomas Edison. The Royal Academy of Science of Sweden replied a half century later saying that was untrue. Neither Tesla or Edison ever subsequently won the Nobel Prize.Tesla, who had always been very eccentric, grew reclusive in his later years. He spent all of his time either feeding beloved pigeons in Bryant Park , or conducting experiments in his New York City hotel rooms (he never lived in an apartment, always opting for hotels).Tesla did however conduct an annual press conference on his birthday … and each year the claims about his work grew more and more strange to the public. His statements were partially misunderstood because his complex inventions were not yet easily deciphered by laymen, and partly due to his ever-growing eccentricity — including claiming the large wireless tower at his Wardenclyffe laboratory in Long Island could produce a “Death Ray.” Tesla gained a reputation in popular culture as the archetypal “mad scientist”. He died, penniless, at 87 years-old in his room at the New Yorker Hotel.