STAR-DELTA Conversion

The Y-Δ transform, can also be spelt as wye-delta.This star-delta transformation theory was proposed by Arthur edwin kennelly in 1899.Star-delta transformations allows to convert impedances that are connected together from one type of connection to another type.

   We can now solve series, parallel or bridge type resistive networks using Kirchoff´s Circuit Laws, mesh analysis or nodal analysis techniques but in a balanced three-phase circuit. we now can reduce by mathematical solutions.

         The networks star and delta are obtained from resolving the T and PI resistor networks respectively.If we consider some different examples of T and PI they are shown aa below.

PI to DELTA

T to STAR

Star-delta & Delta-star transformations are used in DC Circuit Theory for analysis of Complex Circuits.Star-Delta Transformer Connection is now commonly used for power supply transformers.

8085 Micro Processor in real world

1. The Intel 8085 ("eighty-eighty-five") is an eight-bit microprocessor introduced by intel in 1977. It was the backward binary compatible one with the famous Intel 8080 ,only difference is addition of a few minor instructions, but required less supporting hardware, thus allowing simpler and less expensive microcomputer systems to be built.

2. 

   8085 MP architecture

   A device that uses a microprocessor is normally capable of many functions, such as word processing, calculation, and communication via Internet or telephone. However,  to work properly, the microprocessor itself has to communicate with other parts of the device. For example, a microprocessor would need to communicate with the video display to control the output data that a program may produce. Therefore, a microprocessor would act as device's "brain" in that it transmits, receives and interprets the data needed to operate a device.

                                            

8085 MP pin diagram

1. Microprocessors can be found in calculators, gaming consoles, wristwatches, consumer electronics and even automobiles.Real time image of a 8085MP is below.

                                                   

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DIODE -Its different types

Universal diode form

A diode is a semi-conductor device,with two terminals allowing flow of current in only one direction.The discovery of crystals rectifying abilities was made by German physicist Ferdinand Braun in 1874. The first semiconductor diodes, called cat's whisker diode, developed around 1906, were made of mineral crystals such as Galena.In these days,most of the diodes are made of si, but other semiconductors such as selenim or germanium are also sometimes used.

                            

                    

voltage vs current characteristics

The characteristics of a diode define the transfer of charge carriers as of called depletion layer formation during semiconductor state and variations takes place.If an external voltage is placed across the diode with the same polarity as the built-in potential, the depletion zone continues to act as an insulator, preventing any significant electric current flow . This is the Reverse Bias phenomenon.

                                        

Different Types Of Diodes

As well, there are many different types of diodes we use in our dialy lives.The above figure shows the diodes which we use generally.If we consider about the symbols i.e symbols reflecting different diodes
can be seen in below figure.

These symbols are mainly used while representing the electronic circuits in our studies.These different diodes make their use in respective functions as per their working limits.

LONDON ARRAY - The Largest Wind Power Plant

The London Array is an 175 turbine 630MW Round 2 offshore wind farm located 20 km off the Kent coast in the outer Thames Estuary in the United Kingdom. At the time of its construction it was the largest offshore wind farm in the world.The London Array project has been started in 2001, when a series of environmental studies in the outer Thames Estuary confirmed the area as a suitable wind farm site. Two years later, the Crown Estate gave London Array Ltd a 50-year lease for the site and cable route to shore.

       Planning consent for a 1GW offshore wind farm was granted in 2006, with the onshore works approved in 2007.Construction of the onshore substation at Cleve Hill started in July 2009 and was completed in October 2012. Offshore construction started in March 2011, when we installed the first of 177 foundations for the project.The first turbine was installed in January 2012, first power was achieved in October that year and the final turbine was installed in December 2012.

                  Turbines were supplied by Siemens Wind Power.^{www.electricfacts.blogspot.in} Their foundations were built by the joint-venture between Per Aarsleff and Bilfinger Berger Ingenieurbau. The same company supplied and installed the monopiles. Generators were installed by MPI and A2SEA by using an installation vessel TIV MPI Adventure and a jack-up barge Sea Worker. Two offshore substations were designed, fabricated and installed by Future Energy, a joint venture between Fabricom, Iemants and Geosea, while electrical systems and onshore substation work was undertaken by Siemens Transmission & Distribution. The subsea export cable was supplied by and array cables by JDR Cable Systems. The array cables and the export cables were installed by VSMC Nexans.

The wind farm started producing electricity at the end of October 2012. All 175 turbines of phase 1 were confirmed fully operational on 8 April 2013, and the wind farm was formally inaugurated by the Prime minister David Cameron on 4 July 2013.

  Phase 2 planning: 

A second phase was planned which would have seen a further 166 turbines installed to increase the capacity to 1000MW. However, the second phase was scaled back and finally cancelled in February 2014 after concerns were raised by the Royal Society for the Protection of Birds about its effect on a local population of red-throated divers.