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Sunday, February 10, 2013

Difference Between Normal and Power Diode


Assalam o Alaikum ! Today I want to Share my Assignment of Power Electronics , Hope You find it Informative. 

Diode

Diode is a simple Semiconductor device which is used for many purposes in electronic applications.
Diode is specially known for conversion of AC to DC or Rectification process. It is opted for its unique characteristics such as Uni-Directional current provision and infinite resistance to the Reverse current.

SYMBOL:


Diode consists of two doped semiconductors, one of a P-type and other of N-type. When Tetravalent semiconductor is doped with pentavalent impurities , then electrons are the majority carriers and N-type semiconductor is formed. Secondly, P-type with holes as the majority carriers is formed, when trivalent impurities are added to the tetravalent semiconductor material. After that, P-type semiconductor and N-type Semiconductor are diffused together. By Diffusion, electrons from N-type region flow to P-type region and holes flow from P-type to the N-type region leaving behind negatively charged ions. In this process, electric field is created with opposite polarities to the respective (n-type or p-type) regions which blocks the further transfer of both carriers and as a result, a potential barrier is formed in between the semiconductors which is called Depletion region.




This PN juction can be used according to the need and in a controlled manner. It can be used in three modes, Zero bias , Forward Bias and Reverse Bias. In Zero Bias mode, it remains at its neutral behaviour. In Forward Bias mode, a potential difference is applied to the junction where P-type material is connected with the positive terminal and N-type is connected with the negative terminal of the Source.

When this arrangement is made , opposite polarity potential (w.r.t depletion region) breaks the potential barrier(inside) and flow of charges is started from both ends and as a result the current is observed.

In Reverse Bias, P-type is connected with negative terminal and N-type is connected with the positive terminal of the source.

This arrangement keeps the majority carriers of both materials away from breaking the depletion region and source potential(outside) attracts the majority carriers which results in increment of depletion region and a large voltage is observed.

Diodes are used in almost every electronic device both on small and large scales . However, diode needs some modification in high power applications. Diode undergoes some problems such as ability to conduct high current in forward bias and to hold high voltage and avoid breakdown in reverse bias. To overcome these problems, concept of Power diodes is introduced.

Power Diode

Power diode is built with vertical orientation to provide extra cross-sectional area which is required to handle large amount of current . The other problem of controlling breakdown voltage in reverse bias is overcome by controlling the relative factors.

Breakdown occurs due to the high electric field in potential barrier. Electric field and depletion width has inverse relation (E=V/d), so to control the break down at very high voltage, depletion width has to be altered, and to alter the depletion width, Doping of the material has to be changed. This is done by the following arrangement of normal and less doped semiconductors.

      


In this arrangement,an extra layer of N-type material is introduced. Here, N-type in the middle region is less doped and the other P-type and N-type materials are normally doped. When the diode comes in reverse bias mode, it sees a large potential barrier across the lightly doped N-type region, which makes it able to withstand more voltage than normal. Extra layer used here, has to provide required majority carriers to maintain the current without reduction during the forward bias mode.

Major Differences

1- Design

Simple diodes consist of a simple PN junction. They are smaller in size and lighter in weight, while power diodes are in modified form and they are larger and heavier normally. Power diodes are usually available in metal form.

2- Voltage Rating

Simple diodes are used in normal low power components so they have a relatively low voltage ratings as compared to power diodes. Power diodes can have very high voltage ratings usually in thousands of volts.

3- Current Rating

Power diodes have a high hand in Current ratings over normal diodes , that can be in several hundred amperes.

4-Temperature

Major probelm in handling high power applications is the generation of heat and temperature. Power diodes have the accessiblity of operation at higher temperature whereas normal diodes do not need this feature in high priority.

5- Cost

Power Diodes are costly as compared to the simple diodes due to the additional components and features.



















Copyright : M.Shahzaib S. Qureshi
---------------------------------------------------- The End -----------------------------------------------

Sunday, February 3, 2013

Quran Pak with Urdu-English Translations (Java-Mobiles + Android Link)


Assalam o Alaikum !

Today I want to share a software for Java Mobile Phones ( Almost every phone supports it ) ,
This is Quran Software with Urdu and English Translations.



This is the best one I have found so far , You can change the font size and colours as well of both Arabic and its Translations.

LINKS


OR


OR

3- http://www.cell11.com/download/s60v5/s60v5-softwares/new-apps/eIslamExplorer_V3_0.jar

Its size is 2.8 MB , if your mobile phone does not support it then try the basic version without translation .

LINKS


For Basic Quran:



OR


Installation: 

1- You can directly download it from the cell phones (Smartphones)
2- You can download it to your pc and then transfer to your phone through respective software for your mobile ( PCsuite, Htc Sync etc.)
3- You can download it to PC, then transfer it to the memory card through card reader , then put memory card in your mobile, and install it from your mobile file browser(Gallery-MemoryCARD).
4. For Android Users Copy and paste this link in your mobile browser :

https://play.google.com/store/apps/details?id=com.eIslamExplorer


Jazakallah !



NOTE : This is a free software by Eislamexplorer.org , for their great work , you should visit and register yourself at their website on the address :

http://www.eislamexplorer.org/index.php?ID=Soft_0_0_0  ..

Thursday, January 24, 2013

FM Transmitter

Assalam o Alaikum !

Today I want to share my first electronic project in my student life . which is a simple FM Transmitter.






Requirements :

1- Breadboard
2- Resistors , Capacitors as in figure
3- 9 volt DC Battery
4- Mic

Note: Don't buy Inductor as it wont work,until its in wounded wire shape and take a good mic with long legs :)

You have to make it yourself. You have to take a 15/22 gauge wire and wound it on anything with less diameter(pencil,pen,etc) or You can make it through this formula.

 L  = [dn2] / [18d + 40l]

  • Where’ L ‘  is the inductance in Micro Henries [µH]
  • ‘d’ is the diameter of the coil from one wire centre to another wire centre. It should be specifies in inches.
  • ‘l’ is the length of the coil specified in inches.
  • ‘n’ is the number of turns.

Mine worked within 5,6 turns of 15 gauge wire on a HB-2 pencil. (Can vary Definitely :) )

Steps:

1- Wire all these components on the breadboard and importantly this circuit should take as little place as possible, try to make it congested and turn the long legs of the components into small legs ( By cutter ofcourse :) )

2- Now connect the DC battery and Tune the radio (e.g in Cellphone ), it would automatically tune a station without any voice output( means circuit is working) , Now you can sing Opera on the Mic :D..

3- You can introduce antenna with inductor capacitor combination (as in figure ) to extend the range.


Description :

1- R1,R2,R6 are DC biasing resistors for keeping the transistor Q1 forward Biased.
2- C1 is used to remove any DC signal in AC signal(voice from mic).
3- Transistor Q1 is just amplifying the voice signal which is in milivolts (mv)
4- Then again R4,R5,R8 are DC biasing resistors for Q2.
5- Now Q2 is amplifying the coming voltage and C7 and inductor are performing the Frequency Modulation.

Precautions :

Wiring should be congested , Mic should be connected with right polarity with the DC battery , Receiver should not be touching the inductor when the transmitter is on , Battery should at least be 6 volts.

You can use Circuit Maker from National Instruments .

Torrent Link :
http://thepiratebay.se/torrent/5295859/National_Instruments_Circuit_Design_Suite_11.0

Best Of Luck !!

Monday, December 31, 2012

1946 Elections British India


Assalam o alaikum!

I did very hard to write this article. This is written in simple words Hope you find it Informative

General & Provincial Elections
1945-46
British India









M.S.S.Qureshi
Applied Physics University of Karachi,2011





This article is dedicated to my Parents. They made myself able to write this article. May they live long. (AAMEEN)






Preface


As a student of Pakistan Studies, I always tried to get the most of the events in creation of Pakistan.
I found many events interesting , but I selected 1946 election to do some study on. So, this article is just a simple study of the event. I tried to make it easy as I could. This article is written with the help of my respected teacher “ SYED HUMAYYUN” and the great library “MAHMOOD HUSSAIN LIBRARY” of “UNIVERSITY OF KARACHI” .Hopefully, this article will help the reader to understand a part of history of the Subcontinent.


Muhammad Shahzaib Shahzad Qureshi

Contents

Topics 
Introduction 
Reaction of parties 
Preparations 
General Elections 
Provincial Elections 
Formation of Ministries 
Short Analysis 
References 
Bibliography




Introduction:



1946 Elections of British India have a great role in the creation of Pakistan. These elections determined the path to a separate sovereign state for the Muslims. Background of the elections is that, Simla conference was held to settle the issues between Muslim League and the Congress, but it failed at least in part , because both the Congress and Muslim
League had made claims about the representatives standing unsupported by electoral evidence. The general elections had been held since 1934 to the central legislative and since 1937 to the Provincial assemblies. The balance of political power had shifted so much in ten years that new elections were imperative. With the failure of the Simla Conference, Prime minister Clement Attlee (1883-1967) reconstructed the India committee of the cabinet. In the first meeting of the committee it was decided to bring Lord Wavell to London for consultations and to press for early elections to form a constitution making body. On 21 august 1945 the viceroy made two important announcements, The first was that elections to the central and provincial legislatures would be held in the coming winter. The second informed the public that he would shortly be going to London for consultations with the British government. His visit to Britain lasted from 24 august to 16 September. Wavell presented his view in the House of commons, he said “ The announcement that election would be held soon was regarded by Muslims as a matter of great relief, because it was by this means they hoped to settle, once for all, the questions of who was their rightful representative –the All India Muslim League or the Indian National Congress”.
1On 19 September, Lord Wavell confirmed on behalf of his majesty’s Government that the Central and Provincial Legislature elections would be held in the winter of 1945-46, after which a constitution-making body would be set up. He also announced that after the elections, the Viceroy also take steps to bring into being an Executive Council that would have the support of the main Indian political parties.2Wavell wanted the Indian people especially Muslims to select their party and these elections decided the representative parties of the Indian people quite clearly.

Reaction of Parties:

Wavell’s announcement of General elections was criticized by both the parties. Both the Muslim League and the Congress opposed the proposals.
Quaid-e-Azam declared that Muslims were not ready to accept any settlement except on the basis of Pakistan.3 All India Congress Committee characterized the proposal as vague, inadequate and unsatisfactory because it had not addressed the issue of independence and pointed out the omission of any reference to independence.4 After thus expressing the disapproval of the official plan, both parties launched huge election campaigns. They knew that the elections would be crucial for the future of India, as the results were to play an important role in determining their standing. The Muslim League wanted to sweep the Muslim constituencies so as to prove that they were the sole representatives of the Muslims of Sub-continent, while Congress wanted to prove that, irrespective of religion, they represent all the Indians Both the Muslim League and the Congress promulgated opposite slogans during their campaigns.




Preparations:


Muslim League:

The elections were fought on the simplest platform by the Muslim League. The league was fighting to vindicate its claim of speaking for Muslims of India to prove the popular backing for the Pakistan demand. its manifesto maybe summarized in two sentences; Pakistan is the only sensible solution of the Indian problem.


Quaid’s Election Campaign Tour of India:


Quaid-e-Azam himself toured the length and breadth of India and tried to unite the Muslim community under the banner of the Muslim League. He spoke of the dire need for unity, for the sinking of all differences, for facing the enemy with resolution and confidence; and for standings as a one united nation. The hour made one peremptory demand: to “vindicate not only your national character but your national claim”. He appealed to all non-league Muslims to join the party at that critical Juncture.

Islamic Fat’was:

Muslim League leaders got “Fatwas” from some well-known Ulama-e-Kirams of India that it is necessary for Muslims now to vote to Muslim League and sinful to vote for others. This strategy of the Muslim League brought great number of votes to their bank.

Communal Strategy:

The 1945-46 election campaign was also conducted by Muslim League with a patently communal strategy to which was added skillfully the question of class oppression. In the Muslim majority provinces trade and commerce were dominated by Hindus while most Muslims were agriculturalists, many of whom were debt-ridden. On the other hand, most of the big landlords were also Muslims. The indebted landowners and peasantry of sindh were convinced by the Muslim League that the debt burden incurred to Hindu money-lenders would be cancelled if they supported the PAKISTAN idea. 9

Congress:

The Congress on the other hand stood on two exactly opposed slogans:
1. The congress represented all Indians
2. India would remain one undivided country.

Propaganda against Pakistan:

Congress acted militantly to mobilize the mass opinion for the Indian independence. Nehru declared “A revolution is inevitable”. To counter the Muslim League, the Congress press abused the Quaid and termed his demand for Pakistan as the "vivisection of Mother India", "reactionary primitivism" and "religious barbarism". Congress tried to brand Muslim League as an ultra-conservative clique of knights, Khan Bahadurs, capitalists, toadies and government pensioners. The Congress also tried to get the support of all the provincial and central Muslim parties who had some differences with the Muslim League such as the Momins, the Ahrars, the Shia conference and Jamiat Ulama-e-Hind and backed them in the elections. In Punjab it supported the Unionist Party against the league.5
The 1945-46 elections were held in two stages; in December 1945 members of the central legislative assembly were elected, and in the early 1946members to provincial assemblies were elected.


General Elections:


Muslim League:

The hard work of the League Members showed a great result and the Muslim League swept polls in India. The results clearly showed the division of the assembly between the Congress and the Muslim League. The Muslim League won every single Muslim seat, the “Nationalist Muslims forfeiting their deposits in many instances”.6 The Muslim League won 86.6 percent of the total Muslims. Quaid-e-Azam Muhammad Ali Jinnah congratulated the Muslims of India for the tremendous victory and termed it as the biggest achievement in the way of Pakistan.

Congress:

Congress had spectacular victory in the non Muslim constituencies. Congress got 91.3 percent of the total general votes. The central Election Board of the Congress issued a bulletin on 6 January 1946, in which it claimed that the election results has vindicated the Congress as “The biggest, strongest and the most representative organization in the country”.7
The final figures for the central Assembly were:
Congress: 57
Muslim League 30
Independents 5
Akali Sikhs 2
Europeans 8
[ Total: 102]


In the previous assembly, elected in 1934, the figures at the time of dissolution were:
Congress 36
Muslim league 25
Independents 21
Nationalist party 10
Europeans 8
[Total : 100 ]


Congress’ claim to be the biggest representative party was gone down as they won only 57 seats out of 102 seats, a little over a half while Muslim League clean swept the legislative Assembly and proved to be the right representatives of the Indian Muslims.

Provincial Elections:

Provincial elections were held in February 1946, and again two main parties swept their respective constituencies. The congress won a total of 930 seats, gaining an absolute majority in eight provinces. The Muslim league captured 428 out of the possible 492 Muslim seats. In Sindh the league commanded exactly half the votes in the assembly. Therefore, a fresh election was held in December 1946, in which the league gained a majority over all other parties.


Formation Of Ministries:


Congress:


In Assam, Congress had a clear majority to form the government and it did so under the leader Gopinath Baedolai. One nationalist Muslim was included in the cabinet. Two seats were offered to Muslim League with a condition that it agreed to work with Congress parliamentary, which was rejected by the Muslim League because of the presence of a Nationalist party member in the ministry.
Congress formed ministries in Bihar, Bombay, Madras, United Provinces, Central Provinces and Orissa. Muslim League was offered ministries with conditions by the congress, but League rejected to accept their offer.
In North-West Frontier Province congress formed their government under “Abdul-Ghaffar Khan”, also called “Frontier Gandhi”.


Muslim League:


In Sindh, league won 27 seats and one independent Muslim joined the party later. Nationalist party got 3 seats and four seats were given to G.M.Sayyad’s group which had left the Muslim league just before the elections. The Congress had 21 seats, the Europeans three and there was one Independent Labour member. The sayyad group formed a coalition with congress and the Nationalist Muslims. Thus each of the two sides came to have 28 seats. The governor asked the league leader, G.H.Hidayatullah, to form the government. He offered two Hindu seats to the congress, but it insisted that G.M.Sayyad, the leader of the coalition should be approached. As the league did not, on principle, deal with non-league Muslims, the offer was suspended. Later, another election was held in which the league won a clear majority.
In Bengal, ministry was formed under H.S.Suhrawardy by the coalition of the Independent elements and the Muslim league which had 113 seats in the house of 250.Although, congress was offered a coalition earlier, but the talks were not successful.
In Punjab, ruling Unionist party faced a great defeat and their strength was reduced to 20. The Muslim league had 75 out of 86 Muslim seats. Four Unionists later joined the Muslim League (increasing their strength to 79) and six went over to independent and other benches leaving Unionist party with a total of 10 seats. The Congress and the Akali-Sikhs formed an alliance and offered their co-operation in the ministry to the Muslim League with three conditions.

1. Congress should have right to nominate its minister from any community.
2. Congress-Akali group would have half seats in the Government.
3. Non-Provincial topics like Pakistan would not be discussed in the Assembly.
These conditions were not acceptable by the League, so they tried to reach understanding with the Akali Sikhs but they insisted that in the event of creation of Pakistan a Sikh state would be formed in Punjab. League could not give any assurance so the coalition was not formed. Then Congress made alliance with Akali Sikhs and the Unionists to form a coalition ministry.8


Short Analysis:


With the results of elections 1945-46 many results were observed which are shortly listed.
1. Jinnah had campaigned to secure a mandate for Pakistan and in this he was successful.
2. Muslims got a clearer view of their goal which was a sovereign separate state named Pakistan.
3. It was cleared that the Muslims are a separate nation.
4. Muslim League was chosen to be the true representative party for the Muslims.
5. Muslims of India agreed to Muslim League’s view of separate state as a solution of conflicts between Muslims and other communities.
6. Muslims showed their unity for a purpose.
7. Muslim league got the rule of Muslim provinces from where they could help Pakistan movement quite nicely.
8. Muslim league eliminated the unionist party and became a single party for the Muslims of India.
9. Congress’ view of united India was broken down.
10. British government realized that there are two different forces in India now.
So, these elections have a big role in the achievement of Pakistan. It is the most crucial and the important part of the history of the subcontinent. These elections almost decided the future of Indian people and the Muslims could visualize their goal nearer to them. They realized that although this is not a finish line but it is a great step towards the foal under the great leadership of Muhammad Ali Jinnah.

REFERENCES


1. Justice Shameem Hussain Kadri: Creation of Pakistan, (Lahore: Wajid ali’s limited, 1982), p.316
2. Wavell, Lord: Speeches of Lord Wavell 1943-47 (Delhi: 1948), pp. 83-85
3. Menon, V.P: The Transfer of Power in India (Calcutta: 1957), p.220
4. India Annual Register, 1945, vol. II, pp.93-94
5. A.B.Rajput: Muslim League yesterday and Today (Lahore: 1948), p.97
6. Menon, V.P: op.cit. , p.226
7. Quraishi, Ishtiaq, H: The Struggle for Pakistan (Karachi: University of Karachi, 1965), p.238
8. I.bid, p.240
9. Ahmed, Ishtiaq : State, Nation and Ethnicity in Contemporary South Asia (A & C Black, 1998), p.89

Bibliography



  1. A.B.Rajput: Muslim League yesterday and Today.
  2. India Annual Register, 1945, vol. II.
  3. Justice Shameem Hussain Kadri: Creation of Pakistan.
  4. Menon, V.P: The Transfer of Power in India.
  5. Quraishi, Ishtiaq, H: The Struggle for Pakistan
  6. Wavell, Lord: Speeches of Lord Wavell 1943-47

Introduction





Assalam u Alaikum !
I am Muhammad Shahzaib Shahzad .. Studying BS in Applied Physics from University of Karachi, Pakistan.
Welcome to My Blog.
You can contact me on my linkedin profile : pk.linkedin.com/in/msqureshi17