Skip to main content

खनन और खनिज उद्योगों में पर्यावरणीय स्थिरता विषय पर विशेषज्ञों का मंथन

खनन और खनिज उद्योगों में पर्यावरणीय स्थिरता  विषय पर विशेषज्ञों का मंथन पर्यावरणीय स्थिरता मानव समाज के निरन्तर अस्तित्व, समृद्धि और स्वास्थ्य के लिए मूलभूत शर्त है। हमारी न्यू जनरेशन को स्पीड और टेक्नोलॉजी पर ध्यान केंद्रित करना होगा ताकि भविष्य को सुनहरा बनाया जा सके। उक्त विचार मुख्य अतिथि श्री एमपी सिंह, प्रधान मुख्य अभियंता, केंद्रीय विद्युत प्राधिकरण विद्युत मंत्रालय भारत सरकार, नई दिल्ली ने व्यक्त किए श्री सिंह भूपाल नोबल्स स्नातकोत्तर महाविद्यालय में भूविज्ञान विभाग द्वारा "खनन और खनिज उद्योगों में पर्यावरणीय स्थिरता" विषय पर आयोजित दो दिवसीय राष्ट्रीय कॉन्फ्रेंस के समापन पर बोल रहे थे। दो दिवसीय राष्ट्रीय कान्फ्रेंस का भव्य समापन सम्मानित अतिथि प्रो विनोद अग्रवाल सदस्य, भारत सरकार नई दिल्ली स्थित MOEFCC की विशेषज्ञ मूल्यांकन समिति, (सि एण्ड टीपी) अपने उद्बोधन में कहा कि पर्यावरण स्थिरता सरकार और समाज दोनों की जिम्मेदारी है। वर्तमान में खनन उद्योग विभिन्न प्रावधानों एवं कानूनों के तहत कार्य कर रहा है ताकि पर्यावरण को सुरक्षित रखा जा सके। आयोजन सचिव डॉ. हेमंत सेन न...
Post a Comment

MCT | MOS- controlled thyristor | Power electronics

MOS Controlled thyristor (MCT)

  • It is basically a thyristor with two MOSFETs built into the gate structure.
  • One MOSFET is used for turning on the MCT and the other for turning off the device.
  • MCT is a high frequency, high power, low-conducting drop switching device.
  • A practical MCT consists of thousands of these basic cells connected in parallel just like a power MOSFET.
  • This is done to achieve a high current carrying capacity of the device.
Basic structure of MCT
  • The equivalent circuit of MCT consists of one on-FET, one off-FET and two transistors.
  • The on-FET is a p-channel MOSFET and off-FET is an n-channel MOSFET.
  • An arrow towards the gate terminal indicates n-channel MOSFET and the arrow away form the gate terminal is the p-channel MOSFET.
  • The two transistor in the equivalent circuit represents that there is regenerative feedback in the MCT just same as in an ordinary thyristor.
(a) Equivalent circuit of MCT and (b) Circuit symbol of MCT

Turn-on process

  • An MCT can be turned on by applying a negative voltage pulse at the gate with respect to anode.
  • By getting this negative voltage pulse, on-FET gets turned-on and the off-FET is off.
  • During this time current begins to flow from anode A, through on-FET and then as the base current (iB) and emitter current (iE) of npn transistor and then to cathode C.
  • It turns on transistor and therefore collector current (iC) begins to flow in npn transistor.
  • Since off-FET is off, so this iC of npn transistor acts as the iB of pnp transistor, and hence pnp transistor is also turned on.
  • When both the transistors are on, the regenerative action of the connection scheme takes place, and the MCT is turned on.

Turn-off process

  • For turning-off the MCT, off-FET is energized by positive voltage pulse at the gate with respect to anode.
  • So this FET is turned on, and on-FET is tuned off.
  • After off-FET is tuned on, either base terminals of pnp transistor are short circuited by it.
  • So the anode current begins to flow through off-FET and therefore iB of pnp begins to decrease.
  • So iC of pnp transistor that forms the iB also begins to decrease.
  • In this way iB of pnp and npn transistors divide storage charge in their n and p bases respectively, begins to decay.
  • This regenerative action turns off the MCT.

Advantages of MCT

  • MCT has low forward conduction drop.
  • The turn-on and turn-off time of MCT is very fast.
  • The switching loss of MCT is very low.
  • The gate input impedance of MCT is very high.
To know about this lecture in more detail please visit on https://youtu.be/KtNQJ3Sueo0
Labels:

Comments

Post a Comment

Popular posts from this blog

Electric field due to circular loop of charge | Electromagnetics

Electric field due to circular loop of charge Electric field The space around a charged particle in which another charge experience a force is known as electric field. The source of electric field is either a charge or a time varying magnetic field. If the value of electric field does not change with time, then it will be uniform electric field, otherwise it will be non-uniform electric field. Electric field due to circular loop of charge If λ is linear charge density, then the charge on d l dq = λ d l      ⇒     dq = (q / 2πa) d l Electric field at P due to charge dq Special cases When P lies at the centre of the loop i. e., r = 0, then E = 0 When P lies very far from the centre of the loop i. e., r >> a, then E = kq / r 2 In this case circular loop behaves as a point charge. To know more about this topic please click on the link  https://youtu.be/54MIe0Ow43w   or...
Post a Comment
Read more

American Activity in Venezuela: A Simple Guide for Students

American activity in Venezuela is an important topic in international relations. It includes political involvement, economic decisions, oil interests, and humanitarian support. This blog explains the topic in simple terms for students. History of U.S.–Venezuela Relations For many years, the United States and Venezuela shared friendly relations. Venezuela was a major supplier of oil to the U.S., and many American companies invested in Venezuela’s oil industry. These strong economic ties helped both countries grow. Impact of Hugo Chávez on U.S.–Venezuela Relations In 1999, Hugo Chávez became the President of Venezuela. His socialist ideas and strong opposition to U.S. influence changed the relationship. He reduced the role of American companies and strengthened ties with countries that opposed U.S. policies. This marked the beginning of political tension. U.S. Political Involvement in Venezuela The United States claims that its actions in Venezuela are aimed at supporting democracy...
Post a Comment
Read more

Thomson’s parabola method | EMFT and Relativity | Motion of charged particles in E and B fields

Thomson’s parabola method Positive ray analysis This method is used to find the charge to mass ratio. Thomson parabola method T = Discharge tube, the pressure of gas in this tube is kept 0.01 mm of Hg E = Capillary tube C = Cathode, which is perforated with an extremely small holes W = Water jacket, used to cool the cathode A and B = Metallic plates, the electric field is applied between these plates N and S = North and south poles of a heavy magnet K = Highly evacuated camera P = Photographic plate R = Liquid air trap, used to keep the pressure in K quite low Working To ensure the supply of the gas, a steady steam of the gas is allowed to pass through E and after circulating the tube, it is escaped through M. The positive ion produced in T move towards C. The ion which reaches C axially. pass through its fine hole in the form of narrow beam. After crossing C, the parallel beam of ions enters into the electric and magnetic...
Post a Comment
Read more