Basic construction and characteristics of thyristor, semiconductor controlled device scr, characteristics and two transistor model of scr. Explain the construction and characteristics of emosfet. Write equivalent circuit of ujt and show that vpeak vemitter v. Explain the switching characteristic of pn junction diode. The construction technology program provides learners the opportunity to acquire fundamental knowledge and skills in preparation for a career in building construction and associated businesses. Heres a look at how crews from across the nation are working to restore our national historic landmark. Ujt is an excellent switch with switching times in the order of nano seconds. Unijunction transistor ujt construction, working, characteristics.
A pulse transformer can operate correctly only when the magnetic saturation is avoided. Scr as a half wave and full wave rectifier application of scr, ujt equivalent circuit of. To rotate a stamp, click it, move the pointer over the handle at the top of the stamp, and drag when the rotate stamp icon appears. Maharashtra state board of technical education autonomous isoiec 27001 2005 certified summer14 examination subject code. Paperless document control for primavera and sharepoint for engineering and construction. The structure of a ujt is similar to that of an nchannel jfet, but ptype. The universal motor is a rotating electric machine designed to operate either from. This is the threshold value of ve that puts the ujt into conduction. Ujt is a threeterminal, singlejunction, twolayered device, and it is similar to a thyristor compare to a transistors. The direction of the arrow always points from the positive p. The 2n2646 model is the most commonly used version of the ujt. Once ve reaches a peak value vp the ujt begins to conduct. Ujt relaxation oscillator is a type of rc resistorcapacitor oscillator where the active element is a ujt unijunction transistor.
Explain the working of ac operated time delay relay using scr with circuit 6x2 diagram. Ec6401 electronic circuitsii previous year question papers. Ec6401 electronic circuitsii previous year question. This application is important for large ac current control. If youd like to receive email updates or want more information about the repair and restoration of union terminal, visit. Download ec6401 electronics circuits ii ec ii books lecture notes syllabus part a 2 marks with answers ec6401 electronics circuits ii ec ii important part b 16 marks questions, pdf books, question bank with answers key, ec6401. In the previous post we have seen how does a 3 point starter works. The ujt is consist of a light doped ntype of silicon bar, there is a heavily doped ptype of region at one side of the ntype of bar. Maharashtra state board of technical education autonomous. An operating system os is a powerful program that manages and controls the software and hardware on a computing device so as to make the device behave in a predictable but flexible way. The unijunction transistor was one of the most attractive, simple and versatile. Here the no volt coil and field are not connected in series as in 3 point starter but the nvc is connected to the supply independently through a point called n which can be seen clearly in the below figure.
Explain the construction and characteristics of jfet. Ec6401 electronic circuitsii previous year question papers february 21, 2018 may 24, 2019 syed afrith b. D draw circuit diagram of single stage ce amplifier with input and output waveforms. Introduction to unijunction transistor construction and. Structure and operation, characteristics, spectral response and applications of ldr, photo voltaic cell, photo diode, photo transistor.
Junction field effect transistor jfet the single channel junction fieldeffect transistor jfet is probably the simplest transistor available. September 2016 history and technology are coming together to restore an icon as art conservators and historic preservation architects work alongside masonry workers and welders. Jfet construction, working and iv characteristics output and transfer, expression for pinch off voltage numerical. Breakdown devices 2391 c intrinsic standoff ratioas seen from fig. Explain the performance and working operation of singlephase full controlled rectifier with relevant waveforms for resistive load, inductive load. Embedded system characteristics, types, advantages. Jay inslees construction working group recommendations 4232020. Paper ii semesteri transducers and network theorems. Explain the construction and characteristics of dmosfet. It is seen that only terminals e and b1 are the active terminals whereas b2 is the bias terminal i. The six applications of scr like power control, switching, zero voltage.
How the malatide operation of scr can be prevented. The basic construction of a 4layer diode and its schematic symbol are shown the 4layer diode has two leads, labeled the anode a and the cathode k. With the help of suitable diagram, explain the working of enhancement mosfet btl 3 applying 2. Paper ii semesteri transducers and network theorems unit i concept of transducer needs of transducers, definition of active and passive transducer, and classification of transducer. Circuit diagram for common base configuration 2m circuit diagram,2m output characteristics.
Among these three transistors, this article talks about ujt transistors working features and its construction in brief. Estimate the performance of bjt and ujt on the basis of their operation and working. To resize a stamp, click it, and then drag a corner handle. University important questions 16 mark questions unit i 1. Analyze various transistor configurations and asses merits and demerits for different applications. Explain the working and principle of operation of ujt and mention its applications.
Principles involving new construction, remodeling, renovation and repair work for residential and nonresidential construction are presented. Model curriculum national skill development corporation. Pnp, which basically describes the physical arrangement of. Double break single break spdt double break single break dpst, 2 n. At the point where ve vp, the current ie is at minimum. Ujt construction, working, equivalent circuit and iv characteristics numerical. University important questions 16 mark questions unit i. Elaborate the construction and operation of npn transistor with neat sketch. Nasar, schaums outline series, tata mcgraw hill 2004. Generally, ujt is triggered into conduction by applying a suitable positive pulse at its emitter. It has a negative resistance region in the characteristics and can be easily employed in relaxation oscillators. Ujt, n base e b2 b1 ujt, p base e b2 b1 gate turnof thyristor g a k standard elementary diagram symbols.
Pdf silicon strain sensitive unijunction transistor with controlling p. Unijunction transistor table 1 standard elementary diagram symbols contd battery bell annunciator buzzer horn, alarm, siren,etc. C describe working of ujt relaxation oscillator with circuit and waveforms. The original unijunction transistor, or ujt, is a simple device that is essentially a bar of ntype semiconductor material into which ptype material has been diffused somewhere along its length, fixing the device parameter the intrinsic standoff ratio. Construction, working and iv characteristics of ujt. Rc scr i explain the phase controlling in scr using rc circuit.
Integrated circuits are being used in an everincreasing variety of applications. Ujt characteristic curve a voltage is applied across the ujt vbb and to the emitter input ve. Thus, in general sense, an os is that software which helps a user to run other applications on his. Any existing construction projects complying with the points below may resume only those work activities that do not require workers to be closer than sixfeet.
Pdf theoretical studies of a silicon integral pressure transducer characteristics are made. The ujt as the name implies, is characterized by a single pn junction. For this reason most electronic pulse transformers have a rating voltsecond product given in their data sheets. Wiring diagram book a1 15 b1 b2 16 18 b3 a2 b1 b3 15 supply voltage 16 18 l m h 2 levels b2 l1 f u 1 460 v f u 2 l2 l3 gnd h1 h3 h2 h4 f u 3 x1a f u 4 f u 5 x2a r power on optional x1 x2115 v.
Scr as a half wave and full wave rectifier application of scr, ujt equivalent circuit of a ujt and its characteristics. There are two basic types of bipolar transistor construction, npn. Initially the capacitor charges through r whose voltage is applied to the emitter of ujt. May 24, 2019 ec6401 electronic circuitsii previous year question papers february 21, 2018 may 24, 2019 syed afrith b. Thermister, thermocouple, lvdt and piezoelectric transducer. Construction, operating principles, characteristics 7. Speed control of universal motor using ac voltage controller. In the business receipt template, it provides a list of all construction services provided by the construction workers including the terms of payment and. With a neat diagrams explain the working of a pn junction diode in forward bias and reverse bias and plot the vi characteristics. Construction, working, characteristics and advantages of triac, diac and ujt. Enter your euid and well send you a link to change your password. Navedtra 14027a construction electrician advanced part 6.
Discuss about the effects of temperature on pn junction diodes forward and reverse. Ujt symbol and construction the symbol for unijunction transistor is shown in figure. To delete a stamp, rightclick the stamp and choose delete. A unijunction transistor ujt is a threelead electronic semiconductor device with only one. E electronics and communication engineering, second year 4th semester ec6401 electronic circuitsii previous year question papers for the regulation 20. Passive circuit elements and their equilibrium equation, kirchoffs laws, concepts of independent voltage and current sources, controlled sources. This value indicates what amount of energy can be safely applied to the primary winding before the saturation occurs. Phase 1 construction restart covid19 job site requirements. Electromagnetic and static relays, over current relay, impedance relay, directional relay 7. Derive the expression for frequency of triggering and firing angle delay in terms of eta, charging resistance etc. Jfet construction, working and iv characteristics output and transfer,expression for pinch off voltage no derivation. Describe the construction and working of ujt with its equivalent circuit and vi characteristics. The emitter leg is drawn at an angle to the vertical line representing the ntype material slab and the arrowhead points in the direction of conventional current when the device is forwardbiased, active or in the conducting state.
There is only one difference in construction between 3 point starter and four point starter. Scr explain the principle, construction, working and characteristic curves of scr. Ujt relaxation oscillator, circuit diagram, ujt theory and. The operation of the sscujt is best described in terms of. Ujt construction, working, equivalent circuit and iv characteristics ujt relaxation oscillator 15 lectures reference books. Comparison jfet construction, working and characteristics, parameters. Construction and working of mosfet depletion and enhancement, advantages and disadvantages of mosfet construction, working and characteristics of scr, scr as a switch. May 25, 2011 maintain record of incoming documents. This post will give you a detailed idea about ujt, its basic construction, symbol, how it works, its characteristics curve, various applications, advantages and. An os acts an interface between a user and a device.
564 1175 529 1473 454 693 1311 404 751 811 950 257 804 1148 190 807 34 633 648 1249 355 123 396 102 841 1644 1296 1476 523 138 1295 894 1273 282 614 1292 717 168 418 1361 1018 958 574 168 563