Explain about direct-current machines, Electrical Engineering

Assignment Help:

Q. Explain about Direct-current machines?

Generally speaking, conventional dc generators are becoming obsolete and increasingly often are being replaced by solid-state rectifiers in most applications for which an ac supply is available. The same is not true for dc motors. The torque-speed characteristics of dc motors are what makes them extremely valuable in many industrial applications. The significant features of the dc drives include adjustable motor speed over wide ranges, constant mechanical power output or torque, rapid acceleration or deceleration, and responsiveness to feedback signals.

The dc commutator machines are built in a wide range of sizes, from small control devices with a 1-W power rating up to the enormous motors of 10,000 hp or more used in rolling-mill applications. The dcmachines today are principally applied as industrial drivemotors, particularly when high degrees of flexibility in controlling speed and torque are required. Such motors are used in steel and aluminumrollingmills, tractionmotors, overhead cranes, forklift trucks, electric trains, and golf carts.Commutatormachines are also used in portable tools supplied frombatteries, in automobiles as starter motors, in blower motors, and in control applications as actuators and speed-sensing or position-sensing devices.


Related Discussions:- Explain about direct-current machines

What effect do non-tradable goods have on ppp, Q. What effect do non-tradab...

Q. What effect do non-tradable goods have on PPP? Answer: The consequence is quite substantial. In 1997 the production of non-tradable goods accounted for about 55% of U.S GN

Wiring a plug , Wiring a Plug : Let us consider the problem of connect...

Wiring a Plug : Let us consider the problem of connecting a 16 A plug, commonly known as 15 A or power plug to an electrical appliance. Do you use any old bit of wire, or any

Explain how to represent power lines, Explain How to Represent Power Lines?...

Explain How to Represent Power Lines? The equivalent circuit of a power line depends on the length of the line and on the accuracy of the model required. In general, any power

Illustrate about crossbar exchange, Q. Explain crossbar exchange, with all ...

Q. Explain crossbar exchange, with all call processing steps and diagrams. Ans: The basic concept of crossbar switching is to provide a matrix of n x m sets of contacts with

What is meant by blanking, a. Explain the following terms: (6) (i) Persi...

a. Explain the following terms: (6) (i) Persistence of vision (ii) Flicker in motion pictures b. What is meant by blanking? What is the need of blanking pulses? Compare th

Find the effective noise temperature, Q. An antenna with an effective noise...

Q. An antenna with an effective noise temperature of 130 K couples through a waveguide that has a loss of 0.8 dB to a receiver. Find the effective noise temperature presented by th

Clipper, merits amd demerits of series and shunt clipper

merits amd demerits of series and shunt clipper

Sequential diagram, 1) Draw the state diagram for the state machine describ...

1) Draw the state diagram for the state machine described by Table 7.5 in the text. Note, the table shows the transition to the next state S* from the current state S for the next

Minimized circuit not -or and gate, 1.  Given S(D1) = !Q1 X + !Q1 Q0 + Q1 !...

1.  Given S(D1) = !Q1 X + !Q1 Q0 + Q1 !Q0 !X                                                        and       S(D0) = !Q1 !Q0 !X + Q0 X + Q1 !Q0 !X       A.  DRAW A MINIMI

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd