Explain commutator action in dc machine, Electrical Engineering

Assignment Help:

Q. Explain Commutator Action in dc machine?

As a consequence of the arrangement of the commutator and brushes, the currents in all conductors under the north pole are in one direction and the currents in all conductors under the south pole are in the opposite direction. Thus, the magnetic field of the armature currents is stationary in space in spite of the rotation of the armature.

1899_Explain Commutator Action in dc machine.png

The process of reversal of currents in the coil is known as commutation. The current changes from +I to -I in time Δ t . Ideally, the current in the coils being commutated should reverse linearly with time, as shown in Figure. Serious departure from linear commutation results in sparking at the brushes. Means for achieving sparkless commutation are touched upon later. As shown in Figure, with linear commutation, the waveform of the current in any coil as a function of time is trapezoidal.


Related Discussions:- Explain commutator action in dc machine

Explain the function of the pins psen and ea of 8051, Explain the function ...

Explain the function of the pins PSEN and EA of 8051. PSEN: PSEN stands for program store enable. In 8051 based system in which an external ROM holds the program code, this pin

Meters and measurements, The subject of electrical measurements is such a l...

The subject of electrical measurements is such a large one that entire books have been written on the topic. Only a few basic principles will be introduced here. Practical measurem

Find how long the bulb can be lighted, Q A12-V, 115-Ah automobile storage b...

Q A12-V, 115-Ah automobile storage battery is used to light a 6-W bulb. Assuming the battery to be a constant-voltage source, find how long the bulb can be lighted before the batte

What do you mean by companding, Q. What do you mean by Companding? In o...

Q. What do you mean by Companding? In order to lower the crest factor of a waveform, so as to produce better performance, a process known as companding is used. It works like a

Compute the average number of open links, A zipper has N links every link h...

A zipper has N links every link has a state in which it is closed with energy 0 and a state in which it is open with energy 0 We require that the zipper only unzip from one side (s

Binary to hexadecimal conversion, Binary  to Hexadecimal  Conversion ...

Binary  to Hexadecimal  Conversion To convert a binary  number  into  hexadecimal  divide the number into group  of four  bits  each starting from the least significant bit. Th

Bjt amplifiers, Explain the working of BJT Amplifiers? The purpose of e...

Explain the working of BJT Amplifiers? The purpose of electronic amplifiers is essentially to increase the amplitude and power of a signal so that either useful work is done or

Singular value decomposition, Singular Value Decomposition (i) initial...

Singular Value Decomposition (i) initialize a 2x2 matrix m=[4 0.5;0.5 7]  Factorize the matrix with SVD [u d v]=svd(m) How the matrix u and v differ? Why is that?

Define capacitor construction, Define Capacitor Construction In its mo...

Define Capacitor Construction In its most elementary state a capacitor having of two metal plates separated by a certain distance d, in among the plates lies a dielectric mate

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