Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
In the conventional dc machine (with a closed continuous commutator winding on its armature), for example, full-wave rectification of the alternating voltage induced in individual armature coils is achieved by means of a commutator, which makes a unidirectional voltage available to the external circuit through the stationary carbon brushes held against the commutator surface.The armaturewindings of dcmachines are located on the rotor because of this necessity for commutation and are of the closed continuous type, known as lap and wavewindings. The simplex lap winding has as many parallel paths as there are poles, whereas the simplex wave winding always has two parallel paths. The winding connected to the commutator, called the commutator winding, can be viewed as a pseudostationary winding because it produces a stationary flux when carrying a direct current, as a stationarywindingwould. The direction of the flux axis is determined by the position of the brushes. In a conventional dc machine, in fact, the flux axis corresponds to the brush axis (the line joining the two brushes). The brushes are located so that commutation (i.e., reversal of current in the commutated coil) occurs when the coil sides are in the neutral zone, midway between the field poles. The axis of the armature mmf is then in the quadrature axis, whereas the stator mmf acts in the field (or direct) axis. Figure shows schematic representations of a dc machine. The commutator is thus a device for changing the connections between a rotating closed winding and an external circuit at the instants when the individual coil-generated voltages reverse. In a dc machine, then, this arrangement enables a constant and unidirectional output voltage. The armature mmf axis is fixed in space because of the switching action of the commutator (even though the closed armature winding on the rotor is rotating), so the commutator winding becomes pseudostationary.
Q. Define Transconductance? The control that the gate voltage has over the drain current is measured by the transconductance gfs and is similar to the transconductance gm of t
Explain how materials can be classified into three groups on the basis of atomic structure. An atom has a positively charged nucleus surrounded through a group of negatively ch
Determine the Disadvantages of expert systems - Lacks common sense in some decision making processes - Errors in the knowledge base can result in incorrect decisions being
Q. (a) Draw the logic diagram of the enabled D latch using only NAND gates. (b) Complete the timing diagram of Figure (a) of theDlatchwhose block diagram and truth table are giv
Q. Explain about Transistor Amplifiers? Amplifiers are circuits that produce an output signal which is larger than, but proportional to, an input signal. The input and output s
whatis motor protection
Gaussian derivatives Generate Gaussian kernels for a given scale "sigma", and display the kernel. The size of the kernel should be floor(3*sigm)+1; (i) Write an m-file "
Calculate the cross-sectional area, in mm 2 , of a piece of aluminium wire 100 m long and having a resistance of 2Ω. Take the resistivity of aluminium as 0.03 x 10-6 Ωm.
The programming Model of 8085 Microprocessor The programming model of 8085 microprocessor is shown in figure below in this model various 8 bit and 16 bit registers a
Explain Nodal analysis (supernode)
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd