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.
examples in building electric helicopter using cardboard, balsa wood, scotch tape, glue, binder clips, rubber bands, rubber stoppers, etc. attached to a 12v power supply
Q What do you mean by Direct coupling? In this method the a.c. output signal is fed directly to the next stage. No reactance is included in this coupling network. Special d.c.
Q. Show Typical performance parameters for voltage regulators ? Typical performance parameters for voltage regulators are · Line regualtion · Load regulation · Tempara
# asmD CHART #
I need some help for doing the assignment
Output Characteristics The output or drain characteristic of N - Channel power MOSFET. When gate is made positive with respect to the source an N type channel is formed
Responsibilities of Regulatory Body The basic responsibilities of the Central Regulatory Commission are to: Fix tariff of Central Sector producing plants as well as of
merits amd demerits of series and shunt clipper
Antenna Fundamentals We shall discuss here only the fundamental concepts needed to understand the role of an antenna as a power-coupling element of a system. Figure illustrates
(i) Sketch a fully-labelled electro-pneumatic circuit showing your actuators in the START position and employ metered out speed control with mono-stable 5/2 DCV's having solenoid a
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