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.
importance of electromechanical energy conversion and device in electrical engineering
Connect the 2 kHz (sin ωt) signal to input A of the "Adder" module Connect input B to ground (GND). Connect the outputof the"Adder"(GA+gB) to input A-CH1 of "Scope Selector".
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
bias compensation using diode and thermistor
Q. Illustrate Inductance with example? An ideal inductor is also an energy-storage circuit element (with no loss associated with it) like a capacitor, but representing the magn
What is XMS? XMS: The memory system is splits in three major parts as: system area, XMS (extended memory system) and TPA (transient program area). The kind of microprocessor in
Role of Consumers in Distribution Reform In the reforms procedure, mandatory metering for all consumers is being implemented. Consumers should implement this measure. Public
circuit used in window air conditioning
charactersticks of pn junction
1) Assume that we are given the continuous-time signal xa (t) = xa1 (t) + xa2 (t) + xa3 (t), where, xa1 (t) = 2 + cos3 (2pf1 t + p 3 ) + 2 cos(2pf2 t), xa2 (t) = 2 cos(2pf3 t)
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