Machine Parts

In lap winding it is seen that the coils are connected in series .So that the induced voltages are additive, that is one coil side under north pole is connected by end connections to the coil side under the south pole. This is in turn is connected in series with another coil having a coil side under the same north pole as the previous coil. But in a wave winding coil A has one coil side under the north pole and the other side under the south pole, coil B is connected in series with coil A. Coil B is not located under the same poles as coil A but under the next pair of poles as demonstrated in figure 1. As a sequence coil B and C is under the set of poles.                                   Protecting Coating Shop                                       Why Poppet Valve is Universal used in Automobile sector?                                                                                        What is shaping operation? What are the classifications?

In a series motor the flux depends upon the current in the series field, which is the same current that flows through the armature. At light loads the armature current is small; therefore the flux and torque are small. An increase in the load increases both the armature current and the flux. The basic speed equation                                    S =        Vt   - IaRa   - IaRa           KФ Since the current in the series field is the armature current, the equation may be rewritten substituting Ia for Ф.                                        S =    Vt   - IaRa   - IaRa           KIa With no load connection to the motor the value of I is very small. The numerator of the speed equation is large, while the denominator is very small, indicating that the speed of   the motor   will be extremely large. In fact, the speed of the motor may reach such a value as to cause the centrifugal force to destroy the motor. It is