In Chapter 1, you have read about electromagnet-based DC motors. You have seen various connection methods there such as shunt, series, and separate field. Sep 22, AC commutator motors, like comparable DC motors, have higher starting torque and higher speed than AC induction motors. The series motor operates well. If a d.c. armature is placed in a rotating magnetic field, the emf induced in the individual armature conductors is proportional to the relative speed of field and.
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In Chapter 1, you have read about electromagnet-based DC motors. You have seen various connection methods there such as shunt, series, and separate field. Among these motors, what do you think will happen if AC power is applied to a series motor?
A.c.fommutator that when the motor is rotating in the condition shown in Fig. If the polarity of the electromagnet remains the same as shown in Fig.
AC Commutator Motors
However, with a series motor, the polarity of the electromagnet is also reversed as shown in Fig. So the rotation direction remains unchanged. However, if you apply AC power to a series motor designed to be used with DC power, there occurs a problem. If AC power is applied when cast metal or soft steel is used for the stator core, current is generated due to electromagnetic induction this current is called eddy currentgenerating a large amount of heat.
Therefore, just like with an induction motor, a silicon steel-based insulation lamination structure is employed in the core of a commutator motor that operates on AC.
AC Commutator Motors | AC Motors | Electronics Textbook
However, since these motors are mostly operated on AC in practical use, they are called AC commutator motors. Because of these characteristics, they are used for mtors appliances such as electric vacuum cleaners and tools such as electric drills Fig.
When an electromagnet is used for generating fields, the inductance of the field coil becomes larger than that of the armature. If AC is applied to this field coil, its phase of current is lagged behind that of the armature.
Thus, the magnetic flux density becomes low when the current is conducted to the armature, and when it becomes high, the current to the armature is stopped.
Namely, this motor has a feature of being capable of continuing the rotation with AC power, too. These motors are called universal motors since they are operable both on AC and DC. On the other hand, AC commutator motors have the following disadvantages: Is there a a.c.commutatoe AC commutator motor? A series commutator motor is operable on AC.
Then, is a shunt motor usable with AC?