Different types of motors and their use. When purchasing a motor, it's often asked which technology is better, AC or DC, but the fact is that it is. Let's see the basics of each type as well as their advantages and disadvantages. Permanent Magnet Motors. Permanent Magnet Motor. The permanent magnet motor uses a magnet to supply field flux. Series Motors. Series DC motor. Shunt Motors. DC Shunt Motor. Compound Motors. Compound DC motor. There are three types of electrical connections between the stator and rotor possible for DC electric motors: series, shunt/parallel and compound (various blends of series and shunt/parallel) and each has unique speed/torque characteristics appropriate for different loading torque profiles/signatures.


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Speed characteristics of compound DC motors. Figure 5 shows the speed vs.

Types of DC Motor Separately Excited Shunt Series Compound DC Motor

The dashed curve has a heavy series field and exhibits poorer speed regulation while the solid curve has a weaker series field and acts more like different types of dc motors shunt motor.

Figure 6 shows the torque vs. As we have seen, the torque-current characteristic is linear for a shunt motor and parabolic for the series motor.

Comparison of torque characteristics for series, shunt, and compound DC motors. Figure 7 shows the connections for cumulative compounding of both long- and short-shunt motors.

Current is entering the motor and must enter both field windings at terminal 1 for the two field windings to produce flux in the same direction.

What are the types of DC Motors? - Quora

Thus, the series winding has been reversed from what it was for generator operation. Cumulative-compound machines will have positive speed regulation; i.

Figure 8 shows the torque-speed characteristics of three compound machines.


The solid curve droops slightly, corresponding to a light series winding, while the dashed curve droops much more, corresponding to a heavy series winding.

The third curve, shown dotted, is one possibility which might arise in a differentially compounded motor.

DC motor - Wikipedia

Different types of dc motors torque-speed characteristics of compound motors. Differentially Compounded DC Motors This connection is almost never used deliberately, but occasionally motors are connected this way by accident.

Speed Regulation of Differentially Compounded DC Motor However, the differential connection can provide excellent speed regulation, because applying load causes a drop in speed which means the C-EMF drops.

For brushes intended to carry more than an ampere or two, a flying lead will be molded into the brush and connected to different types of dc motors motor terminals. Very small brushes may rely on sliding contact with a metal brush holder to carry current into the brush, or may rely on a contact spring pressing on the end of the brush.

4 Types of DC Motors and Their Characteristics

The brushes in very small, short-lived motors, such as are used in toys, may be made of a folded strip of metal that contacts the commutator. Brushless DC electric motor and Switched reluctance motor Typical brushless DC motors use one or more permanent magnets in the rotor and electromagnets on the motor housing for the stator.

A motor controller converts DC to AC. This design is mechanically simpler than that of brushed motors because it eliminates the complication of transferring power from outside the motor to the spinning rotor.

The motor controller can sense the rotor's position via Hall effect sensors or similar devices and can different types of dc motors control the timing, phase, etc. Advantages of brushless motors include long life span, little or no maintenance, and high efficiency.

Disadvantages different types of dc motors high initial cost, and more complicated motor speed controllers. Some such brushless motors are sometimes referred to as "synchronous motors" although they have no external power supply to be synchronized with, as would be the case with normal AC synchronous motors.

Uncommutated[ edit ] Other types of DC motors require no commutation. Homopolar motor — A homopolar motor has a magnetic field along the axis of rotation and an electric current that at some point is not parallel to the magnetic field.

The name homopolar refers to the absence of polarity change. Homopolar motors necessarily have a single-turn coil, which limits them to very low voltages.

This has restricted the practical application of this type different types of dc motors motor. Ball bearing motor — A ball bearing motor is an unusual electric motor that consists different types of dc motors two ball bearing -type bearings, with the inner races mounted on a common conductive shaft, and the outer races connected to a high current, low voltage power supply.

An alternative construction fits the outer races inside a metal tube, while the inner races are mounted on a shaft with a non-conductive section e.

The net flux produced in this case is lesser than the original flux and hence does not find much of a practical application.


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