Dc motors are widely used in

Permanent magnet (PM) motors are probably the most commonly used DC motors , but there are also some other type of DC motors (types which use coils to make the permanent magnetic field also). However, speed varies widely between no load and full load. Movement of the magnetic field is achieved by switching current . DC motors were first developed in the early 19th century and continue to be used today. The DC Motors speed can be controlled by varying the .

Shunt and separately excited DC motors.

Mostly every power supply, PC, UPS, motor car and embedded controller uses small PM DC motors (separately excited ) for fans.

At this low power level separately excited DC machines are predominant. One may even classify speakers in sound systems as being . Through the VF Drive, AC motors speed can be regulated eve. Gear-train reductions are typically needed to reduce the speed and increase the torque output of the motor.

DC motors are used in applications that the connected load has to have its speed controlled.

There are four kinds of DC motors commonly used in industrial applications: shunt, series, compound wound or stabilized shunt, and permanent magnet. The reason is that the velocity of series motors varies greatly with varying load. The shunt DC motor is commonly used because of its best speed regulation.

To obtain comparable low-speed performance from an AC motor, much more expensive AC-inverter duty motors and VFDs must be used. Many common small brushed DC motors used in toys and small . A motor is an actuator, converting electrical energy in to rotational mechanical energy. Motor requiring DC supply for operation is termed as DC motor.

This self-regulating feature makes it widely used in industrial constant-speed applications.

AC to DC motor ,it can rotate slow with in reverse direction but dc shut motor stand still. INduction motor is more commonly used for small applications as. These type of motors are brush type DC motors. Brush type motors are cheaper than brushless motors and they are more commonly used.

During the last 1years high power DC brushed motors , once the mainstay of industry, were replaced by alternating current (AC) synchronous motors.

These 6mm pecision gear motors are widely used in electronic rotating mascaras , robotic mechanisms, medical equipments, etc. The gearbox is made of plastic material, RoHS compliant. Although various types of motors are available, all of them are not suitable.

Limitations of ac syn- chronous motors and brushes and commutators of conventional dc motors are given.

Brushless dc motors and stepper motors, which are widely used , are discussed in detail. Problems of conventional lubrication andbearings . The brushless dc motors are widely used in the servo motor application because of their different advantages over conventional DC motors. Nowadays stability and accuracy are required for the automatic control system.

This is why DC motors with wound stators are more commonly used for industrial applications.

With good characteristics and performance, the separately or shunt excited DC motor is widely used in the laboratory and on the precision machine tool in factory. For better application , this paper first analyses the mechanical characteristics of the separately or shunt exited DC motor , and theirs difference was drawn by . For better application, this paper first analyses the mechanical characteristics of the separately or shunt exited DC motor , and theirs difference was drawn by . Principle of electric braking – qualitative explanation. Although in this section we shall mainly discuss shunt motor , however, a brief descriptions of (i).

C shunt, (ii) separately excited and (iii) series motor widely used are given at the beginning.