1. Which DC motor is generally preferred for cranes and hoists? Explanation: DC series motor is used where high starting torque is required, thus in cranes and hoists DC series motor is used widely. Torque-speed characteristics of DC series motor suits perfectly to these applications.
Which motor is preferred for use in Crane?
Synchronous motor. For crane travel, trolley travel and boom hoist of traveling crane requires high starting torque and constant speed in operation. Hence slip ring induction motor is preferred. 07․
Which of the following motor is used in hoist and traction?
Explanation: DC motors are used for traction as, according to the characteristics of DC motors speed is inversely proportional to torque and square of armature current as well, if linear magnetization is concerned. Thus, DC motors are perfectly suitable for traction. 2.
Which motor is suitable for lift?
AC slip ring or DC compound motors are prefer for lifts. Shunt type commutator motors are preferred in case of single phase installation. The latest lift designs use 3-phase induction motors with variable frequency drive electronic controls.
Which DC motor is used for the conveyor?
ElectroCraft’s brush or brushless DC motors and gearmotors provide the power, durability and compact size that is required for distributed control of motorized conveyor sections and diverter systems.
Why is the DC motor preferred over AC motor?
AC motors are generally considered to be more powerful than DC motors because they can generate higher torque by using a more powerful current. However, DC motors are typically more efficient and make better use of their input energy.
Why DC motor is used in crane?
The DC series motor provides high starting torque because the field and armature winding are connected in the series and carry the same current. The starting torque of the DC series motor is proportional to the square of the armature current. … The DC series motor is used in cranes.
Which motor is used in tramways?
The DC motor was the mainstay of electric traction drives on electric and diesel-electric locomotives, street-cars/trams and diesel electric drilling rigs for many years. It consists of two parts, a rotating armature and fixed field windings surrounding the rotating armature mounted around a shaft.
Which motor is used in railway electric traction?
DC motors are used on trains is because of their high torque and good speed control. Compared to AC motors, DC motors can provide industry applications with a fine balance of strong starting torque and controllable speed for seamless yet precise performance.
Why commutator is used in DC machine?
The commutator on the DC generator converts the AC into pulsating DC. … On DC and most AC motors the purpose of the commutator is to insure that the current flowing through the rotor windings is always in the same direction, and the proper coil on the rotor is energized in respect to the field coils.
Which motor is constant speed?
This motor combines a power on activated type clutch and brake with an induction motor. It is ideal for high-frequency starting and stopping. Suitable for applications where the motor is operated starting, stopping and reversing repeatedly and the motor is operated at synchronous speed regardless of load torque.
What is difference between brushless DC motor and brushed DC motor?
What is the Difference Between Brushed and Brushless DC Motors? A brushed DC motor uses a configuration of wound wire coils, the armature, acting as a two-pole electromagnet. … A brushless motor, by contrast, utilizes a permanent magnet as its external rotor.
Which motor is suitable for blower and fan?
Induction motors — or (in the context of blowers in particular) often called by the more playful squirrel-cage motors (to avoid confusion with inducer-blower products). In fact, these motors are the most common used in blowers today, as they excel in high-horsepower blower and cooling-fan applications.
What are the 3 types of DC motors?
Main Types of DC Motors
- Permanent Magnet DC Motors. The permanent magnet motor uses a permanent magnet to create field flux. …
- Series DC Motors. In a series DC motor, the field is wound with a few turns of a large wire carrying the full armature current. …
- Shunt DC Motors. …
- Compound DC Motors.
Where is dc series motor used?
⇒ DC series motors are used where high starting torque required. These motors are only used where the variation of speed is possible. series motors are not suitable for constant speed applications. ⇒ DC series motor is used in a vacuum cleaner, traction systems, sewing machines, cranes, air compressors etc.
What will happen if the back EMF of a DC motor vanishes suddenly?
Explanation: If back emf vanishes suddenly, motor circuit will try to retain back emf by drawing more current from supply. … So, with the increase in speed, the back emf also increases. Therefore, armature current is also decreased, in case of series motor, armature current is equal to the line or load current.