•  
agra,ahmedabad,ajmer,akola,aligarh,ambala,amravati,amritsar,aurangabad,ayodhya,bangalore,bareilly,bathinda,bhagalpur,bhilai,bhiwani,bhopal,bhubaneswar,bikaner,bilaspur,bokaro,chandigarh,chennai,coimbatore,cuttack,dehradun,delhi ncr,dhanbad,dibrugarh,durgapur,faridabad,ferozpur,gandhinagar,gaya,ghaziabad,goa,gorakhpur,greater noida,gurugram,guwahati,gwalior,haldwani,haridwar,hisar,hyderabad,indore,jabalpur,jaipur,jalandhar,jammu,jamshedpur,jhansi,jodhpur,jorhat,kaithal,kanpur,karimnagar,karnal,kashipur,khammam,kharagpur,kochi,kolhapur,kolkata,kota,kottayam,kozhikode,kurnool,kurukshetra,latur,lucknow,ludhiana,madurai,mangaluru,mathura,meerut,moradabad,mumbai,muzaffarpur,mysore,nagpur,nanded,narnaul,nashik,nellore,noida,palwal,panchkula,panipat,pathankot,patiala,patna,prayagraj,puducherry,pune,raipur,rajahmundry,ranchi,rewa,rewari,rohtak,rudrapur,saharanpur,salem,secunderabad,silchar,siliguri,sirsa,solapur,sri-ganganagar,srinagar,surat,thrissur,tinsukia,tiruchirapalli,tirupati,trivandrum,udaipur,udhampur,ujjain,vadodara,vapi,varanasi,vellore,vijayawada,visakhapatnam,warangal,yamuna-nagar
Types of DC Motor

Types of DC Motor

DC motors are rotary motors that operate on electrical energy. They are primarily used for converting electrical energy into mechanical energy. Most of the DC motors rely on magnetic fields to generate torque inside them. DC motors' most prominent feature is that it contains a mechanism to periodically change the current direction. This is done to maintain the unidirectional nature of current in parts of the motor. Small DC motors find use in many toys, tools and appliances.

DC motors can be differentiated based on the type of windings they use or the operating mechanism they employ. Some common types of DC motors are described below.

Separately excited DC motors.

In these motors, a different electrical source is used to power the field and the armature windings. The most important feature is that the armature current does not flow through the field windings. A separate DC source usually operates field windings. This source is external to the motor itself but acts in accordance with it. The torque of a separately excited DC motor can be changed by changing the field flux. This can be done independently of the armature current.

Permanent magnet DC motor

A permanent magnet DC motor does not have field windings on the stator frame. The magnetic field is instead provided by the magnetic field exerted by the permanent magnet. Windings are used in series with the armature. This is generally used on large motors, and it improves the commutation under the load of the motor.

Since the magnetic field generated by a permanent magnet does not change with time, the field of a permanent magnet DC motor is fixed. Therefore it is not possible to vary or control the speed of this motor. However, these motors are useful in miniature form because they eliminate the power consumption due to field windings. In addition, the motor does not heat up unnecessarily, which also reduces the fire hazard due to overheating.

Series DC motors

The armature and field windings in series DC motors are connected in series with a common DC power source. This means that a common current flows through both armature windings and the field windings. The motor speed of such motors changes non-linearly with load torque and the armature current. This leads to slower speed with a high load, but conversely, it rotates very fast with no load.

The common current in the stator and rotor leads to the motor exhibiting current squared behaviour. The series DC motor has a very high starting torque. That is why it is used to start motors with a very high inertial load. Examples can be trains, elevators and hoists. The properties that the series DC motor has with respect to speed and torque are very useful in dragline excavations.

A series DC motor should never be started with no load. This can lead to overspeeding in the rotor, and as a result, the motor may end up getting damaged. This condition is called the runaway condition.

Shunt DC motors

Shunt DC motors have armature and field windings connected in parallel, which is also called a shunt, with the external DC source. As in series DC motors, the external power source is common to both armature and the field windings. Shunt DC motors give good speed regulation. This is independent of the change in load. This makes them useful in situations where high-speed control is desired, for example, industries where the machines and humans work in close proximity.

Shunt motors do have a very high starting torque. They are, therefore, not suited to be operated in motors with a high inertial load. They are most commonly used in industrial adjustable speed appliances like machine tools, winding and unwinding machines and tensioners.

Compound DC motors

Compound DC motors possess the feature of both series DC motors and parallel DC motors. In the compound, DC motors, the armature windings and the field windings are connected in series and shunt to give the motor high starting torque and good speed regulation. This is very useful in situations where high initial torque and speed regulation are very important. In addition, a compound DC motor gives flexibility in how the user desires to operate the motor in a specific situation.

Compound DC motors have two different arrangements. The first arrangement is called cumulative arrangement. In this arrangement, the series field is connected to help the shunt field. This gives a very high starting torque and speed regulation to a lesser extent. The second arrangement is called the differential arrangement. This arrangement provides good speed regulation and is commonly operated at a constant speed.

Aakashians JEE Topper

Aakashians NEET UG 2023 Champions Again

Historic Results 2023 Aakashians Qualified +1 Lakh

JEE Advanced 2023

JEE Advanced 2023 Stats

JEE Advanced 2022 Topper

NEET Related Links

NEET Exam 2024

NEET 2024 Exam Dates

NEET 2024 Exam pattern

NEET 2024 Syllabus

NEET 2024 Eligibility Criteria

NEET 2024 Application

NEET UG Counselling

NEET FAQ

NEET UG Result

NEET 2024 Cut Off

Neet 2023 Toppers List Names & Rank

Neet Result 2023 Toppers list rank cut off

Neet Answer key Live Download PDF

Neet 2023 State Toppers List

JEE MAIN Related Links

JEE Main 2024

JEE Main Rank Predictor 2024

JEE Main College Predictor 2024

JEE Main 2024 Exam Dates

JEE Main 2024 Exam pattern

JEE Main 2024 Application

JEE Main 2024 Eligibility Criteria

JEE Main 2024 Syllabus

JEE Main 2024 Physics Syllabus

JEE Main 2024 Maths Syllabus

JEE Main 2024 Chemistry Syllabus

JEE Main 2024 Admit Card

JEE Main 2024 Counselling

JEE Main marks vs rank vs percentile

JEE Advanced Result 2023 live topper list

JEE Exam Preparation - How to calculate your rank jee

JEE Maths Syllabus - Important topics and weightage

JEE Advanced Related Links

JEE Advanced 2024 Exam Dates

JEE Advanced 2024 Application

JEE Advanced 2024 Eligibility Criteria

JEE Advanced 2024 Syllabus

JEE Advanced 2024 Maths Syllabus

JEE Advanced 2024 Physics Syllabus

JEE Advanced 2024 Chemistry Syllabus

JEE Advanced Exam Result

JEE Advanced Exam Dates

JEE Advanced Registration Dates

CUET Related Links

CUET 2024 Eligibility Criteria

CUET 2024 Admit Card

CUET 2024 Exam Pattern

CUET 2024 FAQs

CUET 2024 Counselling

CUET 2024 Syllabus

CUET 2024 Result

CUET 2024 Answer Key

CUET 2024 Preparation

CUET CUTOFF

CUET 2024 Application Form

Talk to our expert
Resend OTP Timer =
By submitting up, I agree to receive all the Whatsapp communication on my registered number and Aakash terms and conditions and privacy policy