The document compares the working of a brushless DC (BLDC) motor and an ordinary DC motor. Both motors work on the principle of Lorentz's law, which states that a current-carrying conductor in a magnetic field experiences a force. The BLDC motor has a stator, rotor, magnets, and Hall sensors instead of brushes. It has advantages like higher efficiency, power density, and lower noise. The ordinary DC motor uses brushes to conduct current and has advantages like lower cost and ability to be rebuilt.

1. PROJECT REPORT
ELECTROMECHANICAL SYSTEM II
Project title:
Comparison Between The Working Of BLDC
Motor And Ordinary DC Motor
Submitted To:
Sir kashif Iqbal
Submitted By:
Hasaan Ali (UW-18-EE-BSc-028)
Osama Bin Javed (UW-18-EE-BSc-002)
ELECTRICAL DEPARTMENT
WAH ENGINEERING COLLEGE
UNIVERSITY OF WAH
WAH CANTT

2. Page | 2
Contents :
• Introduction
• Construction component
• Construction
• Working principle
• Working
• Flemings Left Hand Rule
• Advantage
• Conclusion
Introduction :
Bldc Motor :
A motorconvertssuppliedelectricalenergyintomechanical energy.Varioustypesof motorsare in
commonuse.Amongthese,brushlessDCmotors(BLDC) feature highefficiencyandexcellent
controllability,andare widelyusedinmanyapplications.The BLDC motorhas power-saving
advantagesrelative toothermotortypes.
Ordinary Dc Motor :
A DC motor isany of a classof rotary electrical motorsthatconvertsdirectcurrentelectrical energy
intomechanical energy.The mostcommontypesrelyonthe forcesproducedbymagneticfields.
Construction Components :
BLDC motor:
• Stator
• Rotor
• Magnet
• Electromagnet
• Senior

3. Page | 3
Ordinary DC motor:
• Stator
• Rotor
• Magnet
• Electromagnet
• Brushes
Construction :
• BLDC Motor
• Ordinary Motor
Working Principle :

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BLDC Motor:
• It works on the principle of Lorentz Law state:
“The current carrying conductor placed in a
magnetic and electric field experience a force”.
Ordinary Motor:
• It works on the principle of Lorentz Law state:
“The current carrying conductor placed in a
magnetic and electric field experience a force”.
Working :
• When the DC supply is given to the armature coil through the
brushes current starts flowing through it and the coil start the
rotation around the magnet.
• The very basic construction of a DC motor contains a current
carrying armature, connected to the supply end through
commutator segments and brushes. The armature is placed in
between north pole and south pole of a permanent or an
electromagnet as shown in the diagram above.
• As soon as we supply direct current in the armature, a
mechanical force acts on it due to the electromagnetic effect of
the magnet on armature conductors. Now to go into the details
of the operating principle of DC motor it is important that we
have a clear understanding of Fleming’s left-hand rule to
determine the direction of the force acting on the armature
conductors of DC motor.
Fleming’s left-hand rule :

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If a current carrying conductor is placed in a magnetic field
perpendicularly, then the conductor experiences a force in the
direction mutually perpendicular to both the direction of field and the
current carrying conductor. Fleming’s Left-Hand Rule can determine
the direction of rotation of the motor. This rule says if we extend the
index finger, middle finger and thumb of our left-hand perpendicular
to each is such a way that middle finger is in the direction of current
in the conductor, and index finger is along the direction of magnetic
field, i.e., north to south pole, then thumb indicates the direction of
the created mechanical force.
Hall Sensor :
In brushless DC (BLDC) motors effect Hall sensors, are used in place
of a mechanical commutator and brushes. Hall effect sensors are
solid-state, magnetic field sensors. ... Therefore, in order to keep the
motor turning, the stator's magnetic field should change position as
the rotor field “catches up” with it.

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Advantages :
BLDC Motor:
● Less overall maintenance due to lack of brushes.
● Operates effectively at all speeds with rated load.
● High efficiency and high output power to size ratio.
● Reduced size with far superior thermal characteristics.
● Higher speed range and lower electric noise generation.
Ordinary Motor:
● Low overall construction costs.
● Can often be rebuilt to extend life.
● Simple and inexpensive controller.
● Controller not needed for fixed speed.
Conclusion :
Today, the brushless motor is far more common than the brushed
motor. But both can be found in a wide range of applications.
• Brushed DC motors are still used frequently in household
appliances and in automobiles.
• BLDC use in the computers and in many manufacturing.