Motors were developed a long time ago and have been a blessing to people due to the convenience with which they can convert mechanical energy to electronic energy. It is therefore necessary to understand what Is a DC Motor and what principles it works on. In this article, we will also study the advantages and disadvantages of DC motors.
We will discuss the applications of DC Motor in detail and later conclude the article by discussing some future trends of DC Motor. Readers are advised to go through the frequently asked questions in case of any doubts.
What is DC Motor?
The most basic definition of a DC motor is an electrical device, which operates on direct current. It is used for converting any form of energy main; mainly electrical energy into mechanical energy. This energy conversion is achieved by placing a current-carrying conductor in the magnetic field generated in the motor and causing the conductor to rotate.
The motor can be categorized into different types. Let us look at the principle on which the motor operates.
Working Principle of DC Motor
Take a look at the diagram of a DC motor to understand the working principle of this motor.
DC motor works on "Faraday's law of electromagnetic induction" which states that a current-carrying conductor placed in a magnetic field will experience a force. Let us understand it.
The North-South magnetic poles of the DC motor create a magnetic field inside the motor. Due to the power supplied to the motor, certain direct current flows into the coil. This situation can be described as in Faraday's law. A current-carrying wire which behaves as a conductor is placed in the magnetic field of the motor poles.
Since the magnetic field above the conductor is different from the magnetic field below the conductor, a flux is developed across the conductor. The difference in flux density between the top and bottom of the conductor will generate a torque and cause the wire to rotate at a certain speed.
This is how the electrical energy provided to the motor is converted into mechanical energy by the rotation of the current-carrying conductor.
Applications of DC Motor
Let us stodgy some applications of DC Motor
DC Motor is an Industry
DC motors usually have a high power output which can be used for driving various equipment, especially in industries. Therefore, DC motors are used in industries for converting one form of energy to another. The magnetic field generated in the motor is used for exerting force on the conductor generating enough torque to cause its mechanical rotation. This principle is applied to using machine tools, industry, and elevators. In an elevator, the motor drives the cable that holds the cable.
DC Series Motor for Carrying a Load
Cranes are known for carrying heavy weight at construction sites and some petroleum refineries where heavy material needs to be shifted from one place to another. The cranes that carry this load are powered by motors that give them the ability to hold a full load at zero and stop to apply brakes when needed. The small size of the DC motor makes it the best choice since it can be easily installed in cranes without adding much weight. DC motors can also be used in lifts for the same reason they are used in cranes.
Shunt DC Motors in Centrifugal Machines
DC motor is a specific type of motor with parallel windings that have the same voltage across them. The important characteristic of these motors is that they provide a constant speed i.e. high speed regulation with a high initial torque. Due to this, the DC motors are employed in centrifuge machines that need a constant torque that can be increased or decreased manually. This includes machines like Centrifugal Pumps, Lifts, Weaving Machines, Lathe Machines, Blowers, Fans, Conveyors, and Spinning Machines.
DC Motor in Computer Peripherals
The brushless DC motor is characterized by the absence of brushes and efficient energy conversion. This motor is capable of achieving high speed with full efficiency. The motor is used in various computer peripherals like disks, drives, and printers. This is because these devices need special speed control with discrete angular increments in order to ensure the proper working of these devices. The brushless DC motor is able to achieve this so that it can read/write head assembly across the spinning disks for reading and writing.
DC Motor in Automobiles
DC motor is used in a vast number of automobiles and even aircraft. The cars or other automobiles that operate on batteries, supply the necessary electrical energy to the motor which is then converted to mechanical energy due to the rotor rotation in the DC motor. the simple structure of these motors and efficient controls make them a good choice for retracting, and positioning the vehicles. They can also be used for controlling the side windows by operating them using the motor controls.
Difference Between AC and DC Motors
Let us study the difference between AC and DC motors.
Parameter | DC Motor | AC Motor |
|---|---|---|
Nature of Current | Direct current is the input current. | The alternating current is the input current. |
Commutation | Present | Absent |
Input terminals | There are two input terminals(positive and negative) | Three input terminals. |
Carbon Brushes | Carbon brushes are present. | Carbon brushes are absent. |
Applications | Used for daily life small applications. | Used for industrial applications like energy conversion. |
Advantages of DC Motor
Let us study some advantages of DC Motor
- DC motor Is easier to install than AC motor and requires less maintenance.
- The initial torque generated when the DC motor starts is very high, giving the motor a high Start-up power for operation.
- The response time of the DC Motor Is quite low. This means the DC motor reacts very quickly when turned on, turned off, or accelerated.
- Since the DC motors operate at 0 frequency with DC Current, they have no harmonic effects that are seen in the case of AC motors.
- DC motors have fewer components than AC motors therefore they are cheaper and cost-effective making them a preferred choice.
Disadvantages of DC Motor
Let us study some disadvantages of DC Motor.
- Due to the huge setup, the initial cost of setting up a DC motor is quite high, adding to the total installation cost.
- The presence of brushes in the motor can serve as a potential threat due to the sparking and potential of burnt windings mainly due to high current.
- The efficiency of DC motors is less compared to AC motors when high power is needed. This is because of brushes present in motors that can't operate at high voltage.
- The brush life of brushes installed in a DC motor is very low which means that frequent maintenance of these brushes is needed.
- In a brushless motor, cogging is an undesirable phenomenon that results in unnecessary noises and vibrations in the DC motor.
Future Trends of DC Motor
Although the current design of DC motors allows you to fulfill many tasks there still is a scope of development in the design of DC Motor. It is expected that in the near future, the new designs will emphasize minimizing the energy loss during the conversion.
In addition to this, automation tools along with IOT and AI can be used to enhance the already available motor controls in the DC motor. Lastly, the motor should be designed in a way that it is durable and requires minimum maintenance once installed.
Conclusion
We have seen how the DC motor Is an appliance of great use. The ability of the motor to perform tasks efficiently makes it an integral component of different energy conversion circuits. It is used in. We have also drawn a comparison between AC and DC motors to understand the properties of DC motors.
Despite the advantages offered, there are certain limitations in the design of the DC motor which can be overcome as the technology advances. This has been discussed in future trends of DC Motors.
