# Direct Current (Dc) Motors . Student’S Name. University.

1027 WordsApr 18, 20175 Pages
Direct Current (DC) Motors Student’s Name University Course Code Date of Submission Direct Current (DC) Motors 1.0 Overview of DC Motors A Direct Current (DC) motor is a broad classification of electric motors that operate from a direct current (DC). Nearly all mechanical devices used in electric applications are powered by electric motors. Motors transform electrical energy to mechanical energy. Thus, they are essential for energy conversion in electrical machines. All types of electrical motors comprise a stationary field commonly referred to as stator, and a rotating field (or rotor). According to Krishnan, (2010), the mechanism of operation of DC motors is based on the interaction between electric current and the…show more content…
Rizzoni (2004) asserts that when electrical energy is supplied to the windings perpendicular to the direction of the magnetic field, the flowing current and the magnetic field will interact. As a result, mechanical energy will be produced by the magnetic field, leading to motion. Fleming’s Left Hand Rule can be used to determine the direction of the motion Figure 1: Fleming’s Left Hand Rule (Rizzoni, 2004) The direction of both the magnetic field and the current are pointed by the first and second fingers respectively. The thumb indicates the direction in which the conductor is pushed by effects of the magnetic field (Rizzoni, 2004). 1.3 Operation Principles of a DC Motor In order to demonstrate the operating principles of a DC motor, this paper will focus on a coil subjected to a magnetic field with a flux density of B (Hambley et al., 2008). When a D.C voltage is supplied to the coil, it induces current to flow through the coil. The electric current and the magnetic field will therefore interact and create a force that pushes the coil to move in the direction shown in Figure 2 below. Figure 2: Torque production in a DC motor (Hambley et al., 2008) A practical DC motor comprises several coils wound on the rotor as shown in Figure 1. The coils are aligned in the direction of the force that induces them to rotate. The current flowing in the coil is directly proportional to the magnetic field produced as well as the rate