A DC motor is an electric motor that runs on direct current power. I'll assume that answer is being explained to a layman and hence try explaining it from very much basics. Back emf act as governor i.e it makes motor self-regulating because it draws as much current as is just necessary. By increasing the flux, speed can be controlled, and. The DC motor working principle is the Lorentz force equation. Working Principle of DC Motor. A force acts on the coil which rotates it continuously. In this section, we will study about the Principle of DC motor, its working, and rules related to DC machine. Here the input voltage is in the form of voltage and electrical and the mechanical output is in the form of torque (T) and speed  (ω). Working Principle of DC generator Let the coil ABCD be initially in the horizontal position, and be rotated anticlockwise. The most common types rely on the forces produced by magnetic fields. So the question arises how the Back EMF comes from and why we are calling it as Back Emf? In this series, we explore the most popular types of motors that makers utilize. In short back emf is generated by the generating action (moving conductor cutting the magnetic flux). Let us start from understanding the question which is 'How does a DC motor work?'. Your email address will not be published. A DC motor is an electrical machine which converts electrical energy into mechanical energy. Fig.1 The working of DC motor. Now we will discuss the basic operating principle of electric motor one by one for better understanding the subject. The working of DC motor is based on the principle that when a current carrying conductor is placed in a magnetic field, it experiences a mechanical force. Magnitude of force experienced by the armature conductor is Working of electric motor mainly depends upon the interaction of magnetic field with current. Because an electromagnetic force is induced in the coil when this coil is rotated in the magnetic field. As per Newton’s 3rd law which is applicable to electrical circuits as Lenz’s law says that every action opposes its cause. Similarly, in motors, the voltage applied is the cause for the motion and hence the applied voltage is opposed by the emf developed by the motor which is called as back emf. Armature winding acts as a current-carrying conductor. Induction motor and synchronous motors are AC motors. When the motor starts rotating its conductor will cut the magnetic flux produced by the field winding. The first DC motor was developed around the 1830’s-1840s. 3-DC machine mainly used as DC m otors and the DC generators are rarely used. As per Newton’s 3rd law which is applicable to electrical circuits as Lenz’s law says that every action opposes its cause. In the given figure the DC motor is in series with the armature resistance R. When the supply voltage is applied across the motor brushes the field magnets are excited and the electric current starts to flow through the rotor armature, therefore, driving torque ” T ” is produced. A DC motor is any of a class of electrical machines that converts direct current electrical power into mechanical power. The armature is connected to a DC power source through a pair of commutator rings. 3/7/2011 2 Fleming Left Hand Rule. Controlling a DC Motor. Simply put, a DC motor controller is any device that can manipulate the position, speed, or torque of a DC-powered motor. To briefly summarize, the speed/torque cu… Nearly all types of DC motors have some internal mechanism, either electromechanical or electronic, to periodically change the direction of current in part of the motor. A = Number of Parallel Path By decreasing the terminal voltage, the overall speed of the motor can be decreased. N = Speed of a DC motor. An electromechanical energy conversion device will take electrical energy at the input and produces a mechanical energy at the output side. An electric motor is an electrical machine which converts electrical energy into... Back EMF. In all the … It works on the principle of Lorentz Law, which states that “the current-carrying conductor placed in a magnetic and electric field experience a force”. DC MOTOR 2. The force is experienced from high flux density to low flux density. The same D.C machine can be used as the D.C motor and generator. Working principle of DC motor A current-carrying conductor, when kept in a magnetic field, gains torque and develops a tendency to move. A DC  motor is a machine which converts DC power or current into the mechanical output. Working principle of D.C. motor is very simple. The coil during this motion cuts the magnetic lines of force and an induced current is produced in the coil. 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