Torque or moment or moment of force is the tendency of a force to rotate or move an object about an axis. A force is a push or pull, likewise, torque is a twist to an object. Mathematically, torque, T = F × r.
What is equation of DC motor?
EMF equation and Torque equation of a DC machine
1. Flux cut by one conductor in one revolution = dΦ = PΦ …. (Weber), Number of revolutions per second (speed in RPS) = N/60.
Which is torque expression of DC series motor?
Ka = (PZ/2πa). Since Ka depends upon the constructional design of DC Motor or generator, it is known as armature constant. Here P is number of poles, Z is total number of armature conductor and ‘a’ is the number of parallel paths in armature. Equation (1) is the torque equation for DC machine.
What is DC motor with diagram?
Difference Between Dynamo and DC Motor – definition
|Sr No.||Dynamo||DC Motor|
|2.||Here normally permanent magnet is used or electromagnets made up of windings||Made of miniature size of permanent magnet|
|3.||It can operate through Self Excitation or Separate Excitation||It is usually excited by permanent magnet present.|
What is the speed of DC motor?
DC controls adjust speed by varying the voltage sent to the motor (this differs from AC motor controls which adjust the line frequency to the motor). Typical no load or synchronous speeds for an AC fractional horsepower motor are 1800 or 3600 rpm, and 1000-5000 rpm for DC fractional hp motors.
Which is proportional to the torque in DC motor?
For DC Machine, torque is directly proportional to armature current and flux. In dc shunt motors, flux is constant (not dependent on armature current). Hence torque is proportional to armature current.
How do you increase the torque of a DC motor?
Any DC motor will experience a decrease in speed when a load is applied, which causes the back EMF to decrease. The reduction in back EMF increases the net voltage, since the supply voltage remains constant. The net voltage increase causes the armature current to increase, which increases the motor torque.
WHAT IS A in DC generator EMF equation?
As the armature rotates, a voltage is generated in its coils. In the case of a generator, the emf of rotation is called the Generated emf or Armature emf and is denoted as Er = Eg. In the case of a motor, the emf of rotation is known as Back emf or Counter emf and represented as Er = Eb.
What are the 3 types of DC motors?
Types of DC Motors. There are 3 main types of DC motor that are available:- Series, Shunt and Compound. These terms relate to the type of connection of the field windings with respect to the armature circuit.