About DC Motor
The Machine which converts the electrical energy inti the Mechanical energy is called motor . if works on the principle that when a current carrying conductor in placed in a magnetic field , it experience a mechanical force whose direction is given by Fleming's Left-Hand Rule .
Working Principle
A machine that converts DC power into mechanical power is known as a DC motor. Its operation is based or the principle that when a current carrying conductor is placed in a magnetic field, the conductor experiences a mechanical force. The direction of this force is given by Fleming's left on hand rule and magnitude is given by;
F = BIl newtons
Basically, there is no constructional difference between a DC motor and a DC generator. The same DC
machine can be run as a generator or motor.
Consider a part of a multipolar DC motor When the terminals of the motor are connected to an external source of DC supply
- The field magnets are excited, developing alternate N and S poles.
- The armature conductors carry currents. All conductors under N-pole carry currents in one direction while All the conductor under S-pole carry currents in the opposite direction
Fleming's Left Hand Rule
The direction of rotation of an armature can be determine forefinger and middle finger of the left hand mutually at right angles to each other, such that the forefinger is in the direction of flux and the middle finger is in the direction of current flow in the conductor, then the thumb points the direction of motion of the conductor.
Back E.M.F. In DC Motor
When armature of a DC motor rotates, The armature conductors cut the magnetic flux generate the field poles. Due to this, an e.m.f. is induced in the Conductors. This induced e.m.f. is in opposition to the applied voltage (V). It is called back e.m.f. or counter e.m.f. it is represented by Eb
he armature current (Ia) flows due to this voltage
Where V - Eb = Resultant voltage
Torque In DC Motor
The term which expresses the turning or twisting movement of force about an axis, is called torque.
Torque =Force x Radius of pulley or armature
Assume, a pulley of radius 'r' meters which acts upon Circumferential force 'F' Newton and rotates at a speed or N r.p.s.
Torque Production in a Motor
Torque T = F x r (N m)
Work done by this force in one revolution
= force x distance
= F x 2 Pie r
Power developed in one second
=F x 2 pie r x N Joule / second or watts
= ( F x r ) 2 pie N watts
= (F x r) 27TN watts
These types of suggestions are very useful to me. You are providing good knowledge about Magnetic Bead Separation. I hope everyone will enjoy this article as much as me. Thank you for sharing this with you.
ReplyDelete