D.C. MOTOR PRINCIPLE

explain DC MOTOR PRINCIPLE .

When a conductor is placed in magnetic field is produced on the conductor.

This force is given by F = B.L.I. Newton.

The direction of the force is given by Fleming's left hand rule.

F = B.LI. newtons

B = magnetic flux density in weber/m2

I = current in conductor in amperes

1 = length of conductor in metres

The electric motor converts electrical energy into mechanical energy or motion by using electromagnetic induction.

When the field magnets of the motor are excited and it's Armature conductors are supplied with current from the supply mains, then they experience a force tending to rotate the armature

Armature conductors under North pole are assumed to carry currents downwards (crosses) and those under South-pole to carry currents upwards (dots). The direction of this force is given by Fleming's Left Hand Rule (also known as motor rule).

. It is seen that each conductor experiences a force F which tends to rotate the armature in anti-clock wise direction as shown by the arrows placed above conductors.

. These forces combine and produce driving torque to keep the armature rotating.

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