Farm Power And Machinery (1+1)

Introduction

• Electric motor is a machine which converts electrical energy in to mechanical energy at much higher efficiencies than I.C. engines.
• Electrical motors operate at efficiencies ranging from 50 to 90 % as against I.C. engines having thermal efficiencies between 28 to 38 %.
• The most important feature are the low initial cost, low operating cost, easy to start even at loads etc. besides, the motors are designed to take up temporary over loads.
• These motors have long life, compact construction, low noise levels, nothing like exhaust smokes, operational simplicity and minimum safety hazards.
• A motor has primarily consists of armature coil and a field coil.
• When armature coil are supplied with electric current from the supply and the field magnets are excited and they experience a force tending to rotate the armature.
• Each conductor experiences a force which tends to rotate the armature in either clockwise or anticlockwise direction.
• These forces collectively produce a twisting effect or a torque. This causes the armature to rotate in one of the direction.