The electric motor is sometimes called the "work horse" of his industry, because it is estimated that motors use about 70% of the total electrical load in the industry.
Mechanism of action for all types of electric motors are generally similar (Figure 1), namely: • An electric current in a magnetic field will exert a force. • If the wire that carries the flow is bent into a circle / loop, then both sides of the loop, ie at right angles to the magnetic field, will gain force in the opposite direction. • Couple style produces power play / torque to rotate the coil. • motors have several loops on dinamonya to provide a more uniform torque and the magnetic field generated by the electromagnetic structure of the so-called field coils.
In understanding an electric motor, it is important to understand what is meant by the motor load. Expense refers to the output power play / torque in accordance with the required speed. Expenses can generally be categorized into three groups: • constant torque load, is the burden which the demand for its energy output varies with the speed of operation, but its torque does not vary. Examples of constant torque loads are conveyors, rotary kilns, and the constant displacement pump. • Expenses with variable torque, is the load torque that varies with the speed of operation. Examples of variable torque loads are centrifugal pumps and fans (torque varies as the square of velocity). • Expenses with constant energy, is the load torque change with demand and inversely proportional to speed. Examples for the constant power load is machine tools.
Figure 1. Working Principles of Electric Motors.
