Electric Motors

An electric motor is a device that produces mechanical energy by using electrical energy. It uses interactions between magnetic fields and conductors which carry electricity to produce motion. Electric motors use the exact concept of dynamos and generators in reverse where they use mechanical energy to produce electrical energy. In this way it is possible to run motors as alternators and dynamos. Electric motors are used everywhere from household use to industry. Simple appliances like drills, fans, CD players and even clocks may use electric motors. In industry where motion is required, heavy duty motors are used to supply automation to large loads.

The mechanism in motors is that if you take a length of ordinary wire and make a loop out of it, after placing it between the two poles of a magnet and connecting it to a current; it will jump. This happens because when a current travels in a wire, a magnetic field is produced. The magnetic fields of the other two poles interact with the wire to create motion. This principle is used to create motion in a motor.

There are two main types of electric motors which are in common use in the present day. The two types are Alternating Current motors (AC) and Direct Current motors (DC). As the two names suggest the different categories of motors require two forms of current; alternating current and direct current. Direct and alternating current indicates the way in which electricity is transferred to the motor and inside it. DC motors are subdivided into brush-less or with brushes, AC motors on the other hand can be categorized into three phase or single phase motors.

AC motors are made of two basic parts, a stator which is the outside stationery component with a coil wound around it with an electric current. The second component is a rotor which is attached to the output shaft. The rotating field gives a rotating motion to the rotor. Induction AC motors are larger AC motors which are fitted with capacitors to create a second phase from the supplied typical single phase electricity. Induction motors are of two types which can be capacitor starter motors or capacitor run motors. The second capacitor created phase and the initial phase of current interact to start the AC motor. Induction AC motors are made efficient and long lasting by the use of a capacitor to induce a current unlike DC motors which use brushes. Brushes tend to wear over time and are more probable to be damaged or fail easily.

The basic DC motor has six parts: field magnets, brushes stator, rotor, commutator and axle. Motors use electromagnetism to produce motion where a conductor carrying a current generates a magnetic field. When this magnetic field is placed in an external magnetic field, a force is produced which depends on the current supplied to the conductor. The interaction between a conductor carrying an electric current and the external magnetic field causes a rotational motion in a DC motor.

Electric motors are used in any machine that needs a form of rotating, vibrating and oscillating. They are also widely used in robotics. Electric motors have been replacing hydraulic systems which were used in military and aeronautical systems. At home, blenders, ovens and grinders use electric motors in the kitchen. Tiny electric motors are used in toys for movement.