What is Alternative Current (AC) electric motors?
As we start with The AC electric motor( alternative current) converts AC (alternating current) electrical energy into mechanical energy. These electric motors operate on single-phase or three-phase alternating current. The basic operating principle of AC motors is the rotating magnetic field (RMF) produced by the stator windings when alternating current is passed through them. The rotor (which has its own magnetic field) follows the RMF and starts spinning.
The basic working principle of AC motors mainly relies on magnetism. A simple AC motor contains a coil of wire and two permanent magnets near the shaft. When AC power is applied to a coil of wire, it turns into an electromagnet and creates a magnetic field. This motor consists of two important parts like stator and rotor. The stator includes loops of wire, a sturdy metal axle, free-moving metal parts that conduct electricity, coils, and a squirrel-cage rotor.
If the conductor used is a wire or ring, the current will loop around it. Or if the conductor is just a solid piece of metal, eddy currents will flow around it. Induced currents can create magnetic fields, and according to another law of electromagnetism, rotating magnetic fields also rotate. When the magnets interact, the wire and shaft coils start to rotate the motor.
What is Direct Current (DC) electric motors?
DC motors belong to a class of rotary electric motors that convert direct current (DC) electrical energy into mechanical energy. The most common type relies on the force produced by the magnetic field induced by the current flowing through the coil. Almost all types of DC motors have an internal electromechanical or electronic mechanism for periodically changing the direction of current flow in some part of the motor. The
DC motor is the first motor to be widely adopted because it can be powered from the existing DC lighting power distribution system. The speed of a DC motor can be controlled over a wide range by using variable supply voltages or by changing the current strength in the field windings. Small DC motors are used in tools, toys and appliances. Universal motors, lightweight brushed motors used in portable power tools and equipment, operate on DC and AC power. Large DC motors are now used to drive electric vehicles, elevators, hoists, and steel rolling mills. The advent of power electronics has made it possible to replace DC motors with AC motors in many applications.
Difference between AC and DC electric motors;
AC motors also differ from DC motors in that most AC motors do not contain brushes. This often means that the need for AC motor maintenance and parts replacement is greatly reduced, and most users generally attribute longer life expectancy as a result. Also, unlike DC motors, the output speed of many types of AC motors is usually determined by frequency converter control. A little further down in this guide, we briefly discuss the different possible variations of the basic AC motor model.
As mentioned earlier, an important feature that distinguishes AC motors from many other types of motors (especially DC motors) is the fact that they are AC powered. There are other differences, but this is key to understanding exactly how AC motors work.
The difference between AC and DC motors is very important not only from a testing point of view, but also for various projects and practical demonstrations. Understanding the difference between AC and DC motors makes it easier to choose the right motor for a particular demo.
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