When you feed in DC, the electromagnet functions like 
a conventional permanent magnet and creates a magnetic field that’s usually pointing in the same direction. The commutator reverses the coil current each time the coil flips over, just like in a simple DC motor, so the coil constantly spins in the same path.
When you feed in AC, however, the current flowing through the electromagnet and the current flowing through the coil both invert, exactly in step, therefore the force on the coil is usually in the same direction and the electric motor always spins either clockwise or counter-clockwise. What about the commutator? The frequency of the existing changes much faster than the electric motor rotates and, since the field and the existing are always in stage, it generally does not actually matter what placement the commutator is certainly in at any provided moment.
Small electric motors are used in a multitude of applications in almost every industry because they’re cleaner and less costly to run than fuel-driven motors. They are still able to operate at high speeds and effectively produce mechanical power; nonetheless it will be in much smaller amounts compared to larger electric motors. Small motors or miniature motors are typically used in welding, little centrifuge devices, pitching machines, wheel chair, door openers, pumps, and frozen yogurt devices. Another common usage of small electric motors is in the automobile accessory industry where EP motors are accustomed to power gadgets such as electric windows, windscreen wipers, mirrors and locking systems. In some cases, motors can be categorized as fractional horsepower motors even if the horsepower exceeds one device. If the frame size of the electric motor is a 42, 48, or 56, the main one horsepower guideline does not apply. Because of their size, it may sometimes be easier to basically replace a engine than to try and repair it, but as they are simple contraptions, small electrical motors are reliable pieces of equipment when used for their intended purposes.
DC motors like this are excellent for battery-powered toys (things such as model trains, radio-controlled cars, or electric razors), but you don’t find them in many household appliances. Small devices (things like coffee grinders or electric food blenders) have a tendency to use what are called universal motors, which can be driven by either AC or DC. Unlike a straightforward DC engine, a universal motor comes with an electromagnet, instead of a permanent magnet, and it requires its power from the DC or AC power you feed in:
The small electric motor spins in different directions based on how the battery qualified prospects are installed. These motors are usually single phase or three phase depending on required result and intended application. Considerations to be made when identifying EP motor use include: whether a electric motor will be needed for constant or intermittent duty, voltage rankings, desired weight of electric motor, fan-cooling, adjustable speeds etc. Like all electrical motors, small electrical motors convert electricity into mechanical energy. They change electric powered energy into rotational motion by using the natural behavior of magnetism, or the attracting and repelling forces of a magnet solid enough to trigger rotation. These little motors are typically low cost and easy maintenance choices for motor needs.