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An alternating current generator, or AC generator, produces an alternating current, which means the voltage produced alternately reverses from positive to negative polarity, producing a corresponding change in the direction of current flow. Much like a DC generator, an AC generator requires a coil to cut across the force lines of a magnetic field. This coil is attached to two slip rings, which deliver the current to and from the load destination, thus completing the circuit. Alternating current generators are often called “Alternators”.

The magnitude of AC voltage generated by an AC generator is dependent on:

• The strength of the magnetic field (number of lines of force)
• The speed at which the loop rotates
• The number of loops of wire that cut the magnetic field.

A rotation speed of 3000 revolutions per minute(RPM) produces 50 Hz, and 3600 RPM produces 60 Hz. The electric current in North American homes has a frequency of 60 hertz, while in Europe it is 50 Hz.

An alternating current motor, or AC motor uses electrical energy to produce motion and torque. Very simple AC motors are called "Squirrel cage motors"; these have only one or more stationary coils within which a special kind of mechanical rotor is free to rotate. There is no electrical connection to the rotor from the outside. Most AC motors require a starter, or method of limiting the inrush current to a reasonable level. Types of motor starting include reactive (capacitor start and inductive start), and electronic (frequency drives and soft start drives). The reactive start method is usually used on fractional horsepower motors, and the electronic method is usually reserved for larger motors.

This 4-hr course provides a basic understanding of AC motors and generators, explaining how to use them, how to calculate power, and determine torque considerations. The course is based entirely on Naval Education and Training Materials (NAVEDTRA 14177), Electricity and Electronic Training Series; Module-5 and covers Chapter 3 and 4 titled “Alternating Current Generators and Alternating Current Motors”.

The student must take a multiple-choice quiz consisting of twenty (20) questions at the end of this course to obtain PDH credits.

State Board Acceptance

This course can be used by professional engineers to fulfill PDH requirements mandated by state and provincial licensing boards. Decatur Professional Development is an approved provider of continuing education in all states that pre-approve course providers. In all other states that mandate continuing education for engineers, it is the individual engineer's responsibility to determine the suitability of activities for PDH credit. The state boards typically accept online* courses that cover technical, managerial** or ethical content and which are relevant to the practice of engineering. The course must have a clear purpose or objective with a content that will maintain, improve or expand the skills and knowledge of the licensee's field of practice. For questions about your mandatory PDH requirements, visit the website of your state licensing board.

*Online courses are accepted by all state licensing boards that mandate continuing education. Other than New York (which limits online courses to 18 PDH) and Iowa (which limits online courses to 6 PDH), there are no limits placed by other states on the number of hours that can be earned through online continuing education. Consult with your state licensing board if you have any questions about the acceptability of online courses.

**The New York State Board of Engineers does not accept general office management courses, but will accept project management courses that are offered by an approved provider and that are technical in nature and contribute to the engineer's professional practice.

Please Note: Continuing Education credits for this course are awarded as PDH (Professional Development Hour Credits).