The Amateur Electrical Engineer

By Perry Henderson

The student of electrical engineering must understand many concepts to be successful, but perhaps no concept is more important than an understanding of the concept of current. Current simply is the flow of electrons. There is a far more complex definition of current but for our purposes it simply is the rate of electron flow. The two types of current are alternating current (AC) and direct current (DC). Essentially the two types of current have their own very specialized properties and characteristics. The two current types also have different applications, benefits, uses in engineering and in the ultimate final product. Nothing will say novice to an experienced electrical practitioner than someone who does not understand the difference between AC and DC.

DC or direct current is the most basic type of current. DC has a constant voltage and a single direction of electron flow. The basic source of DC is a simple battery, which is a component that stores energy in chemical form and then ultimately changes that energy into electrical energy. A battery has electrochemical cells that may contain more than a single external connection. DC is utilized with devices such as laptops and flashlights. The unique properties of DC allow for it to be useful for electronics and in places where a high amount of voltage is not needed. DC allows by its nature a stable and accurate form of electrical energy.

AC or alternating current was aided in its development by Nikola Tesla, the famed electrical engineer. AC differs from DC in that it alternates direction in a periodic fashion. What makes AC superior to DC from an engineering standpoint, is that it can go from a higher voltage to lower voltage with the use of an electrical device called a transformer. The beauty of AC which was discovered is that it is incredible for the transmission of electrical power over a long distance. An important concept in AC is the concept of hertz. Hertz is simply the change in direction of the current or one cycle per second. In European nations, 50 hertz is utilized for their electrical systems, in the U.S.A, 60 hertz is the standard hertz for electrical devices.

What has been discovered by electrical engineers and other electrical professionals is that there are inherent strengths and weaknesses in both types of electrical current. AC is superior in the transmission of power over longer distances. DC is excellent at adding stability to electronic circuits. The application and the technology will help the engineer to determine which current type will be utilized. For these reasons, it is of great importance that the electrical engineer or professional have a solid grounding in the basics of electrical theory and application.

Modern technology makes use of both types of current to a high degree. The movement towards electric vehicles has created a great need for engineers that understand battery technology and DC. With more computers and other electronics being built and purchased by a gadget demanding public, DC has become significant to the modern world. Hybrid types of systems are also being developed for various technologies that will shape the 21^st century and beyond. Modern electrical engineering demands understanding of both types of current for new and dynamic electrical systems.

© Copyright 2025 Perry Henderson