Basic electrical engineering

Basic electrical engineering, Basic electrical engineering.

No single discovery has affected our lives, our culture and our survival more than electricity. Electricity is everywhere; it lights our way, cooks our food and can even brush your teeth. For an example, imagine where the medical field would be without electricity and in that sense how many lives have been saved due to electrical devices like defibrillators, pacemakers, etc.  From talkies to eight tracks to screaming “I want my MTV”, even hashtagging, none of it would be possible #WithoutElectricity.

So what is electricity and where does it come from? More importantly, why is carpet, socks and a doorknob a bad combination? In its simplest terms, electricity is the movement of charge, which is considered by convention to be, from positive to negative. No matter how the charge is created, chemically (like in batteries) or physically (friction from socks and carpet), the movement of the discharge is electricity.

This flow of electrical charge is referred to as electric current. There are two types of current, direct current (DC) and alternating current (AC). DC is current that flows in one direction with a constant voltage polarity while AC is current that changes direction periodically along with its voltage polarity. Thomas Edison and Alessandro Volta were pioneers in DC current and wrote much of electricity’s history. But as societies grew the use of DC over long transmission distances became too inefficient. Nikola Tesla changed all that with the invention of alternating current electrical systems. With AC it is possible to produce the high voltages needed for long transmissions. Therefore today, most portable devices use DC power while power plants produce AC.