Tutorial - How Electricity Works

What is Electricity? How does it work? what can you do with it?

In today's age, the above questions does not need to be answered because our live are surrounded with electronic devices. From a Flash light to a Calculator to a mobile phone,computers, to Industrial Machines. It is quite scary how dependent we are of this power we can't see. In Most of the tutorials we will focus mostly on DC supplies and circuits.

Power is distributed in two forms: 

• DC ( Direct Current )
• AC ( Alternating Current)  most commonly Single Phase and Three-Phase

DC Direct Current

It is the Flow of electrons through a conductive wire from the  negative side to the positive side of a power source. a common source of DC power is an alkaline battery.

Electricity flows in a closed circuit and does not flow when a circuit is open. 

AC Alternating Current

Alternating current is defined when the direction of current changes at a predetermined time period. In South Africa, the direction changes 50 times per second (50 Hz or 50 Hertz). Great care must be taken when working with electricity as the electricity of a power outlet in South Africa is +/- 240 Volts and can Kill you. in Single phase AC outlets in South Africa the following wire colours are used. Live (L) Brown  , Neutral (N) Blue, Earth (E) Green.

Three phase electricity is usually found in factories and other industrial buildings where high power is required. 3 or four wires are used to transfer the power to the buildings. 3 Wires for the three phases and one wire for neutral. Neutral is not always present. The three phases are offset by 120 Degrees as shown on the drawing below: