Science

Generation and transmission of electricity

This article will briefly consider the different ways that electricity is generated and transmitted in the UK. Electricity is a convenient energy source because it is easily transmitted over distance via electricity cables, and has a wide variety of uses. However, electricity is not a primary energy source – it must be generated before it can be used, whether using coal, oil, natural gas or other fuels. Once it has…

Alternating Current & Direct Current

Mains electricity in the UK is an alternating current (AC) supply (230V). But what is AC and how does it differ to direct current (DC)? AC produces voltages with alternating polarity, moving forwards and backwards in a circuit over time, either through voltage switching polarity or a current changing direction and back and forth. It appears in a variety of electrical sources, most notably rotary electro-mechanical generators. An alternating current…

What are the basic principles of electricity?

Get to grips with electricity and electrical theory with this brief introduction of the basic princples. At its simplest, electricity can be described as a form of energy brought about by charged particles either statically, or through charge or current. Essential to understanding where electricity comes from and what it is, you first need to gain a simple understanding of atomic theory. All matter is formed of atoms, which can…

An introduction to transformers

This article serves as an introduction to transformers and the theory behind them. What is a transformer? A transformer is a device that increases or reduces the voltage of an alternating (AC) current. What is the principle of Mutual Inductance? A transformer works on the principle of Mutual Inductance. This is the principle that a change in the current of one coil on a conductor will affect the current…

How does an MCB work?

This excerpt from ABB introduces the technology inside and miniature circuit breaker (MCB). What does an MCB do? The short answer: it protects wires from overloads and short-circuits. When we look on the inside of an MCB we can see how that actually works. For overload protection the temperature of a bimetal, through which the current passes (yellow area), is decisive. If the nominal current—the current the circuit breaker is…