Science

The basic principles of electromagnetism

This article will provide a basic introduction to the principles of electromagnetism and electric motors. As the name suggests, electromagnetism is a branch of physics that focuses on the interaction between electricity and magnetism. It plays a major role in most objects encountered in daily life. Electromagnetism is the interaction between conductors and fixed magnetic fields. This video provides an excellent overview of magnetic fields, flux density and motor effect.…

A review of electromagnetic induction

In this video, Gary Hayers of Tresham College takes a closer look at electromagnetism and the principles of generating AC. Student training aid to prove the basic principles of producing an alternating current (A.C) and developing and increasing an electromotive force (EMF) E = BLv. Videos are training aids for City and Guilds (C and G) and EAL courses Level 1, 2 and 3.

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…

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…