We are pleased to present below all posts archived in 'May 2012'. If you still can't find what you are looking for, try using the search box.
How often installations are inspected is up to the owner of the installation, provided such durations do not exceed any regulatory maximums in force. The criticality of the electrical installation to th... read more..
Laplace transforms and their inverse are a mathematical technique which allows us to solve differential equations, by primarily using algebraic methods. This simplification in the solving of equat... read more..
I have been thinking recently that there appears to be less professional integrity around than when I first started my career in electrical engineering. Recently the IET has also had a discussion around... read more..
A single phase system is perhaps the most common type of system most people are familiar with. This is what people have in their homes and what appliances are plugged in to. For larger amounts of power,... read more..
A fundamental concept behind the operation of alternating current systems is that voltage and current waveforms will be sinusoidal – a Sine Wave. This is best explained by considering how a coil of wire... read more..
Circuit breakers are switching devices whose primary function is to isolate parts of an electrical distribution system in the even of abnormal conditions. Abnormal conditions are generally caused ... read more..
In 2011, with the introduction of it’s Panda search ranking algorithms, Google introduced tools for determining the original author of posts. The intention is to provide more relevant search... read more..
From the earliest times, humans have found ways to create light. Pre-historic peoples used natural materials (moss, grass, etc.) soaked in animal fat and then ignited. Around 3000 to 4500 BC, oil lam... read more..
The International System of Units (abbreviated SI) is the world's most widely used system of units. The system consists of a set of units and prefixes. read more..
IEC 60228 is the International Electrotechnical Commission's international standard on conductors of insulated cables. Among other things, it defines a set of standard wire cross-sections. In the United... read more..
One of the requirements to ensuring that everything works is to have equipment selected, manufactured and verified [tested] to IEC standards. Not all equipment out there meets this requirements. It is t... read more..
A battery consists of one or more cells, each of which use stored chemical energy to produce electrical energy, There are many types of cells and these are combined in a multitude of ways to produce ... read more..
Circuit breakers are switching devices whose primary function is to isolate parts of an electrical distribution system in the even of abnormal conditions...
IEC 62305 'Protection against lightning' requires a risk assessment be carried out to determine the characteristics of any lightning protection system...
A couple of months ago I came Microsoft's OneNote and downloaded the 60 day free trail. Since then I have been using it regularly and now have a full license...
Modelica is an open source (free) software language for modelling complex systems. Having never used it before, I thought I would download a development...
Light Emitting Diodes (LED ) are increasing gaining favour in both the domestic and commercial sectors; due to their efficiency, sustainability and durability...
Variable frequency drives are widely used to control the speed of ac motors. This note looks at the mechanisms which enable drive units to control the...
The image (reproduced from IEC 60909) shows a typical fault in an ac system. From the illustration it can seen that there is an initial dc component ...
Fire resistant and fire retardant cable sheaths are design to resist combustion and limit the propagation of flames. Low smokes cables have a sheath designed...
In the previous note we looked at the approach taken by the standard to the sizing of cables and illustrated this with an example. We then looked at one...
I've recently come across this question a couple times browsing the internet. Decided to give a quick answer here. A rectifier transformer is a transformer...
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