We are pleased to present below all posts archived in 'April 2012'. If you still can't find what you are looking for, try using the search box.
Control theory looks at how systems work and are controlled from a mathematical view. This note gives a brief introduction to some of the concepts – more of a notepad of concepts really, whi... read more..
Sometimes it’s useful to be able to quickly lookup a piece of technical information. This note is a collection of information related to motors, and in particular ac induction motors. read more..
Variable frequency drives are widely used to control the speed of ac motors. This note looks at the mechanisms which enable d... read more..
Electric motors are one of the most widely used items of electrical equipment. Improving motor efficiency benefits include, reduced power demand, lower operating costs and reduced environment impact.... read more..
Collection of links to various places with useful motor information. I’ll try and return to the page every now and again to update it with any motor notes added to the site. read more..
Insulation on a motor prevents interconnection of windings and the winding to earth. When looking at motors, it is important to understand how the insulation functions and its practical applicatio... read more..
Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent mag... read more..
We have had the Wiki with us for a long time now, but at last I have decided to say bye bye – more details on why below. read more..
The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of REF protection. read more..
Electrical notes are a collaborative collection of electrical engineering information and educational material. Any registered user can add content.
Think of Notes as an online book;&#... read more..
The widely used United Sates standard ANSI/IEEE C37.2 'Electrical Power System Device Function Numbers, Acronyms, and Contact Designations' deals with protective device function numbering and acronyms. ... read more..
Here’s list of some famous scientists. Deliberately short, with the aim to provide a quick memory jog or overview. If your looking for more detailed information, Google and Wikipedia have tons of ... read more..
IEEE TV has a part series of videos on wind power and it's implication. For a really good overview to the technologies and issues around wind power, these...
The other day I was talking to a colleague who is a building services consultant. Despite regularly specifying dry-type/cast resin transformers he was...
Motor starting and its associated problems are well-known to many people who have worked on large industrial processes. However, these things are, of course...
"I can live with doubt and uncertainty and not knowing. I think it is much more interesting to live not knowing than to have answers that might be wrong...
Power cables can basically be classified into earthed and unearthed cables, where earthed and unearthed refer to the application for which the cable is...
Many medium voltage (MV) indoor switchgear rooms exist worldwide. The complexity of these rooms varies considerably depending on location, function and...
Light Emitting Diodes (LED ) are increasing gaining favour in both the domestic and commercial sectors; due to their efficiency, sustainability and durability...
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...
In 2011, with the introduction of it’s Panda search ranking algorithms, Google introduced tools for determining the original author of posts. The intention...
The new standard IEC 61439 replaces the old 60439. Compared to the old standard, the new 61439 is a more clearly defined and takes into account the assembly...
If you have some expert knowledge or experience, why not consider sharing this with our community.
By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.
To get started and understand our policy, you can read our How to Write an Electrical Note.