From the monthly archives: April 2012

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

By Steven McFadyen on 3/29/2012 10:18 PM

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..


Useful Motor Technical Information

By Steven McFadyen on 3/28/2012 10:09 PM

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 Drive

By Steven McFadyen on 3/28/2012 9:58 PM

Variable frequency drives are widely used to control the speed of ac motors.  This note looks at the mechanisms which enable d... read more..


Motor Efficiency Classification

By Steven McFadyen on 3/28/2012 2:05 PM

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..


Electric Motors

By Steven McFadyen on 3/28/2012 1:12 PM

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..


Motor Insulation

By Steven McFadyen on 3/28/2012 1:02 PM

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..


DC Motor Operation

By Steven McFadyen on 3/28/2012 1:00 PM

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..


Wiki Depreciation

By Steven McFadyen on 3/27/2012 4:06 PM

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..


Restricted Earth Fault Protection

By Steven McFadyen on 3/25/2012 12:49 PM

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..


How to Write an Electrical Note

By Steven McFadyen on 3/24/2012 11:47 AM

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..


ANSI (IEEE) Protective Device Numbering

By Steven McFadyen on 3/22/2012 11:40 AM

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..


Famous Scientists

By Steven McFadyen on 3/22/2012 11:35 AM

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..


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ANSI (IEEE) Protective Device Numbering

The widely used United Sates standard ANSI/IEEE C37.2 'Electrical Power System Device Function Numbers, Acronyms, and Contact Designations' deals with...

What are you reading!

Reading is a bit of a hobby of mine and I"ve done a few off-topic posts in the past on this. Rather than continue doing the occasional post I thought ...

Occam's Razor

I was reminded of Occam's Razor while reading a book. It's quite a simple principal of logic which has stood the test of time and is accepted as central...

How to measure power supply quality

If your are ever called out to troubleshoot something on your electrical system, one of the first things consider is the supply voltage. You want to ensure...

Calculating Cable Fault Ratings

When selecting a cable, the performance of the cable under fault conditions is an important consideration. It is important that calculations be carried...

Meeting room of the future

The IET site has a video of a visit showing of a high tech meeting room developed at Napier University in Edinburgh. It a good demonstration of innovative...

Surface Treatment – Ladders, Trays and Baskets

Steel ladders, trays and baskets form the backbone of cable containment systems. Often these items need some form of surface treatment to prevent corrosion...

Are We Losing Professional Integrity

I have been thinking recently that there appears to be less professional integrity around than when I first started my career in electrical engineering...

Voltage Drop in Installations - Concepts

Problems on achieving maximum voltage drop within an installation come up often. Depending where you live, local regulations will have different limits...

Railway Electrification Voltages

This post is quick introduction and overview to different railway electrification voltages used in answer to a question sent in via email. While there...

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