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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Lead Acid Batteries

Lead acid batteries are cost effect and reliable, making them suitable for many applications.This note examines topics of interest associated with the...

How to Check a Circuit is Dead

If you want to check a circuit is dead (not live), you should always use the three point method. First check a known live circuit, then check the dead...

New Mail Chimp

We've been sending out Newsletters on a regular basis for a few weeks now. To do this we have been using Google's Feedburner service. While Feedburner...

Electrical Engineering

Electrical engineering is a field that covers a wide variety of sub-fields, including electricity and electronics. It is a field that goes back to the...

Skin Tapping Input

Tapping your forearm or hand with a finger could soon be the way you interact with gadgets. A new technology created by Microsoft and Carnegie Mellon ...

What happened to the cable notes?

If you are wondering what happened to our cable notes, the short answer is that we have moved them to myCableEngineering.com.  The "Knowledge Base" at...

Generator Sizing & Operation Limits

When selecting a generator, there are inherent limits on the active and reactive power which can be delivered. Generators are normally sized for a certain...

Operational Amplifier

The fundamental component of any analogue computer is the operational amplifier, or op amp. An operational amplifier (often called an op-amp,) is a high...

Why a Sine Wave?

I received this question by email a few weeks. First thoughts was that it is a product of the mathematics of rotating a straight conductor in a magnetic...

Lightning Risk Assessment (IEC 62305)

IEC 62305 'Protection against lightning' requires a risk assessment be carried out to determine the characteristics of any lightning protection system...

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