DC Component of Asymmetrical Faults
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 ...
Introduction to Lighting
When looking at the design of a lighting scheme it is useful to have an understanding on the nature of light itself and some of the basic theory associated...
Lighting Design - An Introduction
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...
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...
A mechanical engineering paper, some history and memories
I was digging in my bookshelf and came across the 80th Anniversary Association of Mine Resident Engineers, Papers and Discussions Commemorative Edition...
UPS Battery Sizing
Various techniques exist to enable the correct selection of batteries for UPS applications. The procedure described below is one of the more common. ...
IEC 61439 - The Switchgear Standard
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...
What does N+1 mean?
The term 'N+1' relates to redundancy and simply means that if you required 'N' items of equipment for something to work, you would have one additional...
Random Numbers
Using laser optical pulses the random number generator utilizes the time between arrival of random photos to generate the numbers, ensuring true accuracy...
Capacitors - Energy Storage Application
Capacitors have numerous applications in electrical and electronic applications. This note examines the use of capacitors to store electrical energy....