UPS Sizing - Rules of Thumb
It wasn't so long ago I was telling someone that I don't use rules of thumb as most things are easily calculated anyhow. As it turns out I last week...
Useful Motor Technical Information
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...
Introduction to Traction Substations
Following on from my post on railway electrification voltages, I thought an introduction to traction substations would be a good idea. Traction substations...
Batteries
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...
Power Transformers - An Introduction
One of the fundamental requirements of an alternating current distribution systems it to have the ability to change the magnitude of voltages. It is more...
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...
Variable Frequency Drive
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...
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...
Electromagnetic Compatibility (EMC)
Electromagnetic compatibility (EMC) is the study of coordinating electromagnetic fields give off equipment, with the withstand (compatibility) of other...
Smarter Electrical Distribution
The other day I came across an article in Technology Review on the development of a smart transformer. A professor at North Carolina State University is...