DC Motor Operation
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 magnets or...
Software Usage Guidelines
Using software in our work is essential for most of us and we are becoming even more dependant on it's use. While software is a great asset, many times...
E-Ink
Before the technical, some general information. E-ink display are found in a lot of e-readers, some mobile phones and similar devices and the intent is...
Photovoltaic (PV) Panel - Performance Modelling
In an earlier note on the site [Photovoltaic (PV) - Electrical Calculations], the theory of solar (PV) cell calculations was introduced. In particular...
Understanding LV Circuit Breaker Fault Ratings
I think this post is going to be helpful to several of our readers. While the IEC low voltage circuit breaker Standard [IEC 60947-2, Low voltage switchgear...
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 ...
Cable Sizing Tool
Our cable sizing tool is one of the more popular tools on the site. The tool enables cables to be sized in compliance with BS 7671 (the IEE Wiring Regulations...
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...
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...
Understanding electric motor insulation & temperature
Anyone specifying or using electric motors should have a basic understanding how the insulation is related to temperature. Three classes of insulation...