Generation of a Sine Wave
A fundamental concept behind the operation of alternating current systems is that voltage and current waveforms will be sinusoidal – a Sine Wave. This...
HTML Symbol Entities
HTML supports a variety of entity symbols which can be entered using either numbers or an entity name. The number or name is preceded by the ‘&’ sign...
Electromagnetic Fields - Exposure Limits
Exposure to time varying magnetic fields, from power frequencies to the gigahertz range can have harmful consequences. A lot of research has been conducted...
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...
Bows and Arrows
It starts with me reading one of the Horrible History books with my son (Groovy Greeks). Arrows were mentioned which lead to the discussion of the bodkin...
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...
Nikola Tesla
Nikola Tesla was born exactly at midnight on July 10, 1856 in the tiny village of Smiljan, Lika in Croatia. In his late teens, Tesla left the village to...
Motor Starting - Introduction
Motor starting and its associated problems are well-known to many people who have worked on large industrial processes. However, these things are, of course...
Lighting - Lamps
Lamps are the essential part of any luminaire. These are the light generating components. Since the advent of electrical lighting in the middle of the...
Lithium Ion Battery
Over recent years the Lithium Ion battery has become popular in applications requiring high power densities with small weight and footprint. Today Lithium...