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...

Most installations involve some form of lightning protection system which is connected to an earth electrode.  The function of the earth electrode is to...

For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical...

‘Kept looking at a card, y’see? Kept looking at it. Welcome back Bottle. Gods below welcome home. The Crippled God A Tale of the Malazan Book of the...

A single phase system is perhaps the most common type of system most people are familiar with. This is what people have in their homes and what appliances...

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...

The calculation of current in a three phase system has been brought up on our site feedback and is a discussion I seem to get involved in every now and...

MIT OpenCourseWare, makes the materials used in teaching all MIT subjects available on the Web, free of charge, to any user in the world.

We have a sister note to this (Robots - Interesting Video), in which I have posted some videos of interesting robots developed by commercial corporations...

Capacitors are widely used in electrical engineering for functions such as energy storage, power factor correction, voltage compensation and many others...