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...

I've been considering a blog on the 110 or 230 Volt issue for a while.  While browsing the Internet I came across a great summary by Borat over at  engineering...

Electrical engineering has a multitude of laws and theorems. It is fair to say the Ohm's Law is one of the more widely known; it not the most known. Developed...

Electrical notes are a collaborative collection of electrical engineering information and educational material. Any registered user can add content. ...

This post is quick introduction and overview to different railway electrification voltages used in answer to a question sent in via email. While there...

We have had the Wiki with us for a long time now, but at last I have decided to say bye bye – more details on why below.

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

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...

While there are a vast array of cable insulation materials, these are often divided into two general types; Thermoplastic or Thermosetting. For example...

When thinking about watts (W) or kilowatt (kW = 1000 W) it can be useful too keep in mind the fundamental ideas behind the unit. Watt is not a pure electrical...