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...
In electrical engineering, Network Theory is the study of how to solve circuit problems. By analyzing circuits, the engineer looks to determine the various...
The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...
When selecting a cable, the performance of the cable under fault conditions is an important consideration. It is important that calculations be carried...
Battery powered cars are a hot topic and widely debated. The pros, cons, issues and time frames can be talked about endlessly. An article by the Telegraph...
This post is quick introduction and overview to different railway electrification voltages used in answer to a question sent in via email. While there...
Request to look at induction motor starting time have come up a few times on the site. Hopefully in this post, I give you guys some idea on how to calculate...
The (relatively new) switchgear and control gear standard, IEC 61439 'Low-voltage switchgear and controlgear assemblies' has three methods which can be...
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...
Maxwell's Equations are a set of fundamental relationships, which govern how electric and magnetic fields interact. The equations explain how these fields...
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