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...

IEEE TV has a part series of videos on wind power and it's implication. For a really good overview to the technologies and issues around wind power, these...

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...

Maxwell's Equations are a set of fundamental relationships, which govern how electric and magnetic fields interact. The equations explain how these fields...

Traditionally generation of electricity has involved rotating machines to produce alternating sinusoidal voltage and current (a.c. systems). With the development...

Control theory looks at how systems work and are controlled from a mathematical view.  This note gives a brief introduction to some of the concepts – more...

Depending where in the world you work, you are likely following one of two standards International Electrotechnical Commission (IEC) National...

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...

Fire resistant and fire retardant cable sheaths are design to resist combustion and limit the propagation of flames. Low smokes cables have a sheath designed...

Gauss's Electrical law defines the relation between charge ("Positive" & "Negative") and electric field.  The law was initially formulated by Carl Friedrich...