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...

Exposure to time varying magnetic fields, from power frequencies to the gigahertz range can have harmful consequences.  A lot of research has been conducted...

If you are working on a large plan, get the real coordinates [latitude, longitude] for two or more points and add them to the drawing. That way you can...

Here’s list of some famous scientists. Deliberately short, with the aim to provide a quick memory jog or overview. If your looking for more detailed information...

Three phase systems are derived from three separate windings, either connected in delta or star (wye). Each winding can be treated separately, leading...

Ever wondered what kind of power an aircraft uses when parked at the airport stand. Normally the aircraft generates it own power, but when parked with...

This is the first of two posts on the resistance of conductors. In the next post I will look at the ac resistance, including skin effect and we deal with...

In 2011, with the introduction of it’s Panda search ranking algorithms, Google introduced tools for determining the original author of posts.  The intention...

While not as popular as it once was, frame leakage protection does still have some use in some circumstances.  In essence frame leakage is an earth fault...

In an earlier note on the site [Photovoltaic (PV) - Electrical Calculations], the theory of solar (PV) cell calculations was introduced.  In particular...