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...

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...

Nikola Tesla was born exactly at midnight on July 10, 1856 in the tiny village of Smiljan, Lika in Croatia. In his late teens, Tesla left the village to...

Years ago I was told that you should always try to write the best report you can.  Many years later I still think on this as one of the better pieces of...

Lead acid batteries are cost effect and reliable, making them suitable for many applications.This note examines topics of interest associated with the...

Power factor is the ratio between the real power (P in kW) and apparent power (S in kVA) drawn by an electrical load. The reactive power (Q in kVAr)...

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

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

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.

This is the second post in a series of two on periodic electrical inspections. In the first post, I discussed how often inspections should be carried out...