The ac resistance of conductors
In a previous article I looked at the dc resistance of conductors and in this article we turn our attention to ac resistance. If you have not read the...
Multimeter
Multimeters are undoubtedly the most common item of electrical test equipment in use. Often it is the first piece of equipment people will turn to when...
Maxwell's Equations - Gauss's Electric Field Law
Gauss's Electrical law defines the relation between charge ("Positive" & "Negative") and electric field. The law was initially formulated by Carl Friedrich...
IEC 60287 Current Capacity of Cables - An Introduction
IEC 60287 "Calculation of the continuous current rating of cables (100% load factor)" is the International Standard which defines the procedures and equations...
Variable Frequency Drive
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...
Introduction to Cathodic Protection
If two dissimilar metals are touching and an external conducting path exists, corrosion of one the metals can take place. Moisture or other materials...
8 Steps to Low Voltage Power Cable Selection and Sizing
A recurring theme on our forums is cable sizing. Now many installations are unique and require special consideration. However, a lot of the time things...
Capacitors - Energy Storage Application
Capacitors have numerous applications in electrical and electronic applications. This note examines the use of capacitors to store electrical energy....
Power Transformers - An Introduction
One of the fundamental requirements of an alternating current distribution systems it to have the ability to change the magnitude of voltages. It is more...
What is an Open Delta Transformer
In three phase systems, the use of transformers with three windings (or legs) per side is common. These three windings are often connected in delta or...