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...

Everything physical in electrical engineering from insulations to conductors revolves around materials. Here we are listing common materials along with...

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...

The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.

Dielectrics (insulating materials for example) when subjected to a varying electric field, will have some energy loss.   The varying electric field causes...

Problems on achieving maximum voltage drop within an installation come up often. Depending where you live, local regulations will have different limits...

Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent magnets or...

If you want to check a circuit is dead (not live), you should always use the three point method. First check a known live circuit, then check the dead...

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

The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods...