Just added a page to the tools, which will allow you to calculate the synchronous speed, slip and rated torque for an induction motor. Not a particularly...

A UPS is an uninterruptible power supply.  It is a device which maintains a continuous supply of electrical power, even in the event of failure of the...

The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...

The fundamental component of any analogue computer is the operational amplifier, or op amp. An operational amplifier (often called an op-amp,) is a high...

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...

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...

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...

The (relatively new) switchgear and control gear standard, IEC 61439 'Low-voltage switchgear and controlgear assemblies' has three methods which can be...

How often installations are inspected is up to the owner of the installation, provided such durations do not exceed any regulatory maximums in force. ...

When looking at the design of a lighting scheme it is useful to have an understanding on the nature of light itself and some of the basic theory associated...