We are pleased to present below all posts archived in 'April 2012'. If you still can't find what you are looking for, try using the search box.
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 of a notepad of concepts really, whi... read more..
Sometimes it’s useful to be able to quickly lookup a piece of technical information. This note is a collection of information related to motors, and in particular ac induction motors. read more..
Variable frequency drives are widely used to control the speed of ac motors. This note looks at the mechanisms which enable d... read more..
Electric motors are one of the most widely used items of electrical equipment. Improving motor efficiency benefits include, reduced power demand, lower operating costs and reduced environment impact.... read more..
Collection of links to various places with useful motor information. I’ll try and return to the page every now and again to update it with any motor notes added to the site. read more..
Insulation on a motor prevents interconnection of windings and the winding to earth. When looking at motors, it is important to understand how the insulation functions and its practical applicatio... read more..
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 mag... read more..
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. read more..
The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of REF protection. read more..
Electrical notes are a collaborative collection of electrical engineering information and educational material. Any registered user can add content.
Think of Notes as an online book;&#... read more..
The widely used United Sates standard ANSI/IEEE C37.2 'Electrical Power System Device Function Numbers, Acronyms, and Contact Designations' deals with protective device function numbering and acronyms. ... read more..
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, Google and Wikipedia have tons of ... read more..
Working in the vicinity of electrical equipment poses an hazard. In addition to electric shock hazard, fault currents passing through air causes Arc Flash...
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...
Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...
Current transformers (CTs) are used to convert high level currents to a smaller more reasonable level for use as inputs to protection relays and metering...
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...
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...
We have a sister note to this (Robots - Interesting Video), in which I have posted some videos of interesting robots developed by commercial corporations...
MIT OpenCourseWare, makes the materials used in teaching all MIT subjects available on the Web, free of charge, to any user in the world.
The (relatively new) switchgear and control gear standard, IEC 61439 'Low-voltage switchgear and controlgear assemblies' has three methods which can be...
I have been thinking recently that there appears to be less professional integrity around than when I first started my career in electrical engineering...
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