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...

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...

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...

Recently I have seen a few interesting articles on viable cold fusion; the combining of atoms at room like temperatures to create boundless energy. Now...

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...

A frequent problem in fault calculations is the obtaining of equipment parameters.  While it is always preferable to use the actual parameters of the equipment...

We have a sister note to this (Robots - Interesting Video), in which I have posted some videos of interesting robots developed by commercial corporations...

Estimating maximum demand is a topic frequently discussed. Working out how much power to allow for a building can be very subjective . Allowing too much...

MIT OpenCourseWare, makes the materials used in teaching all MIT subjects available on the Web, free of charge, to any user in the world.

When sizing cables, the heat generated  by losses within any sheath or armour need to be evaluated. When significant, it becomes a factor to be considered...