## Saturday, 16 August 2008

### Eye Pattern - An Interesting Analytical Concept

This post talks about what exactly a sine wave is, and a very unique application of this sine wave as an analytical tool.

So what is a sine wave or what does it represents?

The diagram below will explain the concept of this sine wave.

On the left side of the above diagram is a rotor cycling anti-clockwise. What it produces, in vertical measurement, is a variation in height over time. This results in a sine wave.

Therefore, the rotational frequency defines the period of one cycle.

If this frequency changes, the period changes as a result.

This concept is used to test the consistency of rotation. It is an engineering application that has a useful indication.

See an example below for a slowly deviating rotational frequency of the rotor.

The eye pattern shown in the diagram is an indication of how consistent is the rotation.

If the area of the eye pattern is small, it indicates that there is large fluctuation to the rotational speed. The target is to have a large area for this eye pattern.

If the speed does not change, the sine wave will be only one, and the above diagram will not reflect many of the other sine waves.

Therefore, a simple sine wave, if understood properly, can be used as a useful analytical or measurement tool to detect any defect or inconsistency in the motor.

This concept is mainly applied in the rotating disc industries. Compact disc player, hard disc control, DVD player are some examples utilising this eye pattern detection.

Maths, thus, serves many applications besides purely training the mind to think systematically.
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