__Introduction
__

The notion of oscillator is essential to the study of the dynamic of evolutions.

Periodic phenomena are extremely spread. And moreover, with the Fourier transformation, an evolution can be devided in a sum of periodical contributions.

So you easily understand the essential role for analysis of the oscillator.

The pendulum is a simple example of oscillator.

The aim of this presentation of many configurations of pendulum is to introduce some of the most important notions.

From the simple to the parametric pendulum, the idea of instability will be summarized.

And, to make this report less formal, some internet links will allow you to visualize the possible cases and their evolutions...

__Structure
of this report__

__I. The FREE
oscillator : the simple pendulum without any friction ( non-dissipativ
system)__

__II. The
ABSORBED oscillator : the pendulum with
fluid friction__

__III. MAINTAINED
oscillators : pendulum and equation of Van der Pol__

__IV. The PARAMETRIC
oscillator : the simple pendulum without friction in a various gravitational
range__

__V. A SPECIAL
oscillator. The notion of Bifurcation__

__VI. The Interview of
PIERRE BERGE.__