1. Electronic An electronic oscillator is an electronic circuit that is capable of creating a repetitive waveform. The most common is a sinusoidal[?] wave, but ramp, step, square, and triangular wave-form oscillators are possible. The oscillator circuits are sometimes contained within a device called a signal generator. The signal generator is a box with a variable frequency dial, a waveform selector an attenuator, and a least one pair of output plugs. See diagram on the right.

2. Mechanical

A reciprocating or vibrating mechanical device like a piston or a tuning fork are both mechnical oscillators.

3. Mathematical

The mathematical description of an oscillator involves a description of a continuous function that varies cyclically above and below a mean or other reference, extending from -infinity to +infinity, never fading, never diverging. This can be represented as a sequence:

For example the sequence 1, -1, 1, -1, 1, -1,... is an oscillation that is analogous to a square-wave generator. [This paragraph is horribly written; a mathematician who knows the conventions of this area could correct it. I have changed the incorrect word "series" to "sequence".]

See also:

• harmonic oscillator
• simple harmonic motion
• differential equation