Electronic Oscillator

It is an electronic circuit that produces a periodic, oscillating or alternating current (AC) signal, usually a sine wave, a square wave, or a triangle wave, powered by a DC source.

Classification

By the frequency of their signal

• Low Frequency Oscillator (LFO): Produces frequencies below 20 Hz
  • This term is used in the field of audio synthesizers, to distinguish it from audio frequency oscillators
• Audio Oscillator: Produces frequencies between 20 Hz to 20 kHz
• RF Oscillator

By behaviour

• Linear / Harmonic Oscillator (makes sinusoidal waves)
• Nonlinear / Relaxation Oscillator (makes square / triangular waves)

Examples

The most common linear oscillator is a crystal oscillator, in which the output frequency is controlled by a piezo-electric Resonator consisting of a vibrating quartz crystal.

In common language, resonators refer to low budget, or ceramic oscillators, while oscillators refer to crystal oscillators.