Electronic oscillator

Definition:

An electronic oscillator is an electronic circuit that produces a repetitive electronic signal, often a sine wave or a square wave. The output frequency is determined by the characteristics of the devices used in the circuit.

Oscillators are often characterized by the frequency of their output signal:

  A low-frequency oscillator (LFO) is an electronic oscillator that generates a frequency below approximately 20 Hz. This term is typically used in the field of audio synthesizers, to distinguish it from an audio frequency oscillator.

An audio oscillator produces frequencies in the audio range, about 16 Hz to 20 kHz.

An RF oscillator produces signals in the radio frequency (RF) range of about 100 kHz to 100 GHz.

Oscillators designed to produce a high-power AC output from a DC supply are usually called inverters.

types of electronic oscillator

 – the linear or harmonic oscillator [ Harmonic oscillator ] :

• Feedback oscillator   
  
• Negative-resistance oscillator
  

Types:

*Armstrong oscillator, a.k.a. Meissner oscillator

*Clapp oscillator

*Colpitts oscillator

*Cross-coupled oscillator

*Dynatron oscillator

*Hartley oscillator

*Opto-electronic oscillator

*Pierce oscillator

*Phase-shift oscillator

*Robinson oscillator

*Tri-tet oscillator

*Vackář oscillator

*Wien bridge oscillator

 - the nonlinear or relaxation oscillator [ Relaxation oscillator ] :

Types

*Multivibrator

*Pearson–Anson oscillator

*Ring oscillator

*Delay-line oscillator

*Royer oscillator

A voltage-controlled oscillator (VCO):

       Voltage controlled oscillator is a type of oscillator where the frequency of the output oscillations can be varied by varying the amplitude of an input voltage signal. Voltage controlled oscillators  are commonly used in frequency (FM), pulse (PM) modulators and phase locked loops (PLL). Another application of the voltage controlled oscillator is the variable frequency signal generator itself.