Introduction To Oscillator Circuits

ABHIRAJ BOHRA

What is Oscillation?

• repetitive variation of some measure about a central value

• swinging pendulum and AC power. 

Electronic Oscillator• An electronic circuit that produces a

repetitive, oscillating electronic signal.• Oscillators are often characterized by

the frequency of their output signal: • Audio• RF• LFO

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

• There are two main types of electronic oscillator: the linear or harmonic oscillator and the nonlinear or relaxation oscillator.

Linear Oscillator• produces a sinusoidal output. • There are two types of linear oscillators: Feedback oscillator Negative resistance oscillator

Linear Oscillator Circuits

• Hartley oscillator• Colpitts oscillator• Clapp oscillator• Phase-shift oscillator• RC oscillator (Wien Bridge and "Twin-T")• Cross-coupled LC oscillator

Hartley Oscillator

Colpitts Oscillator

Clapp Oscillator

Phase – Shift Oscillator

RC Oscillator

LC Circuit

Relaxation oscillator

• produces a non-sinusoidal output.

• Types of relaxation oscillator circuits include:

multivibrator

ring oscillator

delay line oscillator

Royer oscillator

rotary traveling wave oscillator

Applications

• Harmonic Oscillator

Harmonic oscillators, also known as sine-wave oscillators, are used in transmitters to create carrier waves, waveforms created for the purpose of transmitting information. They are also used in radios as a way of changing the modulation of information-carrying waveforms to allow the device (the radio receiver) to receive and interpret them.

Applications

• Relaxation Oscillator

Relaxation oscillators, also known as non-sinusoidal oscillators, are often found in computers and televisions as timers and switches. The jagged waveforms created by relaxation oscillators are caused by abrupt, arrhythmic events, such as the sudden discharge of a capacitor. Variations of this type of oscillator can also be found in strobe lights and electronic camera flashes.

Applications

• Crystal-controlled Oscillator

Crystal-controlled oscillators are a form of relaxation oscillator. The distinction between the two is that a crystal-controlled oscillator uses a crystal in place of a standard inductor-capacitor circuit to improve waveform frequency stability. They are used in a number of technical electronic devices, such as MTI radars, wireless base stations, telecom timing modules, satellite terminals and ethernet transceivers.

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