Basics of Oscillator

Oscillator is a mechanical or electronic device works on the principle of oscillation i.e. a periodic fluctuation between two things based on changes in energy. It is of two types; linear oscillators and non linear oscillators. The wave shape and amplitude are determined by the design of the oscillator circuit and choice of component values.

1. Oscillators

2. It is an electronic circuit that produces a periodic, oscillating signal often a square wave and a sine wave. C onverts direct current from a power supply to an alternating current signal. Common signals generated by the oscillators includes clock signals, sound signals produced by video games, electronic beepers and broadcast signals by television and radio transmitters. Introduction

3. Conditions For Oscillations The loop phase shift must be  0 ͦ and 360 ͦ . The loop gain must be slightly greater than  unity . The voltage gain around the closed feedback loop A cl  is the product of the amplifier gain A v  and the attenuation B of the feedback circuit . A cl  = A v B

4. A loop gain greater than 1 will rapidly cause the output to saturate at both peaks of the waveform and producing unacceptable distortion . If the amplifier gain is greater than 100, it will cause the oscillator limit both peaks of the waveform.

5. Oscillator Circuit Oscillator Circuit is divided into three sections:

6. Tank Circuit produces oscillations which are amplified by the transistor and produces amplified output in the collector side . Amplifier circuit   basically amplifying the small sinusoidal oscillations present in the base-emitter circuit and generates output in the amplified form . Feedback circuit fed back the energy of the collector circuit to the base circuit through the phenomenon of Mutual induction . 

7. Types Of Oscillator Oscillator Types Linear or Harmonic Oscillator Non Linear or Relaxation oscillator Feedback Oscillator Negative Resistance oscillator LC Oscillator RC Oscillator Crystal Oscillator

8. LC Oscillator In LC oscillators, the inductor and capacitor are connected in parallel form a  Tank circuit . Tuned circuit can store electrical energy oscillating at its resonant frequency. Used in radio frequency circuits because of their ease of implementation and good phase noise characteristics. 

9. Types of LC Oscillator LC Oscillator Hartley Oscillator Colpitts Oscillator Clapps Oscillator Used to generate high-frequency waveforms or signals into which the oscillation frequency is determined by a tank circuit comprising of two  inductors  and one  capacitor . U sed to produce an oscillation at certain frequency and it take feedback from the active device from the voltage divider made of two  capacitors  in series across the inductor. C onstructed from a transistor and positive feedback network using the combination of an inductance with a capacitor for frequency determination.

10. RC Oscillator Type of feedback oscilIator consist of an amplifying device, resistor, vacuum tubes and op amps. To achieve positive feedback output energy is fed back to its input through a network of resistors and capacitors. RC filter type combinations are preferred to generate sine waves at low frequencies .

11. Types of RC Oscillator LC Oscillator Wien Bridge Oscillator Phase shift oscillator Used to generate sine waves at a large range of frequencies and has a two stage RC coupled  amplifier  circuit that has low distortion and good stability at its resonant frequency Linear electronic circuit that produces a sine wave output whose output is fed back to its input through a phase shift network consisting of resistors and capacitors in a ladder network. 

12. Crystal Oscillator It  is an electronic oscillator  used to create an electrical signal of precise frequency by using the vibrating crystal mechanical resonance made of piezoelectric material.

13. Thank You For more detail of Oscillators go to http://analyseameter.com