Oscillators are used almost in all electronic devices such as computers, receiver, transmitters, audio frequency equipments, etc. They are basically used to generate signals. Different types of oscillators are available in the market; however same principle drives them all. Every oscillator consists of an active device which is known as amplifier. This sensitive amplifier is used in the oscillator to produce certain output. This output is supplied back to input in phase which further help in regenerating and sustaining the signal.
To understand the concept of oscillator, there is none other than the commonest example of pendulum of a clock. Whenever a pendulum is set in motion, it begins swinging and oscillating at a particular frequency. Apart from this, the length of the oscillator is also a factor in determining the frequency of an oscillator.
Oscillator makes use of energy to move back and forth. The transformation of energy causes oscillation in the pendulum. For example in case of pendulum, the potential energy gets converted in to kinetic energy which leads to oscillation. However, any physical force can stop oscillator's physical movement. Even, electronic oscillators are designed to work on the same principle.
Electronic oscillators are basically categorized into two, namely harmonic oscillators and relaxation oscillators.
Harmonic oscillators: These types of oscillators are used in the components where sinusoidal waveform needs to be generated. Amplifier in harmonic oscillators delivers gain and a resonant circuit supply a back signal to the input. Oscillation occurs at resonant circuit where gain takes place around the loop. Crystal oscillators and LC-tank oscillators are some of the examples of harmonic oscillators.
Relaxation oscillators: These types of oscillators generate triangular waveform that is usually used in monolithic integrated circuits. Relaxation oscillator helps to get operational frequencies with least number of external components. These types of oscillators are also categorized into three topologies, namely grounded-capacitor VCOs, emitter-coupled VCOs and delay-based ring VCOs.
All these Os are manufactured at a desired frequency which is set according to the application. In which it going to be used. These oscillators are very compact in size by which it takes very less space on the circuit board which helps to reduce the board size. These oscillators are so designed that it works in very shaky conditions. Because the setting of the oscillator's frequency is change when the device is in shaky condition. So at the the time of design we kept these things in mind.
