Q. What is an oscillator? Discuss the advantages of Oscillators ?

An oscillator is a system consisting of active and passive circuit elements to produce a sinusoidal or other repetitive waveforms at the output without the application of an external input signal. The function of an oscillator is opposite to that of a rectifier that converts ac power into a dc power. Oscillations are produced without any external signal source. The only input power to an oscillator is the d. c. power supply. It receives d. c. energy and changes it into a. c. energy of desired frequency. The frequency of oscillations depend upon the constants of the device.