In this video, the Voltage Controlled Oscillator (VCO) is explained in detail. By watching this video, you will learn the following topics: 0:00 Introduction 0:21 What is Voltage Controlled OScillator 1:56 Applications of Voltage Controlled Oscillator 2:09 Types of VCO and Basic Working Principle 5:53 Voltage Controlled Oscillator using 555 timer 6:48 Specifications of Voltage Controlled Oscillator (VCO) What is Voltage Controlled oscillator (VCO)? It is the oscillator whose frequency can be controlled using the external control voltage. In the conventional oscillators, to change the oscillator frequency, it is required to tune the passive components like a resistor and the capacitor. But in the VCO, with the given set of passive components, just by changing the control voltage the output oscillation frequency can be changed. Applications of VCO: The Voltage Controlled Oscillators are used in many communications of applications. Here is the list of some of the applications: 1) Phase Lock Loop 2) Modulation and Demodulation Circuits 3) Frequency Synthesizers 4) Function Generators Types of VCO: The Voltage Controlled Oscillators mainly can be classified into two categories. 1) Harmonic Oscillators 2) Relaxation Oscillators In this video, the basic working principle of both types of oscillators is explained. And the different important specifications of the VCO is also explained in the detail: Specification of VCO: 1) Tuning Range 2) Tuning Gain 3) Supply Pushing and Load Pulling 4) Spectral Purity (Phase Noise) The link for the other useful videos: 1) How Oscillator Works: https://www.youtube.com/watch?v=XVS8Puf4tiw 2) Varactor Diode https://www.youtube.com/watch?v=OnVNOGL1nOc 3) 555 timer https://www.youtube.com/watch?v=EGmreVQ-yNM 4) 555 timer as Astable Multivibrator https://www.youtube.com/watch?v=iJYm_BGqa1A This video will be helpful to everyone in understanding what is Voltage Controlled Oscillator. #VoltageControlledOscillator #VCO Follow my second channel: https://www.youtube.com/channel/UCGA2TO8ylVqFHpucwn_6Jlw Follow me on Facebook: https://www.facebook.com/ALLABOUTELECRONICS/ Follow me on Instagram: https://www.instagram.com/all_about.electronics/ Music Credit: http://www.bensound.com/