Crystal oscillator

Crystal oscillator:

• An electronic circuit that is used to generate an electrical signal of precise frequency by utilizing the vibrating crystal's mechanical resonance made of piezoelectric material. 
• There are different types of piezoelectric resonators, but typically, quartzcrystal is used in these types of oscillators

RC phase shift oscillator

RC phase shift oscillator:

• A phase-shift oscillator is a linear electronic oscillator circuit that produces a sine wave output.
• It consists of an inverting amplifier element such as a transistor or op amp with its output fed back to its input through a phase-shift network consisting of resistors and capacitors in a ladder network.                                                                                                                  

  

  RC phase shift oscillator

RC oscillator

RC oscillator:

• RC oscillators are a type of feedback oscillator; they consist of an amplifying device, a transistor, vacuum tube, or op-amp, with some of its output energy fed back into its input through a network of resistors and capacitors, an RC network, to achieve positive feedback, causing it to generate an oscillating.

Principle of oscillator

• A clock pendulum is a simple type of mechanical oscillator.
• There are many types of electronic oscillators, but they all operate according to the same basic principle: an oscillator always employs a sensitive amplifier whose output is fed back to the input in phase.
• Thus, the signal regenerates and sustains itself.  

LC oscillator

LC oscillator:

• An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, is an electric circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together.                                                                                           
  

Types of oscillator

• Armstrong Oscillator
• Crystal Oscillator
• Hartley oscillator
• RC Phase Shift Oscillator
• Colpitts Oscillators
• Cross-Coupled Oscillator
• Dynatron Oscillator
• Meissner Oscillator
• Optoelectronic Oscillator
• Phase Shift Oscillator
• Wine Bridge Oscillator
• Robinson Oscillator
• Tri-Tet Oscillator