Different types of transistor oscillator

A transistor can work as a oscillators to produce undamped oscillations of any desired frequency it tank and feedback circuits properly connected to it. All oscilltions under different names have similar function i.e the produce continuous undemped output. The following are the transistor oscillators commonly used at various place in electronic circuits.
i) Tuned collector oscillator
ii) Colpitts oscillator
iii) Hartley oscillator
iv) Phase shift oscillator
v)  Bridge oscillator
vi) Crystal oscillator.

Tuned Collector Oscillator

The circuit of tuned collector oscillator it contains tuned circuit L₁-C₁ in the collector and hence the name. The frequency of oscillations depends upon the value of L₁ and C₁ is given by

 The feedback coil L2 in the base circuit is anagnetically to tank circuit L_{1. In practice} L_{1 and} L2 from the primary and secondary of the transformer respectively.