Difference Colpitts Oscillator and Hartley Oscillator in tamil

HARTLEY OSCILLATOR
Hartley Oscillator is a device that generates oscillatory output (sinusoidal). It consists of an amplifier linked to an oscillatory circuit, also called LC circuit or tank circuit. The function of tank circuit is to tune a certain frequency.
LC oscillators are designed to operate in the radio-frequency range. Its inductance will be in micro Henries. However they can also be designed to produce oscillations in the low audio-frequency range. But for the low-frequency operation, the inductors used will be very large in value, i.e of milli Henrie range and hence very large in physical size.

The circuit oscillates when the components are suitably selected to satisfy the Barkhausen criteria.
WORKING
When the supply is switched–on, a voltage V1 is developed across L1 and V2 across L2.V1 is the oscillator output. There is a phase difference of 1800 between the voltage of L1 and L2.The voltage across L2 (V2) is given as the feedback signal. Since the amplifier is in CE configuration, it produces a phase difference of 1800.Therfore amplifier and the feedback network together produces a phase difference of 360.i.e, a positive feedback is achieved and circuit work as an oscillator.
                  
Once energy is supplied to the tank circuit, cycle begins. The capacitor stores energy in its electric field whenever there is a potential difference across its plates. As the current begins to flow out of the capacitor and into the inductor, a magnetic field builds up around the coil. Capacitor loses its energy and current will continue to flow in the inductor caused by the effect of the energy in the magnetic field. This current will start to send current back into the capacitor, in reverse direction. The cycle then repeats, over and over, at a period (frequency) that is determined by the values of the inductor, the capacitor.