AIM: To construct and simulate the RC phase shift oscillator and to verify the frequency of oscillation theoretically and by simulation..
THEORY:
RC-Phase shift Oscillator has a CE amplifier followed by three sections of RC phase shift feed back networks. The out put of the last stage is return to the input of the amplifier. The values of R and C are chosen such that the phase shift of each RC section is 60º. Thus The RC ladder network produces a total phase shift of 180º between its input and output voltage for the given frequencies. Since CE Amplifier produces 180 º phases shift the total phase shift from the base of the transistor around the circuit and back to the base will be exactly 360º or 0º. This satisfies the Barkhausen condition for sustaining oscillations and total loop gain of this circuit is greater than or equal to 1, this condition used to generate the sinusoidal oscillations.
The frequency of oscillations of RC-Phase Shift Oscillator is,
1
f = -----------
2∏RC* √6