In the figure we have an oscillator circuit by Wien Bridge (Wien Bridge Oscillator). The frequency of the generated signal is calculated using the following equation:
When = 2fc = 1 / RC the feedback is in phase (positive feedback) and the gain is 1/3, which means that the circuit requires an amplifier with a 3 gain.
When Rf = 2RC the amplifier gain is 3 and the oscillation occurs at a frequency f = 2RC. The circuit shown in the figure oscillates at a frequency of 1.65 kHz as much as 1.59 kHz with the components shown.
