WIEN BRIDGE OSCILLATOR CIRCUIT USING OP AMP

 WIEN BRIDGE OSCILLATOR CIRCUIT USING OP AMP

This Wien bridge oscillator is made up of an Op Amp with an RC feedback connected in parallel and series into the non inverting input of the Op Amp as shown in the circuit diagram below.

This RC feedback path has a zero degree phase shift. At the selected resonance the voltage input at the inverting and the non inverting input are equal and in phase, therefore the negative and positive feedback will cancel out causing the output of the op amp to oscillate.

The frequency oscillation is given as

               f=1/2pieRC

In circuit diagram R=R2=R3=29kΩ

                                   C=C1=C2=0.1uf

The gain is given as;

A=1+Rf/Rin

In the circuit diagram Rf=RV1, a variable set at 60kΩ, Rin=33kΩ

CIRCUIT DIAGRAM

The output is a pure sine wave.