Here is an Operational amplifier based sine wave generator circuit , it is basically a wein bridge oscillator . Because of its simplicity and stability, one of the most commonly used audio frequency oscillator is wein-bridge. The wein bridge oscillator in which the weinbridge circuit is connected between the amplifier input and output terminals. The bridge has a series RC network in one arm and a parallel RC network in the adjoining arm. in the remaining arms of bridge, input resistor R1 and Feedback Resistor Rf is connected. Read More.....