Wien bridge sine wave oscillator circuit composed of LM101A

The chart shows the Wien bridge sine wave oscillator circuit. The amount of negative feedback circuit is determined by the internal resistance of FET. When the peak value of oscillator output reaches the regulated voltage of regulator diode D1, Q2 turns on, then the grid of Q1 FET becomes negative, Q1`s drain - source resistance increases, the neg

ative feedback increases, loop gain decreases. Similarly, when the oscillation amplitude decreases, the loop gain will increase, therefore, it can maintain a certain output range. C1, C2, R1 and R2 constitute a positive feedback loop to ensure the circuit oscillation. Connecting a l00k © resistor between drain and gate or gate and source of FET will ensure the FET working in the linear region and reducing distortion. Circuit oscillation frequency: f0 = 1/2. According to the component value of the figure, the oscillation frequency R1C1 is calculated approximately 1. 6kHz.

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