Simple VCO

The frequency of the sine wave oscillator shown here is determined by a direct voltage, Uc, of 0-15 V. The distortion on output signals of up to 10 V p-p is not greater than 1%; when the output is reduced with the aid of P1 to 1 V p-p. the distortion drops to below 0.1%. It is not recommended to use output signals below 1 V p-p, because the oscillator then become unstable and temperature-dependent.