| 摘要 |
PURPOSE:To obtain a sinusoidal wave oscillating output having a constant amplitude and less distortion, by constituting a positive feedback loop with a band- pass filter, a comparator and an amplitude adjusting circuit and adjusting the amount of adjustment of the amplitude adjusting circuit in response to the filter output. CONSTITUTION:The comparator 1 converts a sinusoidal wave signal of the band- pass filter 3 and adjusts the amplitude of the rectangular wave signal at the amplitude adjusting circuit 2. The band-pass filter 3 extracts the basic wave component of the rectangular wave signal and consists of the 2nd order band- pass filter of multiplex feedback type or the like. The automatic gain adjusting circuit 4 compares the amplitude of an output signal of the band-pass filter 3 with a reference voltage and controls the amplitude of the output signal by feeding back the output to the amplitude adjusting circuit. |
