| 摘要 |
PURPOSE:To obtain a stable output level even when an input level is fluctuated. CONSTITUTION:A band pass filter 4 extracts a pilot signal (p) from the output signal of an amplifier 3. A band pass filter 7 and a detector 8 are provided in parallel with the band pass filter 4 and a detector 5. The passing band of the band pass filter 7 is at the outside of the signal and shares a different frequency band from that of the band pass filter 4. The band pass filter 7 extracts a noise having a frequency component at the passing band of the passing filter 4 from the output of the amplifier 3 and sends the noise to the detector 8. |
