Title:
SERVO SIGNAL DEMODULATION CIRCUIT FOR MAGNETIC DISK DEVICE
Document Type and Number:
Japanese Patent JPS6394477
Kind Code:
A
Abstract:
PURPOSE:To obtain a stable positioning accuracy by adding a feedback circuit to a buffer amplifier so as to eliminate the amplitude of a servo signal attended with temperature change. CONSTITUTION:An AGC amplifier 1 amplifies a servo signal to a prescribed amplitude and this signal is fed to a peak hold circuit group 4 and a feedback circuit 3 via a buffer amplifier 2. A specific peak value of an input signal of the circuit group 4 is detected respectively. The circuit 3 amplifies a difference between a DC potential of the input signal and a prescribed potential, uses a forward voltage drop of diodes connected in series, the voltage level is converted and fed to a bias set section of the amplifier 2. Then a potential difference between the outputs of the circuit group 4 is obtained by a subtractor 5 to form it as a position signal and the potential difference is fed to an AGC amplifier control circuit 6, and its output controls the amplification of the amplifier 1.
Inventors:
KABURAGI CHIHARU
Application Number:
JP23960386A
Publication Date:
April 25, 1988
Filing Date:
October 08, 1986
Export Citation:
Assignee:
SEIKO EPSON CORP
International Classes:
G11B21/10; (IPC1-7): G11B21/10
Attorney, Agent or Firm:
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