| 摘要 |
PURPOSE:To enhance the response performance of an arm feeding motor, by controlling the gain of a servo circuit that produces the arm position control signal in accordance with the declination of the arm. CONSTITUTION:The declination of a linear tracking arm 3 containing a cartridge stylus 4 at an end is detected by a Hall element 21 to receive the comparison from comparators 35 and 36 having the set prescribed threshold value via an amplifier 34. In case the detected voltage is a value between both threshold values, a switch 32 is closed to increase the gain of an amplifier 23 which amplifies the declination detection signal by an amount equivalent to the resistance ratio of resistances 31 and 32. Accordingly the gain of a servo circuit which produces the arm position control signal is increased in case the arm declination is small to drive an arm feeding motor 27. As a result, the response performance is enhanced for a linear tracking arm feeding motor to ensure a smooth turning action of the motor from the stop mode. |
