| 摘要 |
PURPOSE:To attain quick and accurate positioning by increasing stepwise an output gain of an operational amplifier when the motor approaches near an object track to increase the decelerating current of a servo motor thereby reducing the repetition of overshoot/undershoot. CONSTITUTION:Suppose that a difference counter 13 is set that a prescribed signal is outputted stepwise over plural number of times from a point of time while being incremented to a count value corresponding to a prescribed position near an object track to a moving distance signal 5 to a preset object track. Further, as a decrement pulse incoming to the counter 13, a pulse generated once at track crossing and generated from a track crossing pulse generating circuit 11 is used. Contacts SW1-SW2 of an electronic switch 14 are closed and every time a prescribed signal comes stepwise from the counter 13, the corresponding contact is released sequentially and the connection of resistors R1-Rn is released. Thus, a feedback resistance of an operational amplifier 4 is increased to increase the output gain and the deceleration of the servo motor is increased stepwise. |
