| 摘要 |
PURPOSE:To attain a high degree of integration and general-purpose application for a servo control circuit by constituting a circuit which detects the position and moving speed of a head as a digital signal processing circuit in a servo control system. CONSTITUTION:The peak values A-D are held at peak holding circuits 3a-3d by a servo signal Sv, and signals A-D are supplied to a selecting circuit 21. The circuit 21 selects the signal A held by a sampling pulse P1, for example, in the period of a pulse P2 and delivers it to an A/D converter 22. Then the signal A is converted into a digital signal Ad and stored in a register 23a during the start of a pulse P3. This action is successively repeated to store digital signals Ad-Dd corresponding to the envelope signals of the position information into registers 23a-23d respectively and then applied to multiplexers 24a and 24b. Here signals Ad and Bd corresponding to position information A and B, for example, are selected. At the same time, a digital adder/subtractor 25a performs a subtraction, for instance, to deliver a signal A-B. |
