公开(公告)号：JPH1169872A

公开(公告)日：1999-03-09

申请号：JP15081998

申请日：1998-06-01

Applicant: ST MICROELECTRON INC

Inventor： CAROBOLANTE FRANCESCO

IPC: G11B21/10 ,  G11B21/08 ,  H02P25/02 ,  H02P25/06 ,  H02P7/00

Abstract: PROBLEM TO BE SOLVED: To change a through rate, by conducting selective connection to a voltage supply source in response to a driver signal connected to inductive load and received by an input terminal, and performing through rate control of voltage on inductive load in response to a through rate control signal received from a through rate control circuit. SOLUTION: A signal which a reading head 24 supplies include positional data on a rotating disc 26. A microprocessor 14 controls a driver circuit 12 with a through rate control signal and an analog control signal 20. The through rate control circuit 11 supplies the through rate control signal to the driver circuit 12 as a power supply signal. When the microprocessor 14 supplies a digital control signal 16 to a digital-analog converter 18, a DAC18 converts it into an analog control signal 20 to apply it to the input terminal of the driver circuit 12. The driver circuit 12 drives PWM current in the forward and reverse directions through a coil, and conducts acceleration/deceleration in response to the current to position the reading head 24 above a rotating disc 26.

公开(公告)号：JPH10271876A

公开(公告)日：1998-10-09

申请号：JP4701398

申请日：1998-02-27

Applicant: ST MICROELECTRON INC

Inventor： CAROBOLANTE FRANCESCO

IPC: H02P6/06 ,  H02P6/08 ,  H02P6/10

Abstract: PROBLEM TO BE SOLVED: To reduce the occurrence of torque ripples by excellently controlling all torques impressed upon a motor and gradually through-processing PWM driving signals during a communication period. SOLUTION: A through-processing type current switch stage 106 generates through-processed control phase signals by using phase control signals from a buffer stage 104, and each of the signals reaches during a transition period and is proportional to its succeeding phase control signal. The through-processed phase signals are through-processed from one state to the next state (for a given phase) with respect to time during the transition period. The through- processed phase control signals are supplied to a comparator 108. The comparator 108 compares the through-processed phase control signals with a triangular wave signal supplied from a triangular wave generator 112 and outputs proportional PWM (pulse width modulation) phase control signals for each phase. Therefore, the occurrence of torque ripples can be reduced.