Invention Grant
- Patent Title: Voice coil motor control system and method
- Patent Title (中): 音圈电机控制系统及方法
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Application No.: US13607974Application Date: 2012-09-10
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Publication No.: US08593096B1Publication Date: 2013-11-26
- Inventor: Jye Sheng Hong , Siew Yong Chui
- Applicant: Jye Sheng Hong , Siew Yong Chui
- Applicant Address: BM Hamilton
- Assignee: Marvell International Ltd.
- Current Assignee: Marvell International Ltd.
- Current Assignee Address: BM Hamilton
- Main IPC: H02P7/00
- IPC: H02P7/00 ; H02P7/29 ; G05B11/28

Abstract:
Analog control of the pulse width used to control the speed of a voice coil motor may be implemented using a “constant-current-charging-capacitor” configuration where the time needed to charge the capacitor is directly related to how far the actual motor speed is from the target speed. The BEMF voltage, indicative of motor speed, is sampled, and then stored in a storage capacitor, which is allowed to charge/discharge to a target voltage level. The time required to charge/discharge the capacitor to the target voltage is directly proportional to the difference between the BEMF voltage and the target voltage, and may be used directly as the pulse width (i.e., the charging time) in the PWM velocity control system. To avoid larger capacitors, a pulse multiplier circuit can be added, allowing charging/discharging the sampled voltage to the target voltage to be repeated by a number, N, of times.
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