Motor control device and motor control method
US7183737B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 16, 2004 |
| Grant date | Feb 27, 2007 |
| Priority date | — |
| Expiry date | Jun 2, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P29/68
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor control device selectively turns on or off a drive transistor in-accordance with a PWM control signal Sp, such that a drive current Im supplied to a motor is adjusted. The device also samples and holds a motor current Sm for obtaining a motor current value Ih. With reference to the motor current value Ih, the device protects the motor from an overcurrent. Sampling and holding of the motor current Sm is performed for a sampling and holding time Ts. The sampling and holding time Ts corresponds to a time period between a first point in time when the level of the PWM control signal Sp is switched for turning off the drive transistor and a second point in time that precedes the first point in time by a predetermined period. As a result, the motor current value Ih is detected with high accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.