Motor drive circuit with short startup time
US8310188B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 29, 2007 |
| Grant date | Nov 13, 2012 |
| Priority date | — |
| Expiry date | Dec 15, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/20
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An H-bridge circuit is connected to a coil of the vibration motor that is to be driven. A comparator receives Hall signals indicating position information of a rotor of the vibration motor, and converts to an FG signal. A pulse width modulator generates a pulse-modulated pulse signal specifying energization time of the coil of the vibration motor. The pulse width modulator, in a first mode, after commencing start-up of the vibration motor, sets a duty ratio of the pulse signal to 100%, and after that, switches the duty ratio to a predetermined value in accordance with rotational frequency of the motor. In a second mode, the duty ratio of the pulse signal continues to be set to 100%. In a third mode, frequency and the duty ratio of the pulse signal are set based on a control signal of a pulse form inputted from outside. The control signal is used also in switching mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.