Electronic watch
US8848492B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Feb 9, 2011 |
| Grant date | Sep 30, 2014 |
| Priority date | — |
| Expiry date | Apr 2, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04G19/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
When recovering power from a motor driver, a forward voltage across a parasitic diode can reduce the recovery efficiency, and control of a power recovery operation can take an unnecessarily long time. In order to address this problem, the power recovery operation is performed as follows without being affected by a parasitic diode: near a peak position of a waveform of an induced current resulting from free oscillation of a rotor after a drive pulse is output, a recovery pulse having such a level that the rotor does not rotate is output from a terminal different from a motor driver terminal to which the drive pulse was output. Also, by adjusting the width and output timing of the recovery pulse based on a power supply voltage, the power recovery can be optimized for the power supply voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.