Stationary position detection circuit and motor drive circuit
US7176677B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2006 |
| Grant date | Feb 13, 2007 |
| Priority date | — |
| Expiry date | Jun 28, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/208
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A stationary position detection circuit and a motor drive circuit capable of more properly detecting the rotor position are disclosed. The stationary position detection circuit supplies an alternating current to each phase load of the motor. The time during which the current flows in a first direction and the time during which the current flows in a second direction opposite to the first direction are converted into electrical signals and amplified. In accordance with the value of the electrical signals, the position of the motor rotor in stationary mode is determined. The use of the alternating current, unlike the kickback voltage, makes it possible to improve the detection accuracy by amplifying the electrical signals with an increased number of alternations. An increased number of alternations can amplify the electrical signals without increasing the value of the alternating current, and therefore, unlike in the case of the kickback voltage, the alternating current of a large value is not required. As a result, the alternating current can be reduced to a small value and the vibration can be suppressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.