Motor speed detection apparatus and motor control apparatus
US8836321B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 2012 |
| Grant date | Sep 16, 2014 |
| Priority date | — |
| Expiry date | Mar 13, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/489
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The motor speed detection apparatus detects rotational speed of a motor. The apparatus includes an FG coil (21) and a magnet (22) to be relatively moved with rotation of the motor, the FG coil outputting an alternating-current signal to be sampled by the apparatus, an A/D converter (1) to convert the alternating-current signal into a digital signal, an integrator (2) to perform time integration on the digital signal, a first determiner (3, 9) to determine which one of plural threshold ranges includes an integration value obtained by the integrator, a second determiner (3, 8) to determine whether change of the integration value is increase or decrease, and a logical product calculator (3, 10) to produce a binary signal showing a logical product of determination results of the first and second determiners. The apparatus calculates the rotational speed based on a production cycle of the binary signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.