Device for controlling rotational speed of motor
US5130626A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 1990 |
| Grant date | Jul 14, 1992 |
| Priority date | — |
| Expiry date | Nov 29, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P7/293
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A device for controlling the rotational speed of a motor carries out feedback control by a speed difference control signal and a phase difference control signal. A first time period from a reference time point to a time when a newest detection pulse is outputted is calculated every time a predetermined number of detection pulses are counted by detection pulse counters. A second time period from the reference time point to the time when a command pulse, which is assigned an ordinal number equal to the ordinal number of the newest detection pulse and which thereby corresponds to the newest detection pulse, is calculated on the basis of the total number of pulses counted by the detection pulse counters in the time period from the reference time point to the time when the newest detection pulse is outputted, and the period of the command pulse. The phase difference between the newest detection pulse and the command pulse corresponding thereto is calculated on the basis of the first time period and the second time period and the period of the command pulse. A phase difference control signal proportional to the phase difference calculated is thus determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.