Rotation speed detecting apparatus
US4794551A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 23, 1986 |
| Grant date | Dec 27, 1988 |
| Priority date | — |
| Expiry date | May 23, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/489
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for detecting the rotation speed of a rotatory member such as a rotary shaft of an electric motor comprises a first counter for counting the pulses of a pulse signal of a frequency proportional to the rotation speed of the rotatory member, a presettable down-counter for counting down a predetermined value sequentially in response to clock pulses, and a CPU for reading out the count value of the first counter upon completion of prescribed count-down of the presettable down-counter and computing the rotation speed of the rotatory member on the basis of the count value thus read out. And upon termination of such computation, the CPU changes the count value of the presettable down-counter back to the predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.