Patent · US Expired

Digital detector

US4028686A · kind A · utility

18Cited by
3References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 10, 1976
Grant dateJun 7, 1977
Priority date
Expiry dateMay 10, 1996

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01P13/00
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A detector for a dynamic phenomenon with a cyclically varying condition, as motion of a rotating part. At least three digital sensors are separated in phase with respect to the cyclic condition. The instantaneous outputs of the sensors have a plurality of repeating sequential states so long as the dynamic phenomenon exists. The instantaneous outputs of the sensors have at least one state which does not occur during existence of the dynamic phenomenon but which does occur in the absence thereof. Logic circuits respond to the digital sensor outputs and detect information about the dynamic phenomenon. Detection of the repetition rate of an instantaneous output state of the sensors provides a measure of speed. An absence of rotation is indicated by the occurrence of another output state. In another disclosed embodiment, the detector monitors a three phase power system and detects a phase outage by the occurrence of an abnormal sensor output state.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.