Patent · US Expired

Line voltage monitor system

US4558275A · kind A · utility

49Cited by
38References
21Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 21, 1981
Grant dateDec 10, 1985
Priority date
Expiry dateApr 21, 2001

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R19/16528
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

The Detector Module derives a synchronization signal from the half-wave crossovers of the AC power line. A half-wave peak detector detects the peak voltage of each half wave. An impulse detector detects the voltage of any impulses occurring during a half-wave. A common mode detector detects the peak value of each half-wave across the common mode terminals. A microcomputer is provided together with a clock/calendar for recording threshold values and for each half-cycle if a SAG or SURGE is detected; the time that the SAG or SURGE was initiated; the voltage of the half cycle of greatest SAG or SURGE during the event and the number of cycles is recorded. For LO and HI AVERAGE an average resistor stores the average of the peak values for each of the last thirty-two half cycles and that average is compared with the threshold to determine if an event has occurred. If an event has occurred, the duration and the lowest average occurring during the event is stored. The time an impulse occurs is recorded to the nearest second along with the voltage of the peak impulse during the half cycle of the event is stored. For COMMON mode the value of the worst half cycle occurring during any event is…

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