Patent · US Expired

Cryopump synchronous motor load monitor

US5900822A · kind A · utility

40Cited by
20References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 25, 1997
Grant dateMay 4, 1999
Priority date
Expiry dateJul 25, 2017

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P70/10
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

An apparatus and method for monitoring the torque load condition of a cryopump motor includes a power transducer for monitoring the electrical power input to the cryopump motor. A preferred embodiment of the power transducer includes a Hall-effect multiplier which measures the instantaneous and average electrical power input to the cryopump motor to determine torque load. Another preferred embodiment includes a power transducer which measures the Power Factor of the electrical power input to the cryopump motor to determine torque load. The Power Factor transducer includes a phase detector which detects the phase difference between the input voltage and the input current applied to the cryopump motor.

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