Patent · US Expired

Method for testing DC motors

US4744041A · kind A · utility

122Cited by
8References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 4, 1985
Grant dateMay 10, 1988
Priority date
Expiry dateMar 4, 2005

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01P3/48
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Disclosed is a DC parameter motor tester based on current time response, which tester does not require coupling of the motor (14) to some mechanical device or measuring other noise sensitive parameters taken from only a few discrete data points. As is disclosed, the steady state speed of the motor is determined from the frequency composition of the commutation noise and ripple in the steady state current by performing a fast fourier transform on the steady state current to determine its power-spectral-density which shows the frequency composition of the steady state current waveform by giving the power in the waveform at each frequency. The frequency at which the most power exists is divided by the number or twice the number, depending upon the construction of the motor, of commutation segments in the motor to determine the motor's frequency of rotation or velocity at measured power input. The parameters which are derived from the current time response points are taken from data in which such data has a significant, if not dominant influence.

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