High speed starter operations monitor
US5212437A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 1991 |
| Grant date | May 18, 1993 |
| Priority date | — |
| Expiry date | Aug 2, 2011 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B6/4021
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An x-ray tube (10) of a CT scanner has a rotating anode and rotor combination which is propelled by AC currents applied to run and phase windings (42, 46) by a starter (22). A monitor (24) includes Hall effect current detectors (40, 44) which detect the actual current flowing through the run and phase windings. The detected analog current values, voltage values, and the like are multiplexed (132) and digitized in a preselected order by an analog to digital converter (60) and stored in that order in a FIFO memory (62). A microprocessor (64) performs a Fourier transform (94, 96) to convert the digital run and phase signals into frequency spectra. The run and phase frequency spectra are compared (100, 102, 104, 106) with frequency spectra indicative of rotor speed, bearing wear, anode vibration, failure of the anode to rotate, and other conditions, analyzed for symmetry or other characteristics, or the like (FIG. 5 ) to generate digital run and phase reference signals. An error amplifier (54) controls a pulse width modulator ( 56) or other power amplifier controls in accordance with a deviation between analog reference signals converted from the digital signals by a reference digital …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.