Digital output rotational position detection device
US4754220A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1984 |
| Grant date | Jun 28, 1988 |
| Priority date | — |
| Expiry date | Oct 15, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D2205/776
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present device comprises a stator having a plurality of poles on which primary coils and at least one secondary coil is wound, and a rotor opposing the respective poles of the stator with gaps therebetween. A clock pulse generator is provided, and the respective primary coils are separately excited by reference AC signals which are out of phase with each other and are generated in response to a count of a counter counting a clock pulse signal from the clock pulse generator. The output of the secondary coil or coils provides an output signal resulting by phase shifting the reference AC signals in accordance with the rotational position of the rotor. The phase difference between the reference AC signal and the output signal is detected by obtaining a digital count representing the phase difference in synchronization with the counting by the counter to obtain detected digital phase difference data as an absolute rotational position data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.