Cross coil type indicator
US5214597A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Nov 4, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R7/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a cross coil type indicator having a pair of cross coils arranged in quadrature, a magnet rotor having a shaft and a pointer attached to the shaft and rotatably positioned within the coils, the pointer is positioned to indicate a variable by flowing pulse currents through the coils in which the duty ratio is related to the variable value. Digital data corresponding to the pointer angle is stored as sin or cos .theta. data in a memory such as a read only memory (ROM) to enable simple calculation of pointer position from the duty ratio of the current pulse. The configuration disclosed requires only a minimum memory size. The need for extra memory capacity is minimized by storing, within a sin .theta. and cosine .theta. generating means, only sin .theta. data within the range of .phi..degree..ltoreq..theta..ltoreq.90.degree..
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.