Digital rod position detector system
US4629983A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 1984 |
| Grant date | Dec 16, 1986 |
| Priority date | — |
| Expiry date | Oct 3, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Coils placed at spaced locations along the path of an axially movable magnetically permeable and/or electrically conductive rod, which changes the impedance of each coil as it passes through, are connected in sets with each set comprising two series connected groups of equal numbers of parallel connected, non-adjacent coils energized by an a-c source. The voltage at the common node of each set of coils, which fluctuates as equal and unequal numbers of coils in the two groups in a given set are penetrated by the end of the rod, is compared with the voltage at the common node of a pair of series connected resistors, also energized by the a-c source, to generate one digit of an unambiguous, multi-digit, digital rod position signal. Since only one signal wire to the remote electronics is required for each set of coils, and since they only carry a voltage signal, the required wiring is minimized. Compensation is provided to maintain the location of the rod end relative to each coil at which the digital signal changes state despite variations in temperature and voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.