Process and apparatus for the recognition of the state of a solenoid valve
US6017017A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1998 |
| Grant date | Jan 25, 2000 |
| Priority date | — |
| Expiry date | Sep 18, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8242
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for the recognition of the state of a solenoid valve supplies an on/off control switching current to the coil of the solenoid valve. A high level of current is caused to flow through the coil for switching the device on, and a reduced level of current is applied to the coil for holding the solenoid armature in its on position. If the armature should be caused to drop off from its on position by a mechanical shock, an increase in the frequency of the switching current occurs, due to the decrease in magnetic circuit inductance. This frequency increase is detected and compared to a predetermined threshold value. If the detected frequency exceeds the threshold value, it is recognized as an armature drop off, and corrective action can be taken immediately.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.