Induction sensor having conductive concentrator with measuring gap
US6057683A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 1998 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | Mar 31, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An induction head for sensing a magnetic strip or other magnetically permeable security structures includes an exciting coil associated with an electrically conductive concentrator, which produces a primary field and induces a responsive secondary field in the concentrator. The concentrator has an endwall and sidewalls defining a central cavity. The endwall has a narrow measuring gap dividing the endwall into two opposed sections. The sidewalls are also interrupted adjacent the measuring gap to cause a concentrated current of the secondary field to pass along the gap. This concentrated current can be monitored for a change in induction due to the presence of an elongate magnetic strip or other magnetically permeable security structure which is moved past the measuring gap.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.