Fault tolerant apparatus for detecting the passage of a moving body
US5889478A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 1997 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Mar 31, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10316
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
On the moving body, the apparatus comprises an active transponder, and on the track it comprises a passive responder. The transponder has an LF transmitter and an MF transmitter which, during displacement of the moving body, transmit to a zone through which the responder passes during said displacement. The responder has an LF receiver circuit and an MF receiver circuit having tuned radiating circuits that are associated so that an LF signal induced in the LF circuit causes the MF radiating circuit of the responder to be closed at the LF rate. The transponder responds to disturbances in the MF transmitter caused by the MF circuit of the responder being closed. The MF circuit of the responder includes two units having respective tuned radiating circuits that are strongly coupled together. Each is connected to a respective logic unit which, when excited, delivers a digital message causing the MF radiating circuit to be closed only for bits of a determined value in the digital message.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.