Co-ordinate measuring system
US4918263A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1989 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Jul 21, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B7/008
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A co-ordinate measuring system determines the position of a coil member relative to a grid member defined by a set of equidistant, parallel conductors associated with a co-ordinate axis of the system. The system includes a switching circuit that is constructed and arranged to produce a measuring signal in the form of a train of induced pulses in one of the members when a time variable current is applied to the other of the members. According to the present invention, a low pass filter at the front end of an evaluation circuit is responsive to the measuring signal for reducing frequency components therein due to operation of the switching circuit, and producing an output signal that is the first derivative of the envelope of the time variable magnetic flux. The second zero-axis crossing of the derivative of the output signal yields a representation of the co-ordinate of the coil relative to the grid member.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.