John C Silva

US Patent:

D2766833, Dec 11, 1984

Filed:

Jul 8, 1982

Appl. No.:

6/396350

Inventors:

John J. Silva - Johnston RI

US Classification:

D 7 75

US Patent:

53173856, May 31, 1994

Filed:

Dec 16, 1992

Appl. No.:

7/991441

Inventors:

John R. Silva - Rehoboth MA
Geert J. Wyntjes - Chelsea MA

Assignee:

Federal Products Corporation - Providence RI

International Classification:

G01B 902

US Classification:

356356

Abstract:

A portable extended life metrology system is disclosed. The system is of the kind which includes means for generating an interference fringe pattern as a function of a parameter to be measured, transducer apparatus for simultaneously generating three intensity-modulated optical signals, I. sub. R, I. sub. S and I. sub. T that are related to the interference fringe pattern; signal processing apparatus for accurately determining an aspect of the interference fringe pattern form the three signals; means for accumulating phase information proportional to the aspect of the interference fringe pattern; and means for converting the accumulated phase and aspect information to desired outputs indicative of the parameter to be measured. The system includes a pulsed drive circuit designed to minimize its power drain without affecting its measurement accuracy and an energy source connected by the pulsed drive circuit to a radiation source to power the same in two operative states: a low, standby mode and a higher operational mode, with incremental and self-adaptive switching therebetween. The pulsed drive circuit controls the energy per pulse, the pulse repetition rate, and returns residual energy to the energy source of the system.