Honeywell G.m.b.h.

Other

Nt International, Inc.

Paul E Bjork

Thomas J Wagener

James E Lenz

Hans W Mocker

Gerald R Cucci

Peter Stasz

Nick Anthony Demma

Gordon L Mitchell

Milford M Gesin

Stephen J Postma

Hisatoshi Fujiwara

A fiber-optic data-link used to interface a remote process variable sensor/transmitter to a local process control system includes a local light source module and a remote interface module interconnected by one or more optical fibers. Energy for operating the remote interface module and its associated process variable sensor/transmitter is provided by light energy transmitted from the local site to the remote site and converted at the remote site to an electrical signal. The local light source module and the remote interface module each may include a microcontroller. The controllers not only control the flow of status messages in either analog or digital or analog and digital form simultaneously from the remote site to the local site, but also insure the integrity of the system and minimizes the amount of optical power delivered to the remote site to that which is required to electrically power the remote interface module and the process variable sensor/transmitter, thus extending the useful life of the light source. The system is also arranged to check the integrity of the optical fibers to ensure that the light intensity is always below a minimum eye-safe value whenever the optical fiber is not correctly connected between the local light source module and the remote interface module.

Fiber-optic interface system

An indicating system for measuring movement of a material, having a magnetic pickup device, waveform conditioning circuit and light signal emitter functioning under the system's own self-made power, having a light waveguide or optic fiber connecting the light signal emitter to a light signal receiver which in turn is connected to a signal processor for outputting information such as speed, acceleration and/or position of the material.

Self-powered electro-optic rotational position sensor with magnetic

Optically powered sensing apparatus which has a photodiode for converting optical power to electrical energy and a switching voltage converter for optimizing power transfer from the photo diode. A controller intermittently provides a synchronizing pulse train and a synchronizing receiver detects periods when optical power drops to zero. A transducer with driving and readout electronics provides electrical parameter signals which are digitized and synchronously transmitted to the controller during the periods of no optical power from the controller. Voltage regulation, impedance matching, and temperature compensation of the photodiode optimize power transfer.

Optically powered remote sensor apparatus with synchronizing means

A position sensor is provided which incorporates the first and second magnetic members which are attached to an object whose position is to be determined. First and second magnetic sensors are disposed at positions in association with the two magnetic members. As the object moves along a predetermined path, the first and second magnetic members dispose a predetermined amount of magnetic material in the zones of the two sensors. By measuring the changing impedance of the winding of one of the sensors and comparing that value to the impedance of the winding of the other sensor, corrections can be made to determine the position of the object notwithstanding the fact that external effects may have changed the conditions under which the measurements are being taken. For example, gaps between the magnetic members and the sensors can possibly change from one time to another or the ambient temperature surrounding the sensors and the magnetic members could have changed. By comparing the values of the two sensor readings, these variabilities can be factored out of the determination and the accurate position of the object can be measured.

Apparatus for determining the position of an object

A proximity sensor is provided with a means for directly measuring parameters of a proximity sensor coil which permit the determination of both the AC and DC resistances of the coil. These parameters are then used to determine a discriminator value magnitude according to a mathematical relationship that has been predetermined through previous analysis of empirical data for the particular coil and application intended for the proximity sensor. In one particular application of the present invention, the rear AC resistance is utilized and is added to the DC resistance after the DC resistance has been mathematically altered by a preselected factor. Alternative embodiments of the present invention can also utilize the imaginary AC component of the impedance either by itself or in conjunction with the rear AC component of the impedance. Whether the real or imaginary AC components of the impedance are used individually or together, the DC resistance is used in the determination of the discriminator value magnitude because of its reliable relationship to the temperature of the coil.

Proximity sensor with reduced temperature sensitivity using A.C. and

A Doppler velocimeter having a semiconductor laser which sends a laser beam through a polarization beam splitter onto an fractional-wavelength plate. The plate both reflects the beam back to the polarization beam splitter and sends the beam on through the beam expander to the target. The beam is returned by the target. The returned beam passes through the fractional-wavelength plate to the polarization beam splitter. The returned and reflected beams are directed by the splitter to a detector. The detector mixes the beams and sends a signal to a spectrum analyzer on which the velocity of the target can be accurately determined.

High accuracy semiconductor laser doppler velocimeter

An optically powered fiber optic sensor system having a control end sending, with a laser diode or light-emitting diode, optical power and a clock signal exclusively through an optic fiber to a sensing end having sensors, a clock signal picking-off circuit, a return signal light-emitting diode, and needed analog and digital circuitry, all energy dependent upon the optical power transmitted through the optic fiber to the control end. The optically powered sensor end is feasible because of recent advances in technology resulting in micro-powered devices such as the analog-to-digital converter, operational amplifiers, logic circuits, and other low-powered items.

Optically powered remote sensors with timing discrimination

An optical fiber is processed by ablating cladding material with an intense electromagnetic energy source. The intensity of another beam directed along the propagation axis of the fiber is monitored to detect near exposure of the fiber core. The ablating electromagnetic energy source is preferably circularly polarized. Apparatus for performing this process is disclosed. Fibers produced by this process are used to form optical couplers or, when a metallic layer is provided over the nearly exposed core region, an optical polarizer.

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Forest Lake, MN, United States of America

Paul E Bjork