Thomson-csf

Compagnie Internationale Pour L'informatique Cii-honeywell Bull

Compagnie Internationale Pour L'informatique Cii-honeywell Bull (societe

Jean M Dupont

Jean P Castera

Pierre Hartemann

Tunable selective devices utilizing forward magnetostatic bulk waves. A filter is able to act as an oscillator loop or as a passive transmission system in which two resonant cavities including gratings are so arranged that via a selective reflector grating they may exchange magnetostatic bulk waves energized and intercepted by transducers of the microstrip type. The invention relates in particular to the filtering of very high frequency electric signals, and to the production of tunable oscillators and to measuring magnetic fields.

Tunable selective device using magnetostatic bulk waves

The position of a tape loop in a vacuum chamber is capacitively detected. e capacitive detector includes a flexible electrode that is deflected between a pair of walls parallel to a wall of a vacuum chamber in which the loop is formed by differential pressure in the chamber and by the pressure of a vacuum source having a pressure between the two pressures in the vacuum chamber. Between the flexible electrode and a stationary electrode is a fixed, solid dielectric. The wall includes plural apertures forming separate fluid flow paths. The vacuum source includes a partition with a plurality of apertures forming separate fluid flow paths. The apertures of the wall and partition are aligned and positioned in a direction between opposite ends of the vacuum chamber. The vacuum chamber wall is electrically grounded and an electrical insulator is positioned between an end of the flexible electrode adjacent the wall to maintain the flexible electrode electrically insulated from and a different potential from the grounded wall.

Tape loop position detector

A magnetic transducer is disclosed which utilizes the magnetostrictive effect for creating an easy axis of magnetization in the longitudinal axis of a magnetic wire having a high cobalt content by bending the wire, which is then placed in a non-magnetic hollow tube. This tube is placed in the axis of a detection coil. The application of a magnetic field, alternately in one direction and the other in the longitudinal axis of the assembly creates a flux variation due to the magnetization change in the easy axis. The pulses detected have a high amplitude and a low rise time.

Magnetic transducer comprising a strained magnetic wire in a sheath of

A separately excited D.C. motor employs an analog servo control responsive to a speed control input signal that controls the derivation of a compensating signal for the motor back emf. The speed control and compensating signals are combined to control the motor speed via an analog regulator. A digital shaft encoder responsive to the motor position supplies a pulsed signal to a comparator that is also responsive to a desired position signal that is derived from the speed control signal. The comparator derives an integrated error signal that is supplied to the analog regulator. Application of the speed control signal to the regulator is delayed if a thermal simulator for the motor characteristics indicates motor overheating. In response to the compensated, desired speed indicating signal indicating that the motor has been ordered to stop, the error signal is decoupled from the analog regulator. The integrated error signal is reduced to zero if the compensated desired speed indicating signal indicates either a theoretical halt of the motor capstan, or a high speed instruction. The error signal remains briefly at zero if the compensated desired speed indicating signal orders a start cycle.

System for servocontrolling a separately excited DC motor

The invention relates to a magnetostatic-wave device whose ferrimagnetic layer supports an exchange structure formed by an array of conducting strips having their ends connected by conducting bridges. The invention applies particularly to the construction of magnetostatic-wave devices using couplers, hybrid junctions, reflecting mirrors, extraction structures and resonators.

Magnetostatic-wave device comprising a conducting strip exchange

A separately excited constant load DC electric motor is controlled in resse to a source of current for the desired motor speed. Current from the source applied to the motor armature is modified by a motor loss simulator circuit responsive to the source. The circuit simulates the losses the motor is expected to have in response to the current derived from the source, whereby the actual motor speed corresponds with the desired motor speed despite the loss. The losses are simulated during acceleration and deceleration as well as steady state intervals of the current source, which can be actuated to drive the motor in both directions.

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Paris, France

Jean M Dupont