Commissariat a L'energie Atomique

Commissariat À L'énergie Atomique Et Aux Énergies Alternatives

Denis Duret

Marc Beranger

Jean Crescini

Jean-Marc Fedeli

Pierre Gaud

Robert Cuchet

Cyril Condemine

Helene Lhermet

Daniel Bloyet

Didier Robbes

Hélène Lhermet

Jacques Lepaisant

Khalid Benhida

Christian Dubuc

Daniel Pascal

A DC voltage conversion device including a DC/DC converter and an energy reservoir capable of providing a starting voltage to the DC/DC converter.

Monolithic miniature voltage converter with very low input voltage

The present invention relates to a device intended for locating the tip of a pen on a writing board, the pen and the board being part of a writing digitizing system further comprising at least two magnetic dipoles, each being coupled with a current source so as to create distinct magnetic fields which are perpendicular to the writing board. According to the invention, the pen comprises a first sensor intended for measuring the magnetic fields produced by each magnetic dipole, and a second sensor intended for measuring the inclination angle &#x3b8; of the pen with respect to the vertical, and transmission means for delivering data supplied by the first and second sensors to a processing unit to compute the position of the pen tip onto the writing surface in terms of the measured magnetic fields and angle &#x3b8; values.

Device and system for locating the position of the tip of a pen on a digitising board

A fluxgate micro-magnetometer with perpendicular detection and a process of realization thereof. A ferromagnetic core is perpendicular to a substrate. The axes of excitation coils and pick-up coils are also perpendicular to the substrate. A magnetic field component which is perpendicular to the substrate is thus measured. The two other components can be measured by magnetometers of classical type whose core is parallel to the substrate. Such a device may find application in the domain of magnetic measurement, as an example.

Perpendicular detection fluxgate micromagnetometer and method for the production thereof

A short distance positioning system for a mobile object with respect to a fixed reference system. The mobile object is equipped with a probe, and at least one resonant circuit enabling reception of a magnetic field. A detection and comparison circuit detects the amplitude of the voltage induced at the terminals of the resonant circuit, thereby deducing the displacement of the probe with respect to the reference system.

Short-distance locating system

Method for measuring a conductive volume and device for implementing this method

A differential resonance magnetometer, which includes a reference assembly and at least one measurement assembly. A polarization current is produced by the reference assembly is the same as a polarization current used in the measurement assembly. A feedback signal produced by the measurement assembly directly gives a difference between fields in the reference and measurement assemblies. Such a device may find particular application to magnetometry.

Differential resonance magnetometer

The magnetometer according to the invention comprises a logic unit (50) receiving a resonance detection signal, a digital processor (60) supplying a number N, a digital-analog converter converting said number into current for establishing a feedback. The measurement of the field is directly digitally given by the processor. Use in magnetometry.

Digital directional resonance magnetometer

Multiaxial resonance magnetometer. The magnetometer according to the invention incorporates means (40, 50, 60, Wx, Wy, Wz) for the sequential application of polarization fields having different directions. It then supplies (70) the components (Hmx, Hmy, Hmz) of the ambient field in accordance with these directions. Application in magnetometry.

Multiaxial resonance magnetometer

A current sensor using a resonance directional magnetometer which includes a magnetic circuit having a gap and a device supplying a voltage representative of a magnetic field produced in the gap by a current when the current passes through the circuit. The value of the field is a function of the intensity of the current. The device is a resonance directional magnetometer having a sample with resonant spins placed in the gap and exposed to a magnetic field having a polarization parallel to the field produced in the gap or coinciding with this field and a measuring device for exciting the resonance and detecting the excited resonance and for supplying a voltage representative of the amount of excited resonance.

Current sensor using a resonance directional magnetometer

It is used for measuring a magnetic-field Hlex, which is the projection, in a given direction, of a field Hex and which incorporates a sample (2) containing resonant spins, first means (4) for exciting the resonance and detecting the latter, second means (32) for producing a polarization field Hb in accordance with the direction and compensating Hlex, processing and closed loop control means (6, 8, 16 to 20, 34 to 38, 48 to 52, 40, 44), which are connected to the first and second means and which make it possible to obtain voltages proportional to Hb-Ho+hlex and to Ho-Hb+Hlex in the vicinity of the resonance, Ho being the value of the field at resonance, with Ho being well above Hex, and a pulsed square-wave current for inducing Hb and for supplying a voltage proportional to Hlex in particular to the second magnetic means.

Directional resonance magnetometer

An improved shielded magnetometer including a resonant probe containing a magnetically resonating material held in a resonator. The magnetometer has a spherical electromagnetic shield which exhibits improvements in the sensitivity characteristics by removing the effects of interference fields when the magnetometer is rotated about its axis.

Shielded magnetometer

Process for the digitization and linearization of a quasi-sinusoidal periodic characteristic transducer and the corresponding apparatus. The process consist of measuring a variation (.DELTA..phi..sub.x) of a signal (.phi..sub.x) received by the transducer in accordance with the following operations:

Process for the digitization and linearization of a transducer with a

Continuous vectorial magnetometer having a magnetostrictive pickup including a capacitive pickup which contains a capacitor at least one of whose electrodes is constituted of a material having magnetostrictive properties, and means for measuring the variation of the capacity of the said capacitive pickup under the action of an external magnetic field. The invention also relates to a gradiometer entailing the application of two capacitive pickups of the kind used in a magnetometer. The magnetometer is applied to the measurement of continuous or slowly varying magnetic fields, and the gradiometer to the measurement of a magnetic field gradient.

Continuous vectorial magnetometer with capacitive magnetostriction

The invention relates to a process for the manufacture and adjustment of a Josephson effect magnetic flux pick-up. This process comprises depositing a thin, uniform layer (1) of a superconducting material on a cylindrical insulating bar (2) having an axis and a cylindrical surface, then making a cut (5) through the layer of superconducting material on a line along the cylindrical surface of the cylindrical bar (2), which line is parallel to the axis of the cylindrical bar, while leaving a bridge (7) between two edges of the layer of superconducting material defined by the cut, then subjecting the pickup thus manufactured to pulses for adjustment of the critical current, by induction, and in measuring, by induction, the parameters of the pick-up.

Growing community of inventors

Grenoble, France

Denis Duret