Abstract:
A synchronous electrical machine comprising a rotor and a stator, each having a plurality of notches, wherein the rotor is a stack of laminations without conductor windings and without permanent magnets, and wherein the stator has magnetizing means defining at least one pair of poles thereon, while the notches of said stator receive at least one secondary winding.
Abstract:
A circuit for measuring the duration of a cut-off period in the power supply to an electronic system, for example the control system of a motor vehicle starter, comprises a voltage splitting bridge and a processing unit receiving the output of the splitting bridge. The bridge supply voltage is derived from the power supply to the electronic system, and the bridge has a branch which includes a temperature variable resistor. The processing unit determines the duration of the cut-off period as a function of the value of the output voltage from the splitting bridge at the end of a cut-off period.
Abstract:
The miniaturizable sensor comprises an insulating substrate (10) supporting first measurement electrode (24) and comprising a flexible measurement arm (18) of conductive or semiconductor material, one end of which is secured to the substrate (10) and the other end of which constitutes a second electrode facing the first electrode. The first end of the measurement arm is secured to the substrate via a beam (16) having a bending modulus at least ten times greater than that of the measurement arm (18) and substantially parallel to the measurement arm and via a foot (14) rigidly secured to the substrate (10) and situated between the two ends of the measurement arm, the connections of the beam (16) to the measurement arm (18) and to the foot (14) being of the fixed-end type.
Abstract:
A circuit for measuring variations in the capacitance of a variable capacr forming part of a sensor includes an oscillator which generates an alternating signal which is supplied to two branches of a detection bridge. The first branch includes the variable capacitor connected in series with a variable capacitance diode. The second branch includes a capacitor connected in series with a variable capacitance diode. A differential stage has each of its in puts connected to the common point of a respective one of the branches. Synchronous demodulation means connected to the oscillator, are connected to the output of the differential stage for delivering a DC unbalance voltage Ve which is injected by a feedback line to the common point of the first branch, thereby continuously balancing the detection bridge.
Abstract:
A mechanical magnitude sensor integrated on silicon, and a method of manufacture. The sensor comprises a bendably deformable conductive blade (4) whose free end (43) constitutes the first plate of a variable capacitor whose fixed second plate (24) is constituted by a conductive zone formed on the silicon substrate. A JFET type structure is formed in the vicinity of the anchor point (41) of the blade (4) with a gate zone (21) situated beneath the anchor portion (41) and with drain and source zones (22, 23) being provided on either side of the gate zone (21) in order to amplify a signal representative of variations in the position of the flexible blade (4). The sensor may be used as an accelerometer or as a pressure sensor.