Sagem Defense Securite

Safran Electronics & Defense

Tony Fourmont

Roland Casimir

Jérôme Piaton

Franck Delnaud

Nicolas Domblides

Marc Pontrucher

Joël Vanoli

Lisandra Kittel Riel

Lisandra Kittel Ries

A device for detecting a drop in voltage of an AC supply delivering electrical energy to an energy converter in order to supply electrical equipment, the device being connected to an electrical energy reserve for supplying the energy converter. The device includes a full-wave rectifier for rectifying the AC supply, a comparator that compares a first predetermined voltage with a full-wave rectified voltage, a circuit for charging a capacitor in order to charge the capacitor when the rectified voltage is below the predetermined threshold, a circuit for discharging the capacitor in order to discharge the capacitor when the rectified voltage is above the predetermined threshold, a comparator for comparing the voltage at the terminals of the capacitor with a second predetermined voltage, and a circuit for controlling the reserve of electrical energy.

System for detecting a drop in voltage of an AC power supply

The invention concerns a method for detecting a failure in a three-phase alternator connected to a three-phase rectifier bridge. The method comprises the following steps &#x2014; rectifying () the voltages generated by the three-phase alternator; &#x2014; adding () the rectified voltages taken at the first and second phases in order to obtain a voltage sum; &#x2014; subtracting (), from said voltage sum, twice the rectified voltage taken at the third phase, in order to obtain a voltage difference; &#x2014; comparing () the voltage difference to a high threshold and a low threshold; &#x2014; detecting () a failure when the voltage difference is less than said low threshold or when the voltage difference is greater than said high threshold. The invention also concerns a device for detecting failures and an associated computer programme.

Method for detecting a failure in a three-phase alternator, device for detecting failures and associated computer programme

An AC/DC converter comprising an input rectifier circuit connected in series with a primary winding () of an isolating transformer () and to a chopper switch (T) driven by a control circuit () using pulse width modulation on the basis of a signal representative of a primary current, the isolating transformer having a first secondary winding () that is wound in the same direction as the primary winding and that is connected to an output line () of the converter via a diode (D) and a filter coil (L), and a second secondary winding () that is wound in the opposite direction to the primary winding and that is connected directly to the output line via a diode (D), the output line being connected to an output capacitor (Cout). The converter includes an analog correction circuit for correcting the primary current, which circuit is connected to the control circuit and to a measurement element () delivering a signal representative of the primary current, and is arranged to transform said signal into a triangular signal suitable for driving the control circuit.

AC/DC converter with galvanic insulation and signal corrector

A damper circuit for damping a synchronous servo-motor having at least one winding, at least one main damper resistor, connection means for connecting the main damper resistor in series with the winding, and at least one additional damper cell including at least one additional damper resistor connected in parallel with the main damper resistor via a static switch connected to a control module for controlling the switch as a function of a voltage of the winding. The control module has a shunt in parallel with the main damper resistor. The shunt has an output connected to the control input of the switch and a divider bridge connected to the shunt to form a comparator between the voltage of the winding and a conduction voltage of the shunt.

Variable damping circuit for a synchronous servomotor

A power supply circuit for an electric motor, the circuit comprising a plurality of inverter bridge arms, each having means for connection to a respective winding of the motor, each inverter bridge arm comprising in series a first insulated gate bipolar transistor and a junction field effect transistor that are connected to a controller, the circuit including a second insulated gate bipolar transistor connected in series with each field effect transistor and connected to the controller, and a damping resistor connected in parallel with the second bipolar transistor. An aircraft flight control member including a movable airfoil associated with at least one drive motor connected to such a power supply circuit.

Growing community of inventors

Paris, France

Tony Fourmont