Abstract: An electronic device for modeling the temperature of a motor by utilizing signals output from current sensors placed on motor power supply phases. Signals from the current sensors are sent to an interface that outputs a voltage which is an image of a summation a ratio of the motor currents sensed by each of the current sensors to a corresponding adjustment current for each of the phases. A calculation circuit utilizes the voltage as an input and outputs a charging current wave stream, the amplitude and the duration of the charging current being proportional to the summation the ratio. An RC type modeling circuit is provided to receive the charging current wave stream and to model the thermal state of the motor based on the charging current wave stream.

Abstract: Device designed to control a coil forming part of a solenoid valve, for example in a contactor type device.A switching power supply 14 includes a winding S1 powering a control circuit 15 and another winding S2 placed with a switch T2 at the coil terminals. Switch T2 is controlled by the control circuit to power the coil in the hold phase starting from the switching power supply. This reduces disturbances during the hold phase.

Abstract: A control device for an electromechanical circuit breaker device. The device includes a bistable type electromagnet to deliberately control power contacts and a monostable trip electromagnet to open the contacts in case of a fault. The bistable electromagnetic coil and the trip electromagnetic coil are placed in parallel with a capacitance. The control device includes a maintained control switch and an H bridge of two-way switches associated with the bistable coil. The control device acts on the bridge of switches and a trip switch opens the contacts depending on the current in the coils measured by sensors.

Abstract: A circuit for the protected alternating current power supply of an electrical load, the circuit including, in series, a protective circuit breaker and a bi-directional electronic switch in parallel to which a shunt contactor is connected. An electrical component is connected in series and upstream from the shunt contactor. The electrical component is intended to establish a continuous voltage (V) at the terminals of the electronic switch and its impedance is chosen in such a way that the electronic switch to which command pulses are sent periodically, is made a conductor, when an overload current appears in the circuit and when the contactor is closed.

Abstract: Contactor-circuit breaker housing firstly power poles and an electromagnet serving to activate the moving contacts in contactor mode and including a fixed magnetic circuit, a moving magnetic circuit and a coil whose electric supply is controlled by a switch, and secondly at least one current sensor serving to control a releasing electromagnet. The activating electromagnet and the releasing electromagnet are constituted by a single electromagnet whose moving magnetic circuit is a pivoting pallet linked mechanically to the contact-holders of the poles and having a weak moment of inertia. An electric unit is provided for the rapid reduction of the magnetic flux, triggered by an electronic control device associated with the current sensor.

Abstract: A power supply circuit, using direct current or rectified alternating current sources having output and return supply lines (a, b), for a coil of an electromagnet having at least one principal winding (B1) and a secondary winding (B2). The power supply circuit includes a first semiconductor element (T2) having a gate and a source drain path and capable of providing or blocking a supply of current to the secondary winding (B2), the source drain path connected between the secondary winding (B2) and the return supply line (b); and a switching means (10) connected between the primary winding (B1) and the gate of the first semiconductor element (T2).

Abstract: A power switching circuit (T115, T5) including at least one bipolar transistor stage (T5) and a control circuit for that stage, the control circuit including first bias means for applying forward bias to that stage during first time intervals (t3), and second bias means for applying reverse bias to that stage during second time intervals (t2, t4), the reverse bias being intended to prevent charge accumulating in the transistor while it is subjected to a reverse voltage.

Abstract: A frequency converter is provided for the power supply of an asychronous motor, comprising:a rectifier bridge (11) connected to a multiphase network and to an intermediate DC circuit (12);an inverter (13) comprising three pairs of static switches (T1-T6) connected in a Graetz bridge; characterized by;a means (21) for reading the current associated with the intermediate circuit (12) and elaborating an image signal of the reverse circuit and delivering an image signal of the current in this circuit;a stabilization control circuit (22) connected to said means (21) and delivering a reverse current excess signal (ST) when the signal (I.sub.d) exceeds an adjustable threshold; anda means (25) for reducing the output voltages of the inverter, and adapted for modifying the modulated pulses, this means being controlled by the output signal (ST) of the stabilization control circuit (22).