Abstract: The present invention relates to an AC input cell for data acquisition circuits, comprising at least one circuit for detecting a voltage greater than the reference for the positive half-cycle at the input voltage, and a device for detecting a voltage greater than the reference for the negative half-cycle of the input voltage. Each detection circuit comprises a Zener diode, an optocoupler including an emission LED, a diode and a resistor arranged in series. Each detection circuit is arranged on a branch, and the two branches are in parallel with the devices arranged in opposite directions so that the two circuits conduct on alternate half cycles of the input AC signal.

Abstract: A continuous input cell for data acquisition circuits, particularly in railway applications. The cell consists of at least two parallel lines of identical elements, and each line includes at least one Zener diode (DZ1 or DZ2), a switch (SW1 or SW2) preferably consisting of an optocoupler (U1 or U2), and an optocoupler (U3 or U4) including an LED.

Abstract: A method for processing PWM waves for a voltage inverter or a voltage-controlled rectifier, including at least one pair of switches, said inverter or rectifier being controlled by a modulator and a discriminator. According to the method, two set waves corrected according to the current direction in the load or the source are applied to the discriminator. The corrected set wave for the output current has a high level to which a delay is added during transition from the high level to the low level, and the corrected set wave for the input current has a low level to which a delay is added during transition from the low level to the high level. The high level is defined by the fact that the switch connected to the most positive load is closed while the switch connected to the most negative load is open, and the low level is defined by the reverse.

Abstract: Quick-action circuit breaker assisted by a semi-conductor control circuit, comprising a repulsion coil, a repulsion disk (37) associated with a contact bridge (39) bearing the mobile contacts (41), the repulsion disk (37) interacting with the repulsion coil (35), and a bearing means for holding the contacts in the closed state, wherein the bearing means comprises a holding spring (27) acting on the repulsion disk (37) associated with the contact bridge (39) via a retaining ball (33) acting on the repulsion disk (37) associated with the contact bridge (39), which retaining ball (37) exerts a sufficient pressure to resist an imposed contact pressure and is arranged to be retractable when the disk (37) is repulsed under the action of the repulsion coil (35).

Abstract: An ultra-fast contact breaker is described which includes an ultra-fast cut-off mechanism provided with a repulsion disk fitted with moving contacts (7, 7'), the said mechanism also including fixed contacts (9, 9'), to the input and output terminals (1, 3) of which there is connected an assistance circuit (10) including a capacitor (21) and a coil (23) as well as a group of semiconductors (13, 15, 17, 19), the coil (23) wholly or partly constituting the repulsion coil of the said ultra-fast mechanism, which includes at least two parallel branches (CD, EF), a first branch (CD) including two opposed diodes (13, 15) or similar in series, each directed in the non-conducting direction for the current entering the circuit, a second branch (EF) including two opposed thyristors or similar (17, 19), each directed in the conducting direction for the current entering the circuit, and the LC oscillating circuit (21, 23) which connects the common point of the two diodes (13, 15) or similar and the common point of the two