Abstract: An electronic circuit senses that at least one circuit of rectifying diodes has been opened and response initiates an alarm. To sense one of the diode circuits being opened, the electronic circuit detects a temporary crossing of a low threshold by a DC voltage supplied at the rectifier output. The circuit is particularly applicable to high-power transformer-rectifiers aboard aircraft.

Abstract: A method for the radioelectric synchronization of slave stations by a master station, especially for a MLS type landing control system. The method consists in transmitting by the azimuth station a synchronization data coded in the form of a series of short duration pulses, prior to each MLS cycle, a cycle being constituted by a plurality of successive transmission of MLS functions.

Abstract: The present invention concerns a device for generating a signal having a complex form through approximation, by utilizing straight-lined segments having variable slopes. It mainly comprises a generator for generating a constant current supplying in parallel a capacitor and a circuit which varies the current i.sub.1 flowing through the capacitor. The variation of i.sub.1 influences the current flowing through the capacitor. The output signal sampled at the terminals of the capacitor is thus a sequence of linear segments, the slope of which is discretely variable, and controlled by the circuit for varying the current i.sub.1.

Abstract: A device for detecting, among noise, each of the pulses of a pulse train, comprising essentially: a detector detecting the peak of a pulse; a first delay line; a first comparator comparing the level of the first delayed pulse with the half peak value; a second delay line for delaying the pulse train with a second delay different from the first one; a second comparator comparing the signal delivered by a second delay line with the signal delivered by the first delay line and with the half peak value, and an AND gate delivering an output signal when there is coincidence of the output signals from said two comparators.

Abstract: In a microwave landing system or MLS, the bearing and/or elevation angular messages are in two parts a preamble transmitted by a sector antenna and a specific message transmitted by an electronic scan or scanning beam antenna. As the gain of the sector antenna is below that of the scanning beam antenna, the preamble is much more vulnerable to scanning than the message.According to the invention, a preamble is transmitted, which is reinforced in a narrow angular sector and movable so as to cover the sector covered by the sector antenna by superimposing the radiation patterns of the sector antenna and the scanning beam antenna in said direction.

Abstract: A device for determining the arrival time of a fast or slow rising front pulse is provided comprising a first comparator to which are applied at its inputs a delayed pulse and an attenuated non-delayed pulse, and a second comparator connected in parallel across the first, through an AND logic circuit receiving the pulse applied to the input of the device through a circuit connected to one of its inputs, acting on the noise and/or the signal.This circuit is either a low-pass filter or a divider circuit.