Abstract: The invention relates to a method of monitoring anti-lightning protection equipment that includes a grounding line (1), the method being characterized in that a "lightning" electrical current travelling along the grounding line is measured. The measurement may be obtained, in particular, by means of a magnetic circuit (2) constituting a closed loop around the grounding line, and electrical circuit that includes a winding (5) disposed around the magnetic circuit so that a lightning current travelling along the grounding line induces current in said winding, the magnetic circuit including a core (3) of solid magnetic material that has at least one gap in the magnetic circuit, said gap being occupied by material that is not magnetic.

Abstract: The device for detecting the presence of smoke includes a dark chamber which receives the smoke to be detected, a source suitable for emitting into said chamber a light pencil made up of short duration pulses spaced apart from one another by identical much longer periods, a detector suitable for generating response signals associated with the smoke reflecting part of the successive light pulses, and means for comparing said signals with a threshold and for triggering an alarm in the event of said threshold being exceeded by a plurality of said successive signals. The device further comprises means for automatically increasing the frequency at which said pulses are emitted from the first occasion on which a signal exceeding said threshold is detected, the alarm then possibly being triggered, as a function of the signals generated by the detector in response to a plurality of successive pulses emitted at the higher frequency.

Abstract: The invention relates to fire detector comprising a CPU and a sensor providing an analog measurement signal to the CPU. The CPU includes a non-volatile memory in which at least one normal value for the measurement signal and maintenance dates are recorded, the fire detector also including an interface giving access to the contents of the non-volatile memory without disassembling the fire detector. On each occasion that maintenance has been performed, a new maintenance date is recorded in the non-volatile memory. Nevertheless, such recordal is prevented if the measurement signal differs excessively from its normal value.

Abstract: A device is provided for grounding a metal vehicle body or the like, comprising an arrangement for automatically creating at desired times, between the body (1) and the ground (3), ions which, under the effect of the electric field which may exist between the body and the ground, are driven towards the body or towards the ground depending on their polarity and thus equalize the potentials of the body and the ground.

Abstract: The invention relates to an electronic circuit for remote interrogation of a receiver through a two wire line and to detect the response signals emitted by this receiver. The circuit comprises means for comparing with a reference voltage the actual voltage defining said response signals. This reference voltage is a weighted variable voltage obtained by low band-pass filtering, in a resistance-capacity circuit, of said actual voltage.