Abstract: A device is provided for generating an AC current ramp for checking the tripping current of the circuit-breaker, in which the current is regulated by a power transistor driven by the voltage available at the middle point of a potentiometric divider, this latter comprising a field effect transistor which is itself driven by a voltage depending on the voltage at the terminals of a capacitor charged by an auxiliary battery. It further comprises a constant current generator which is fed with current by the auxiliary battery for charging said capacitor and a comparator amplifier a first input of which is connected to said capacitor, a second input of which is connected to the junction point between a measuring resistor and said power transistor and the output of which is connected to the gate of said field effect transistor.

Abstract: The invention provides a measuring attachment connectible to a multimeter for measuring earth resistances, comprising a casing having a first group of terminals for a measurement signal and a second group of terminals for electrical connection of the attachment to a multimeter, and electric circuits housed in the casing and comprising generator means for generating an AC current of constant value but of a frequency different from that of the mains and its harmonics, said generator means having an output connected to first and second terminals of said first group of terminals, and a synchronous detector having a measurement signal input which is connected to said second terminal and to a third terminal of said first group of terminals, a control input which is connected to said generator means and an output which is connected to first and second terminals of said second group of terminals.

Abstract: The invention relates to an airfoil shape for flight at high subsonic speeds, of the type comprising a flat convex upper surface, a thick leading edge and a lower surface convex towards the leading edge and concave towards the trailing, in which airfoil the upper surface comprises a maximum curvature in the vicinity of its rear part, in a zone delimited by points located at distances from the leading edge equal to 65 and 90% of the chord of the airfoil. The invention is applicable to the production of fixed or rotary wings for aircraft, having a high divergence Mach number and a low drag.