Abstract: A screen-forming sphere is made of a front translucent half-sphere and of a rear half-sphere which is opaque except in a central region. An image projector is situated behind the screen and has a front face comprising a platen mounted in front of the optic of the image projector. The platen contains a rotary polarization filter rotated by a first motor. The filter is occultable by a rotary flap mounted on spindles rigidly connected to two rotary vertically aligned disc members which rotate in synchronism under action of a second motor.

Abstract: A power current regulator, in particular for airport lighting, includes transformers in series with intermediate taps on their secondary windings staged a various different numerical weights. In each case, one of said taps is selected by a latch memory (MV) preceded by an up/down counter (CD). These circuits are actuated by a control circuit as a function of the current detected by a current transformer (TIC) connected in series with the load.

Abstract: An installation for controlling the electric supply of charge elements, such as high pressure discharge lighting lamps, which are distributed along supply lines to which are applied an alternating supply voltage and periodical control transitions superposed to said alternating supply with a selected phase angle. The installation comprises supply circuits through which said charge elements are connected across supply lines. Said supply circuit includes a pulse transformer having two windings, one of the windings being connected via a capacitor in parallel to a choke coil. The other winding triggers a controlled switching device which supplies the charge elements.

Abstract: A rotary screen mounted in the median area of a preferably spherical enclosure, the rear face of which being made opaque except in its central portion, while its front face is perfectly transparent, a projector being placed rearwardly of the enclosure in central axis of the portion which is not opaque in order to enable light rays from the prospector to pass through the enclosure to reach the rotary screen.