Abstract: The device includes two detectors of overvoltage (8, 9) each connected between a respective one of a pair of power line conductors (1, 2) and a respective input of an arrester (7). The outputs of the detectors are connected to an OR-gate (10) the output signal of which is applied to a threshold gate (12). The output of gate (12) is connected to a first monostable trigger (13) having a first time constant and controlling, through a latch gate (14), a bipolar insulating device (3, 4) isolating the load (90) from the power network. In order to achieve the automatic reconnection of the load after each perturbance, the output of the latch gate (14) is also connected to a second monostable trigger (16) having a second time constant higher than the first, and to the clock input of a counter (15) having its return-to-zero terminal connected at the output of the second monostable trigger. Preferably, an integrator (11) is connected between the OR-gate (10) and the threshold gate ( 12).

Abstract: A display unit for jewelry articles of substantially circular shape is disclosed comprising a small plate which is fabricated with a band or strip. This band is cut out from a strip of flexible material possessing good elasticity. At the small plate there is formed an opening or slot or the like to allow for the passage of the jewelry article which is to be displayed, for instance a bracelet, wrist watch, necklace or ring. In this manner, the small plate is located outside the ring or annular body formed by the jewelry article where it can serve to support the most different data concerning this jewelry article, and the band or strip is wrapped-up around the interior of the jewelry article. Owing to its elasticity, the band or strip supports the jewelry article which, if necessary, can then be set on a shelf of a display window.

Abstract: An automatic domestic power line breaker comprising a current-to-voltage converter to which is applied an input signal obtained from the secondary of a differential transformer coupled to the power line. The converter output is coupled through a low pass filter to a rectifier, the output of which is connected to a function generator, which provides an output signal comprising a voltage having a slope proportional to the peak amplitude of the rectifier output signal. The function generator output is applied to a first input of a comparator having a second input to which is applied a d.c. threshold voltage. The comparator output signal is applied through an amplifier to control the state of a set of normally open relay contacts series connected in the power line conductors. A feed-back diode shunts the first input and output of the comparator to lock the relay contacts in the open state if the breaker has controlled opening of the contacts.

Abstract: A starter circuit for a high power discharge lamp connected to an AC source via a series inductor. The starter circuit comprises a capacitor connected in series with a triac across the lamp, and a branch including a first resistor connected in series with a zener diode and a second resistor between the junction of the capacitor and triac and one side of the AC source. A driving circuit for the triac includes a diac connected to the junction of the second resistor and zener diode.

Abstract: A lightning arrester including a metallic enclosure with an opening, a first electrode of electrically conducting metal traversing the enclosure opening and having a first discharge surface within the enclosure, a plug of electrically insulating material placed about the first electrode to hermetically seal the enclosure opening, and an inert gas mixture filling the enclosure. The first electrode has a thin long cylindrical portion and a flat end portion, like a nailhead, which provides the first discharge surface. Portions of the enclosure provide a second electrode having a second discharge surface within the enclosure which faces the first discharge surface, with a predetermined gap therebetween. The long thin portion of the first electrode within the enclosure is surrounded by a sleeve composed of a fusible, electrically and thermally conducting material.