Abstract: A circuit system for igniting and lighting a high-pressure discharge lamp, particularly a sodium vapor lamp, comprising a pulse generator for generating signals of at least 1 kHz frequency being a high-frequency DC/AC converter connected to a direct current source and an ignition circuit coupled with the pulse generator including a high-pressure discharge lamp, a condenser connected in parallel to the high-pressure discharge lamp and an inductive member connected to the condenser and the high-pressure discharge lamp and forming a series member with the condenser the ignition circuit is provided with a transformer having a secondary winding connected in series with the inductive member for ensuring high reliability of igniting and for improving the conditions of lighting.

Abstract: A fuse-element for electric fuses is shaped as a metal strip with one or more zones of diminished cross-section.The temperature rise conditions of the fuse-element and of its zones of diminished cross-section can be established and evaluated in combination and--based on these data--a fuse-element can be designed the temperature distribution characteristics of which include different local peak values and the spots where such peak values develop can be set in a manner that the whole fuse-element consists of two parts as far as the temperature distribution is concerned, i.e. a first part where this distribution is in accordance with a steady state distribution (the highest current value still failing to cause any melting), and a second part where the temperature rise distribution determines the character of the melting process, this being the so-called transient distribution characteristic.

Abstract: A fuse-element for use in an electric network, includes a metal strip including at least one portion having a reduced cross-section, a shunt element of conductive material shunting the portion, bonding means conductively bonding the shunt element to the metal strip and being capable of being released at a temperature higher than a predetermined temperature, the shunt element defining a chamber facing towards the metal strip and being sealed by the bonding means between the metal strip and the shunt element, and a material disposed in the chamber having a boiling temperature below the predetermined temperature and capable of producing an internal gas pressure within the chamber sufficient to break the bond when the material is heated to a temperature higher than the boiling temperature.