U.S. Philips Corporation

Wolf-Dieter Bauch

Rolf Gervelmeyer

Heinz B Merker

Heinz Helmus

Heinrich B Merker

A circuit arrangement for generating a pulsatory supply voltage for a load (1), such as a halogen incandescent lamp, from a source of direct voltage, in which a predetermined effective value of the supply voltage remains substantially constant in the case of a varying direct voltage. A switch (2) supplies the supply voltage from which a low-pass filter generates a mean value voltage. The mean value voltage is applied to a Schmitt trigger circuit (3) which controls the switch whose first switching threshold is constant and is derived from a reference voltage which is present at a first input of the Schmitt trigger circuit. A second switching threshold of the switch varies oppositely with respect to a decreasing direct voltage.

Circuit arrangement for generating a pulsatory supply voltage for a load

The electric lamp for series arrangement comprises at least one current-supply wire of nickel wire, copper wire or copper cladded wire. A shortcircuit switch is provided, which consists of a vitreous mass, in which copper powder is dispersed and which is fused with the current-supply wires, and of an oxide skin, which is present on the said current-supply wire at the sealing-in area in the mass. The vitreous mass is electrically conducting. An electrical connection between the current-supply wires is not obtained, however, until the filament burns through and the oxide skin breaks down due to the overvoltage then occurring.

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Niederzier, Germany

Wolf-Dieter Bauch