Process for producing electric resistors having a wide range of specific resistance values
AssigneeLeda Logarithmic Electrical Devices for Automation S.r.l.
InventorPaolo Lodini
Life of this patent
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Abstract
A process consisting in preparing a homogeneous system comprising particles of a first electrically conductive material arranged in substantially uniform manner inside a mass of a second liquid material which, when solidified, is both flexible and electrically insulating; and in solidifying the aforementioned mass of the aforementioned second liquid material, so as to form a matrix for supporting the aforementioned particles; throughout solidification of the aforementioned second material, a given pressure being applied on the system for the purpose of producing triaxial precompression of the aforementioned second material when solidified.
Claims13
A method of producing an electric resistor for use as an electric conducting element in an electric circuit, and which is capable of varying the electrical resistance as a function of pressure exerted thereon, said method comprising the steps of:
- providing an electrically conductive homogeneous material comprising a plurality of conductive particles;
- placing said electrically conductive material in a closed vessel;
- compacting said electrically conductive material in said closed vessel by subjecting said electrically conductive material to a first predetermined pressure, wherein said first predetermined pressure is exerted by means of a thrust element for a surface of said electrically conductive material;
- injecting a liquid material into said closed vessel so as to uniformly mix with said electrically conductive material under pressure and so as to fill gaps between said particles of said electrically conductive material, wherein said injecting includes feeding said liquid material through a channel in said thrust element while gradually withdrawing said thrust element from said surface so as to form a layer of a desired height of said liquid material over said electrically conductive material and then exerting a second predetermined pressure on said layer by means of said thrust element such that said liquid material fills gaps between said particles;
- solidifying said liquid material so as to form a flexible and electrically insulating matrix for supporting said particles;
- and
- producing triaxial precompression of said liquid material during solidification thereof by applying a third predetermined pressure during said solidification.
Dependencies are inferred from the claim text.