Process for adapting the frequency band of an oscillating circuit made from a metal-plastic-metal sandwich foil useful as an identification label, and sandwich foil for implementing the process

US5124523A · kind A · utility

Assignee

• Swiss Aluminium Ltd. · CH

Inventors

• Klaus Oehlmann · Engen, DE
• Franz Kolb · Offenburg, DE
• Dietrich Bubeck · Singen, DE
• Martin Werner · Langenau, DE

Key dates

• Filing date: Jul 26, 1989
• Grant date: Jun 23, 1992
• Expiry date: Jul 26, 2009

Classification

• Technology area (CPC H): Electricity
• CPC primary: H05K2203/1572
• WIPO field: Control
• WIPO sector: Instruments

Abstract

To adapt the frequency band of oscillating circuits with frequencies greater than the set frequency, made from a metal-plastic-metal sandwich foil useful as an identification label and manufactured from rolls (1) of sandwich foil connected to each other by at least one plastic film, the oscillating circuits are conveyed almost continuously through two frequency-measuring cells (5,6) between which is located a reduction unit (7). After comparison of the set value and actual value, the frequency band of an oscillating circuit is adapted by reduction of the capacitor part of the oscillating circuit by means of the reduction unit (7), which is controlled by the correction unit (8). The position of the reduction unit (7) determined by the correction unit is used as a base value by the reduction unit (7) during adjustment of a subsequent oscillating circuit, in such a way that only minor corrections are necessary for the final adjustment of the reduction unit (7) during reduction of the subsequent oscillating circuit. The process can be used if the choice of components and dimensions of the sandwich foil does not entail large differences in frequency between closely-spaced oscillating ci…