Elongated member serving as a pulse generator in an electromagnetic anti-theft or article identification system and method for manufacturing same and method for producing a pronounced pulse in the system

US5757272A · kind A · utility

Assignee

• Vacuumschmelze GmbH & Co. KG · DE

Inventors

• Giselher Herzer · Bruchköbel, DE
• Gerd Rauscher · Alzenau, DE

Key dates

• Filing date: Sep 9, 1996
• Grant date: May 26, 1998
• Expiry date: Sep 9, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01F1/15391
• WIPO field: Control
• WIPO sector: Instruments

Abstract

For security against theft or for identification of products using an electronic alternating field in an interrogation zone, a pulse generator, upon magnetic reversal due to a Barkhausen jump, exhibits an impulse behavior that produces characteristic harmonics and largely prevents confusion with other magnetically soft materials in the interrogation zone. This pulse generator is formed of an amorphous strip or an amorphous wire with a cobalt content of at least 20 at-%, subjected to a heat treatment by a current flowing through the strip or wire, to produce a ratio of remanence induction to saturation induction of between 0.2 and 0.9.