Modulated magnet field bulk degaussing system

• US 5,721,665 A
• Filed: 08/18/1995
• Issued: 02/24/1998
• Est. Priority Date: 08/18/1995
• Status: Expired due to Fees

• Current Assignee: Data Security, Inc. (Telesis, Inc.)
• Original Assignee: Data Security, Inc. (Telesis, Inc.)
• Inventors: Schultz, Robert A.
• Primary Examiner(s): FLEMING, FRITZ M
• Application Number:
  US08/516,723
• Time in Patent Office: 921 Days
• Field of Search: 361/149-151, 361/267
• US Class Current: 361/149
• CPC Class Codes: G11B 5/0245 Bulk erasing

Abstract

A bulk degaussing system for bulk erasure of various magnetic media includes a source of magnetic flux for generating a magnetic field with a predetermined field strength within a predetermined volume defining a predetermined degaussing window, a transport system for transporting the magnetic media relative to the degaussing window such that every point on the magnetic media is exposed to the magnetic field. A control circuit is included which modulates the magnetic field to reduce power consumption. In addition to reducing power consumption, the modulated magnetic field minimizes system performance degradation due to stalls of the magnetic media transport system due to interactions between the magnetic field and ferromagnetic components associated with certain magnetic media.

Claims

1. A bulk degaussing system for bulk erasing various predetermined magnetic media, the system comprising:

means for generating magnetic flux with a predetermined field strength in a predetermined volume defining a degaussing window;

means for transporting a portion of said magnetic media relative to said degaussing window; and

means for enabling automatic recovery of said transporting means from stalls due to magnetic interaction between the magnetic media and said generating mean by de-energizing said generating means during predetermined intervals.

2. A bulk degaussing system as recited in claim 1, wherein said enabling means includes means for modulating said generating means.