Bulk degausser
US4751608A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 14, 1986 |
| Grant date | Jun 14, 1988 |
| Priority date | — |
| Expiry date | Oct 14, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/0245
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A bulk degausser for erasing a reel of high energy magnetic tape. The degausser includes a circuit for generating magnetic fields including a coil defining a window for passage of the reel of tape. The coil includes a first winding having relatively few turns and a second winding, inductively coupled to the first winding, having relatively many turns. The circuit also includes an ac power supply connected to the first winding and a dc power supply connected to the second winding. A resonance capacitor is interconnected with the second winding for substantially balancing the inductive reactance of the second winding at the frequency of the ac power supply. The circuit also includes an isolation relay, interconnecting the capacitor and the second winding with the dc power supply, for isolating the dc power supply when the first winding is energized by the ac power supply. Energization of the second winding by the dc power supply causes a tape in said window to undergo a dc magnetic field, and energization of the first winding by the ac power supply induces ac current in the second winding resulting in a reel in said window experiencing an ac magnetic field. A drive mechanism for tran…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.