Resonant degaussing apparatus
AssigneeRCA Corporation
InventorJuergen F. Hemme
Life of this patent
Estimating the term…
Abstract
First and second capacitors are charged prior to a degaussing interval. A first switch couples the first capacitor to a degaussing coil to initiate the degaussing interval. The first capacitor and the degaussing coil form a resonant circuit that resonates to generate a decaying degaussing current. During a predetermined portion of each cycle of the degaussing current, a second switch couples a precharged second capacitor in parallel with the first capacitor to form a charge transfer arrangement that transfers charge from the second to the first capacitor for replenishing energy losses in the first capacitor. The charge transfer arrangement increases the duration of the time it takes to the amplitude of the degaussing current to decay and, hence, the length of the degaussing interval.
Claims10
A resonant degaussing circuit of a television apparatus, comprising:
- a degaussing coil;
- a first switch;
- a first capacitance that is precharged prior to a degaussing interval, said first capacitance being coupled to said degaussing coil by said first switch to form with said degaussing coil a resonant circuit that generates a plurality of cycles of a degaussing current in said degaussing coil, during said degaussing interval;
- a second capacitance that is precharged prior to at least one of said plurality of cycles of said degaussing current;
- and
- a second switch for coupling said second capacitance to said first capacitance during a predetermined portion of said at least one cycle of said degaussing current to couple charge from said second capacitance to said resonant circuit during said degaussing interval.
A resonant degaussing circuit of a television apparatus, comprising:
- a degaussing coil;
- a first switch;
- a first capacitance that is precharged prior to a degaussing interval, said first capacitance being coupled to said degaussing coil by said first switch to form with said degaussing coil a resonant circuit that generates, in accordance with a charge that is stored therein, a plurality of cycles of a degaussing current in said degaussing coil during said degaussing interval;
- and
- means responsive to said degaussing current for generating a pulse of current that is coupled to said first capacitance during a portion of at least one cycle of said plurality of cycles that augments said charge that is stored in said first capacitance.
Dependencies are inferred from the claim text.