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US 4,621,299 AGranted
High energy degausser
AssigneeGeneral Kinetics, Incorporated
InventorJames D. Hill
Life of this patent
Estimating the term…
Abstract
A magnetic material degausser in which the material to be degaussed is placed within the center of a degaussing coil. A capacitive discharge system is employed for energizing the degaussing coil. The capacitor is repeatedly discharged through the coil in such a way that for at least a portion of the degaussing cycle, the energy applied to the coil decreases with each energization. The magnetic material may be rotated within the coil as the degaussing cycle progresses. In one embodiment of the present invention, the energy discharged from the capacitor first increases and then decreases during the degaussing cycle with each energization of the coil. The rotational speed of the magnetic material within the coil may be related to the frequency at which the capacitor is discharged.
Claims42
Apparatus for degaussing a magnetized object comprising:
- means for storing energy:
- means for gradually applying energy to said storing means;
- means for monitoring the amount of energy stored in said storing means;
- and
- means, responsive to said monitoring means, for repeatedly releasing energy from said storing means to said object, said releasing means reducing the energy stored in said storage means as determined by said monitoring means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
2 more elements
Apparatus for degaussing a magnetized object comprising:
- means for storing energy;
- means for gradually applying energy to said storing means;
- a coil for surrounding said object, said coil including at least two separable sections to ease insertion and removal of said object;
- and
- means for repeatedly releasing energy from said storing means through said coil, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
2 more elements
Apparatus for degaussing a magnetized object comprising:
- means for storing energy;
- means for gradually applying energy to said storing means;
- a coil defining a space;
- switch means, responsive to a trigger signal and connected in a circuit with said coil and said storing means, for selectively permitting current to flow through said circuit to generate a magnetic field in said space;
- means for repeatedly generating said trigger signal to cause the amount of energy stored in said storing means at the time of current flow to decrease with each current flow so that current flowing through said coil decreases with each trigger signal for at least a portion of a degaussing cycle;
- means for mounting said object in said space;
- and
- means for rotating said object within said space to reverse the polarity of said magnetic field with respect to said object over said repetitions, said rotating means gradually increasing the speed of rotation of said object over said repetitions.
5 more elements
Apparatus as in claim 12 wherein said storing means includes a capacitor.
Apparatus for degaussing a magnetic tape comprising:
- a capacitor;
- means for applying a charge to said capacitor;
- a coil defining a space;
- a silicon controlled rectifier connected in a circuit with said coil and said capacitor;
- a diode connected in parallel with said silicon controlled rectifier so as to have a polarity opposite to said silicon controlled rectifier;
- means for generating a control voltage that gradually increases and then decreases during a degaussing cycle;
- comparator means for producing a trigger signal for said silicon controlled rectifier when a signal related to a voltage across said capacitor exceeds said control voltage;
- means for rotatably mounting said tape in said space;
- and
- means for rotating said tape at a speed related to the frequency of said trigger signals.
7 more elements
A method for degaussing a magnetized object comprising the steps of:
- gradually storing energy in an energy storage device;
- monitoring the amount of energy stored in said energy storage device;
- repeatedly releasing the energy from said energy storage device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases, as determined by said monitoring step, is reduced with each release;
- and
- reversing the plurality of said energy with respect to said object.
2 more elements
A method for degaussing a magnetic tape comprising the steps of:
- gradually applying a charge to a capacitor;
- repeatedly conducting said charge on said capacitor through a coil defining a space in response to a trigger signal;
- alternately reversing the direction of said magnetic field;
- generating a control voltage that gradually increases and then decreases during a degaussing cycle;
- producing said trigger signal when a voltage across said capacitor exceeds said control voltage;
- rotatably mounting said tape in said space;
- and
- rotating said tape at a speed related to the frequency of said trigger signals.
5 more elements
Apparatus for degaussing a magnetized object comprising:
- means for storing energy;
- means for gradually applying energy to said storing means;
- means for repeatedly releasing energy from said storing means to said object, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the timc of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions;
- and
- means for reapplying energy from said object to said storing means after having been released from said storing means to said object, said reapplying means recapturing energy in said degaussing apparatus to conserve energy.
2 more elements
Apparatus for degaussing a magnetized object comprising:
- means for storing energy;
- means for gradually applying energy to said storing means;
- and
- means for repeatedly releasing energy from said storing means to said object, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for increasing the frequency at which said releasing occurs during degaussing and means for reversing the polarity of said energy with respect to said object over said repetitions.
1 more element
Apparatus for degaussing a magnetized object comprising:
- means for storing energy;
- means for gradually applying energy to said storing means;
- a coil defining a space, said object being disposed in said space;
- electrically conductive, non-ferromagnetic blocks disposed in said space about said object;
- and
- means for repeatedly releasing energy from said storing means to said coil, said releasing means cooperating with said applying means to reduce the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
3 more elements
Apparatus for deguassing a magnetized object comprising:
- means for storing energy;
- means for gradually applying energy to said storing means;
- and
- means for repeatedly releasing energy from said storing means to said object, said releasing means cooperating with said applying means to first gradually increae and then gradually decrease the energy stored in said storage means at the time of release with each said repeated release of energy, said releasing means including means for reversing the polarity of said energy with respect to said object over said repetitions.
1 more element
A method of degaussing a magnetized object comprising the steps of:
- gradually storing energy in an energy storage device;
- repeatedly releasing the energy from said energy storing device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases is reduced with each release;
- reversing the polarity of said energy with respect to said object;
- and
- reapplying energy to said energy storage device from said object after said energy has been released from said energy storage device to said object.
2 more elements
A method of deguassing a magnetized object comprising the steps of:
- gradually storing energy in an energy storage device;
- repeatedly releasing the energy from said energy storage device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases is reduced with each release;
- and
- rotating said object to reverse the polarity of said energy with respect to said object, said rotating step including the step of increasing the rotational speed of said object during degaussing.
1 more element
A method of degaussing a magnetized object comprising the steps of:
- gradually storing energy in an energy storage device;
- repeatedly releasing the energy from said energy storing device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases is reduced with each release, the frequency of said repeated releases increasing during degaussing;
- and
- reversing the polarity of said energy with respect to said object.
1 more element
A method for deguassing a magnetized object comprising the steps of:
- gradually storing energy in an energy storage device;
- repeatedly releasing the energy from said energy storage device to said object so that the amount of energy stored in said energy storage device at the time of each of said repeated releases first increases and then decreases with each release;
- and
- reversing the polarity of said energy with respect to said object.
1 more element
Dependencies are inferred from the claim text.