Apparatus for the electromagnetic control of the suspension of an object
First Claim
1. An apparatus for the electromagnetic control of the suspension of an object including:
- an electromagnet including an inductive coil,a source of electric power for the electromagnet which source includes a controllable electric supply device capable of delivering a controlled electric supply to the coil of the electromagnet,a control signal producer for producing an error control signal in response to an incremental change in a parameter related to the position of the object relative to the electromagnet, anda negative feedback control loop for feeding said error control signal generated by the control signal producer to said source of electric power to adjust the electric supply to the coil so as to stabilize the suspension of the object relative to the electromagnet, wherein said control signal producer includes;
means for detecting a component VL of voltage across the coil which is a function of pure inductance L of the coil,means for detecting a current i flowing through the coil,means for deriving, from the detected value of VL and the detected value of i, opposing signals, andmeans for balancing said opposing signals whereby said error control signal generated by the control signal producer represents a deviation from perfect balance of said opposing signals and comprises a correction signal applied to the electrical supply device for restoring said balance.
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Accused Products
Abstract
An apparatus for the electromagnetic control of the suspension of an object including an electromagnet including an inductive coil, a source of electric power for the electromagnet which source includes a controllable electric supply device capable of delivering a controlled electric supply to the coil of the electromagnet, a control signal producer for producing an error control signal in response to an incremental change in a parameter related to the position of the object relative to the electromagnet and a negative feedback control loop for feeding an error control signal generated by the control signal producer to the electrical supply device to adjust the electrical supply to the coil so as to stabilise the suspension of the object relative to the electromagnet, wherein the control signal producer includes a detector for detecting the component VL of voltage across the coil which is due to pure inductance L of the coil, a detector for detecting the current i flowing through the coil, a device for deriving from the detected value of VL and the detected value of i opposing signals and a balances for balancing the opposing signals whereby an error control signal generated by the control signal producer represents a deviation from the perfect balance of the opposing signals and causes a correction signal to be applied by the electrical supply to restore the balance.
34 Citations
21 Claims
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1. An apparatus for the electromagnetic control of the suspension of an object including:
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an electromagnet including an inductive coil, a source of electric power for the electromagnet which source includes a controllable electric supply device capable of delivering a controlled electric supply to the coil of the electromagnet, a control signal producer for producing an error control signal in response to an incremental change in a parameter related to the position of the object relative to the electromagnet, and a negative feedback control loop for feeding said error control signal generated by the control signal producer to said source of electric power to adjust the electric supply to the coil so as to stabilize the suspension of the object relative to the electromagnet, wherein said control signal producer includes; means for detecting a component VL of voltage across the coil which is a function of pure inductance L of the coil, means for detecting a current i flowing through the coil, means for deriving, from the detected value of VL and the detected value of i, opposing signals, and means for balancing said opposing signals whereby said error control signal generated by the control signal producer represents a deviation from perfect balance of said opposing signals and comprises a correction signal applied to the electrical supply device for restoring said balance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. Apparatus for the electromagnetic control of the suspension of an object including:
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an electromagnet including at least one inductive coil, a source of electric power for the electromagnet which source includes a controllable electric supply device capable of delivering a controlled electric supply to the coil of the electromagnet, a control signal producer for producing an error control signal in response to an incremental change in a parameter related to the position of the object relative to the electromagnet and a negative feedback control loop for feeding said error control signal generated by the control signal producer to said source of electric power to adjust the electric supply to the coil so as to stabilize the suspension of the object relative to the electromagnet, wherein said control signal producer includes; means for detecting a component VL of voltage across the coil which is a function of pure inductance L of the coil, means for detecting a current i flowing through the coil, means for deriving, from the detected value of VL and the detected value of i, opposing signals, and means for balancing said opposing signals whereby said error control signal generated by the control signal producer represents a deviation from perfect balance of said opposing signals and comprises a correction signal applied to the electrical supply device for restoring said balance wherein said at least one coil comprises two coils, each coil being connected to said electric supply device, and to said control signal producer, a feedback loop being provided from the control signal producer to said electric supply device, wherein said electric supply device for the two coils comprises; two voltage sources; and a common power amplifier driving two transistor devices, each transistor device connected to one of the coils and one of the two voltage sources, the two voltage sources being of opposite polarity whereby the incremental current changes applied to the two coils are equal and opposite.
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20. An apparatus for the electromagnetic control of the suspension of an object said apparatus including:
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a first electromagnet including a first inductive control coil; a second electromagnet including a second inductive control coil; a source of electric power for each of the electromagnets, said source including; a first controllable electric supply device for delivering a controlled electric supply to the first, coil; and a second controllable electric supply device for delivering a controlled electric supply to the second coil, a first control signal for producer for monitoring voltage across and current through the first, control coil and for producing, from the monitored voltage and current values, a first error control signal in response to an incremental change in a parameter related to the position, relative to the first electromagnet, of the object being suspended, a second control signal producer for monitoring voltage across and current through the second control coil and for producing, from the monitored voltage and current values, a second error control signal in response to an incremental change in a parameter related to the position, relative to the second electromagnet, of the object being suspended, and first, second third and fourth feedback control loops, the first loop being connected from the first control signal producer to the first controllable electric supply device, the second loop being connected from the second control signal producer to the second controllable electric supply device, the third loop being connected from the first control signal producer to the second controllable electric supply device and the fourth loop being connected from the second control signal producer to the first controllable electric supply device, wherein the first error control signal provided by the first control signal producer is connected in an equal but opposite manner to the first, and third loops, and the second error control signal provided by the second control signal producer is connected in an equal but opposite manner to the second and fourth loops. - View Dependent Claims (21)
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Specification