Process for the non-contacting detection of eddy current-induced bodies, particularly metal objects, as well as to sensors based on the process
First Claim
1. A process for the detection and location of a movable body in which eddy currents can be induced by a magnetic field when the body is within the field of an inductive resonant circuit component in a resonant circuit comprising the steps ofexciting the inductive resonant circuit component with a short duration step function electrical pulse,measuring the quantitive response of the resonant circuit to the step function pulse,retaining the measurement as being representative of an instantaneous position of the body,repeatedly exciting the inductive resonant circuit component with step function pulses,measuring the response to each pulse, andretaining the response measurements representative of a sequence of instantaneous positions as a locus of points defining a path of movement of the body.
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Accused Products
Abstract
The process for the detection of an eddy current-induced body in the action range of an inductive resonant circuit component (L) uses in place of a continuous operation and detection of the current change, a network containing a resonant circuit (L,C) is briefly excited with an electric function and the system response of the network is evaluated. The proximity sensor is constituted by an oscillatable network (L,C) operated on the input side with a function generator and, on the output side, the system response is investigated with an evaluation circuit.
60 Citations
13 Claims
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1. A process for the detection and location of a movable body in which eddy currents can be induced by a magnetic field when the body is within the field of an inductive resonant circuit component in a resonant circuit comprising the steps of
exciting the inductive resonant circuit component with a short duration step function electrical pulse, measuring the quantitive response of the resonant circuit to the step function pulse, retaining the measurement as being representative of an instantaneous position of the body, repeatedly exciting the inductive resonant circuit component with step function pulses, measuring the response to each pulse, and retaining the response measurements representative of a sequence of instantaneous positions as a locus of points defining a path of movement of the body.
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4. A proximity sensor apparatus for detecting and locating a movable body in which eddy currents can be induced by a magnetic field when the body is within the field of an inductive resonant circuit component in a resonant circuit, the apparatus comprising
a proximity sensor including a detector coil connected in operative resonant circuit relationship with a capacitor; -
function generator circuit means connected to said proximity sensor for exciting said resonant circuit with a short duration step function electrical pulse; amplifier circuit means connected to said resonant circuit for amplifying the response of said resonant circuit to said step function pulse; evaluation circuit means connected to the output of said amplifier circuit means for measuring the response of the resonant circuit to said step function pulse as being representative of an instantaneous position of the body; and control means connected to said function generator and said evaluation circuit means for controlling the operation of said function generator and said evaluation circuit means. - View Dependent Claims (5, 6, 7, 8)
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9. A proximity sensor apparatus for detecting and locating a movable body in which eddy currents can be induced by a magnetic field when the body is within the field of an inductive resonant circuit component in a resonant circuit, the apparatus comprising
a proximity sensor including a detector coil connected in operative resonant circuit relationship with a capacitor; -
function generator circuit means connected to said proximity sensor for exciting said resonant circuit with a short duration step function electrical pulse; amplifier circuit means connected to the output of said resonant circuit for amplifying the response of said resonant circuit to said step function pulse; evaluation circuit means connected to the output of said amplifier circuit means for measuring the response of the resonant circuit to said step function pulse as being representative of an instantaneous position of the body; and trigger circuit means responsive to the output of said function generator circuit means for producing a trigger signal; and
wherein said evaluation circuit means includeslevel indicating circuit means responsive to said trigger signal to indicate the response level of said response signal. - View Dependent Claims (10, 11, 12, 13)
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Specification