Precision coin analyzer for numismatic application
OwnerJoseph L. Dautremontinventor
Life of this patent
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Abstract
A device for testing coins or other metallic articles is disclosed whereby the article to be tested is introduced into the field generated by the inductor of an oscillator and the change in amplitude of the oscillations resulting from the interaction of the field generated and the article to be tested is measured.
Claims11
A means of positioning coins within the field of a substantially cylindrical inductor comprising three substantially plane restraining surfaces and a right circular cylinder having first and second bases;
- the first and second of said surfaces being portions of planes which intersect in a line parallel to the axis of said cylindrical inductor, the third surface being a portion of a plane which intersects the first base of said cylindrical inductor and proceeding in the direction of the second base, forms a vertex with said first and second planes so that a coin moving down the ramp formed by the third surface is restrained in said vertex.
A coin positioning receptacle for positioning coins within the field of a substantially cylindrical inductor comprising portions of the three lateral faces of a tetrahedron which would be formed by a base in a plane extending normal to an edge formed by two of the lateral faces.
A device for analyzing metallic articles comprising:
- an inductance capacitance resonant circuit arranged so that said inductance is inductively coupled to the article to be analyzed;
- a differential input amplifier whose input is connected to the terminals of said inductor, whose output current is connected to a terminal of said inductor so as to increase the amplifier input voltage and whose current level can be adjusted;
- a feedback metering circuit comprising a differential amplifier incorporating rectifying and filtering means, a feedback network coupling a portion of the amplifier output current to an input of said amplifier to reduce the output current and a meter connected to measure the output current of said amplifier.
A method for measuring alternating currents comprising the steps of amplifying the difference between the alternating voltage to be measured and a direct voltage, rectifying and filtering the amplified difference, feeding back a portion of said amplified and filtered voltage to the direct voltage input of said amplifier so as to reduce said amplified and filtered voltage and measuring the magnitude of said amplified and filtered voltage.
Dependencies are inferred from the claim text.