The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 22, 1983
Filed:
Aug. 21, 1981
Frederic P Heiman, Philadelphia, PA (US);
Mars, Inc., McLean, VA (US);
Abstract
An apparatus for coin testing including an improved inductive sensing arrangement. A coin to be tested is passed through an electromagnetic field produced by an inductor which is part of a resistor-inductor type relaxation oscillator operating at a frequency in the range of approximately 100 kHz to 1 MHz. The resulting shift in frequency of the relaxation oscillator forms the basis for testing the coin. The resistor-inductor relaxation oscillator has a linear frequency response with respect to changes in the effective inductance in the oscillator over a range of inductance suitable for testing coins and produces an output signal which is digital in nature and requires no amplitude discrimination or shaping to be suitable for counting.