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:
Mar. 11, 1986
Filed:
Mar. 20, 1984
David Partridge, West Wickham, GB;
501 Starpoint Electrics Limited, Surrey, GB;
Abstract
A coin 12 to be checked is passed through a test coil 1 connected in parallel with a capacitor 2. A comparison coil 3 having an adjustable core 5 is also connected in parallel with a capacitor 4 and a direct current is passed through both coils in parallel from a rail 13 to an interrupter 14. The simultaneous interruption of the current through both coils produces between each coil and its capacitor a respective oscillatory discharge in the form of a decaying wave train and the characteristics and dimensions of the two coils and their capacitors are such that when a coin of the selected denomination passes through the test coil, the two wave trains are substantially identical. The two wave trains are compared by a comparator device 6 and a voltage comparator 7 generates a signal when the result of the comparison is below a predetermined datum, thus indicating that the coin is a genuine one.