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:
Apr. 27, 1999
Filed:
Jan. 29, 1998
Carl Ganderillas, Beacon Falls, CT (US);
HID Corporation, Irvine, CA (US);
Abstract
A read head for a Wiegand wire has two C-shaped ferro-magnetic yokes in lateral alignment with one another, two magnets sandwiched between respective first and second legs-of the yokes, and a pickup coil wound on one of the legs of the read head. One magnet has a first polarity adjacent to the first leg of the first yoke, the other magnet has the first polarity adjacent to the second leg of the second yoke, and the reluctances of the two yokes are equal. When used in combination with a processor that processes the output pulses, a Wiegand token having one or more Wiegand wires therein may be detected by counting the number of output pulses of the read head and ascertaining the duration of time between occurrences of those pulses. Wiegand tokens having different values may have different numbers of Wiegand wires therein and/or different spacings between the Wiegand wires within the Wiegand token and, thus, the read head in combination with a processor can identify Wiegand tokens of different values.