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:
Oct. 17, 1995
Filed:
Dec. 17, 1993
Mark C Hansen, Ann Arbor, MI (US);
Roger D Allison, Kokomo, IN (US);
Thomas D Cook, Kokomo, IN (US);
Walter K Kosiak, Kokomo, IN (US);
Delco Electronics Corporation, Kokomo, IN (US);
Abstract
An adaptive threshold circuit for use with a magnetic type of sensor that has a pick-up coil. The pick-up coil has an alternating voltage induced therein when a slot formed in a wheel rotates past the sensor. The circuit produces a square wave pulse voltage during positive half-cycles of the voltage generated in the pick-up coil. The circuit includes a digital to analog converter the input of which is connected to a pulse counter. The output of the converter is a function of the count magnitude in the counter and provides a variable threshold voltage that is compared by a voltage comparator with a voltage that is a function of the magnitude of the voltage generated in the pick-up coil. The circuit has an input circuit connected to the pick-up coil that includes a voltage attenuating circuit and a diode. The pulse count of the counter is, at times, incremented under control of a comparator that compares the output voltage of the converter with a voltage that is a function of the magnitude of the voltage generated in the pick-up coil.