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:
May. 14, 1996
Filed:
Feb. 28, 1994
Tamas I Pattantyus, North Olmsted, OH (US);
Ronald E Squires, Grafton, OH (US);
AlliedSignal Truck Brake Systems, Elyria, OH (US);
Abstract
A speed signal conditioning and test circuit includes a comparator which is connected to a digital input port of a microprocessor and which switches its output in response to the alternating current generated by the sensor when sensing wheel speed. A test sequence is initiated by injecting a signal into a tuned circuit formed by the inductance of the sensor coil, the filtering capacitors, and associated circuit resistances. The voltage output of the tuned circuit increases exponentially and switches the comparator to provide a test pulse of a predetermined time period. The microprocessor times the pulse to establish that an operative sensor is present. Since the inductance of the coil is switched out of the circuit in the case of an open or shorted sensor coil, no pulse is generated and the microprocessor accordingly determines that a defective sensor is present.