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. 02, 1989
Filed:
Feb. 09, 1988
Donald L Mueller, Dayton, OH (US);
Glen A Nyberg, Warren, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A pair of outer conducting members on the outside of a windshield are separated by a long common insulating border defining a border resistance in parallel with a first capacitance. Each of the outer conducting members is capacitively coupled through a layer of the windshield to an inner conducting member to form coupling capacitances in series with the combination of the border resistance and first capacitance. The preceding elements form a timing circuit for an oscillator, the timing circuit having an equivalent capacitance varying with the border resistance. When water droplets bridge the border of the outer conducting members, the border resistance decreases from infinity to change the equivalent capacitance of the timing circuit and thus the frequency of the oscillator circuit; and this change is detected to modify wiper operation.