Motor vehicle electrically heated windshield and backlight system

Claim 1

An electrically heated windshield and backlight system for a motor vehicle, which comprises: a windshield having first and second transparent conductive surfaces, said first and second conductive surfaces being electrically insulated from one another by an imaginary plane passing vertically through said windshield to divide it into symmetrical halves, said windshield including a first pair of bus bars in electrical contact with said first conductive surface, said first pair of bus bars being spaced from one another to permit electrical charge to flow from one to the other via said first conductive surface, and said windshield further including a second pair of bus bars in electrical contact with said second conductive surface, said second pair of bus bars being spaced from one another to permit electrical charge to flow from one to the other via said second conductive surface; a backlight including a third conductive surface and a third pair of bus bars in electrical contact with said third conductive surface, said third pair of bus bars being spaced from one another to permit electrical charge to flow from one to the other via said third conductive surface; and a three-phase alternator having first, second, and third phase winding line terminals, said first conductive surface being electrically connected between said first and third line terminals, said second conductive surface being electrically connected between said first and second line terminals, said third conductive surface being electrically connected between said second and third line terminals, said alternator being driven by the engine of said motor vehicle and generating voltage in excess of 80 volts between its line terminals; thereby to permit said backlight and windshield conductive surfaces to be heated while permitting substantially balanced loading of said alternator if the resistances of each of said conductive surfaces are made substantially equal.