Rain sensor

A rain sensor comprising:

• two spaced-apart conductive paths lying parallel to each other, wherein, upon installation of the rain sensor upon a windshield of a motor vehicle, the conductive paths are disposed on the windshield and are connected electrically to an evaluation electronics system of the vehicle;
• wherein at least one edge of one of said conductive paths has wavy shape providing for a variation in the width of said at least one of said conductive paths over its length;
• and
• in at least one of said conductive paths, a section of the path undergoes a succession of multiple increases and decreases in width for an increase of effective resistive length by a factor of approximately 5/3.

A rain sensor comprising:

• two spaced-apart conductive paths lying parallel to each other, wherein, upon installation of the rain sensor upon a windshield of a motor vehicle, the conductive paths are disposed on the windshield and are connected electrically to an evaluation electronics system of the vehicle;
• wherein at least one edge of one of said conductive paths has a wavy shape providing for a variation in the width of said at least one of said conductive paths over its length;
• and
• at least one edge of at least one of said conductive paths has an arcuate shape with a succession of multiple undulations.

A rain sensor comprising:

• a first conductor and a second conductor spaced apart by distance from each other and arranged for installation upon a windshield of a motor vehicle;
• a first conductive path extending most of the distance from said first conductor toward said second conductor, but being spaced apart from said second conductor;
• a second conductive path extending most of the distance from said second conductor toward said first conductor but being spaced apart from said first conductor, said second conductive path being spaced apart from and being parallel to said first conductive path;
• wherein an edge of one of said conductive paths is configured with a sequence of multiple arcuate segments producing a sequence of multiple increases and multiple decreases in the width of said one conductive path for an increased effective resistance length of the sensor.

A method of constructing a rain sensor comprising:

• sputter etching onto a windshield a first conductor and a second conductor spaced apart by a distance from each other upon the windshield;
• sputter etching onto the windshield a first conductive path extending most of the distance from said first conductor toward said second conductor, but being spaced apart from said second conductor;
• sputter etching onto the windshield a second conductive path extending most of the distance from said second conductor toward said first conductor, but being spaced apart from said first conductor, said second conductive path being space apart from and being parallel to said first conductive path;
• wherein said sputter etching produces an edge on one of said conductive paths configured with a sequence of multiple arcuate segments resulting in a succession of multiple increases and multiple decreases of said one conductive path.

A method of constructing a rain sensor comprising:

• sputter etching onto a windshield a first conductor and a second conductor spaced apart by a distance from each other upon the windshield;
• sputter etching onto the windshield a first conductive path extending most of the distance from said first conductor toward said second conductor, but being spaced apart from said second conductor;
• sputter etching onto the windshield a second conductive path extending most of the distance from said second conductor toward said first conductor, but being spaced apart from said first conductor, said second conductive path being space apart from and being parallel to said first conductive path;
• wherein said sputter etching produces an edge on one of said conductive paths configured with a sequence of arcuate segments;
• and
• said sputter etching produces a sequence of transparent raster points in said conductors.