Littelfuse, Inc.
AUTOMOBILE RAIN AND TEMPERATURE SENSOR MODULE

Abstract:

A rain and temperature sensing module including a housing having a cover plate formed of a transparent material, a printed circuit board disposed within the housing and having a light emitter, a light receiver, and a temperature sensing element disposed thereon, a transparent compound disposed within the housing and covering the light emitter, the light receiver, and the temperature sensing element, the transparent compound filling a space between the printed circuit board and the cover plate, wherein the transparent compound has a refractive index that is substantially equal to a refractive index of the cover plate, and wherein the transparent compound provides a thermally conductive medium between the cover plate and the temperature sensing element.