Patent ID: 6262407
Filing Date: 2001-07-17
Classification: B60S,G01J

Abstract:
An automatic intensity control unit for a moisture sensor, said moisture sensor including one or more signal emitters for generating one or more emitter signals influenced by the presence of moisture on the surface of a transparent material and one or more detectors for receiving said one or more emitter signals and communicating with moisture sensing circuitry for determining the presence of moisture, said automatic intensity control unit comprising:a comparator connected to said one or more detectors for comparing the intensity of said one or more emitter signals received by said one or more detectors with a predetermined reference signal;a counter communicating with said comparator and having a counter output which increases when the intensity of said one or more emitter signals received by said one or more detectors is less than said reference signal and decreases when the intensity of said one or more emitter signals received by said one or more detectors is more than said reference signal;an emitter driver connected to said one or more emitters for providing power to said one or more emitters in an amount which determines the intensity of said one or more emitter signals, wherein said emitter driver exponentially increases the emitter intensity with linear increases in said emitter control signal and exponentially decreases the emitter intensity with linear decreases in said emitter control signal, andan emitter intensity control signal generator connected to said emitter driver for providing an emitter intensity control signal for increasing the intensity of said one or more emitter signals when said counter output increases and decreasing the intensity of said one or more emitter signals when said counter output decreases.