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Methods and apparatus for detecting fluids

  • US 5,739,534 A
  • Filed: 11/18/1996
  • Issued: 04/14/1998
  • Est. Priority Date: 11/18/1996
  • Status: Expired due to Fees
First Claim
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1. A system for monitoring and adjusting the water level in a washing machine comprising:

  • transmission means for alternately emitting a first infrared electromagnetic signal having a first wavelength and a second electromagnetic signal having a second wavelength;

    sensor means for receiving first reflected infrared signals from said first emitted infrared electromagnetic signals and converting said first reflected infrared signals into a first plurality of electrical signals and for receiving second reflected infrared signals from said second emitted infrared electromagnetic signals and converting said second reflected infrared signals into a second plurality of electrical signals;

    sample and hold means for sampling said first and second plurality of electrical signals and storing the magnitudes of said first and second plurality of electrical signals;

    comparison means for determining the optimum level of water in said washing machine by comparing the magnitudes of said first and second plurality of electrical signals and detecting when the magnitude of either said first or second plurality of electrical signals becomes greater than the magnitude of the other just past a crossing-point;

    control means responsive to the passing of said crossing-point for adjusting the water flow into said washing machine.

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