Patent ID: 6306290
Filing Date: 2001-10-23
Classification: B01D,C02F

Abstract:
A water filter replacement indicator for apparatus having a filter for purifying water comprising:a power supply including means for converting an alternating current to a direct current;an auxiliary power supply interconnected with the power supply such that when voltage of said power supply drops below voltage of the auxiliary power supply the auxiliary power supply continues to furnish current;a timer operable to receive electrical energy from at least one of the power supplies and generate a first square wave output signal indicating timed intervals;a divider operable to receive the first square wave output signal from the timer quantifying the signal until a predetermined number of square wave modulations are perceived, said divider then producing a second square wave output signal;a counter operable to receive the second square wave output signal from the divider until a predetermined number of square wave events are perceived, said counter then producing a third output signal, a fourth output signal and a fifth output signal; andlight means operable to receive the third, fourth, and fifth output signals from the counter to indicate that the filter is operating within its usable life, the filter is about to reach its predetermined life span and a flashing light designating that it is time for filter replacement.