Water filter abstract
A water filter replacement indicator for apparatus that utilizes
a filter for purifying water which has a power supply (20) and an
auxiliary power supply (22). A timer (24) receives electrical energy
from one of the power supplies, generating a first output signal
indicating timed intervals. A divider (26) receives this first output
signal quantifying the signal until a predetermined number of modulations
are perceived at which time it produces a second output signal.
A counter (28) receives the second output until a predetermined
number of events are perceived at which time it produces a third,
fourth and fifth output signal. The third output signal energizes
a green light (30) indicating that the filter is operating within
its usable life. The fourth output signal energizes a yellow light
(32) indicating that the filter is about to reach its predetermined
life span. The fifth output signal energizes a flashing red light
(34) designating that it is time for filter replacement, further,
when the red light is energized the green and yellow light are disengaged.
Water filter claims
What is claimed is:
1. 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; and
light 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.
2. The water filter replacement indicator as recited in claim 1
wherein said light means further comprising,
a green light having a first light circuit in electrical communication
with the counter third output signal energizing said green light
through the first light circuit indicating that the filter is operating
within its usable life,
a yellow light having a second light circuit in electrical communication
with the counter fourth output signal energizing the yellow light
through said second light circuit indicating that the filter is
about to reach its predetermined life span, and
a red light having a third light circuit, including an oscillator,
in electrical communication with the counter fifth output signal
energizing said red light through the third light circuit allowing
the oscillator to produce a momentary interruption in the third
light circuit creating a flashing effect designating that it is
time for filter replacement, further, when said red light is energized
said counter third output signal disconnects the green light and
simultaneously said counter fourth output signal disengages the
yellow light.
3. The water filter replacement indicator as recited in claim 1
further comprising a reset switch in communication with the timer,
divider and counter for returning the timed sequence to zero.
4. A water filter replacement indicator for apparatus having a
filter for purifying water comprising:
a power supply having means for converting an alternating current
to a direct current along with an accompanying voltage reduction,
a direct current 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, generating 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,
a green light having a first light circuit in electrical communication
with the counter third output signal energizing said green light
through the first light circuit indicating that the filter is operating
within its usable life,
a yellow light having a second light circuit in electrical communication
with the counter fourth output signal energizing said yellow light
through the second light circuit indicating that the filter is about
to reach its predetermined life span, and
a red light having a third light circuit, including an oscillator,
in electrical communication with the counter fifth output signal
energizing said red light through the third light circuit allowing
the oscillator to produce a momentary interruption in the third
light circuit creating a flashing effect designating that it is
time for filter replacement, further, when said red light is energized
said counter third output signal disconnects the green light and
simultaneously said counter fourth output signal disengages the
yellow light.
5. The water filter replacement indicator as recited in claim 4
wherein said power supply is an ac-dc inverter.
6. The water filter replacement indicator as recited in claim 4
wherein said auxiliary power supply is an alkaline storage battery.
7. The water filter replacement indicator as recited in claim 4
wherein said timer is a programmable digital timer.
8. The water filter replacement indicator as recited in claim 4
wherein said divider is a programmable digital timer.
9. The water filter replacement indicator as recited in claim 4
wherein said counter is an octal counter.
10. The water filter replacement indicator as recited in claim
4 wherein said green light is a light emitting diode and said first
light circuit comprises a transistor, a plurality of resistors and
at least two integrated circuits.
11. The water filter replacement indicator as recited in claim
4 wherein said yellow light is a light emitting diode and said second
light circuit comprises a transistor, a resistor and a diode.
12. The water filter replacement indicator as recited in claim
4 wherein said red light is a light emitting diode and said third
light circuit comprises a transistor, at least one resistor, a diode,
and at least one integrated circuit and said oscillator comprises
a capacitor a resistor and an integrated circuit.
13. The water filter replacement indicator as recited in claim
4 further comprising a reset switch in communication with the timer,
divider and counter for returning the timed sequence to zero.
14. 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, generating a first square wave signal indicating
timed intervals,
a divider operable to receive the timer first signal 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 signal from the divider
until a predetermined number of square wave events are perceived,
said counter then producing plurality of output signals,
a plurality of lights adapted to receive output signals from the
counter with the lights indicating that the filter is operating
within its usable life, the filter is about to reach its predetermined
life span or a solitary flashing light designating that it is time
for filter replacement.
Water filter description
TECHNICAL FIELD
The present invention relates to indicators in general. More specifically
to a timed indicator that shows when a water filter is to be replaced
in an apparatus that uses a filter for purifying water.
BACKGROUND ART
Previously, many types of indicators have been used in endeavoring
to provide an effective means to monitor and indicate that a water
filter is near or at the end of its useful life and needs to be
replaced.
A cursory search of the prior art did not disclose any patents
that read directly on the claims of the instant invention, however
Kurth et al. in U.S. Pat No. 5188727 teaches a water filter unit
that has a pair of change water filter indicators, one for each
filter cartridge, consisting of discs mounted on a post which are
marked in months and years and may be set manually when the filters
are changed. The indicators are mounted behind the cover with only
the pre-set month and year visible from the outside.
U.S. Pat. No. 5190643 issued to Duncan et al. is for a portable
water treatment device which uses a vessel with a replaceable filter
cartridge inside. A lid has an aperture that communicates with the
filter and a gate member that is reciprocally movable between a
position closing the aperture in the housing and a position opening
the aperture. In the open position water is poured into the filter
cartridge through the aperture. An indicator moves one increment
during a cyclic movement of the gate member which is limited to
a predetermined number of increments preventing further movement
when the filter needs to be changed.
Boldt Jr. et al. in U.S. Pat. No. 5328597 disclose an electronic
unit for monitoring the number of uses of a filter cartridge. This
unit is self contained and may be attached to any device that incorporates
a water filter. A programmed integrated circuit uses different audio
input signals to detect each use of the device and monitors when
the device is operational and when the end of the life of the filter
is eminent. The integrated circuit is programmed to operate a transducer
to produce output signals during each use of the device informing
the user that the device is operational, that the predetermined
end of the filters useful life is eminent or that its life has expired.
The unit includes a battery for supplying power to the transducer
and integrated circuit and signals are visualized by light emitting
diodes.
Parise in the recently issued U.S. Pat. No. 6024867 teaches a
counter top water filter unit that includes a carbon particle filter
cartridge for filtration. A replaceable electronic display monitor
unit is mounted in an outlet housing fitted to the top of the cylindrical
filter housing. The state of the life span of the filter cartridge
is shown on the display monitor in terms of colored indicator lights
which denote whether the filter cartridge is within, nearing an
end or outside its expected life span. A green light indicates that
the cartridge is in its usable life, a yellow light indicates it
is about to reach its predetermined life span and a red light designates
that the life span has been reached. The electronic circuit detects
the time it takes for a ball to flow through a flow channel that
is an integral part of the water flow circuitry thereby comparing
this lapsed time to the equivalent amount of water passing through
the filter. The solid state circuitry translates this information
to the volume of water filtered which determines the life expectancy
of the filter cartridge.
Other prior art, common to water pitchers with filters utilize
floats and mechanical gears to slide a radial indicator a given
direction each time the vessel is filled to its nominal level indicating
that the filter should be changed when a pointer has completed its
travel.
DISCLOSURE OF THE INVENTION
The life expectancy of a conventional filter cartridge used for
potable water is based on two separate principles first the amount
of contaminants that are absorbed by the media in the filter itself
which is determined by its physical size along with the actual absorption
capacity of the specific material. Activated carbon is the most
common substance used as the media and removes organic material,
chlorine and suspended solids usually as small as 5 microns. Normally
when the media has absorbed its limit and the pressure differential
through the filter increases the capacity of the filter has been
reached. When the filter is saturated the water flow declines and
slows down which is important particularly in a gravity feed system.
The second principle of life expectancy is actually the time that
the filter is exposed to water because the water supply, in almost
all city's, contain a certain amount of bacteria, viruses and other
micro-organisms. Since organic matter collected in the filter may
serve as a nutrient for the bacteria, in time the micro-organisms
multiply contaminating the water. The filter manufactures warn against
leaving the filter in place too long therefore time limits are recommended
and warnings imposed.
A primary object of the invention is to circumvent this problem
by taking the latter approach and warn the user that the time has
elapsed and the filter should be changed since it may be obvious,
due to the slowing of the operational sequence, that the filter
was full of unwanted organic matter etc. It would therefore be prudent,
in this matter, to protect the user as a first priority and use
elapsed time as the governing factor. Therefore the invention incorporates
visual indication of the time that the filter has been in place
by using a solid state timing circuit in conjunction with indicating
lights. This indication assures to the user that the unit, to which
the filter is a part, is safe to use and exactly when changing is
necessary. Since logic and colors well known to the public are the
most reasonable type of warning, a green light indicates that the
filter is operating within its usable life, a yellow light indicates
it is about to reach its predetermined life span and a red light
designates that it is time for replacement.
An important object of the invention is that the time duration
may be altered when a larger capacity filter is used which may lengthen
the time span for the green light. This feature is easily accomplished
in the preferred embodiment by simply removing a jumper from a connector
which places another resistor of a different value in the circuit.
Another object of the invention is that reliability is increased
which affects the device in which the invention is connected to
or integrally formed. Further, when the filters are not changed
on a timely basis, chemicals such as lime etc. may build up and
cause a malfunction of the entire unit or at the least a slow down
of its functional operation when water is fed by gravity.
Still another object of the invention is that the water filter
replacement indicator may be incorporated into existing equipment
or it may be a separate device that is added at a later time to
an existing device as a detached element. If the invention is built
in it may share the same electronic circuit and even the same mounting
surface for the indicator lights. As an example if the apparatus
is incorporated into a commercial coffee brewer the solid state
circuit may be included on the same printed circuit board also share
the same power supply.
These and other objects and advantages of the present invention
will become apparent from the subsequent detailed description of
the preferred embodiment and the appended claims taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial isometric view of the preferred embodiment
installed in a commercial coffee brewer.
FIG. 2 is a partial isometric view of the preferred embodiment
installed in a counter top water purifier.
FIG. 3 is a block diagram illustrating the function and operational
sequence of the preferred embodiment.
FIG. 4 is an electronic schematic diagram of the preferred embodiment.
BEST MODE FOR CARRYING OUT THE INVENTION
The best mode for carrying out the invention is presented in terms
of a preferred embodiment. This preferred embodiment is shown in
FIGS. 1 thorough 4 and is comprised of a power supply 20 which is
an ac-dc inverter circuit having means for converting an alternating
current to a direct current utilizing a Wheatstone bridge along
with an accompanying voltage reduction created by a transformer
and regulation with an integrated circuit, diodes and capacitors.
The schematic of FIG. 4 illustrates this circuit with the transformer
designated T1 the bridge diodes D1-D5 capacitors C1-C3 resistor
R2 and the integrated circuit U1.
A direct current auxiliary power supply 22 in the form of a battery
is interconnected with the power supply 20 such that when voltage
of the power supply 20 drops below voltage of the auxiliary power
supply 22 the auxiliary power supply 22 continues to furnish current.
The auxiliary power supply battery, designated as BAT on the schematic,
may be any type however an alkaline storage battery is preferred.
It will be noted that the circuit will not be activated if the battery
produces less than two thirds of its normal power or if the battery
is removed even though the power supply 20 is connected.
Timing means consist of a timer 24 a divider 26 and a counter 28.
The timer 24 is in the form of a programmable digital timer that
receives electrical energy from at least one of the power supplies
20 or 22 and generates a first square wave output signal indicating
timed intervals. The timer 24 is designated as U5 in FIG. 4 and
utilizes resistors R41 and R42 as well as capacitor C15. It should
be noted that the timing rate may be altered by simply changing
the value of the resistors R41 and R42 if another elapsed time is
required.
The divider 26 is also in the form of a programmable digital timer
not unlike the timer 24 and it receives the first square wave output
signal from the timer 24 and quantifies the signal until a predetermined
number of square wave modulations are perceived. The divider 26
then produces a second square wave output signal. The divider 26
is designated U6 in FIG. 4 does not require any ancillary devices.
The counter 28 is in the form of an octal counter that receives
the second square wave output signal from the divider 26 until a
predetermined number of square wave events are perceived, the counter
28 then producing a third output signal, a fourth output signal
and a fifth output signal. The counter 28 is designated as U7 in
FIG. 4 and also stands alone in its functional operation.
Light means consist of a green light 30 a yellow light 32 and
a red light 34. The green light 30 utilizes a light circuit and
is in electrical communication with the third output signal of the
counter energizing the light 30 through the light circuit indicating
that the filter is operating within its usable life. The green light
30 is preferably a light emitting diode and is designated as LT1
in the schematic of FIG. 4. The light circuit for the green light
30 is used for switching it on and off and utilizes solid state
components in the form of a transistor and other devices which include
a transistor Q9 resistors R53 R50 R47 and R49 along with integrated
circuits F17 and F18.
The yellow light 32 also utilizes a light circuit and is in electrical
communication with the fourth output signal of the counter energizing
the light 32 through the light circuit indicating that the filter
is about to reach its predetermined life span. The yellow light
32 is preferably a light emitting diode and is designated as LT2
in the schematic of FIG. 4. The light circuit for the yellow light
32 is used for switching it on and off and employs solid state components
in the form of a transistor and other devices which include a transistor
Q10 and resistors R54 R51 along with diode D33.
The red light 34 also has a light circuit, and an oscillator 36
in electrical communication with the counter 28 fifth output signal
which energizes the light 34 through the light circuit with the
oscillator 36 producing a momentary interruption in the light circuit
creating a flashing effect. The blinking red light 34 designates
that it is time for filter replacement. When the red light 34 is
energized the counter 28 third output signal disconnects the green
light 30 and simultaneously the counter 28 fourth output signal
disengages the yellow light 32.
The red light 34 is preferably a light emitting diode and is designated
as LT3 in the schematic of FIG. 4. The light circuit of the red
light 34 is for switching it on and off and utilizes solid state
components in the form of a transistor and other devices which include
a transistor Q11 resistors R55 R52 R47 and R49 a diode D22 and
integrated circuits F17 and F18. The oscillator 36 uses integrated
circuit F12 resistor R24 and capacitor C13.
It should also be noted that while the components described above
and designated in the schematic utilize solid state lights other
lighting devices may easily replace this preferred embodiment along
with the necessary ancillary components.
A reset switch 38 is in communication with the timer 24 divider
26 and counter 28 for returning the timed sequence of all of the
devices associated with the timing means to zero. This reset switch
38 requires the following components that are designated on the
schematic illustrated in FIG. 4 which include, a push button switch
S1 resistors R45R56 R46R57 R48 diodes D23 and D34 capacitors
C12 and C15 along with integrated circuits F15 and F16.
FIGS. 1 and 2 illustrate typical applications in which the invention
may be used such as FIG. 1 shows a commercial coffee brewer and
FIG. 2 depicts a counter top water purifier. It should also be visualized
that the invention may be used in conjunction with this type of
apparatus as an integral part of the existing solid state control
circuitry or it may be a discrete device that is completely self
contained and simply added as another component in the equipment.
While the invention has been described in complete detail and pictorially
shown in the accompanying drawings, it is not to be limited to such
details, since many changes and modifications may be made to the
invention without departing from the spirit and scope thereof. Hence,
it is described to cover any and all modifications and forms which
may come within the language and scope of the appended claims. |