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CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    Not applicable. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       MICROFICHE APPENDIX 
       [0003]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    This invention relates to the field of fluid handling, particularly with respect to the control of water flow for sinks, baths, and showers. 
         [0006]    2. Description of Related Art 
         [0007]    Traditional faucets for sinks, baths, and showers rely on manually operated handles or knobs to activate and deactivate water flow. The drawbacks associated with such manual means of controlling the flow of water—the increased potential for transmission of disease associated with multiple users, the difficulty of use by persons with physical impairments, and the waste of water when valves are not properly and timely shut off—are well established. 
         [0008]    Various devices allowing for the hands-free operation of water faucets have been developed in an attempt to address these issues. Many of these devices typically employ electrically operated, normally closed solenoid valves that are interposed between hot-water and cold-water inlets and outlets, often leading to a single mixing faucet. 
         [0009]    Ordinarily, some sort of switch means is employed to allow hands-free activation and de-activation of the solenoids, thereby allowing a user to control the flow of water through the faucet or faucets. Among the various switch means employed are touch-sensitive switches that take advantage of the biological property of the human body to act as a good capacitor by storing electrical charge. In contrast to electromechanical switches that provide tactile feedback, such touch-sensitive switches have no moving mechanical parts. When a part of the human body touches a capacitance-triggered switch, the capacitance of an electrical circuit is increased and the circuit, detecting this difference, causes the switch to operate. 
         [0010]    Existing devices utilizing capacitance-based touch-sensitive switches are prone to failure or diminished function more often than is desirable for a number of reasons. First, because their capacitance-based switches must be placed in and around the outlets through which the water flows for the convenience of the user—e.g., near sink faucets, shower heads, bath tub faucets—soap and scum accumulation can cause the switch to be triggered unintentionally at arbitrary times. Second, capacitance-based switches currently employed in these devices simply allow the capacitance of the circuit to dissipate over time, which can shorten the useful life of the switch and result in impaired performance due to continual changes in electrical resistance caused by variations in temperature, ambient humidity levels, corrosion, and other factors. 
         [0011]    The placement of existing devices are generally limited because they are designed to function only in locations in which electrical power sources are reliable, consistent, stable, and safe. Most touch circuits require a 60-cycle power line to operate. Users in locations in which such power sources are unavailable are unable to take ready advantage of such devices. Moreover, these devices normally provide only a pre-established, static way of turning water flow on and off, i.e., touching the switch turns the water on and touching the switch again turns the water off. Frequently, however, those who would potentially benefit from such devices have special requirements that would militate in favor of controlling the way in which water flow was to be activated and de-activated, and how long that water flow would last. 
       BRIEF SUMMARY OF THE INVENTION 
       [0012]    The present invention comprises a new, improved, and long-lasting apparatus and system for hands-free activation and de-activation of water flow to a sink, bathtub, shower, or similar plumbing fixture that can be readily installed and operated safely even in locations in which electrical power sources are unreliable, inconsistent, or unstable. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0013]      FIG. 1  presents a lateral view of one embodiment of the apparatus and system reflecting the interconnection of a touch-sensitive pad and switch circuit board to solenoid valves(s) and water ports. 
           [0014]      FIG. 2  is an overhead perspective of the switch circuit board illustrating one possible configuration of various elements thereon. 
           [0015]      FIG. 3  is an electric diagram of one possible arrangement of various components regulating voltage for the switch components on the switch circuit board. 
           [0016]      FIG. 4  is an electric diagram of one possible arrangement of various components for the switch on the switch circuit board. 
           [0017]      FIG. 5  presents an overhead lateral view of an enclosure box housing the switch circuit board and the solenoid valve(s). 
           [0018]      FIG. 6  presents a lower lateral perspective of an enclosure box, highlighting drainage outlets. 
           [0019]      FIG. 7  is an overhead lateral perspective of the apparatus and system as it might be installed for use with a sink. 
           [0020]      FIG. 8  illustrates in a lateral view one possible arrangement of the components of a touch-sensitive switch pad as mounted. 
           [0021]      FIG. 9  is an illustration of a water by-pass. 
       
    
    
     REFERENCE NUMERALS IN THE DRAWINGS 
       [0022]      1  120/240 volt AC lead 
         [0023]      2  Ground for 120/240 volt AC lead 
         [0024]      3  9-30 volt negative DC lead 
         [0025]      4  9-30 volt positive DC lead 
         [0026]      5  Switch circuit board 
         [0027]      6  Touch-sensitive pad 
         [0028]      7  Voltage input lead for first solenoid valve 
         [0029]      8  Voltage input lead for second solenoid valve 
         [0030]      9  Voltage output lead to first solenoid valve 
         [0031]      10  Voltage output lead to second solenoid valve 
         [0032]      11  Ground(DC)/Neutral(AC) lead from first solenoid valve 
         [0033]      12  Ground(DC)/Neutral(AC) lead from second solenoid valve 
         [0034]      13  First solenoid valve 
         [0035]      14  Second solenoid valve 
         [0036]      15  Threaded male connector(s) 
         [0037]      16  Threaded female connector(s) 
         [0038]      17  First water inlet port 
         [0039]      18  Second water inlet port 
         [0040]      19  First water outlet port 
         [0041]      20  Second water outlet port 
         [0042]      21  Split-winding step-down transformer 
         [0043]      22  Linear regulator (IC1) 
         [0044]      23  Dip switches (SW1) or similar timing control device(s) 
         [0045]      24  Microcontroller (IC3) 
         [0046]      25  Oscillator (IC2) 
         [0047]      26  First low-signal dry-contact relay (K2) 
         [0048]      27  Second low-signal dry-contact relay (K1) 
         [0049]      28  Cable (RG-174 or similar) 
         [0050]      29  Transistor (Q1) 
         [0051]      30  First capacitor (C1) 
         [0052]      31  Second capacitor (C2) 
         [0053]      32  Third capacitor (C3) 
         [0054]      33  Fourth capacitor (C4) 
         [0055]      34  First diode (D1) 
         [0056]      35  Second diode (D2) 
         [0057]      36  Third diode (D3) 
         [0058]      37  Fourth diode (D4) 
         [0059]      38  Fifth diode (D5) 
         [0060]      39  First resistor (R1) 
         [0061]      40  Second resistor (R2) 
         [0062]      41  Third resistor (R3) 
         [0063]      42  Fourth resistor (R4) 
         [0064]      43  5 DC positive volts 
         [0065]      44  First COM (common) relay contact 
         [0066]      45  Second COM (common) relay contact 
         [0067]      46  First NO (normally open) relay contact 
         [0068]      47  Second NO (normally open) relay contact 
         [0069]      48  Enclosure box 
         [0070]      49  Mounting surface for touch-sensitive pad 
         [0071]      50  Insulation 
         [0072]      51  Flat metal washer 
         [0073]      52  Electric connector 
         [0074]      53  Pressure metal washer 
         [0075]      54  Holding nut 
         [0076]      55  Threaded bolt 
         [0077]      56  Drainage outlet(s) 
         [0078]      57  Pipe(s) 
         [0079]      58  T-connector(s) 
         [0080]      50  ¼-turn ball valve(s) 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0081]    This invention utilizes one or more electronic switches, the components of each of which are embedded on a circuit board, to open and close one or more control circuits capable of actuating one or more electrically operated, normally closed solenoid valves to activate and de-activate the flow of water from water inlet ports to water outlet ports. Each capacitance-sensitive switch functions in response to contact by a part of the human body with one or more touch-sensitive pads. 
         [0082]    A lateral overall view of a preferred embodiment of the apparatus and system reflecting the interconnection of a touch-sensitive pad  6  and switch circuit board  5  to two solenoid valves  13 ,  14 , each of which is interposed between water inlet ports  17 ,  18  and water outlet ports  19 ,  20  is presented in  FIG. 1 . While the solenoid valve(s) may be joined to the water ports  17 ,  18 ,  19 ,  20  using various forms of connectors, in the embodiment illustrated in  FIG. 1 , the solenoid valve(s) have threaded male connectors  15  that are joined to companion threaded female connectors  16  attached to the various water ports  17 ,  18 ,  19 ,  20 . Typically, but not always, the first solenoid valve  13  would control a source of hot water, while the second solenoid valve  14  would control a source of cold water. 
         [0083]    Power to the switch may be supplied by a grounded alternating current (AC) of either 120 or 240 volts through the 120/240 volt AC lead  1  and ground lead  2  for the same. Additionally, the switch is designed to operate on direct current (DC) between 9 and 30 volts supplied by way of a positive DC lead  3  and a negative DC lead  4 . 
         [0084]    The one or more touch-sensitive pads  6  may be made of any number of good-conducting, corrosive-resistant metals, such as stainless steel. In one embodiment, a touch-sensitive pad  6  is wired to the switch circuit board  5  by means of an RG-174 or similar cable  28 . When a part of the human body comes into contact with the touch-sensitive pad  6 , this causes the switch to be activated, the accompanying capacitance-sensitive circuit closed, and thus, each solenoid valve  13 ,  14  to be energized. A touch-sensitive pad  6  can be positioned away from the switch circuit board  5  itself in a location convenient to a user, e.g., adjacent to, or, or within a sink or other plumbing fixture. One or more touch-sensitive pads  6  may be employed for the convenience of the user, e.g., one to control the flow of hot water and one to control the flow of cold water. 
         [0085]    The system will accommodate the use of either AC- or DC-powered solenoid valves  13 ,  14 . The power source for the solenoid valve(s)  13 ,  14  therefore may, but need not be, the same power source used for the components of the switch. The voltage for the solenoid valve(s)  13 ,  14  is first carried from input leads  7 ,  8  to the switch circuit board  6  via the COM contact(s)  44 ,  45  (see  FIG. 4 ), then is output from the NO contact(s)  46 ,  47  (see  FIG. 4 ) to the solenoid valve(s)  13 ,  14  by way of output leads  9 ,  10 , allowing each solenoid valve  13 ,  14  to be energized when the switch is activated and the accompanying circuit closed. When energized, each normally closed solenoid valve  13 ,  14  opens to activate the flow of water. When de-energized, each solenoid valve  13 ,  14  closes. 
         [0086]    One possible arrangement of various components of a switch circuit board  5  is illustrated in the overhead view presented by  FIG. 2 . As previously noted, the switch can be powered either by a 120 or 240 AC voltage source through a AC lead  1  and ground lead  2 , or by a DC source operating at between 9 and 30 volts through separate positive and negative leads  3 ,  4 . The incorporation of a split-winding step-down transformer  21  acts as a safety feature to avoid high-voltage AC current from migrating through the system and causing potential harm to the user. A linear regulator  22 , such as an IC1 linear regulator, is employed to regulate the voltage to ensure a positive output of 5 volts  43  to the components of the switch. 
         [0087]    It order to expand the range of power environments in which the apparatus and system will work, and take advantage of DC sources of power, a separate high-frequency, free-running, stable oscillator  25 , such as an NE555 oscillator IC2, is employed in the capacitance-sensitive circuit. Normal oscillation, in one embodiment, typically runs about 270 KHz, but drops to about 100 KHz when a part of the human body comes into contact with the touch-sensitive pad  6 , lowering the capacitance of the circuit. 
         [0088]    When power is supplied to the system, a programmable microcontroller  24  with at least two memory storage registers, such as a microcontroller IC3, initializes and proceeds to determine the frequency of the oscillator  25  by taking two measurements to determine its period across a few microseconds. These values are placed into separate memory storage registers within the microcontroller  24  that, in the case of the IC3, would typically be registers SAMP1 and SAMP2. The values of these two measurements, taken milliseconds apart, are expected to be relatively close to one another. A pre-determined range of “allowable drift” values—in one embodiment, between 80 and 120 pulses—are incorporated within the computer code of the microprocessor  24  to enable it to evaluate its measurement of the frequency of the oscillator  25 . If either of the two measurements of the oscillator  25  exceeds the range of acceptable drift values, the microcontroller  24  will presume an unacceptable level of instability is present and will reset the system. 
         [0089]    As long as the measured frequency of the oscillator  25  does not exceed these pre-established values, the microprocessor  24  will take no action, other than to reset and recalibrate the system periodically. In one embodiment, this resetting and recalibration occurs approximately once every hour. Rather than simply allowing the capacitance of the apparatus and system to dissipate over time, and to compensate for changes in resistance due to temperature, humidity, corrosion, etc., by performing this periodic resetting and recalibration, the microprocessor  24  minimizes malfunctions that might cause the switch to engage at arbitrary times, and improves the longevity of the apparatus and system. When a part of the human body comes into contact with the touch-sensitive pad  6 , however, the measured frequency of the oscillator  25  drops. If the net change in measurement of frequency exceeds a pre-established minimum (‘LO’) value—in one embodiment, this might be 15 pulses—then the microcontroller will proceed to take action based on the settings of the dip switches or similar timing control device(s)  23 . Changes in the sensitivity of the touch-sensitive pad  6  can be made by adjusting the applicable range of acceptable drift values in the computer code of the microprocessor  24 . 
         [0090]    Dip switches  23  allow the apparatus and system to be flexibly adjusted with respect to the manner and timing of activation and de-activation of water flow. In one preferred embodiment, four side-actuated dip switches in a single unit, such as a C&amp;K BP04K, may be employed. If the first dip switch is open (i.e., ungrounded) and the remaining three dip switches are open as well, then the microprocessor  24  will cause the low-signal dry-contact relay(s)  26 ,  27  to be activated and the solenoid valve(s)  13 ,  14  open, i.e., water is allowed to flow, only while a part of the human body is in contact with the touch-sensitive pad  6 . As soon as the touch-sensitive pad  6  is no longer being touched, the water flow ceases. By contrast, when the first dip switch is closed and the remaining three dip switches are open, then the microprocessor  24  will cause the low-signal dry-contact relay(s)  26 ,  27  to be activated and the solenoid valve(s)  13 ,  14  open, i.e., water is allowed to flow, until such time as the touch-sensitive pad  6  again comes into contact with a part of the human body. Water flow alternately will start and stop with each touch of the touch-sensitive pad  6 . 
         [0091]    The second, third, and fourth dip switches can be used to adjust the timing of the water flow, and can be programmed to accommodate different time intervals to meet user requirements. For example, the second dip switch could be programmed for one minute, the third for five minutes, and the fourth for ten minutes. The pre-programmed time interval for each of these three dip switches is activated by closing the applicable dip switch. For example, if the first dip switch is open and the second dip switch is closed, the water will remain running for at least 1 minute after the user contacts the touch-sensitive pad  6 , regardless of whether the user touches the touch-sensitive pad  6  again. Similarly, if the first dip switch is open and the third dip switch is closed, the water will remain running for at least five minutes. 
         [0092]    By different combinations of open and closed settings, the second, third, and fourth dip switches, in this example, would allow the time of water flow to be adjusted in intervals of 1, 5, 6, 10, 11, 15, and 16 minutes to suit the requirements of the user. The total time interval is the sum of the programmed times for each of the closed dip switches. For example, closing the second and third dip switch, but leaving the fourth open, will result in a six-minute interval. 
         [0093]    If the first dip switch is closed while any of the other dip switches are closed, the user can cut off the flow of water by touching the touch-sensitive pad  6  a second time, thus shortening the time interval for the water flow established by the settings of the second, third, and fourth dip switches. Touching the touch-sensitive pad  6  again will initiate another full time interval for the water flow. 
         [0094]      FIG. 3  presents electric diagram of one possible arrangement of a set of components regulating the voltage for the system, located on the switch circuit board  6 . It illustrates how voltage from a 120-volt AC power source, by way of the split-winding step-down transformer  21 , is reduced to six volts. It further reflects how a DC power source, which bypasses the split-winding transformer  21 , may be used in lieu of AC power. Finally, it illustrates how the power from either source passes through the linear regulator  22  to ensure uniform output of 5 DC positive volts  43  to power the switch components. 
         [0095]    An electric diagram of one embodiment of the switch and its components, as integrated with a touch-sensitive pad  6 , appears as  FIG. 4 . This shows how a touch-sensitive pad  6  may be attached to the switch via a cable  28 , such as an RG-174. In one embodiment, the components determining the frequency of the oscillator  25  comprise two resistors  40 ,  41  (R2 and R3), a capacitor  32  (C3), and the capacitance from the cable  23  and the touch-sensitive pad  6  itself. The diagram further illustrates the inter-relationship of the oscillator  25 , the microprocessor  24 , the dip switches  23 , and two low-signal dry-contact relays  26 ,  27 , one for each of two solenoid valves  13 ,  14  (not pictured in  FIG. 4 ), and the contacts for the relays  44 ,  45 ,  46 ,  47  to which the voltage input leads  6 ,  7  and voltage output leads  8 ,  9  for the solenoid valves  13 ,  14  are connected. The use of low-signal dry-contact relays  26 ,  27  allows the system to handle any exterior voltage to power the solenoid valves  13 ,  14  and ensures longer life for the relay contacts  44 ,  45 ,  46 ,  47 . 
         [0096]      FIG. 5  illustrates the incorporation of the one or more solenoid valves  13 ,  14  and the switch circuit board  5  into an enclosure box  48 . This feature facilitates the installation of the apparatus and system and protects the components inside it. By dividing the sensitive electronic components on the switch circuit board  5  and any high-voltage electric current from the components through which the water passes, the enclosure box  48  provides an added measure of safety, system integrity, and long life for the apparatus and system. The inclusion of one or more drainage outlets  56  in the form of holes, slots, or other suitable apertures provides a way for water to drain from the enclosure box  48  in the event of a leak and prevent water from a leak from seeping into the compartment of the enclosure box  48  housing the sensitive electronic components on the switch circuit board  5  and any high voltage AC current. 
         [0097]    In  FIG. 6 , a lower lateral perspective of the enclosure box  48  is presented, highlighting drainage outlets  56 .  FIG. 7  is an overhead lateral perspective of the apparatus and system as it might be installed for use with a sink, showing how the touch-sensitive pad  6  might be positioned relative to the sink for the convenience of a user. Optionally, the apparatus and system may incorporate a water by-pass valve, reflected in  FIG. 9 , to allow water to circumvent the apparatus and system in the event the available sources of power for the system fail and the solenoid valves  13 ,  14  remain closed. 
         [0098]    A lateral view of one possible arrangement of the components of the touch-sensitive pad  6  as mounted is illustrated in  FIG. 8 . The touch-sensitive pad  6  passes through a mounting surface  49 . The touch-sensitive pad  6  is separated from the mounting surface  49 , which could be one or more of any number of materials, such as ceramic, metal, or title, by suitable insulation  50 , such as rubber. A flat metal washer  51  abuts the insulation  50  on the side of the mounting surface  49  opposite the touch-sensitive pad  6 . A pressure metal washer  53  and holding nut  54  secure an electric connector  52  against the flat metal washer  51  and about a threaded bolt  55 . The cable  28  is attached to the electric connector  52 . The insulation  50  prevents the low voltage current of the apparatus and system from making contact with the mounting surface  49 , and in addition, prevents the accumulation of soap, scum, residues, etc. between the touch-sensitive pad  6  and the mounting surface  49 , which aids in preventing malfunctioning of the switch and foreshortened apparatus and system life.

Summary:
The present invention comprises an apparatus and system for automatic activation and de-activation of water flow to a sink, bathtub, shower, or similar plumbing fixture. It can be readily installed and operated safely using AC or DC power of varying voltage, even in locations in which electrical power sources are unreliable, inconsistent, or unstable. 
     One or more normally closed solenoid valves, activated by way of a capacitance-sensitive electronic switch, control water flow. The switch functions in response to contact by a part of the human body with one or more touch-sensitive pads, which are designed to be resistant to malfunctions associated with the buildup of soap and scum. 
     A programmable microprocessor periodically re-calibrates and resets the system to ensure accurate function and longevity. The manner and timing of water flow can be adjusted, and a by-pass is included to allow continued access to water in the event of power failure.