Abstract:
A wave control circuit disclosed herein may be used to control the operation of various plumbing devices and appliances. The wave control circuit uses a sensor to sense presence of objects in the vicinity of the plumbing device and appliance using the wave control circuit and a control circuit to control the operation of the plumbing device or appliance.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is based on and claims the benefit of U.S. Provisional Application No. 60/773,504, filed on Feb. 14, 2006 and entitled “Wave Control Circuit for Plumbing Devices and Appliances,” which is incorporated herein by reference in its entirety. 

   BRIEF DESCRIPTION OF THE DRAWINGS 
   The features and inventive aspects of the present invention will become more apparent upon reading the following detailed description and drawings. In the drawing figures, which are merely illustrative, and wherein like reference numerals depict like elements throughout the several views: 
     FIG. 1  is an is an assembly view of a plumbing fixture and wave control circuit system formed in accordance with the teachings of this invention; 
     FIG. 2  shows a wave control circuit for the system shown in  FIG. 1 ; 
     FIG. 3  is a flow diagram for the system shown in  FIG. 1 ; 
     FIG. 4  illustrates an alternate logic flow diagram for the system shown in  FIG. 1 ; and 
     FIG. 5  shows still another alternate logic flow diagram for the system shown in  FIG. 1 . 

   DETAILED DESCRIPTION 
   The present invention relates to a wave control circuit used to control the operation of various plumbing devices and appliances. An illustrative embodiment of the invention is described herein, with reference to the accompanying drawing figures. A person having ordinary skill in the art will recognize that the invention may be practiced in a variety of orientations without departing from the spirit and scope of the invention. 
     FIG. 1  shows an illustrative embodiment of the invention used to control the operation of a plumbing device such as a faucet. The embodiment of the invention consists of a wave control circuit  10 , a plumbing device  20  and at least one sensor  30 . Alternatively, all or a portion of the plumbing device  20  may comprise the sensor  30 . As best seen in  FIG. 2 , the wave control circuit  10  may include at least one sensor circuit  100 , at least one control circuit  110 , at least one driver circuit  120 , at least one valve  130 , and at least one sensor  30  associated with the plumbing device  20 . Control circuit  110  may comprise digital logic circuitry or a microprocessor  160  that executes software instructions built into the microprocessor  160 . 
   In either case, control circuit  110  reads output from sensor circuit  100  to control the flow of fluid through plumbing device  20 . Control circuit  110  sends an output signal through driver circuit  120  to control the flow of fluid through plumbing device  20 . Driver circuit  120  achieves the proper drive voltage and current necessary to enable or disable valve  130 . Valve  130  enables and disables functions of plumbing device  20 . For example, when valve  130  is open, fluid such as water may flow through plumbing device  20 , which is shown in  FIG. 1  as a faucet. 
   Now referring to  FIG. 2 , the wave control circuit  10  is shown to include a sensor circuit  100 , a control circuit  110 , and a driver circuit  120 . The wave control circuit  10  may be communicatively connected to the valves  130 . As best seen in  FIG. 2 , the sensor circuit  100  may include a capacitive sensing network that is connected to proximity sensor  30 . The proximity sensor  30  may detect the presence of objects placed within the sensor&#39;s sensing field by capacitive charging and discharging. Therefore, when an object is placed within the sensing field of the proximity sensor  30 , the proximity sensor  30  is charged with a potential voltage and then discharged when the object is moved away. When the proximity sensor  30  is discharged, a small current or a voltage drop may be produced and the sensor circuit  100  may detect such a voltage drop. An example of proximity sensor used in such an application may be what is generally referred to as a charge transfer sensor. However, a person having ordinary skill in the art will understand that this is but only one example of the proximity sensor  30  that may be used in the application and other types of sensors may be used to perform the equivalent function. 
   Typically charge transfer sensors are used to detect objects in free space; thus, a very low capacitance field is generally present. However, the presence of running water may change the impedance of the capacitance network and, thus, may change and affect the sensitivity of sensor circuit  100 . To adjust for this possibility, the sensor circuit  100  is put through a recalibration procedure by either power cycling the sensor circuit  100  or engaging a recalibration function of the sensor circuit  100  to adjust to the load impedance presented to the circuit when the water flows. The recalibration accounts for the changed operating conditions and allows the sensor circuit  100  to have identical sensitivity when water is flowing or isn&#39;t flowing through the plumbing device  20 . A person having skill in the art will appreciate that a slight delay may be included before the recalibration. This delay may help to assure that impedance is accurately sensed or measured by the sensor circuit  100 . 
   The control circuit  110  may consist of discrete components such as a sequence of flip-flops, a clock, and logic gates to perform the functions described in  FIGS. 3-5 . In an embodiment of the wave control circuit  10 , the control circuit  110  may further include a control logic circuit and a timer circuit. Upon a successful signal (i.e., detection of an object) from sensor  30 , sensor circuit  100 , which is connected to the control logic circuit, may output a high state. The high state of control logic circuit may trigger the timer circuit to create a timing event. Such timing event may enable the driver circuit  120 , which subsequently enables or disables valve  130 . The timing event may also be used to recalibrate the sensor circuit  100  while the sensor circuit  100  maintains its high output state. The high output state of the sensor circuit  100  may be maintained until a second signal from the sensor  30  is detected. Such second detection may set the output state of sensor circuit  100  to low, which may create another timing signal that disables valve  30  and resets sensor circuit  100 . 
     FIG. 3  represents one possible logical flow for the operation of a hands-free plumbing device such as a faucet. In such an embodiment, the plumbing device  20  may use the proximity sensor  30  of the circuit  100 . As shown in  FIG. 3 , the control circuit  110  initializes at step  200 . At  210 , the proximity sensor  30  may determine if an object has been placed within a predetermined proximity to faucet  20 . If it is determined that no object is within the sensing field of proximity sensor  30 , the process loops to point  212  and repeats step  210 . When an object is found within the sensing field of proximity sensor  30 , the logical control  110  may enable the valve  130  to start the flow of water at step  214 . After a short delay at step  216 , the proximity sensor  30  may be recalibrated at step  218  and the logic control  110  may start a first automatic timer at step  220 . 
   At step  230 , the proximity sensor  30  may determine if an object has been placed in proximity to the faucet  20 . If no object is detected within the sensing field of the proximity sensor  30 , the process loops to point  232  to determine if the first automatic timer has expired. If the automatic timer has not expired, the logical control  110  loops back to step  230 . If the automatic timer has expired or an object is found within the sensing field of proximity sensor  30 , the logical control  110  proceeds to step  234  and disables the valve  130 , stopping the flow of water. After a short delay at step  236 , the logical control  110  moves to point  238  and recalibrates the proximity sensor  30 . Subsequently, the logical control  110  proceeds to the point  212 . 
   A person having ordinary skill in the art will understand that the logical flow of the embodiment of the invention may be modified to incorporate additional features. One such alternate logical flow is described in  FIG. 4 , which discloses a hands free mode to control the water temperature of a plumbing device. As illustrated in  FIG. 4 , at step  214 , the embodiment of the system is modified to include a hot valve and a cold valve, both of which may be enabled or disabled by logic control  110  or another similar control device or circuit. For example at step  220 , a first timer may be started. The hot/cold control shown at step  250  enables and disables the hot and cold valves to control the water temperature. The initial state of the hot/cold control is the warm state. In the illustrated embodiment, the first timer controls the period on which the hot/cold control is active. This permits the user to cycle through the temperature states and select a desired water temperature. 
   In the warm state, both the hot valve and the cold valve are enabled, resulting in a mixture of hot and cold water flowing to the plumbing device. The volume of hot and cold water flowing to the plumbing device may be selectively varied, thus, resulting in the ability to selectively control the water temperature. 
   For a period of time established by first automatic timer at step  200 , the proximity sensor  30  may attempt to detect objects within the sensor&#39;s sensing field. Successful detection of an object causes the hot/cold control shown at step  250  to cycle through several temperature states. The hot/cold control, shown at step  250 , cycles through the warm state, the hot state, and finally the cold state. After changing the state of the hot/cold control at step  250 , the first automatic timer may be reset. When the time period set by first automatic timer expires, the hot/cold control may be disabled and the water temperature cannot be changed. The water flow will then be disabled by either the detection of an object within the sensing field of proximity sensor  30  or the expiration of a time period set by a second automatic timer. If the temperature is changed during the first auto timer period, an appropriate LED may be lit to indicate the water temperature chosen. For example a red LED may be lit to indicate hot temperature and a green LED may be lit to indicate cooler temperature. Such an LED can be on constantly or may be blinking at a rapid rate. When the first auto timer period ends, and the water temperature cannot be changed, the LED may go off or may become a less often blinking indicator (lower duty cycle) to conserve energy. When the water is off, the LED may also be completely off. 
   Now referring to  FIG. 5 , another feature of the invention may be a quarts timer control. Such an embodiment may include a regulator to control the flow of the water. In this embodiment, for a period of time, proximity sensor  30  attempts to detect objects within the sensing field to enable the quarts timer control, step  260 . Once enabled, a user may use the quarts timer control to set the volume of water to be dispensed to a predetermined volume, e.g., 1 quart, 4 quarts, etc. The quarts timer control may also calculate the volume of water that has already flowed and finally reset the first automatic timer. 
   On subsequent detections while the first automatic timer is active, the quarts timer control cycles through water volume to be dispensed and adjusts the regulator accordingly. At the expiration of the time period set by the first automatic timer, the quarts timer control calculates the time required for the desired volume of water to be dispensed and starts the second automatic timer. The flow of water is disabled by either the detection of an object within the sensing field of proximity sensor  30  or the expiration of the time period set by the second automatic timer. 
   Another embodiment of the system may optionally be a hands free bathtub faucet and shower-head. Such an embodiment may include proximity sensors in both the faucet and the shower-head. The successful detection of an object within the sensing field of the proximity sensor of either the faucet or the shower head may accordingly enable the flow of water in the appropriate plumbing device. If the activated plumbing device detects an object within the sensing field of the proximity sensor, the plumbing device may accordingly disable the flow of water. However, if the disabled plumbing device detects an object within the sensing field of its proximity sensor, the active plumbing device will be disabled and the next plumbing device will be activated. 
   While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. The presently disclosed embodiments are therefore to be considered in all respects illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.