Abstract:
Exemplary power systems for dynamically controlling a dispenser drive motor for dispensing soap, sanitizing or lotion. An exemplary soap, sanitizing or lotion dispenser includes a housing, a receptacle for receiving a container for holding a soap, sanitizing or lotion, a container of soap, sanitizing or lotion and a pump secured to the container. The exemplary soap, sanitizing or lotion dispenser includes a power source, a motor and an actuator that couples the motor to the pump. In addition, the exemplary soap, sanitizing or lotion dispenser includes pulse width modulation circuitry in circuit communication with the power source and the motor. Movement of the actuator one actuation cycle dispenses a dose of soap, sanitizing or lotion. The pulse width modulation circuitry provides a plurality of voltage pulses to the motor to move the actuator one actuation cycle.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefits of U.S. Provisional Patent Application Ser. No. 62/208098 filed on Aug. 21, 2015 and entitled “POWER SYSTEMS FOR DYNAMICALLY CONTROLLING A SOAP, SANITIZER OR LOTION DISPENSER DRIVE MOTOR,” which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates generally to touch free soap and sanitizer dispenser systems and more particularly to power systems for touch free dispensers. 
       BACKGROUND OF THE INVENTION 
       [0003]    In hands free (or touch free) dispensers, a liquid or foam pump is activated by a drive actuator through a drive cycle to dispense a dose of fluid. The drive actuator is powered by a direct current (DC) motor with a drive train formed of gears or other mechanical means. The drive train (including the motor) strokes or spins the pump. The motor is typically powered by a battery; however, the power source may be an intermediate energy storage device (i.e. capacitors). The power that is delivered to the motor is determined by the motor draw (or load on the motor) and the power capacity of the power source. Batteries deliver power and behave differently than capacitors; hence the motor and drive train will behave differently depending the power source that is providing power. Dispensers typically use a controller or microprocessor that senses motion through a user sensor and sends a signal to a switch device (such as, for example, a power transistor or relay). The switch device connects the power source to the motor for the duration of the actuation cycle. The motor draws power (or current) from the power source as it needs and the power source provides power at whatever level that it can provide. There is no control on the motor speed, motor noise, energy efficiency of the motor or drive train or limiting power delivery from the power source. 
       SUMMARY 
       [0004]    Exemplary power systems for dynamically controlling a dispenser drive motor for dispensing soap, sanitizing or lotion. An exemplary soap, sanitizing or lotion dispenser includes a housing, a receptacle for receiving a container for holding a soap, sanitizing or lotion, a container of soap, sanitizing or lotion and a pump secured to the container. The exemplary soap, sanitizing or lotion dispenser includes a power source, a motor and an actuator that couples the motor to the pump. In addition, the exemplary soap, sanitizing or lotion dispenser includes pulse width modulation circuitry in circuit communication with the power source and the motor. Movement of the actuator one actuation cycle dispenses a dose of soap, sanitizing or lotion. The pulse width modulation circuitry provides a plurality of voltage pulses to the motor to move the actuator one actuation cycle. 
         [0005]    Another exemplary soap, sanitizing or lotion dispenser includes a housing, a receptacle for receiving a container for holding a soap, sanitizing or lotion, a power source, a motor, an actuator coupled to the motor and pulse width modulation circuitry in circuit communication with the power source and the motor. Movement of the actuator one actuation cycle dispenses a dose of soap, sanitizing or lotion. The pulse width modulation circuitry provides a plurality of voltage pulses to the motor to move the actuator one actuation cycle. 
         [0006]    Another exemplary soap, sanitizing or lotion dispenser includes a housing, a receptacle for receiving a container for holding a soap, sanitizing or lotion, a power source, a motor; and pulse width modulation circuitry in circuit communication with the power source and the motor. The pulse width modulation circuitry provides a plurality of voltage pulses to the motor to dispense a soap, sanitizing or lotion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    These and other features and advantages of the present invention will become better understood with regard to the following description and accompanying drawings in which: 
           [0008]      FIG. 1  is a generic illustrative schematic of an exemplary dispenser having a power system that receives dispensing power from a power source inserted and removed with a refill unit; 
           [0009]      FIGS. 3 and 4  are exemplary illustrations of pulse width modulated duty cycles; 
           [0010]      FIG. 5  is a graph of energy levels verses times for dispense cycles; 
           [0011]      FIG. 6  is an exemplary graph of the time differential of a first and a second cycle time for standard dispenser operation and first and second pulse width modulated dispenser cycle times; 
           [0012]      FIG. 7  is an exemplary illustration of a DC motor efficiency curve; and 
           [0013]      FIG. 8  is an exemplary graph of a load verses displacement curve for a dispenser. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    The following includes definitions of exemplary terms used throughout the disclosure. Both singular and plural forms of all terms fall within each meaning. Except where noted otherwise, capitalized and non-capitalized forms of all terms fall within each meaning: 
         [0015]    “Circuit communication” as used herein indicates a communicative relationship between devices. Direct electrical, electromagnetic and optical connections and indirect electrical, electromagnetic and optical connections are examples of circuit communication. Two devices are in circuit communication if a signal from one is received by the other, regardless of whether the signal is modified by some other device. For example, two devices separated by one or more of the following—amplifiers, filters, transformers, optoisolators, digital or analog buffers, analog integrators, other electronic circuitry, fiber optic transceivers or satellites -- are in circuit communication if a signal from one is communicated to the other, even though the signal is modified by the intermediate device(s). As another example, an electromagnetic sensor is in circuit communication with a signal if it receives electromagnetic radiation from the signal. As a final example, two devices not directly connected to each other, but both capable of interfacing with a third device, such as, for example, a CPU, are in circuit communication. 
         [0016]    Also, as used herein, voltages and values representing digitized voltages are considered to be equivalent for the purposes of this application, and thus the term “voltage” as used herein refers to either a signal, or a value in a processor representing a signal, or a value in a processor determined from a value representing a signal. 
         [0017]    “Signal”, as used herein includes, but is not limited to one or more electrical signals, analog or digital signals, one or more computer instructions, a bit or bit stream, or the like. 
         [0018]    “Logic,” synonymous with “circuit” as used herein includes, but is not limited to hardware, firmware, software and/or combinations of each to perform a function(s) or an action(s). For example, based on a desired application or needs, logic may include a software controlled microprocessor or microcontroller, discrete logic, such as an application specific integrated circuit (ASIC) or other programmed logic device. Logic may also be fully embodied as software. The circuits identified and described herein may have many different configurations to perform the desired functions. 
         [0019]    The values identified in the detailed description are exemplary and they are determined as needed for a particular dispenser and/or refill design. Accordingly, the inventive concepts disclosed and claimed herein are not limited to the particular values or ranges of values used to describe the embodiments disclosed herein. 
         [0020]      FIG. 1  illustrates a dispenser  100  having an exemplary inventive power system. Dispenser  100  includes a housing  102 . Located within housing  102  is system circuitry  130 . System circuitry  130  may be on a single circuit board or may be on multiple circuit boards. In addition, some of the circuitry may not be on a circuit board, but rather individually mounted and electrically connected to the other components as required. In this embodiment, system circuitry  130  includes a processor  132 , memory  133 , a header  134 , a permanent power source  136 , a voltage regulator  138 , door switch circuitry  140 , an object sensor  142 , end of stroke circuitry  147 , actuator drive circuitry  148 , a bank of capacitors  145 , capacitor control circuitry  146 , replaceable power source interface receptacle  144 , pulse with modulation circuitry  180  and switching device  182 . 
         [0021]    Processor  132  may be any type of processor, such as, for example, a microprocessor or microcontroller, discrete logic, such as an application specific integrated circuit (ASIC), other programmed logic device or the like. Processor  132  is in circuit communication with header  134 . Header  134  is a circuit connection port that allows a user to connect to system circuitry  130  to program the circuitry, run diagnostics on the circuitry and/or retrieve information from the circuitry. In some embodiments, header  134  includes wireless transmitting/receiving circuitry, such as for example, wireless RF, BlueTooth®, ANT®, or the like, configured to allow the above identified features to be conducted remotely. 
         [0022]    Processor  132  is in circuit communication with memory  133 . Memory  133  may be any type of memory, such as, for example, Random Access Memory (RAM); Read Only Memory (ROM); programmable read-only memory (PROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash, magnetic disk or tape, optically readable mediums including CD-ROM and DVD-ROM, or the like, or combinations of different types of memory. In some embodiments, the memory  133  is separate from the processor  132 , and in some embodiments, the memory  133  resides on or within processor  132 . 
         [0023]    A permanent power source  136 , such as, for example, one or more batteries, is also provided. The permanent power source  136  is preferably designed so that the permanent power source  136  does not need to be replaced for the life of the dispenser  100 . The permanent power source  136  is in circuit communication with voltage regulator circuitry  138 . In one exemplary embodiment, voltage regulator circuitry  138  provides regulated power to processor  132 , object sensor  142 , end of stroke detection circuitry  147  and door circuitry  140 . Permanent power source  136  may be used to provide power to other circuitry that requires a small amount of power and will not drain the permanent power source  136  prematurely. 
         [0024]    Processor  132  is in circuit communication with door circuitry  140  so that processor  132  knows when the dispenser  100  door (not shown) is closed. In some embodiments, processor  132  will not allow the dispenser  100  to dispense a dose of fluid if the door is open. Door circuitry  140  may be any type of circuitry, such as, for example, a mechanical switch, a magnetic switch, a proximity switch or the like. Processor  132  is also in circuit communication with an object sensor  142  for detecting whether an object is present in the dispense area. Object sensor  142  may be any type of passive or active object sensor, such as, for example, an infrared sensor and detector, a proximity sensor, an imaging sensor, a thermal sensor or the like. 
         [0025]    In addition, processor  132  is in circuit communication with pulse width modulation circuitry  180 . Pulse width modulation circuitry  180  is in circuit communication with switching device  182 . Switching device  182  is in circuit communication with capacitor bank  145  and actuator drive circuitry  148 . During operation, processor  132  provides signals to pulse width modulation circuitry  180 , which cause pulse width circuitry  180  to control switching device  182  to modulate the power provided by caps  145  to drive the actuator drive  148  (which includes a motor). More detailed descriptions of the modulated are described below. 
         [0026]    Actuator drive circuitry  148  causes a motor and associated gearing  150  to operate foam pump  114  (which may be a liquid pump in some embodiments) located on a refill unit  110 . In addition, end of stroke detection circuitry  147  is in circuit communication with processor  132  and provides processor  132  with information relating to the end of stroke for the pump  114  so that the processor  132  can determine when to stop the motor and associated gearing. The end of stroke circuitry  147  may include, for example, an encoder, a physical switch, a magnetic switch, software algorithm or the like. 
         [0027]    In this exemplary embodiment, refill unit  110  is shown in phantom lines inserted in the dispenser  100  in  FIG. 1  and is also illustrated in solid lines in  FIG. 2 . Thus, this illustrates that refill unit  110  is inserted into dispenser  100  and removed from dispenser  100  as a unit. Refill unit  110  includes a container  112 , a foam pump  114  that includes an air compressor  116  and an outlet  118 . In some embodiments, refill unit  110  includes a container and a liquid pump and mates with a permanent air compressor (not shown) located in housing  102  to produce a foam product. Refill unit  110  also includes a foamable liquid  113 , such as, for example, a foamable soap, sanitizer, lotion, moisturizer or other liquid used for personal hygiene. In some embodiments, refill unit  110  is for use in a liquid dispenser, rather than a foam dispenser, and filled with liquid that is not foamed. Accordingly, air compressor  116  is not required. 
         [0028]    In addition, refill unit  110  includes a replaceable power source  120 . Replaceable power source  120  may be any power source, such as, for example, a single “AA” battery, a coin cell battery, a 9 volt battery or the like. In some embodiments, the replaceable power source  120  does not contain enough power to directly power motor and associated gearing  150  to dispense the contents of the refill unit  110 . Replaceable power source  120  is inserted into dispenser  100  with refill unit  110  and is removed from dispenser  100  with refill unit  110 . Preferably refill unit  110  has replaceable power source  120  affixed thereto; however, in some embodiments, the replaceable power source  120  is provided separately with the refill unit  110 . In either case, however, the replaceable power source  120  is provided with and removed with the refill unit  110 . 
         [0029]    System circuitry  130  also includes a bank of capacitors  145  and capacitor control circuitry  146  in circuit communication with processor  132 . The bank of capacitors  145  and capacitor control circuitry  146  is in circuit communication with replaceable power source interface receptacle  144  and actuator drive  148 . Replaceable power source interface receptacle  144  is configured to receive and/or otherwise electrically couple with replaceable power source  120  when a refill unit  110  is inserted in the dispenser  100 . 
         [0030]    During operation, when a refill unit  110  is inserted into dispenser  100 , processor  132  and capacitor control circuitry  146  cause the bank of capacitors  145  to charge in parallel. In one exemplary embodiment, there are three capacitors. In some embodiments the capacitors are oversized for the required power to power the motor and associated gearing  150  to dispense a dose of foam. Oversized capacitors are preferably charged to a level that is less than the rated voltage of the capacitors. Because the bank of capacitors  145  is charged to less than full capacity, there is less discharge in the capacitors when they are idle for a period of time. In some embodiments, the capacitors are charged to less than about 50% of their full capacity. In some embodiments, the capacitors are charged to less than about 75% of their full capacity. In some embodiments, the capacitors are charged to less than about 90% of their full capacity. 
         [0031]    When the processor  132 , through object sensor  142 , determines that an object is within the dispense zone, the processor  132  causes the capacitor control circuitry  146  to place the capacitors  145  in series to provide power to switching device  182 , which provides modulated power to the actuator drive circuitry  148  to power the motor and associated gearing  150  to operate foam pump  114 . Once a dose has been dispensed, processor  132  checks the charge on the capacitors  145 . If the charge is below a threshold, the processor  132  causes the capacitor control circuitry  146  to charge the capacitors  145 . The capacitors  145  are charged in parallel. 
         [0032]    In some embodiments, the processor  132  monitors the amount of fluid left in the refill unit  110 . The processor  132  may monitor the amount of fluid by detecting the fluid level, for example, with a level sensor, with a proximity sensor, with an infrared detection, by counting the amount of doses dispensed and comparing that to a total number of dispenses for the refill unit or the like. When the processor  132  determines that the refill unit  110  is empty, or close to being empty, the processor  132  causes the replaceable power source  120  to charge the capacitors  145  up to their maximum charge, or to charge the capacitors  145  up until the replaceable power source  120  is completely drained or drained as far as possible. Thus, when the refill unit  110  and replaceable power source  120  is removed, as much energy as possible has been removed from the replaceable power source  120 . 
         [0033]    Although the exemplary dispenser  100  is shown and described with capacitors as a power source, other types of power sources may be used, such as, for example, rechargeable batteries. Additional exemplary dispensers as well as more detail on the circuitry for the touch free dispenser described above is more fully described and shown in U.S. patent application Ser. No. 13/770,360 titled Power Systems for Touch Free Dispensers and Refill Units Containing a Power source, filed on Feb. 19, 2013 which is incorporated herein by reference in its entirety. 
         [0034]      FIG. 3  illustrates an exemplary waveform output by pulse width modulation circuitry  180  and switching device  182 . In this exemplary embodiment, the voltage is 5 volts and one cycle is 0.2 seconds. The wave form represents a 25% duty cycle, which means that the motor receives voltage pulses that are approximately 0.05 seconds long at about 5 volts followed by 0.15 seconds of substantially no voltage. Similarly,  FIG. 4  illustrates another exemplary waveform output by pulse width modulation circuitry  180  and switching device  182 . In this exemplary embodiment, the voltage is 5 volts and one cycle is 0.2 seconds. The waveform represents a 50% duty cycle, which means that the motor receive voltage pulses that are approximately 0.1 seconds long at about 5 volts followed by 0.1 seconds of substantially no voltage. Any suitable duty cycle may be used. Typically, the duty cycle is greater than a 10% duty cycle. In addition, the duty cycle need not be consistent for an entire dispense cycle. For example, if a dispense cycle is 1 second, the wave form may start out at a 25% duty cycle and increase to, for example, a 90% duty cycle as the load increases, and drop back down to a 25% duty cycle as the load decreases. 
         [0035]    Duty cycles may be selected based on noise levels of the dispensers. For example, the dispenser may have a high noise level at above a 95% duty cycle and below a 40% duty cycle. Accordingly, in some embodiments, the duty cycle (or duty cycles) may be selected to be within the range for a quieter operation. 
         [0036]      FIG. 5  illustrates the charge level for a capacitor bank. When the capacitor bank is fully charged at e 1  the time to dispense a product (under a “standard” operation without pulse width modulation) is time t 1 , however, when the energy level is at e 2 , the time required for an actuation cycle is time t 2 , at an energy level of e 3 , the actuation cycle takes time t 3 . As can be seen, the charge level of the device greatly changes the time it takes to dispense a dose of fluid. A similar pattern develops when batteries are used, however, the increase in cycle time tends to occur over greater time periods. 
         [0037]    Pulse width modulation circuitry  180  allows cycle times to be standardized.  FIG. 6  illustrates two cycle times for a dispenser under standard operation, without pulse width modulation and two cycle times for the dispense using pulse width modulation circuitry. As can be seen, under standard operation, the first dispense cycle requires only 1 second to dispense a dose of fluid, however, the second dispense cycle requires 1.4 seconds to dispense a dose of fluid. Thus, the change in dispense cycle times is about 0.4 seconds. Using pulse width modulation, the power is limited during the first dispense cycle by pulsing on and off the voltage applied to the dispenser motor during the first cycle, which results in a dispense time of slightly greater than 1.2 seconds. During the second dispense cycle, the pulse width modulation pulses on and off the voltage applied to the dispense cycle with a higher duty cycle than during the first dispense resulting in a dispense time of 1.4 seconds. Thus, with pulse width modulation, the difference in dispense times between is less than 0.2 seconds. Accordingly, in one embodiment, pulse width modulation circuitry reduced the differences in cycle time significantly. As used herein, the higher the duty cycle, the wider the pulse duration is. For example, a 100% duty cycle means that the voltage is constantly applied. A 90% duty cycle means that the voltage is turned on for 90% of the cycle and off for 10% of the cycle. A 40% duty cycle means that the voltage is turned on for 40% of the cycle and off for 60% of the cycle. 
         [0038]    In some embodiments, the pulse width modulation circuitry  180  attempts to reduce the overall power needed and energy needed for the dispense cycle. When dispense power and energy values are reduced, it increased battery life of the device or enables reduction of battery capacity needed for the dispenser. Both of which lead to lower operating costs.  FIG. 7  is a speed torque curve  700  for a DC motor. The graph has a motor efficiency curve  702 , a max power curve  704 , a motor current curve, and a motor speed curve  708 . As can be seen from the graph, the peak efficiency of the motor is at a speed 46 rpm ( 710 ). Accordingly, the pulse width circuitry may be varied based on the load. For example, if the load is light, a lower duty cycle may be used in an attempt to limit the speed of the motor to about 46 rpm. As the load increases, the duty cycle increases in an attempt to maintain the speed. As the load again decreases, the duty cycle decreases to limit the speed of the motor to about 46 rpm. 
         [0039]      FIG. 8  is an exemplary load verses actuator cycle displacement curve  800 , with the load  802  along the y-axis and the displacement  804  along the x-axis. As can be seen from the curve, the motor is lightly loaded at first, more heavily loaded and then is unloaded and then coasts to the end of the cycle. The pulse width modulation circuitry can match the load-displacement curve to the efficiency curve of the motor to efficiently drive the dispenser actuator. One exemplary method of applying pulse width modulation is to limit the power delivered to the motor when the displacement is between 0 and 2 and between 23 and 28 and increasing the power between 2 and 23. Thus, the duty cycles between 1 and 2 and between 23 and 28 are lower than the duty cycle between 2 and 23. In some embodiments, the duty cycle between 2 and 23 is 100%, in some embodiments the duty cycle between 2 and 23 is 95% or less. In some embodiments, the duty cycle gradually increases from 2 to about 12 and gradually decreases from 12 to about 23. 
         [0040]    The pulse width modulation circuitry  180  may be configured differently based on the type of material being dispensed. In some embodiments a selector switch is included that allows a user to identify the type of product to be dispensed. Varies types of products may be dispensed, liquid soap, liquid sanitizer, foam soap, foam sanitizer and the like. In some embodiments interface receptacle  144  includes circuitry for reading information form refill unit  110 . The information may be communicated directly to processor  132  or through capacitor circuitry  146  to processor  132 . Different pulse width frequency modulation schemes may correlate to the different types of fluid. For example, if a liquid soap is being dispensed, the pulse width modulation may be at a lower duty cycle, such as for example 50%, than that required for foam soap dispensing, which may have a higher duty cycle, such as for example 75%. 
         [0041]    While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. It is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Unless expressly excluded herein, all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions—such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure; however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order in which the steps are presented to be construed as required or necessary unless expressly so stated.