Abstract:
Embodiments of the invention provide a stand-alone controller and a method for controlling a pump motor driven by an alternating current source. The stand-alone controller includes a power terminal for connection with the alternating current source and a load terminal for connection with the pump motor. The stand-alone controller further includes an enable switch to form a power line carrying power from the alternating current source to the pump motor. The stand-alone controller can store a first current being drawn through the power line by the pump motor when a control switch is actuated. A state of the enable switch is based on a comparison of the first current to a second current being drawn through the power line by the pump motor.

Description:
[0001]    This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 61/010,506 filed on Jan. 9, 2008, the entire contents of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    Many pump applications include some type of controller to control turning the pump on and off. The use of a controller can save energy by only operating the pump when needed. In addition, some controllers can also protect the pump motor by preventing the pump from running in a dry or clogged condition. 
         [0003]    Some conventional pump controllers include mechanical float switches or flow meters to detect when the pump may be running in a dry condition or is clogged. Conventional controllers are often installed with connections to the pump itself and within the reservoir containing fluid to be pumped. In addition, further construction may be required to install the float switches or flow meters. Because of the multiple connections, controllers are often manufactured as part of a single pump or designed to be used with only one kind of pump or application (e.g., sump pump applications). Thus, most conventional controllers cannot be used on multiple pumps or for multiple applications. 
       SUMMARY 
       [0004]    Some embodiments of the invention provide a stand-alone controller for controlling a pump motor driven by an alternating current source. The controller includes a power terminal for removable connection with the alternating current source and a load terminal for removable connection with the pump motor. The controller also includes an enable switch selectively connecting the alternating current source to the load terminal in order to form a power line carrying power from the alternating current source to the pump motor. The controller further includes a control switch which can signal the controller to store a first current being drawn through the power line by the pump motor. A state of the enable switch is based on a comparison of the first current to a second current being drawn through the power line by the pump motor. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a perspective view of a stand-alone pump shut-off controller according to one embodiment of the invention. 
           [0006]      FIG. 2  is a flow chart of a method of operating the controller of  FIG. 1 . 
           [0007]      FIG. 3  is a schematic of a control circuit for use with the controller of  FIG. 1 . 
           [0008]      FIG. 4  is a schematic of a power circuit included in the control circuit of  FIG. 3 . 
           [0009]      FIG. 5  is a schematic of a microcontroller circuit included in the control circuit of  FIG. 3 . 
           [0010]      FIG. 6  is a schematic of a programming circuit included in the control circuit of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION  
       [0011]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings, whether mechanical or electrical. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
         [0012]    In addition, it should be understood that embodiments of the invention include both hardware and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic based aspects of the invention may be implemented in software. As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be utilized to implement the invention. Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the invention and that other alternative mechanical configurations are possible. 
         [0013]      FIG. 1  illustrates a controller  10  for a pump according to one embodiment of the invention. The controller  10  can include a stand-alone controller box II and can be used in conjunction with any suitable pump. The controller box  11  can include a control circuit  12  (as shown in  FIGS. 3-6 ), a plug outlet  13  (i.e., a female electrical connector or load terminal), a control switch  14 , an indicator  15  (such as a light-emitting diode, LED), a power cord  16 , and a power plug (i.e., a male electrical connector or power terminal, not shown). The pump can be plugged into the plug outlet  13  of the controller box  11 . The power plug of the controller box  11  can be plugged into a power source (such as a wall outlet or AC outlet). In some embodiments, the power plug can be plugged into 110-230 volts AC and the plug outlet  13  can provide about 12 volts AC to about 230 volts AC and up to about 2 amps. 
         [0014]    The pump can be plugged into the plug outlet  13  and the power plug can be plugged into the power source, causing the pump and the indicator  15  to turn on. The indicator  15  can indicate pump conditions to a user. For example, the indicator  15  can be on solid when the controller  10  is on and the pump is running normal. The indicator  15  can be flashing when the pump has run outside a threshold, reaching a shut-off condition. The indicator  15  can be off when no power is provided to the controller  10 . The control switch  14  can be a tact switch, in some embodiments, and can be used to acquire a pump motor current when the pump is running. For example, if the control switch  14  is pressed and held down for a pre-selected time period (e.g., five seconds), a data collection period starts in which the control circuit  12  can read and store a current being drawn by the motor of the pump relating to a current condition (i.e., the shut-off condition) of the pump. The control circuit  12  can then use that current as the limit or threshold to later detect when the pump is running at the shut-off condition. In some embodiments, the shut-off condition can be set by the user before the power plug is plugged into the power source. In other embodiments, the shut-off condition can be set by the user after the power plug is plugged into the power source. 
         [0015]    The control circuit  12  can be used to set the shut-off condition for which the control circuit  12  will stop providing power to the pump. In one example, the control circuit  12  can be set to stop providing power to the pump when a dry-running condition occurs (i.e., a no-load condition). The pump can be plugged into the controller box  11  and the pump can be started in a no-load or dry-running condition. To set this condition, the pump head can be disconnected from the plumbing system. While running in the no-load condition, the user can press the control switch  14  for a time period (e.g., five seconds) starting the data collection period and causing the control circuit  12  to take a current reading. The no-load current reading can be stored in memory in the control circuit  12  as the shut-off condition. Once the control circuit  12  has stored the no-load current, the pump can be operated with a load. If the current being drawn by the pump reaches the stored no-load current reading, indicating a shut-off condition, the indicator  15  can flash and the control circuit  12  can stop providing power to the pump. 
         [0016]    In another example, the control circuit  12  can be set to stop providing power to the pump when a pre-selected pressure condition occurs (e.g., low pressure or high pressure, such as when the pump is running low or is clogged). The pump can be plugged into the controller box  11  and the pump can be started and operated at a particular pressure that the user wants as the lowest or highest operating pressure (i.e., the threshold pressure at which the user wants the pump to be shut down). Once the particular pressure is reached, the user can press the control switch  14  to signal the data collection period and the control circuit  12  can take a current reading for that threshold pressure. The current reading can be stored in memory in the control circuit  12  as the threshold current indicating the shut-off condition. Once the control circuit  12  has stored the threshold current, the pump can be operated normally. If the current being drawn by the pump motor reaches the threshold current reading (i.e., when the pressure reaches the threshold pressure, indicating the shut-off condition), the indicator  15  can flash and the control circuit  12  can stop providing power to the pump. 
         [0017]    The control switch  14  can also be used to reset the controller  10 . For example, if the indicator  15  is flashing because the control circuit  12  had detected a shut-off condition, the user can make adjustments to the pump so the shut-off condition is no longer occurring and press the control switch  14  to reset the controller  10  so the pump can turn on again. 
         [0018]    In some embodiments, the control circuit  12  can operate according to the method shown in  FIG. 2 . Once the pump is plugged into the controller  10  and the power plug is connected to the power source, the control circuit  12  proceeds to the start operation (task  200 ). From the start operation (task  200 ), the control circuit  12  determines if the pump is operating (task  201 ). If the pump is operating, the control circuit  12  turns on the indicator  15 , if it is not already on (task  202 ), and substantially continuously determines if a user is actuating the control switch  14  (task  203 ). If the control switch  14  has been actuated, the control circuit  12  determines how long the control switch  14  is actuated (task  204 ). If the control switch  14  is actuated for longer than a specific time period (e.g., five seconds), indicating a desired data collection period, the control circuit  12  can read and store the current being drawn by the pump motor as a current threshold value and can flash the indicator  15  for a time period (task  205 ). This may occur when the user is running the pump in a desired shut-off condition, such as a no-load, high-pressure, or low-pressure condition. While the indicator  15  is still flashing, the user can start running the pump in normal operation. The control circuit  12  then turns the indicator  15  on solid again. Once the indicator is on solid again, the control circuit  12  substantially continuously determines the current being drawn by the pump motor and can compare it to the current threshold value (tasks  206 - 208 ). If the current being drawn by the pump is above the current threshold value (e.g., if the shut-off condition has occurred), the control circuit  15  can shut off the pump and can flash the indicator  15  (task  209 ), before returning back to the start operation (task  200 ). 
         [0019]    In addition, the control circuit  12  can repeat tasks  206 - 208 . If the control switch  14  has again been actuated for the time period, the control circuit  12  can revert back to task  205  and record and store a new current threshold value. The control circuit  12  can then continue to tasks  206 - 207  using the new current threshold value. 
         [0020]    The user can know if the control switch  14  has been actuated long enough to signal the collection period (i.e., that the control circuit  12  has recorded the current) by making sure the indicator  15  is flashing. If the control circuit  12  detects that the control switch  14  has not been actuated for the time period at task  204 , the control circuit  12  can return back to task  203 , and the indicator  15  will not have flashed. 
         [0021]    If the control circuit  12  detects that the pump is not operating at task  201  (e.g., the pump has been turned off because of a shut-off condition), the control circuit  12  can substantially continuously determine if a user is actuating the control switch  14  (task  210 ). If the user is actuating the control switch  14 , the control circuit  12  turns on the pump and the indicator  15  (i.e., in a non-flashing mode) at task  211  and returns to task  206 . Tasks  210  and  211  can occur when the user resets the device  10  after fixing the shut-off condition. 
         [0022]    The controller  10  can automatically revert to the start operation (task  200 ) whenever a pump is plugged in or the controller  10  is plugged into a power source. The controller  10  can be used with different pumps and can be reset at any time after receiving power from a power source. It is easy to use the controller  10  with different pumps as there is only one connection between the pump and the controller  10  and no part of the controller  10  needs to be in contact with fluid that is being pumped. In addition, the controller  10  can be positioned any distance away from the pump as long as the plug of the pump can reach the plug outlet  13  of the controller  10 . This can allow easy installation and easy access for the user. 
         [0023]    In one embodiment, the control circuit  12  can include a power circuit  17 , a microcontroller circuit  18 , and a programming circuit  19 , as shown in  FIG. 3 . The power circuit  17 , as shown in  FIG. 4 , can include an internal fuse Fl for catastrophic failure. The power circuit  17  can also include the following: a transformer T 1 , such as Part No. 3FD-212, manufactured by Tamura Corporation, or similar; a rectifier D 1 -D 4 , such as Part No. DB101, manufactured by Diodes, Inc., among others; a capacitor C 1  (e.g., 330 micro-farads); and a regulator J 2  (e.g., a 5-volt, 1-amp positive voltage regulator), such as Part No. MC7805, manufactured by Fairchild Semiconductors®, among others. A connector J 1  can represent electrical connections from the power plug. The power plug can be a conventional polarized plug with a hot connection  100 , a neutral connection  101 , and a ground connection  102 . The fuse F 1  can be placed between the connection  100  and a connection  103  to the transformer T 1 . The transformer T 1  can also be connected to the connection  101  and ground. The transformer T 1  can further be connected to the rectifier D 1 -D 4  via connections  104  and  105 . The rectifier D 1 -D 4  can be connected to the regulator J 2  via a connection  106 . An output (connection  107 ) of the regulator J 2  can be an isolated low-voltage node (e.g., five volts, direct-current) to power parts of the microcontroller circuit  18  and the programming circuit  19 . In addition, the controller box  11  can be opened for maintenance if the fuse F 1  or other components need to be replaced. 
         [0024]    In some embodiments, different power circuits  17  can be adapted for different power source voltages. For example, different controllers  10  can be provided for the following power source voltages: 12, 24, 36, 100, 115, and 230 volts AC or volts DC, among others. 
         [0025]    As shown in  FIG. 5 , the microcontroller circuit  18  can include a microcontroller chip M 1  (e.g., Part No. PIC12F675, manufactured by Microchip Technology, Inc.) to control all operations of the controller  10  and provide memory to store the threshold current. The microcontroller chip M 1  can be powered by the output of the regulator J 2  (from the connection  107  shown in  FIG. 4 ) at pin  1 . The microcontroller circuit  18  can also include capacitors C 2  and C 3  for transient protection at pin  1 . Pin  2  of the microcontroller chip M 1  can be dedicated to the indicator  15 , which can include an LED D 5  connected in series connection with a resistor R 2  (e.g., 560 ohms) and ground. Pin  4  of the microcontroller chip M 1  can be dedicated to the control switch  14 , which can be a tact switch in some embodiments. Pin  5  of the microcontroller chip M 1  can be open. Pin  6  of the microcontroller chip Ml can be dedicated to an amplifier A 1  and a transformer T 2  in connection with a connector J 5 . The connector J 5  can represent electrical connections from the plug outlet  13 . The plug outlet  13  can be a conventional polarized outlet with a hot connection  108 , a neutral connection  109 , and a ground connection  110  and can receive a plug of the pump. When the pump is plugged into the plug outlet  13 , the transformer T 2  is in electrical connection with the pump via the connection  109 . 
         [0026]    The transformer T 2  can be a current-sense transformer to read the AC current being drawn by the pump motor and also provide voltage isolation between the pump and the microcontroller chip M 1 . The transformer T 2  can include a parallel connection with a resistor R 7  (e.g., 60 ohms) between connections  111  and  112  and the connection  112  can further be connected to ground. The amplifier A 1  (e.g., an LM358 operational amplifier, manufactured by National Semiconductor, among others) can amplify the current signal from the transformer T 2  at the connection  111 . For proper amplification and transient protection, the amplifier A 1  can be in connection with resistors R 4  (e.g., 10 kilo-ohms), R 5  (e.g., 22 kilo-ohms), and R 6  (e.g., 1 kilo-ohm) and a capacitor C 4  (e.g., 22 micro-farads). The amplifier A 1  can be powered by the output or the regulator J 2  (from the connection  107 ) at a connection  113 . 
         [0027]    Pin  7  of the microcontroller chip Ml can be dedicated to controlling power to the pump motor (P PUMP ) at the connection  108  via an enable switch, such as a relay J 4 . The power to the pump motor, P PUMP , can be connected to the relay J 4  via a connection  114  and can come from the connection  103  of the power circuit  17 . The relay J 4  can be powered by the output of the regulator J 2  (from the connection  107 ) at a connection  115 . A control command from pin  7  of the microcontroller chip Ml can be received by the relay J 4  at a connection  116 . A MOSFET Q 1  (such as Part No. 2n7000, manufactured by National Semiconductors®, among others), a diode D 7 , and a resistor R 3  (e.g., 60 ohms) can be included between pin  7  and the connection  116 . A diode D 6  (such as Part No. 1n4001, manufactured by Fairchild Semiconductor®) can be positioned to prevent voltage powering the relay from controlling the power to the pump (P PUMP ). Pin  8  of the microcontroller chip Ml can be connected to ground for reference. 
         [0028]    The controller box  11  can be opened to expose the control circuit  12  for maintenance or access to the programming circuit. The programming circuit, as shown in  FIG. 6 , can include a programming port J 3  for reprogramming the microcontroller chip M 1 . During normal operation (i.e., not during reprogramming), the microcontroller chip M 1  can be powered by the output of the regulator J 2  (from the connection  107 , as shown in  FIG. 4 ). During reprogramming, power can be removed from the controller  10 , and the output from the regulator J 2  will no longer be supplied to power the microcontroller chip M 1 . In this case, the operating voltage needed (e.g., 5 volts) can be supplied to the microcontroller chip M 1  by the programming port J 3  from pin  4 . A higher voltage, V PP , can also be supplied from the programming port J 3  from a connection  117  (at pin  1  of J 3 ) to pin  3  of the microcontroller chip M 1  to put the microcontroller chip M 1  into a programming mode. Pins  2  and  3  of the programming port J 3  (labeled PGD and PGC, respectively) can also be connected to pins  7  and  6 , respectively, of the microcontroller chip M 1  to synchronize clocks and send and receive data. Pin  5  of the programming port J 3  can be connected to ground for reference. The microcontroller chip M 1  can be reprogrammed to adjust parameters such as the time period needed to actuate the control switch  14  to signal the data collection period, whether above or below the threshold current indicates a shut-off condition, or other parameters. 
         [0029]    It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein. Various features and advantages of the invention are set forth in the following claims.