Abstract:
A multiple compartment dishwasher is disclosed. The multiple compartment dishwasher includes a housing, a first compartment for washing within the housing, a second compartment for washing within the housing, a plurality of dishwasher components each having a power load when activated, at least one of the plurality of dishwasher components operatively disposed within the second compartment, and a power limiting distribution control system operatively connected to each of the plurality of dishwasher components for managing distribution of power.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to multiple compartment dishwashers. More specifically, this invention relates to a control system for distributing power to compartments of a multiple compartment dishwasher.  
           [0002]    Dishwashers have long been known. Conventional dishwashers have a single compartment for washing dishes and other items. In addition, multiple compartment dishwashers are also known. Multiple compartment dishwashers allow dirty items to be placed in one compartment while another compartment is being used to wash dishes. A multiple compartment dishwasher also allows smaller loads of dishes to be washed so that the dishwashing process is not as inefficient as if a small number of dishes were to be washed in a conventional single compartment dishwasher. Despite any advantage of multiple compartment dishwashers, problems remain.  
           [0003]    One problem relates to operating multiple compartments at the same time. When in a dishwashing mode, each compartment has power requirements needed for driving a load. The load being the electrical load of a heater, wash motor, or other types of dishwasher component. If too many of these components are simultaneously drawing current then the total current draw can exceed that which is permissible which can result in damage to the system, the tripping of a fuse or breaker, and/or other undesirable or inconvenient effects.  
           [0004]    A further problem relates to opening a first compartment while a second compartment is in operation. If there is an electrical pathway between components in the first compartment and components in the second compartment, then it is possible for an AC signal to find its way to components in the second compartment; potentially activating the components in the second compartment. This is undesirable.  
           [0005]    Therefore, a primary object of the present invention is the provision of an improved multiple compartment dishwasher.  
           [0006]    A further object of the present invention is the provision of a multiple compartment dishwasher having multiple compartments which can be operated independently of one another.  
           [0007]    A still further object of the present invention is the provision of a multiple compartment dishwasher having multiple compartments that can be operated simultaneously.  
           [0008]    Yet a further object of the present invention is the provision of a multiple compartment dishwasher that does not exceed a rated current draw.  
           [0009]    A still further object of the present invention is the provision of a multiple compartment dishwasher that avoids stray AC signals from one compartment affecting components in another compartment.  
           [0010]    These and other objects, features, or advantages of the present invention will become apparent from the specification and the claims.  
         BRIEF SUMMARY OF THE INVENTION  
         [0011]    The present invention relates to a multiple compartment dishwasher having a power limiting distribution control system. According to the present invention, a multiple compartment dishwasher has a housing with a first compartment for washing within the housing and a second compartment for washing within the housing. Each of the compartments has one or more dishwasher components, each having a power load when activated. The power limiting distribution control system is operatively connected to each of the plurality of dishwasher components for managing the distribution of power. This provides for ensuring that power ratings are not exceeded even while both the first compartment and the second compartment are simultaneously washing dishes.  
           [0012]    The power limiting distribution control system can include one or more electrical isolation circuits in order to protect against any effect of one circuit on another. The power limiting distribution control system of the invention provides for implementation using a single microcontroller to control power consumption. The present invention also provides for multiple microcontrollers, each microcontroller being associated with controlling power management within a particular compartment. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is an isometric view of a multiple compartment dishwasher according to the present invention.  
         [0014]    [0014]FIG. 2 is a diagram of a control system of a multiple compartment dishwasher according to the present invention.  
         [0015]    [0015]FIG. 3 is another embodiment of electrical control system for multiple compartment dishwasher according to the present invention.  
         [0016]    [0016]FIG. 4 is an electrical schematic showing a digital logic circuit for preventing simultaneous operation of two different components. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    The present invention provides for an improved multiple compartment dishwasher. FIG. 1 shows an isometric view of a multiple compartment dishwasher according to the present invention. The multiple compartment dishwasher  10  has a housing  11 . Within the housing  11  is a first compartment  12  and a second compartment  14 . The first compartment  12  and the second compartment  14  are both adapted for independently washing dishes or other items. For example, dishes can be placed in compartment  12  and washed while compartment  14  can remain available for loading. Similarly, the second compartment  14  can be washing dishes while the first compartment  12  can be open. In addition, the electrical control system of the present invention provides for both the first compartment  12  and the second compartment  14  to be simultaneously operating. In this manner, an operator can select whether to wash dishes in one of the compartments or both of the compartments. Preferably, the compartments are of different sizes. When the compartments are different sizes, a small load of dishes can be washed in the smaller of the compartments and a larger load of dishes can be washed in the larger compartments.  
         [0018]    [0018]FIG. 2 illustrates an electrical control system according to the present invention. In FIG. 2, the electrical components associated with the first compartment  12  are shown as well as the electrical components associated with the second compartment  14 . Other electrical components which are associated with both compartments are indicated by reference numeral  16 . The first compartment  12  includes a microcontroller  18 . This microcontroller communicates through isolation circuit  20  with electrical devices  22  having AC loads which are associated with the first compartment  12 . This may include motors, heaters, solenoids, and/or other electronic devices used to activate nozzles, washer arms, and/or other parts. In addition, sensors  24  are electrically connected to the first compartment microcontroller  18 . These sensors are adapted for various purposes associated with the first compartment  12 . For example, one sensor can be used as a motor current sense to detect whether a motor has failed or else is operating properly. Another sensor is a turbidity sensor used to detect the dirtiness of the water. Another example of a sensor that can be used is a thermistor, used to detect the temperature associated with the compartment  12 . These examples of sensors are given only by way of example. The present invention contemplates any number of sensors that may be useful or desirable in the context of a particular design or application.  
         [0019]    Similarly, the second compartment  14  includes a second compartment microcontroller  28 . The second compartment controller is electrically connected to an isolation circuit  30  which is electrically connected to one or more AC loads  32  associated with washing within the second compartment  14 . The isolation circuit, electrically isolating the control system from the AC loads  32  of the second compartment  14 . Further, the AC loads of the first compartment are preferably isolated from the AC loads of the second compartment. Similarly, sensors  34  are electrically connected to the second compartment controller  28 . The sensors may provide for various sensing operations including sensing motor current, turbidity, and temperature. The sensors can also provide for other sensing functions associated with dishwashing.  
         [0020]    Both the compartment one controller  18  and the compartment two controller  28  are electrically connected to a communications bus. This allows the compartment one microcontroller and the compartment two microcontroller to communicate. In addition the user interface controller  36  may be electrically connected to the communications bus. These interface controller provides for controlling both user output  38  functions as well as user input  40  functions. User output functions can include a display, audio feedback, and other types of output. The communications bus can be any number of buses including an I2C bus. Where an I2C bus is used then one of the controllers can be used as a master and the other controllers can be configured as slaves.  
         [0021]    [0021]FIG. 3 is another embodiment of the present invention. In FIG. 3, a single controller  18  is used. The single controller  18  provides control both over compartment one AC loads  22  through an optional isolation circuit  20  as well as control over compartment two AC loads  32  through a second compartment isolation circuit  30 . Preferably the isolation circuit is an opto-coupler so that separation of power can be controlled. The compartment controller  18  and a user interface controller  36  can communicate over the communications bus  26 .  
         [0022]    [0022]FIG. 4 provides for a digital logic circuit used to control one or more devices. Using the logic circuit shown, a first control signal  50  and a second control signal  52  are shown for two different devices that should not be simultaneously operable. Where power is being managed with a microcontroller according to the present invention and in order to avoid exceeding any given power rating, only one of the two devices should be operable at a time. The first control signal is electrically connected to a first NOR gate  54 . The NOR gate  54  can be a part of 74HCO2 integrated circuit or other NOR gate circuit or an equivalent. The first control signal  50  is electrically connected to both of the two inputs of the NOR gate  54 . The second control signal  52  is electrically connected to both of the two inputs of the NOR gate  56 . The output of the NOR gate  54  is electrically connected to one of the inputs to the NOR gate  58 . The second control signal is electrically connected to the second input NOR gate  58 . The output of this NOR gate provides for a first enable signal  62 . This enable signal can be used to enable or turn on a dishwasher component having a high current draw or high power requirements.  
         [0023]    Similarly, the output from the NOR gate  56  is electrically connected to one input of the NOR gate  60 . The first control signal  50  is electrically connected to a second input of the NOR gate  60 . The second enable output  64  provides a signal that can be used to enable a second device having a high current draw or high power requirements. The control logic shown in FIG. 4 ensures that both the output  62  and the output  64  are not both enabling at the same time. This is used to ensure that two components having high power requirements are not driven at the same time. The output  62  and  64  can be used to drive opto-couplers, the opto-couplers will enable allowing the AC load to be driven. Although this example is given in terms of NOR logic gates, the present invention provides for other combinations of digital logic to be used to implement the selection of one of a plurality of devices to be enabled at a time.  
         [0024]    A multiple compartment dishwasher having a power limiting distribution control system has now been disclosed. The present invention contemplates variations in the number of compartments, the use of digital logic and/or microcontrollers and other variations within the spirit and scope of the invention.