Abstract:
The automatic shutoff overflow controller comprises a circuit which engages between a source of power and a water processing device, the controller, sensing an undesirably high water level in a liquid containment into which water drains from the device, shutting off the device and producing an audible warning that such condition exists.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an overflow controller with automatic water shutoff capability. More particularly, the controller is proposed for use in disabling a water processing device temporarily when an excessive level of conductive fluid is detected in an outflow container, such as a utility sink, used for receiving fluid draining from the water processing device.  
         [0003]     2. Prior Art  
         [0004]     Heretofore numerous structures have been proposed for controlling fluid levels in a fluid container and/or for shutting off a source of the fluid upon detection of an excessive level of the fluid.  
         [0005]     As will be described in greater detail hereinafter, it is believed that the controller of the present invention offers a simpler yet more featureful controller than those previously disclosed.  
       SUMMARY OF THE INVENTION  
       [0006]     According to the invention there is provided an automatic shutoff overflow controller for use in shutting off a powered liquid processing device when an undesirably high level of liquid is sensed in a liquid containment for liquid draining from the device, the controller comprising a circuit engaged between the device and a source of power therefor and including conductive sensor probes placed at a desired level within the liquid containment and, when the probes becomes immersed in liquid, causing an audible warning to be produced and interrupting the flow of power from the source to the device.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a detailed schematic diagram of the circuit defining the controller of the present invention.  
         [0008]      FIG. 2  is a perspective view of the controller showing same plugged into a household power outlet and having a plug of a washer plugged into a power outlet thereof with a sensor of the controller shown engaged at an outlet end of a water drain hose of the washer received within a utility sink, as an example, showing the sink with a fluid level below the level of the sensor.  
         [0009]      FIG. 3  is similar to  FIG. 2  but shows a fluid level in the sink which is in contact with the sensor.  
         [0010]      FIG. 4  is a top plan view of the sensor housing.  
         [0011]      FIG. 5  is a cross sectional view through the housing taken along line  5 - 5  of  FIG. 4 .  
         [0012]      FIG. 6  is a cross sectional view taken along line  6 - 6  of  FIG. 5 .  
         [0013]      FIG. 7  is a cross sectional view taken along line  7 - 7  of  FIG. 5 .  
         [0014]      FIG. 8  is a perspective view of the sensor.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]     Referring now to the drawings in greater detail, there is illustrated in  FIG. 1 a  schematic circuit diagram of the auto shutoff overflow controller  1  of the present invention generally identified by reference numeral  10 .  
         [0016]     It will be understood that this circuit  10  is intended for use in situations where a conductive liquid  9 , such as water, can rise above a desired level to overflow a containment  11  therefore. The circuit  10 , when activated, acts to stop a flow of water into the containment  11 , by shuting off a washing machine or similar appliance when the level of liquid draining therefrom has been determined to have risen above a desired level.  
         [0017]     Beginning at the left of the Figure, connectors  12 ,  14  for an external probe sensor assembly  88  are shown. In this circuit  10 , one of two conductive electrodes  13  of the assembly  88  is held at +12V through a 330 K ohm resistor  16 . The presence of this voltage at a positive input  90  of an operational amplifier  18 , which operates in this case as a comparator  94 , forces an output  98  of the operational amplifier to be maintained at +12V. An oscillator section  100  is comprised of an operational amplifier  96 , four 470 K ohm resistors  46 ,  48 ,  50  and  54 , a 2.2 μF capacitor  56 , a diode  60 , and an audio signal generator  58 , with the oscillator section  100  being normally held in an inactive state.  
         [0018]     A 555 timer  26  is also provided and is in a ready state, with an output  104  thereof held low. This condition produces a high level of current at output  104 , turning on a relay  34  and causing a green section  42  of a light emitting diode (LED)  116  to illuminate through a  470  ohm resistor  38 . When the relay  34  is enabled, the normally open contacts  112 ,  114 , controlling a device  39  or the line being monitored, are held closed, allowing AC power to flow in a control circuit atria defined by connectors  64  and  70 .  
         [0019]     At the same time, a negative input  92  of operational amplifier  18  is held at approximately +8V by connection to a control/reference output  108  of timer  26 .  
         [0020]     In an overflow condition, the presence of a conductive liquid between conductive electrodes  13  and  15 , with electrode  15  being tied to ground of assembly  88 , causes current to flow in 330 K ohm resistor  16 . When current flow is sufficient to cause a voltage drop of greater than approximately 8 volts across 330 K ohm resistor  16 , the output  98  of operational amplifier  18  will also drop to a low voltage of approximately 0.3 volts.  
         [0021]     When this low voltage appears at the connection of a 330 K ohm resistor  32 , a diode  60 , and a trigger input  110  of timer  26  through a 470 K ohm resistor  48 , the output  52  of operational amplifier section  96  rises to +12 V. This voltage increase has two effects.  
         [0022]     First, the audio signal generator  58  is powered up and begins to emit a warning tone. The return path for current driving audio signal generator  58  takes the current through diode  60 , which ensures that an audible signal cannot be produced by stray current when the circuit  10  is inactive.  
         [0023]     Second, the voltage increase charges 2.2 μF capacitor  56 , which is initially in a discharged state, through 470 K ohm resistor  54 . When the voltage on 2.2 μF capacitor  56  rises to a level of voltage present at input  102  of operational amplifier  96 , the output  52  of operational amplifier  96  switches to a low state, shutting off the audio signal generator  58  and causing 2.2 μF capacitor  56  to discharge through 470 K ohm resistor  54 . The time required for the charge/discharge cycle is approximately one second, obtained by multiplying 470 K ohms by 2.2 μF, (54×56) producing an intermittent signal by causing the audio signal generator  58  to operate for one second, then become disabled for one second, until conductive liquid in contact with probe sensor assembly  88  is removed.  
         [0024]     Resistors  46 ,  48 , and  50  form a voltage divider applying approximately 4 volts at input  102  of operational amplifier  96  when the output  52  thereof is low, and about 8 volts at input  102  when the output  52  is high, causing an oscillation of capacitor  56  voltage between 4 and 8 volts while circuit  10  is active.  
         [0025]     A further effect of the low signal at operational amplifier  18  is to cause the timer  26  to begin a timing cycle. A 47 μF capacitor  30  begins to charge through a 680 K ohm resistor  28 . When the voltage on 47 μF capacitor  30  reaches ⅔ of the power supply voltage (12V), the output  104  of the timer  26  will go high. This time is approximately 35 seconds (1.1×30×26). An output  106  of timer  26  then discharges 47 μF capacitor  30  and the circuit is held in this state until the low voltage level at trigger pin  110  of timer  26  is raised by decreasing the level of conductive liquid present to a level below that of the probe sensor assembly  88 .  
         [0026]     When the output  104  of timer  26  goes high, the green light emitting diode  42  turns off and a red section  44  of LED  116  turns on, powered through 470 ohm resistor  40 , and relay  34  is de-energized, closing normally open control circuit contacts  112 ,  114 , engaged within the positive (hot) line of atria connectors  64 ,  70  and disabling the appliance connected to atria connectors  64 ,  70  via plug  75 .  
         [0027]     Power for the circuit  10  is provided by step down transformer  74 , which reduces the AC supply voltage to approximately 18 volts.  
         [0028]     This AC voltage is rectified to pulsating DC by rectifier bridge diodes  76 ,  78 ,  80 , and  82 , and the pulsating DC is smoothed by a 470 μF capacitor  84 . A regulator  86  takes the smoothed DC voltage and regulates it down to +12V to operate the circuit  10 .  
         [0029]     A diode  36  is included to prevent the relay  34  coil from generating harmful transients when the relay  34  is de-energized.  
         [0030]     A 0.01 μF capacitor  20  is included to filter the reference voltage at output  108  of timer  26  and to provide a low impedance path to ground for any electrical noise that may be picked up at this sensitive point of circuit  10 .  
         [0031]     Connectors  64 ,  66 ,  72  connect to a source of AC power  73  to operate both the circuit  10  and the controlled device  39  engaged to the atria  64 ,  70  thereof.  
         [0032]      FIGS. 2 through 8  depict the physical configuration of the controller  11  as well as showing same in an exemplary environment of use.  
         [0033]      FIGS. 2 and 3  are similar except for the level of water  9  in the containment  11  into which the device  39 , here a washer  39 , drains its contents via a drain hose  200 .  
         [0034]     The housing  202  of the probe sensor assembly  88  is shown engaged adjacent to and extending past an outlet opening  204  of the drain hose  200  of the washer  39 .  
         [0035]     Washer  39  plugs into a receptacle  64 ,  70  via plug  75  for same in the controller circuit housing  210  which in turn plugs into the source of power  73 .  
         [0036]     The connectors  12 ,  14  extend from the sensor housing  202  to the controller circuit housing  210 , placing probes  13  and  15  within the sensor housing  202  into electrical communication with the controller circuitry  10 .  
         [0037]     Obviously, when the water  9  contacts the probe housing  202  as shown in  FIG. 3 , it forms a complete circuit across the probes  13  and  15 , turning on the red section  44  of the LED  116  and simultaneously cutting off power to the washer  39 .  
         [0038]     Turning to  FIGS. 4-8 , it will be understood that the sensor housing  202  has the two sensors  13  and  15  mounted therein, and that it attaches to the outlet end  206  of drain hose  200 , having a concave undersurface  206 , which eases engagement thereof to the end of the hose  200 .  
         [0039]     Also, the connectors  12  and  14  which extend from the probes  13  and  15  respectively, are better illustrated here.  
         [0040]     Attachment of the probe housing  202  to the hose  200  may be formed in any suitable manner, and use of strap  220  shown in  FIGS. 2 and 3  should not be construed as limiting.  
         [0041]     As described above, the simple circuit  10  provides a number of advantages, some of which have been described above and other of which are inherent in the invention. Also, modifications may be proposed to the circuit  10  without departing from the teachings herein. Accordingly, the scope of the invention is only to be limited as necessitated by the accompanying claims.