Abstract:
A temperature controller device including informative display screens, predeterminable heating cycles, automated system checks and other utilities that reduces human involvement in a monitoring process. The device may be incorporated into a temperature controller or may be a separate “stand alone” unit.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     The present application claims the benefit of U.S. Provisional Patent Application No. 60/724,382 filed Oct. 7, 2005, which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates in general to temperature controllers and in particular to a backup device therefor.  
       BACKGROUND OF THE INVENTION  
       [0003]     Temperature controllers are widely used to control the operation of heating and cooling apparatus used in products and processes where temperature plays an important role. They are routinely used to control heaters and coolers in laboratory and industrial environments where temperature conditions must be tightly controlled. Typically, a temperature controller for use in such environments includes at least one sensor probe and circuitry in communication with the probe which is operable to automatically cut power to a heater or cooler in the event the probe detects a temperature that exceeds a predetermined maximum acceptable temperature or falls below a predetermined minimum acceptable temperature for a particular process under consideration. When the power is cut to the heater, the temperature controller may or may not be manually reset before the monitored process may proceed. Likewise, the temperature controller may or may not be manually reset if a power outage occurs.  
         [0004]     For example, presently available laboratory and industrial controllers for heaters display the target temperature of the process being monitored and the maximum or minimum temperatures permissible for the process (i.e., shut-off temperature). A technician observing the equipment should personally monitor the status of the process and react quickly to manually reset and restart the controller in the event of a power outage. In addition, the technician must physically turn off the controller when the monitored process is believed to be complete. That is, conventional temperature controllers are deployed for an indefinite period of time in either an “on” state or an “off” state, both of which must be manually selected by the technician, which requires the technician to pay close attention to time.  
         [0005]     An advantage exists, therefore, for a fully automated temperature controller device that requires minimal user attention and involvement in the monitoring process.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention provides a backup temperature controller device incorporating several features, modalities and functions heretofore unavailable in presently existing backup temperature controllers. More particularly, the device includes informative display screens, predeterminable finite heating or cooling sequences, automated system checks and other utilities not present in conventional temperature controllers. The result is a device that greatly reduces human involvement in the monitoring process. It may be incorporated into a heating or cooling apparatus temperature controller or may be a separate “stand alone” unit.  
         [0007]     Other details, objects and advantages of the present invention will become apparent as the following description of the presently preferred embodiments and presently preferred methods of practicing the invention proceeds. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The invention will become more readily apparent from the following description of preferred embodiments thereof shown, by way of example only, in the accompanying drawings wherein:  
         [0009]      FIG. 1  is a block diagram of the system architecture of a heating or cooling apparatus temperature controller backup device according to the present invention;  
         [0010]      FIG. 2  is a schematic diagram of testing procedure employing a primary temperature controller backed up by a temperature controller backup device according to the present invention as a separate stand-alone device;  
         [0011]      FIG. 3  is a block diagram of a display sequence demonstrating the manner by which user-adjustable operational parameters of a temperature controller backup device according to the present invention are set when a mode switch of the device is in an “adjust” position;  
         [0012]      FIG. 4  is a block diagram of a display sequence of a temperature controller backup device according to the present invention when a mode switch of the device is in an “reset” position; and  
         [0013]      FIGS. 5A and 5B  are block diagrams of the operational flow and system displays of a temperature controller backup device according to the present invention occurring during a “run” sequence when the device is set according to the operational parameters input by a user pursuant to  FIG. 3 .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]     Referring to the drawings wherein like or similar references indicate like or similar elements throughout the several views, there is shown in  FIG. 1  the system architecture of a temperature controller backup device according to the present invention. The instant device, identified generally by reference numeral  10 , includes a power supply  12  which receives power from a suitable AC power source such as, for example, a 120V 50/60 Hz 15A source (although different voltages and currents are contemplated to be within the scope of the invention depending on the electrical requirements of the country in which testing is performed) and converts the incoming power to  5 V DC. Under control of a power switch  14 , power supply  12  delivers power to a main microprocessor board or central processing unit (CPU)  16 . When the power switch is in the “on” position, the main microprocessor board delivers power via an output power relay, discussed below, to an output light  18  such as an LED or other suitable light source to indicate that the output device is powered up.  
         [0015]     With power switch  14  “on” the operation of device  10  is dictated by the position of a 3-way mode switch  20  that establishes three modes of operation: run, adjust and reset, which are described in greater detail hereinafter. Depending on the position of switch  20 , the main microprocessor board  16  may extract and process information from suitable memory means, for instance, a constantly-powered, erasable and reprogrammable nonvolatile memory such as flash memory preferably carried by the microprocessor board. Likewise, the selected position of switch  20  prescribes what information a user observes on a display screen  24  of a display means  25 .  
         [0016]     A sensor input  30  includes connection means such as a jack for connection to a suitable thermocouple or other temperature sensing device (not illustrated). Sensor input  30  transmits sensed temperature data to microprocessor board  16 , which information in turn is displayed on the display screen  24  during a “run” sequence, described below. In addition to power supply  12 , AC power is delivered directly to an output power relay  32  for controlled delivery by the relay to a main temperature controller. More particularly, depending on the sensed temperature data of the medium or process under scrutiny, or under certain conditions during heater testing (described below), microprocessor board  16  commands output power relay  32  to supply or terminate AC power flow to an output power outlet means  34  in communication with a primary or main temperature controller  36  ( FIG. 2 ). Power outlet means  34  may be a dedicated output jack or similar device.  
         [0017]     For brevity, the present invention is described and illustrated as it would be used in connection with control of a heating device. However, it will be understood that device  10  may be employed to control coolers, refrigerators, freezers and similar cooling apparatus in addition to heating apparatus. Additionally,  FIG. 2  depicts device  10  is shown as a separate stand-alone unit from the main temperature controller. It will be further understood that temperature controller backup device  10  may incorporated into the same housing as the main temperature controller  36 . And, if incorporated into the same housing, it will be understood that power outlet means  34  may be an output jack or a direct jack-free connection between the output power relay and the main temperature controller.  
         [0018]     The arrangement shown in  FIG. 2  is representative, although not limitative, depiction of but one possible implementation of device  10 . That is,  FIG. 2  shows how device  10  might be connected to a main temperature controller in a laboratory environment. As is known, main temperature controller  36  may be an automatically or manually adjustable power/temperature controller whose output controls a heater  38 . A first sensor probe  40  connected to device  10  is immersed in a fluid (liquid or gas) testing medium  41  contained in a vessel or reactor  42 . A second sensor probe  44  connected to main temperature controller  36  is likewise immersed in the medium. Device  10  and controller  36  are arranged in series whereby controller derives its power input directly from the output power of device  10  which in turn is connected to an AC power source.  
         [0019]     Depending on the position of the 3-way mode switch  20  and in response to prompts shown on the display screen  24 , a user may interact with a circuit board  26  of display means  25  via arrow keys or similar input means  28 . Circuit board  26  in turn communicates the user input to microprocessor board  16 .  FIG. 3  reveals a series of display screens  24  a user encounters when the 3-way mode switch  20  is placed in the “adjust” position. In “adjust” a user may program device  10  with desired time and temperature parameters. In the first screen the user is asked to enter a desired “Start Delay” time. With this capability the user may use arrow keys  28  to select the time in minutes he or she wishes to delay the start of device  10 . The right arrow moves the curser to the right, the left arrow moves the cursor to the left, the up arrow increases the numerical digit and the down arrow decreases the numerical digit. The delay start time may range from 1 to 9998 minutes. If 9999 is selected, device  10  remains off. When the desired “Start Delay” time is input, the user then presses the left arrow button to proceed to the next programming display screen.  
         [0020]     At the next screen, the user inputs the desired target process temperature, as well as “high” and “low” temperature limits which together define the maximum and minimum process temperatures of an acceptable temperature band for the monitored process. In the illustrated example, the target process temperature is 90° C. and the “high” and “low” temperature limits are each 20° C. whereby the acceptable temperature range for the process is 70° C.-110° C. It will be understood that the foregoing may also be expressed in ° F., if desired. When the target process temperature and temperature band information has been programmed, the user then presses the left arrow button to proceed to the final “adjust” screen. At this screen, the user selects either a finite or infinite heat sequence time. In the illustrated example, a 70 minute heat sequence is chosen. The heat sequence time may range from 1 to 9998 minutes. If 9999 is selected, device  10  remains on indefinitely during the heat sequence until the user either readjusts the heat sequence time to a finite time or manually switches the device off using power switch  14 . If the user wishes to change any of the input data, he or she simply depresses the left arrow button to select the desired display screen and makes any necessary changes. If the 3-way mode switch  20  is switched from the “reset” position to the “adjust” position output power to the main temperature controller remains off. If the 3-way mode switch  20  is switch from the “run” position to the “adjust” position output power to the main temperature controller is governed by the run sequence until reprogrammed by the user. According to the present invention, a user preferably can switch to “adjust” mode to change the five selectable input values while in the “run” mode, described below, without interrupting the run. The user may then switch back to “run” mode to continue monitoring so long as the “high” and “low” temperature band or timing limits were not exceeded because of the reprogramming.  
         [0021]      FIG. 4  reveals a series of display screens  24  a user encounters when the 3-way mode switch  20  is placed in the “reset” position. Common to each of the screens is the present process “standby” temperature which, prior to a process run, is normally about ambient room temperature (e.g., typically about 20° C.). The first “reset” screen shows the programmed start delay time for 4 seconds. Following elapse of the 4 second delay, a second screen appears which displays the selected heat time for 4 seconds. Thereafter, a process temperature screen appears for 4 seconds which displays the selected temperature for the process, followed thereafter by screens displaying the high and low temperature band limit temperatures, again each for 4 seconds. After display of the low limit temperature, the reset system automatically cycles back to the standby temperature screen. It will be understood that the screen delay time of 4 seconds is merely exemplary. The screen delay time is stored in the aforementioned memory means and can be set to any time suitable for the user or the process under consideration.  
         [0022]     At all times throughout the reset mode output power to the main temperature controller and any run sequences are shut off. If in reviewing the reset mode screens the operator identifies certain parameters that should be changed, the 3-way mode switch  20  is switched to the “adjust” position and appropriate changes may be made to those parameters as described above in connection with  FIG. 3 .  
         [0023]      FIGS. 5A and 5B  depict the operational flow and display sequence of a temperature controller backup device according to the present invention when set according to the operational parameters input by a user pursuant to  FIG. 3 . When the power switch  16  is turned to “on” (and the mode switch  20  is switched to run after reset is initiated and the adjust parameters are satisfactory to the user) no power is supplied to the main temperature controller and the microprocessor board  24  initiates a “Start Delay” sequence  46 . At a predetermined time interval, e.g., 4 seconds, the display screen alternates between displays of the “Start Delay” sequence temperature and time. At any time during the “Start Delay” sequence a user may press the right arrow button to selectively override the sequence, whereby the remainder of the sequence is skipped and the device proceeds to a “Heater Test” sequence  48 . Assuming the right arrow button is not pressed, the “Start Delay” sequence runs to its selected time of completion and device  10  thereafter proceeds to the “Heater Test” sequence. If, however, a power outage occurs during the “Start Delay” sequence, timer means controlled and preferably carried by microprocessor board  16  saves the “Start Delay” time elapsed until the power outage occurred. When power is restored, the microprocessor board restarts the “Start Delay” sequence at the previously elapsed time and the sequence proceeds to completion.  
         [0024]     Following completion of the “Start Delay” sequence, the microprocessor board initiates “Heater Test” sequence  48 . In “Heater Test”, power is supplied from the backup temperature controller device  10  to the main temperature controller  36 . After an optional delay, e.g., one minute, the display screen alternates between displays of the “Heater Test” sequence progress time and temperature at a predetermined time interval, e.g., 4 seconds. At any time during the “Heater Test” sequence a user may press the right arrow button to skip the remainder of the sequence and proceed to a “Warm Up” sequence  50 . Assuming the right arrow button is not pressed, the “Heater Test” sequence runs a test procedure which measures temperature increase in the medium  41  as a function of time. If the test is successful, power continues to be supplied from the backup temperature controller device  10  to the main temperature controller  36  and the “Warm Up” sequence begins. If the test is unsuccessful, power from the backup temperature controller device  10  to the main temperature controller  36  is terminated. By way of example but not limitation, a heater test may be based on a rise in temperature of 3° C. in 10 minutes. Preferably, although not necessarily, the optional delay and heater tests are preprogrammed immutable operations performed by microprocessor board  16  which are suitable for the intended application of device  10 . It will be appreciated that, with respect to cooling apparatus, device  10  is capable of performing a “Cooler Test” sequence which runs a test procedure that measures temperature decrease in a medium as a function of time.  
         [0025]     In the event of a power outage during the “Heater Test” sequence, the microprocessor board  16  restarts the “Heater Test” sequence at its beginning when power is restored. The “Heater Test” sequence is useful in detecting more than a malfunctioning heater  38 . It is also beneficial in determining whether sensor probe  40  is properly connected to the sensor input jack  30  or is properly disposed in medium  41 . Under any of these circumstances, the temperature sensed by sensor probe  40  will not rise, thereby alerting the user to check both the heater and sensor probe for problems. Moreover, if the user is not present during the heater test and the test fails, microprocessor board cuts power to output power relay  32 . And, display screen  24  shows the user “Done 20C Heater Fail Heat.” 
         [0026]     Following successful completion of the “Heater Test” sequence, the microprocessor board initiates the “Warm Up” sequence. In “Warm Up”, power continues to be supplied from the backup temperature controller device  10  to the main temperature controller  36 . At a predetermined time interval, e.g., 4 seconds, the display screen alternates between displays of the “Warm Up” sequence time and temperature. Assuming the right arrow button is not pressed, the “Warm Up” sequence runs a warm up procedure which measures temperature increase in the medium  41  as a function of time. If the procedure is successful, power continues to be supplied from the backup temperature controller device  10  to the main temperature controller  36  and the “Heat” sequence begins. If the procedure is unsuccessful, power from the backup temperature controller device  10  to the main temperature controller  36  is terminated. “Warm Up” sequence time accumulates concurrently with “Heat” time. By way of example but not limitation, a warm up procedure may be based on the “low” limit “Heat” temperature of 70° C. plus a dead band of 4° C. (for a total temperature of 74° C.). The dead band is desirable because it prevents unintended shut off of power to the main temperature controller  36 . For example, without a dead band, sensor probe  40  may momentarily detect a temperature slightly below the 70° C. “low” limit “Heat” temperature for the monitored process. Should that occur, power to the main temperature controller would be shut off. A dead band of several degrees avoids this situation, e.g., if the sensor probe momentarily detects a temperature of 73° C. the temperature controller backup device  10  would continue to supply power to the main temperature controller because the detected temperature would still exceed the “low” limit “Heat” temperature by 3° C.  
         [0027]     If the “Warm Up” sequence does not reach the “low” limit “Heat” temperature (plus dead band) in the dedicated heat time, the procedure is considered a failure and power to the main temperature controller is shut off. If the “Warm Up” sequence does reach the “low” limit “Heat” temperature (plus dead band) in the dedicated heat time, the procedure is considered a success, power continues to be supplied to the main temperature controller  36  and backup temperature controller device  10  proceeds to the “Heat” sequence  52  shown in  FIG. 5B . It will be appreciated that, with respect to cooling apparatus, device  10  is capable of performing a “Cool Down” sequence which determines whether a medium has cooled sufficiently in a desired period of time.  
         [0028]     Assume a power outage occurs during the “Warm Up” sequence. When power is restored, the microprocessor board restarts the “Heater Test” sequence to confirm heater function. This return to the “Heater Test” sequence adds an extra measure of control in the event of a power outage since the process under scrutiny has not yet reached the desired process temperature band. Since the system returns to “Heater Test” following a power outage in “Warm Up”, accumulated heat time is lost and the “Warm Up” sequence must start anew, assuming a successful “Heater Test” sequence.  
         [0029]     Turning to  FIG. 5B , the device  10  initiates the “Heat” sequence  52  following a successful “Warm Up” sequence. In “Heat”, power is supplied from the backup temperature controller device  10  to the main temperature controller  36 . At a predetermined time interval, e.g., 4 seconds, the display screen alternates between displays of the “Heat” sequence temperature information (including real-time sensed temperature and “high” and “low” acceptable process temperature limits) and accumulated time. At any time during the “Heat” sequence a user may press the right arrow button to skip the remainder of the sequence. If a power outage occurs during the “Heat” sequence, the aforementioned timer means saves the accumulated “Warm Up” and “Heat” time elapsed until the power outage occurred. When power is restored, the temperature detected by sensor  40  is checked to determine whether the monitored process is still within its acceptable temperature band. If it is, the “Heat” sequence is restarted at the previously elapsed time and proceeds to completion of the sequence (see flow diagram branch  54 ). If it is not, e.g., the process temperature has fallen to 60° C. and therefore below the “low” temperature limit for the process temperature band, power to the main temperature controller  36  is shut off and the process is terminated (see flow diagram branch  56 ). A significant advantage of this restart functionality is that it permits restart of the monitored process. In presently available backup temperature controller devices, the system simply shuts off and remains shut off following a power outage until it is manually restarted, regardless of the duration of the power outage. If a user is not available to restart the temperature monitoring equipment following a brief power outage of an otherwise acceptable “in-band” process, then the process material might have to be discarded and the entire process must be rerun.  
         [0030]     Assuming there is no power outage, the process may be terminated if the process falls below the “low” limit or exceeds the “high” limit of the acceptable process temperature band (see flow diagram branches  58  and  60 , respectively). If the process temperature remains within-band, the process continues to expiration of the selected heat time at which power to the main temperature controller  36  is shut off. It will be appreciated that, with respect to cooling apparatus, device  10  is capable of performing a “Cool” sequence analogous to the “Heat” sequence described herein.  
         [0031]     While an exemplary implementation of the present invention is disclosed for use in connection with a main temperature controller in a laboratory environment, the invention is not so limited. Indeed, it is contemplated for use in connection with any residential, commercial, research or industrial appliances or equipment where temperature plays a significant role. For example, many aspects and features of the invention may be incorporated into residential/commercial appliances such as ovens, coffee brewing machines, toasters, ovens, freezers, refrigerators and so forth, as well as industrial/research equipment such as kilns, furnaces, cryogenic freezers and so forth.  
         [0032]     Although the invention has been described in detail for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention as claimed herein.