Patent Application
20060191273
The present invention is generally related to programmable thermostats, and more particularly to a programmable thermostat with a preset time clock feature.
Numerous programmable thermostats exist that provide for entry of time and date information by the user of the thermostat. Such thermostats typically require the user to complete a complex series of steps to enter time and date information before the user can program the thermostat. Due to the complexity of inputting information to the thermostat, many users do not set the time or utilize the programming features that could reduce their energy costs. One approach to this problem is to enable the thermostat to receive a time information signal broadcast at 60 kHz by station WWVB for setting the current time. However, buildings and walls surrounding the thermostat often interfere with the reception of this signal. Such a thermostat may not receive the WWVB signal until 3 AM when the broadcast signal strength is increased for a brief time. Thus, the thermostat may still require the user to perform the undesirable step of entering the time setting in order to program the thermostat after installation.
There are provided, in accordance with one aspect of the invention, various embodiments of a digital programmable thermostat that comprise preset information that eliminates the need for the user to enter the time and date information. In one embodiment of a thermostat in accordance with the present invention, the thermostat comprises a battery for powering the thermostat, a connection means for receiving an input signal of time and date data from a device external to the thermostat, a memory for storing the time and date information, a real time clock for subsequently maintaining the current time setting after initial input of the time and date information, and a display means for displaying time and temperature information. The thermostat further comprises a processor for controlling the thermostat, where upon activation of the thermostat by the user, the processor prompts the user to select a time zone. After selection of a time zone, the processor responsively provides the display means with the local time setting for display. The current time and date information are input to the connection means of the thermostat at the time of production.
In some embodiments, the thermostat further comprises a switch means for switching the processor to a low power usage mode for disabling all thermostat operation with the exception of the real time clock function, and also a restoration means for restoring the processor to a normal power usage mode and initiating thermostat operation. Once the time is entered into memory, the processor is switched to a low power usage mode that restricts thermostat operation to that of maintaining the real time clock. At the time of installation, the user or installer can use the restoration means to restore the processor to normal power usage mode. In one embodiment, the restoration means comprises at least one user input means that may be depressed for a predetermined minimum time period to restore the processor to normal power usage mode. A program in the processor then prompts the user to select and enter a time zone, after which the thermostat adjusts the time setting and shows the day and local time on the thermostat display.
In another aspect of the present invention, some embodiments of a thermostat comprise a processor having an input port pin for connecting to an external device to receive initial time and date information at the time of production of the thermostat, a memory means for storing the initial time and date setting received by the processor, a real time clock that is set to the initial time and date setting and subsequently maintains the actual time, a switch means for switching the processor to a low power usage mode that disables all thermostat operation with the exception of the real time clock function, and a restoration means for restoring the processor to normal operation, in which the processor prompts the user to select a time zone. The thermostat is capable of being set with current time data and switched to a low power mode, to provide a thermostat with a preset time and date feature while prolonging the life of the thermostat battery.
One embodiment of a thermostat incorporating the preset time feature according to the principles of the present invention is generally shown at 20 in
Referring to
The thermostat 20 further comprises a series of switches in connection with the microprocessor 26. The microprocessor is capable of sending at least two pulse signals to the series of switches, to enable multiplexing of inputs to the microprocessor 26. For example, the user can enter a Temperature Down Adjustment or Temperature Up Adjustment input to the microprocessor 26 by pressing a button for closing a switch 30 or 32 respectively. The user can enter the thermostat into Hold Temperature mode by pressing a button that closes switch 34. The input for Viewing Program settings of the thermostat 20 is accomplished by pressing a button for closing switch 36. The input to Run the program of the thermostat is accomplished by pressing a button for closing switch 38. The user can also change the preset time setting by pressing a button for closing switch 40 to enter the Time Set mode. The switches 30, 32, 34, 36, 38, 40 and 42 allow the user to provide various input entries to the thermostat, which are input to the microprocessor 26 via input pins 70, 72, 74 and 76. Specifically, when the microprocessor 26 sends a first pulse signal at 50 to a switch 32 that has been closed by the user, the microprocessor 26 receives the first pulse signal input at pin 72 to indicate the user has entered a Temperature Up adjustment input. Similarly, when the microprocessor 26 sends a second pulse at 52 to a switch 34 that has been closed by the user, the microprocessor 26 receives the second pulse signal input at pin 74 to indicate the user has entered the thermostat into Hold Temperature mode. One example of such an embodiment of a thermostat is a 1F95-479 thermostat manufactured by White-Rodgers, a Division of Emerson Electric.
In one embodiment, the thermostat 20 comprises an internal switch 60 within the series of switches connected to the microprocessor 26. The internal switch 60 is not readily accessible to the user of the thermostat, and is switched at the time of production to signal the microprocessor 26 to enter into a low power usage mode. Once the initial time information has been entered at the time of production, the switch 60 is momentarily closed to provide a first pulse signal 50 to input 70 of the microprocessor. The microprocessor 26 responds to this particular input by initiating shut down of the thermostat's LCD display, program, and other functions other than the real time clock function. In this low power usage mode, the microprocessor 26 consumes approximately of six micro-amps from the thermostat battery (not shown). The low current draw helps prolong the life of the battery until the thermostat is received by the consumer or user.
Once the thermostat 20 has been received by the installer, ultimate consumer, or user, the microprocessor 26 can be restored to normal power usage mode by pressing any thermostat button for more than a minimum predetermined time period. In one embodiment of the present invention, the minimum predetermined time period is preferably 3 seconds, but may alternatively be any time period suitable for the application. Pressing any button will provide an input signal to any of the inputs 70, 72, 74 or 76 of the microprocessor 26, which responsively restores normal power usage mode for the microprocessor 26. This action by the user for restoring normal power to the microprocessor 26 activates the thermostat 20, to allow the microprocessor to initiate a program within the microprocessor. The program within the microprocessor 26 defaults to a Time Zone Entry prompt. Specifically, the program initiates the display of the default Eastern Time Zone setting on the thermostat's LCD, and prompts the user to select the desired Time Zone setting using the Temperature Adjustment buttons. The user is then prompted to enter the selected time zone setting by pressing the Run Program button of the thermostat 20. Upon entry of the local time zone setting, the microprocessor 26 responsively updates the real time clock setting to reflect the local time setting corresponding to the entered time zone setting. The program then initiates the display of the current day and local time on the thermostat's LCD display. Upon establishing the time setting for the thermostat, a program of the microprocessor controls the normal operation of the thermostat 20. This program is also configured to automatically adjust the time setting to allow for daylight savings time. Because such software programs for controlling a thermostat's normal operation and temperature settings are prevalently used and well known in the art, the software program will not be described in detail.
It should be noted that the selection and entry of the time zone setting may alternatively be performed using any other combination of user input buttons on the thermostat 20. Likewise, the means of restoring the thermostat to normal power usage mode may also be accomplished using a specific button or combination of buttons simultaneously pressed by the user of the thermostat. The thermostat 20 may also be configured to display the date and local time zone information on the LCD display, in addition to the day and local time.
Additional design considerations, readily apparent to one of ordinary skill in the art, such as the modification of the thermostat to provide date information on the LCD display may also improve the user's ability to program the thermostat. It should be apparent to those skilled in the art that various modifications such as the above may be made without departing from the spirit and scope of the invention. More particularly, the apparatus may be adapted to any digital thermostat independent of programming capability. Accordingly, it is not intended that the invention be limited by the particular form illustrated and described above, but by the appended claims.
