Abstract: The graphic user interface of an HVAC thermostat displays the programming and status information for remote devices in communication with the thermostat, such as various home sensors and appliances. In an embodiment, the thermostat includes a touch screen display to present the user with a plurality of user interface screens. The monthly calendar interface screen includes a calendar graphic area comprising a matrix display of dates for a full month. The user selects a programming interval for which to enter the thermostat programming events from the calendar graphic area. The user interface includes a clock face interface screen for entry of thermostat programming events. The clock face screen includes a pair of clock face graphic areas for each daily thermostat programming event. The user interface also includes a screen for displaying the programming and status information for remote devices selected from a list of devices in communication with the thermostat.

Abstract: The thermostat includes a housing having at least a portion thereof illuminated by a light that changes color via a manual input. The light illuminates the display for easy readability while the variable color of the light allows a user to match the appearance of the thermostat to best complement the surrounding décor. User input elements provide for the manual adjustment of one or more characteristics of the light, such as visible color of the light. The light source comprises at least one LED for displaying a plurality of colors. In this case, to change the color of the light illuminating the translucent portion of the housing or backlighting the display, electronics within the thermostat control the drive signals to the LED in order to operate the LED to provide the desired color. The invention also contemplates filtering the light and manually adjusting the filtering to provide the desired aesthetics.

Abstract: An HVAC system comprises a programmable wireless thermostat and a remote receiver unit. The thermostat includes a user interface having one or more displays, user input devices, such as buttons, sliders, or a touch screen, and a backlight. The thermostat may include a proximity sensor, wherein the user interface is controlled based on a user's presence near the thermostat. A thermostat controller enters into a reduced energy consumption mode and switches the user interface to an idle state when the proximity sensor indicates a lack of user proximity for a predetermined duration. When the proximity sensor indicates user proximity, the controller exits the reduced energy consumption mode and switches the user interface to an active state. During the reduced energy consumption mode, the user interface may be concealed when the user interface is in a housing which is transparent when backlit but is opaque otherwise.

Abstract: An evaporator fan control system is provided for a multi-compartment refrigerator that coordinates operation of the evaporator fan among a cooling cycle for a freezer compartment, a cooling cycle for a fresh food compartment, and an adaptive defrost cycle. An adaptive defrost timer control module is utilized to coordinate operation of the evaporator fan. This control module includes an embedded electronic controller having control logic programmed to operate the evaporator fan whenever either of the thermostats requires cooling, and to lock out operation of the evaporator fan whenever the system is performing a defrost cycle.

Abstract: In order to facilitate determination of which of a plurality of dangerous condition warning devices is issuing an audio failing battery signal, the device incorporates a circuit including: a processor, an audio annunciator such as a horn, at least one visual indicator such as an LED and a processor controlled, periodically invoked battery condition determining procedure to check the output voltage of the battery under load. If a low battery condition is detected, the horn is driven to issue an audio warning (e.g., a pulse of about 10 milliseconds duration every minute) and the LED is driven to issue a distinctive series brief flashes (e.g., five flashes of about 10 milliseconds each spaced about 500 milliseconds apart), the first flash being issued in coordination with the issuance of each brief audio warning.

Abstract: In a dangerous condition sensing alarm system which includes a plurality of interconnected dangerous condition sensing units, such as smoke detectors, of the general type in which each unit responds to an apparently sensed dangerous condition by issuing an audible alarm and also by transmitting, from an input/output terminal, a signal to the other units (received as an external alarm signal at corresponding input/output terminals of the other units) so that an alarm condition sensed by any one of the units results in alarms being sounded by all the units, a unit initiating an alarm (which may be false) is marked by an alarm origination circuit. The alarm origination circuit includes a visual indicator (such as an LED) and a latch device (such as an SCR) connected in-circuit such that, when the SCR is turned "on", the LED is activated and remains lit until the SCR is turned "off".

Abstract: A dangerous condition warning device for issuing an alarm when a dangerous condition is sensed incorporates a circuit including a replaceable dangerous condition sensor, a processor coupled to the sensor for periodically determining the ambient concentration of a potentially dangerous substance (e.g., CO) and a horn to issue alarm signals if indicated, the processor also periodically checking the integrity of the sensor, and the device incorporates sensor placement apparatus for facilitating removing and correctly replacing a sensor of suspect integrity. The sensor has an outer periphery and a reduced dimension portion employed as first and second electrodes. The sensor placement apparatus includes a sensor receptacle; a first contact member positioned to contact the reduced dimension portion of the sensor when the sensor is correctly emplaced and to electrically connect to the outer periphery of the sensor when the sensor is incorrectly emplaced.

Abstract: A CO concentration monitoring device operating under the control of a processor periodically checks the CO sensor to insure its ongoing integrity and to issue a distinctive audio signal to a user if sensor integrity has become suspect. The periodic integrity check procedure places a predetermined DC voltage across the sensor. Then, the voltage source is removed leaving the sensor charged as a capacitor such that reading the voltage remaining across the sensor, reading the temperature of the sensor and comparing a temperature adjusted representation of the voltage appearing across the sensor to at least one predetermined representation of a voltage representing a threshold at which sensor integrity becomes suspect. If this condition is determined, a sensor condition alert signal responsive is issued to drive a horn in a distinctive audio sequence (e.g., three 10 millisecond duration pulses spaced at about 500 millisecond intervals).