Lennox Industries Inc.

Texas Instruments Corporation

Anuradha Sundararajan

Rosa Maria Leal

Rakesh Goel

Harold Gene Havard, Jr

Larry D Dickinson

Bing Ouyang

John Michael Hayden

Troy Lane Ethridge

Mark W Olsen

Alan Edens Bennett

Anna Vishinsky

H Gene Havard

John Manby

Darko Hadzidedic

Der-Kai Hung

Jimmie Lee Curry

William Toombs, Jr

According to one embodiment, a system includes a first and second cooling system, an automation controller, one or more sensors, and a hardware controller separate from the automation controller. The hardware controller processes various temperature set points in conjunction with a timer and configures the activation or deactivation of the first and second cooling systems accordingly.

Automated climate control system with override

Provided are a method and apparatus for verifying or correcting the temperature sensor and compressor pairings within the HVAC system control logic, indicating that a sensor is logically paired with the specific compressor, from amongst a tandem compressor group, to which the sensor is coupled.

Sensor coupling verification in tandem compressor units

According to one embodiment, a system includes at least one of a cooling system and a heating system, an automation controller, a sensor, and a switch. The automation controller provides a first input indicating a first temperature set point. The sensor detects a temperature of a second space proximate the sensor and provides a second input indicating the temperature of the second space and a second temperature set point. The switch activates at least one of the cooling system and the heating system based on the second temperature set point in response to a determination that the second input overrides the first input.

An HVAC system includes a plurality of sensors, a tandem compressor, and a controller. The tandem compressor comprises a first and second compressor, each comprising a crankcase heater. The controller determines that one of the sensors has failed, and in response, initiates the first and second crankcase heaters and transmits an alert indicating that one of the sensors has failed. Further, the controller may disable threshold logic such that the first and second compressors are controlled independently of a determination whether the tandem compressor is operating outside of a threshold range. The controller operates the first and second compressors according to a safe mode, wherein first on or off settings of the compressors are determined based on a first required load operation of the tandem compressor. The first required load operation is determined from a first temperature demand of a structure associated with the HVAC system.

Sensor failure error handling

An HVAC system, comprising a plurality of sensors, a tandem compressor comprising a first compressor and a second compressor, and a controller communicatively coupled to the plurality of sensors and the tandem compressor. The controller may determine a first interruption of power to the tandem compressor and identify a sensor corresponding to the first interruption of power. The controller is further operable to determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding a tolerance condition. The controller may also reconfigure the tandem compressor, wherein on or off settings of the first compressor and the second compressor are determined based on a required load operation of the tandem compressor and the determination that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition.

Tandem compressor discharge pressure and temperature control logic

In various implementations, compressor operation in an air conditioner may be managed by maintaining oil viscosity, a temperature differential, compressor sump temperature, and/or suction pressure. Properties of the air conditioner or portions thereof, such as the compressor, may be determined. To manage compressor operations, operation(s) of the air conditioner may be adjusted based on one or more of the determined properties.

Compressor operation management in air conditioners

A method and apparatus for an analog-to-digital video signal converter. The converter is controlled by a clock with controllable frequency and phase for sampling an analog signal. A circuit corrects the clock frequency using a period of a columnar frame differences as a function of columnar location. The sampling clock frequency is changed by an amount dependent on the period of the columnar differences. A second measure of the difference between successive frames is computed for a sequence of clock phases. The frequency of the clock is verified using a characteristic of the second measure. The characteristic can be the ratio of the maximum to the minimum of the second measure over selected clock phases. Other characteristics can be used such as a difference of a maximum and a minimum measure.

Method and apparatus for analog graphics sample clock frequency offset detection and verification

A method and apparatus for an analog-to-digital video signal converter. The converter is controlled by a clock with controllable frequency and phase for sampling an analog signal. A measure of the difference between successive frames of the image is computed for a sequence of clock phases. The measure can be a count taken over pixels of the magnitude of the difference between a pixel in one frame and the corresponding pixel in a following frame exceeding a threshold value. The frequency of the clock is verified using a characteristic of the frame difference. The characteristic can be the ratio of the maximum measure to the minimum measure over the selected clock phases. Other characteristics can be used such as a difference of a maximum and a minimum measure.

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Allen, TX, United States of America

Anuradha Sundararajan