HVAC controller having multiplexed input signal detection and method of operation thereof
AssigneeLennox Industries Inc.
InventorsDarko Hadzidedic, Sakthi Narayan Kumar Murugesan, Anitha Rajappan
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Abstract
A heating, ventilation and air conditioning (HVAC) controller, a method of detecting multiplexed input signals and an HVAC system employing the controller or the method. In one embodiment, the HVAC controller includes: (1) a signal conditioner configured to convert received alternating current (AC) input signals into corresponding square wave signals of a digital logic voltage, (2) a multiplexer coupled to the signal conditioner and configured to select one of the square wave signals and (3) a sample analyzer coupled to the multiplexer and configured to evaluate multiple samples of the selected one of the square wave signals to derive a binary state.
Claims15
A method of detecting multiplexed input signals, comprising:
- converting, using a signal conditioner, received alternating current (AC) input signals into corresponding square wave signals of a digital logic voltage;
- selecting, using a multiplexer coupled to the signal conditioner, one of the square wave signals;
- and
- evaluating, using a sample analyzer coupled to the multiplexer, the selected one of the square wave signals to derive a binary state, wherein the sample analyzer comprises a gate and a counter and is configured to employ a clock signal to sample the selected one of the square wave signals;
- wherein the evaluating comprises:
- providing the binary state to an interrupt pin of a processor;
- and
- asserting a signal on the interrupt pin if at least a threshold number of assertions is reached during a window of time.
A method detecting multiplexed input signals, comprising:
- converting, using a signal conditioner, received alternating current (AC) input signals into corresponding square wave signals of a digital logic voltage;
- selecting, using a multiplexer coupled to the signal conditioner, one of the square wave signals;
- evaluating, using a sample analyzer coupled to the multiplexer, the selected one of the square wave signals to derive a binary state, wherein the sample analyzer comprises a gate and a counter and is configured to employ a clock signal to sample the selected one of the square wave signals;
- and
- controlling at least one of a compressor, a furnace, and a blower based on the binary state;
- wherein the evaluating comprises:
- providing the binary state to an interrupt pin of a processor;
- and
- asserting a signal on the interrupt pin if at least a threshold number of assertions is reached during a window of time.
A method detecting multiplexed input signals utilizing a controller that includes a signal conditioner, a multiplexer, an interrupt pin, and a sample analyzer, the method comprising:
- converting, using the signal conditioner, received alternating current (AC) input signals into corresponding square wave signals of a digital logic voltage;
- selecting, using the multiplexer coupled to the signal conditioner, one of the square wave signals;
- and
- evaluating, using the sample analyzer coupled to the multiplexer, multiple samples of the selected one of the square wave signals to derive a binary state, wherein the sample analyzer comprises a gate and a counter and is configured to employ a clock signal to sample the selected one of the square wave signals;
- wherein the evaluating comprises:
- providing the binary state to an interrupt pin of a processor;
- and
- asserting a signal on the interrupt pin if at least a threshold number of assertions is reached during a window of time.
Dependencies are inferred from the claim text.