Temperature control device with automatically adjustable backlighting
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Solution Overview
Problem
Temperature control devices, such as thermostats, face challenges in accurately measuring ambient temperature due to heat generated by internal components, which affects their ability to control HVAC systems effectively.
Innovation Solution
A temperature control device with a temperature sensing circuit and control circuit that adjusts its power consumption and sampling frequency to minimize heat generation, using an idle state to reduce power consumption and ambient light detection to optimize backlight intensity, ensuring accurate temperature readings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the display screen operates in high intensity modes to provide adequate illumination, then the illumination intensity is improved, but the heat generated by the display screen increases, causing inaccurate temperature measurements
Solution Approach 1:
The display screen operates in periodic cycles between active and sleep modes. During active mode, the display provides full illumination for user interaction. During sleep mode, the display reduces or eliminates operation to minimize heat generation. The temperature sensor takes measurements during the sleep mode when heat generation is minimal, ensuring accurate temperature readings while still providing adequate illumination when needed.
2Productivity
If the processing system operates in high power consumption modes to perform complex operations, then the productivity is improved, but the heat generation increases, affecting temperature sensor readings
Solution Approach 1:
The processing system alternates between active and sleep modes. During active mode, the processing system performs complex operations at full speed to maintain productivity. During sleep mode, the processing system reduces power consumption and heat generation to allow accurate temperature measurements by the temperature sensor. This periodic cycling enables both high productivity when needed and accurate temperature sensing when the system is idle.
3Speed
If the temperature control device continuously samples the temperature sensor to maintain real-time monitoring, then the measurement frequency is improved, but the power consumption and heat generation increase
Solution Approach 1:
The temperature control device implements periodic sampling rather than continuous monitoring. The system alternates between sampling periods where temperature readings are taken and idle periods where sampling is suspended. This periodic approach maintains adequate temperature monitoring capability while significantly reducing average power consumption and heat generation compared to continuous sampling.
4Illumination intensity
If the button backlight circuit operates at high intensity to provide adequate illumination in dark environments, then the illumination intensity is improved, but the heat generated affects temperature readings
Solution Approach 1:
The button backlight circuit operates periodically rather than continuously. During user interaction periods, the backlight provides full illumination to enable button visibility and operation. During idle periods between user interactions, the backlight remains off or operates at minimal intensity to eliminate heat generation that would interfere with temperature sensor readings. This periodic operation maintains adequate illumination when needed while preventing heat interference during measurement periods.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables accurate temperature measurement and control, reducing heat impact on readings and improving energy efficiency by dynamically managing power usage and backlight intensity based on usage and ambient light levels.
Implementation Method 1
a temperature sensing circuit configured to generate a temperature control signal indicating the present temperature in the space
Implementation Method 2
a button backlight circuit configured to illuminate the buttons during the awake state
Data Source
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AI summary
A temperature control device (e.g., a thermostat) may be configured to control an internal heat-generating electrical load so as to accurately measure a present temperature in a space around the temperature control device. The temperature control device may comprise a temperature sensing circuit configured to generate a temperature control signal indicating the present temperature in the space, and a control circuit configured to receive the temperature control signal and to control the internal electrical load. The control circuit may be configured to energize the internal electrical load in an awake state and to cause the internal electrical load to consume less power in an idle state. The control circuit may be configured to control the internal electrical load to a first energy level (e.g., a first intensity) during the awake state and to a second energy level (e.g., second intensity) that is less than the first during the idle state.