Temperature compensation for an electronic thermostat
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic thermostats face accuracy issues due to internally generated heat from components like microprocessors and displays, which affects ambient temperature measurement, degrading the performance of HVAC systems.
Innovation Solution
A compensation process using temperature compensation sensors and a thermal parameter to isolate and measure the internally generated heat, allowing for accurate ambient temperature calculation by establishing narrow thermal pathways and a sensor chamber to restrict heat flow, ensuring accurate room temperature measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If electronic components (microprocessor, power supply, display) are integrated in the thermostat, then the thermostat provides comprehensive control functions, but internal heat generation degrades temperature measurement accuracy
Solution Approach 1:
The thermostat is divided into two thermal zones: a main compartment containing heat-generating electronic components and a separate sensor chamber containing the temperature sensor. This segmentation isolates the sensor from thermal interference while maintaining all control functions in the main compartment.
Solution Approach 2:
The temperature sensor is extracted from the main compartment and placed in a dedicated sensor chamber that is thermally isolated from the main compartment. This extraction removes the sensor from the harmful thermal environment created by electronic components.
2Ease of manufacture
If the temperature sensor is mounted on the thermostat's PCB, then the sensor is easily integrated, but the sensor is directly affected by heat dissipation from components
Solution Approach 1:
A narrow thermal pathway acts as an intermediary between the main compartment and the sensor chamber. This pathway includes a thermal bridge and ventilation openings that allow controlled thermal interaction, permitting the sensor to be mounted on the PCB while limiting direct heat exposure from components.
3Measurement precision
If a sensor chamber is introduced to thermally isolate the sensor, then temperature measurement accuracy is improved, but the device structure becomes more complex
Solution Approach 1:
The sensor chamber serves multiple functions: it thermally isolates the sensor from the main compartment, provides mounting for the temperature sensor on the PCB, and includes ventilation openings for airflow. This multi-functionality reduces the need for additional separate components.
Solution Approach 2:
The sensor chamber is nested within the thermostat housing, with the temperature sensor mounted on the PCB that extends into the sensor chamber. This nested arrangement integrates multiple components in a compact configuration, minimizing structural complexity.
4Measurement precision
If ventilation openings are provided in the sensor chamber, then ambient air flow for temperature measurement is enabled, but heat flow from the main compartment to the sensor is increased
Solution Approach 1:
The thermal pathway from the main compartment to the sensor chamber is designed with specific local characteristics: a narrow cross-section and controlled length. This creates a high thermal resistance pathway that limits heat flow while ventilation openings provide sufficient airflow for accurate ambient temperature measurement.
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 effectively compensates for internal heat, enhancing the accuracy of ambient temperature measurement, thereby improving the operation of HVAC systems by isolating the ambient temperature sensor from heat sources and using thermal resistance ratios to calculate compensated temperatures.
Implementation Method 1
a narrow thermal pathway is established between the ambient temperature sensor and the one or more temperature compensation sensors
Implementation Method 2
an ambient temperature sensor for measuring the ambient temperature of the proximate region around the electronic thermostat
Implementation Method 3
one or more temperature compensation sensors... the measured compensation temperature (Tc1) from the compensation temperature sensor
Implementation Method 4
The processing device then determines a compensated ambient temperature (Tambient) from the measured ambient temperature, the measured compensation temperature, and the thermal parameter
Data Source
AI summary
An aspect of the embodiments provides a compensation for the temperature rise effect on the printed circuit board (PCB) of an electronic thermostat to obtain better precision and performance. Once the measurements from the temperature sensors have stabilized, the compensated ambient temperature may be used by an associated system (for example, a Heating, Ventilation, and Air Conditioning (HVAC) system).