Dynamic Voltage Control for Thermistor Temperature Measurement
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Solution Overview
Problem
Existing temperature measurement devices face challenges in efficiently handling a wide range of temperature sensitive element constants, leading to increased power consumption and reduced accuracy when the thermistor operates in a low resistance range, as they require adjustments in voltage divider constants to account for varying resistance values.
Innovation Solution
A temperature measurement circuit that includes a voltage control circuit, switching circuits, and a conversion circuit to dynamically adjust control voltages and conversion gains based on current levels and voltage thresholds, allowing for accurate temperature measurement across a wide range of temperature sensitive element constants without the need for constant adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the thermistor operates in a low resistance range and a voltage divider is used to detect temperature, then the current flowing through the thermistor increases, but this leads to increased power consumption
Solution Approach 1:
The patent implements dynamic control of the voltage applied to the thermistor through a transistor-based voltage control circuit. The control voltage is adjusted based on the detected current level, allowing the system to adapt the excitation voltage to maintain optimal measurement conditions while minimizing power consumption. This dynamic adjustment resolves the contradiction by preventing excessive current flow that would increase power consumption while still enabling accurate temperature measurement.
Solution Approach 2:
The patent employs a feedback mechanism where the current flowing through the thermistor is detected and used to control the voltage applied to the thermistor. The voltage control circuit receives feedback about the current level and adjusts the control voltage accordingly. This feedback loop ensures that the thermistor operates in an optimal resistance range for measurement while preventing excessive power consumption that would occur with uncontrolled current flow.
2Adaptability or versatility
If a fixed voltage divider constant is used in the temperature detection system, then the circuit design is simplified, but it becomes difficult to handle a wide range of temperature sensitive element constants
Solution Approach 1:
The patent creates a universal temperature measurement system that can accommodate various temperature sensitive element constants through dynamic control mechanisms. The voltage control circuit and conversion circuit work together to adapt the measurement parameters based on the actual thermistor characteristics. This allows a single circuit design to universally handle different thermistor types and resistance values without requiring multiple fixed configurations, thereby improving adaptability while managing complexity through integrated control.
Solution Approach 2:
The patent dynamically changes the measurement parameters (voltage level and conversion gain) based on the thermistor's resistance value and operating conditions. The conversion circuit adjusts the conversion gain according to the detected voltage level, and the voltage control circuit modifies the excitation voltage based on current feedback. This parameter adaptation enables the system to maintain measurement accuracy across a wide range of temperature sensitive element constants without requiring multiple fixed circuit designs.
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 reduces excessive current flow and improves measurement accuracy by dynamically controlling voltages and conversion gains, enabling precise temperature measurement regardless of the resistance value of the temperature sensitive element, thus accommodating a wide range of constants without the limitations of traditional systems.
Implementation Method 1
a temperature sensitive element 60 having a resistance value that changes according to a temperature
Data Source
AI summary
A temperature measurement circuit for measuring a temperature using a temperature sensitive element includes a voltage control circuit configured to apply a control voltage to the temperature sensitive element. The temperature measurement circuit includes a first switching circuit configured to switch levels of the control voltage based on a current flowing through the temperature sensitive element. The temperature measurement circuit includes a conversion circuit configured to convert the current flowing through the temperature sensitive element into a voltage level corresponding to the measured temperature, by using predetermined conversion gain. The temperature measurement circuit includes a second switching circuit configured to switch values of the conversion gain based on the voltage level.