Series Thermistor Gas Sensor Power Timing for Lower Consumption
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Solution Overview
Problem
Existing gas sensors with series-connected thermistors face high power consumption due to continuous current flow during heating and measurement operations.
Innovation Solution
A gas sensor design that includes first and second thermistors connected in series, with separate heaters and a control circuit to manage heater and power supply timing, applying power only after the heaters have started heating and at optimal times to reduce unnecessary power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If power supply is applied continuously to thermistors during heating and measurement, then measurement can be performed at any time, but power consumption increases
Solution Approach 1:
The patent implements periodic action by dividing operation into distinct phases: a heating period where heaters are activated to raise thermistor temperatures, and a measurement period where power supply is applied to thermistors for gas detection. This periodic switching between heating and measurement phases reduces overall power consumption while ensuring measurements are performed at optimal temperatures.
Solution Approach 2:
The patent applies preliminary action by performing heating operations before measurement operations. The heating period prepares the thermistors by raising their temperatures to optimal operating ranges, ensuring that when the measurement period begins, the thermistors are already at the required temperature for accurate gas detection, eliminating the need for continuous heating during measurement.
2Loss of time
If power supply is applied to thermistors during heating, then measurement can start earlier, but thermal aging of thermistors increases
Solution Approach 1:
The patent uses periodic action to separate heating and measurement into distinct time phases. During the heating period, only heaters are active while thermistors remain unpowered. After heating completes, the system transitions to the measurement period where thermistors are powered for detection. This temporal separation allows measurements to start promptly after heating while minimizing thermistor exposure to high temperatures, thereby reducing thermal aging.
Solution Approach 2:
The patent implements preliminary action by completing the heating process before initiating measurement operations. The heating period serves as a preparatory phase that brings thermistors to optimal temperature without applying measurement power. Only after heating is complete does the system apply power to thermistors for measurement, ensuring measurements start at the right time while protecting thermistors from unnecessary thermal stress during the heating phase.
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
Reduces power consumption and thermal aging of thermistors by delaying power application until the thermistors reach measurement-ready temperatures, thereby optimizing energy use and extending sensor lifespan.
Implementation Method 1
first and second heaters for heating the first and second thermistors, respectively
Data Source
AI summary
Disclosed herein is a gas sensor that includes: first and second thermistors connected in series; first and second heaters configured to heat the first and second thermistors, respectively; and a control circuit configured to control the first and second heaters and apply a power supply to the first and second thermistors In a first period, the control circuit is configured to: start heating the first and second heaters; start applying the power supply to the first and second thermistors after a start of heating the first and second heaters; and generate an output signal indicating a concentration of a gas to be measured based on a detection signal appearing at a connection point between the first and second thermistors in a state where the first and second heaters are heated and the power supply is applied to the first and second thermistors.