Adaptive Bias Control for Wide-Range Resistive Sensor Measurement
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Solution Overview
Problem
Existing methods struggle to measure a wide range of resistance values in resistive sensors, particularly resistive gas sensors, due to variations in baseline resistance and variations in fabrication, aging, and the need to measure multiple gases simultaneously.
Innovation Solution
An apparatus and method that adjust the bias voltage based on sensing current to determine resistance values, using a feedback loop to adjust the bias voltage to adjust the bias voltage to measure the resistance of a plurality of resistive sensors, an integrated circuit to measure a wide range of resistance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed bias voltage is applied to measure resistance, then the measurement circuit is simple, but the measurable resistance range is limited
Solution Approach 1:
The patent implements a feedback control mechanism that dynamically adjusts the bias voltage based on the sensed current magnitude. The controller monitors the current and automatically modifies the bias voltage level, transforming a static measurement system into a dynamic one capable of adapting to varying resistance values across multiple orders of magnitude.
Solution Approach 2:
The patent employs a feedback loop where the measured current is fed back to the bias voltage controller, which then adjusts the bias voltage accordingly. This feedback mechanism enables the system to automatically adapt the excitation voltage to maintain optimal measurement conditions across a wide resistance range, resolving the contradiction between circuit simplicity and measurement versatility.
2Measurement precision
If high bias voltage is applied to measure low resistance sensors, then low resistance measurement is improved, but energy consumption increases and sensor damage risk increases
Solution Approach 1:
The feedback control mechanism continuously monitors the sensed current magnitude and automatically adjusts the bias voltage to the minimum level required for accurate measurement. This prevents excessive voltage application, thereby reducing energy consumption and minimizing the risk of sensor damage while maintaining measurement precision for low resistance sensors.
Solution Approach 2:
The system dynamically changes the bias voltage parameter based on the measured current characteristics. By adjusting this critical parameter in real-time, the system optimizes the balance between measurement accuracy and energy efficiency, applying only the necessary voltage level for each measurement condition.
3Productivity
If multiple sensors are measured simultaneously with fixed voltage, then measurement speed is fast, but measurement precision across different resistance ranges deteriorates
Solution Approach 1:
The system implements dynamic bias voltage adjustment that operates rapidly across multiple sensors, adapting the voltage level for each sensor based on its resistance characteristics. This dynamic approach maintains fast measurement throughput while ensuring precision across the full resistance range by optimizing the excitation voltage for each sensor individually.
Solution Approach 2:
The feedback control mechanism provides a universal measurement capability that works effectively across all resistance ranges for multiple sensors. By making the bias voltage adjustable and adaptive, a single measurement system achieves multi-functionality, handling both high and low resistance sensors with equal precision without requiring separate measurement circuits.
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
Enables accurate measurement of resistance values across a broader range, reduces energy consumption, and allows simultaneous measurement of multiple gases with reduced sensor damage and power consumption.
Implementation Method 1
Ohm's Law states that the voltage V across a resistor of resistance R is directly proportional to the current I flowing through the resistor, i.e. V = R.I, which allows measuring of the resistance R as R = V/I
Data Source
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AI summary
The invention relates to an apparatus (100) for determining a resistance value of one (102) of a plurality of resistive sensors based on a measure of a current responsive to a bias voltage (107) applied to said one resistive sensor (102), the apparatus (100) comprising: a bias voltage generator (101) for applying a bias voltage (107) to said one resistive sensor (102); a bias voltage controller (103) coupled with said bias voltage generator (101) and configured for adjusting said bias voltage (107) based on a sensing current (108, 109) flowing through said one resistive sensor (102); a current measurement unit (104) configured for measuring a sensing current (108, 112) flowing through said one resistive sensor (102) once said bias voltage (107) has been adjusted; a sensor selection unit (105) coupled with the bias voltage controller (103) and the current measurement unit (104), and configured for selecting a resistive sensor (102) in the plurality of resistive sensors.