Single-Sensor Detection Circuit With Switchable Sensitivity Ranges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional detection systems require separate sensors and circuits for different detection parameters, leading to increased complexity, wiring, and maintenance, particularly in applications like fire and toxic gas detection where different sensitivity levels are needed.
Innovation Solution
A detection arrangement using a single sensor with a switchable control circuit that adjusts sensitivity and processing algorithms based on predetermined conditions, allowing a single sensor to detect multiple levels or ranges of a parameter, thereby reducing the need for separate sensors and wiring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate sensors and detection circuits are used for different detection parameters (e.g., fire and toxic gas detection), then measurement precision for each parameter is improved, but device complexity increases
Solution Approach 1:
A single detection circuit is designed to perform multiple detection functions (fire detection and toxic gas detection) by switching between different sensitivity ranges. The circuit uses a single sensor element with a sensitivity range of 0-500 PPM and switches between a first sensitivity range (0-40 PPM for fire detection) and a second sensitivity range (35-500 PPM for toxic gas detection), eliminating the need for separate sensors and circuits while maintaining measurement precision for both applications.
2Measurement precision
If separate detection circuits with different sensitivity ranges are used for fire and gas detection, then measurement precision for each application is improved, but wiring requirements increase
Solution Approach 1:
The patent combines multiple detection functions into a single integrated detection circuit. The single circuit includes a sensor element, a switchable amplifier with variable gain, and a control unit that can detect both fire conditions (0-40 PPM range) and toxic gas conditions (35-500 PPM range) using the same physical sensor and wiring infrastructure, thereby reducing wiring requirements while maintaining measurement precision.
3Reliability
If separate detection circuits are used for different sensitivity levels, then reliability of detection for each condition is improved, but maintenance requirements increase
Solution Approach 1:
The single detection circuit is designed to reliably detect both fire and toxic gas conditions by switching between sensitivity ranges. The control unit determines which sensitivity range to use based on the detected conditions, and the single sensor element is maintained rather than requiring multiple sensors, thereby reducing maintenance requirements while ensuring reliable detection for both applications.
4Device complexity
If a single sensor is used to detect multiple levels of a parameter, then device complexity is reduced, but measurement precision across different ranges may deteriorate
Solution Approach 1:
The detection circuit employs a dynamic sensitivity switching mechanism where the amplifier gain is adjusted based on the detected parameter level. The control unit switches between a first sensitivity range (higher gain for low concentrations 0-40 PPM) and a second sensitivity range (lower gain for high concentrations 35-500 PPM), allowing a single sensor to maintain measurement precision across multiple detection ranges by adaptively changing the circuit's sensitivity.
Data Source
AI summary
A detection system in which a single sensor (14) is employed to detect two, or more, levels, or ranges, of a parameter. The output signal from the sensor (14) is fed to a detection circuit (12) for amplification and thence to a control circuit (24). The control circuit (24) is switchable, either manually, or preferably programmably, for example by a timer, between two or more modes of operation for processing the output signal from the sensor (14) in a different manner, for example using different algorithms, according to the condition that is to be detected. The switching of the control circuit (24) between its modes results in a signal being sent to the detection circuit (12) to change its sensitivity to the signal received from the sensor (14), thereby to maintain accuracy of measurement of the parameter in both or all modes of operation.