Light-Triggered Field Display for Battery-Powered Process Devices
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Solution Overview
Problem
Wireless field devices in industrial process control systems face challenges in power conservation, particularly in hazardous locations where traditional power sources are not available, and existing solutions with buttons are prone to mechanical wear and may not be suitable for environments sensitive to heat, electricity, or sparking.
Innovation Solution
A field device equipped with a photodetector and display controller that powers the local operator interface (LOI) display only briefly in response to changes in light levels, eliminating the need for buttons and reducing mechanical wear, while ensuring reliable operation in sensitive environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the display is continuously powered on to provide information to technicians, then the operator interface functionality is improved, but the battery life is reduced due to increased power consumption
Solution Approach 1:
The display is activated periodically based on light level changes rather than continuously. The controller detects ambient light levels and turns the display on when light levels indicate a technician is present, then turns it off after a predetermined time period, creating a periodic activation pattern that balances usability with power conservation.
2Use of energy by moving object
If mechanical buttons are used to control the display to conserve power, then the power consumption is reduced, but the device reliability deteriorates due to mechanical wear and susceptibility to heat and electricity in hazardous environments
Solution Approach 1:
The patent replaces mechanical buttons with an optical sensing system. The photodetector detects light level changes caused by a technician's presence, and the controller automatically activates the display based on these optical signals, eliminating all mechanical moving parts while maintaining power conservation through automatic control.
3Use of energy by moving object
If the display is activated based on light level changes, then the power consumption is optimized and reliability is improved by eliminating mechanical parts, but the device complexity increases due to additional components
Solution Approach 1:
The photodetector serves multiple functions: it detects technician presence for display activation, and can potentially serve other sensing functions in the device. The controller integrates the light-level-based display control logic into its existing control architecture, allowing a single component to serve multiple purposes and reducing overall system complexity.
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
This solution effectively conserves power by only activating the display when needed, extending the battery life of locally-powered devices and ensuring reliable operation in harsh environments without the need for mechanical switches.
Implementation Method 1
A field device with a photodetector and an integral local operator interface display is provided.
Data Source
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AI summary
A field device comprises a transducer, a photodetector, a display, and a display controller. The transducer controls or monitors process variable, and the display shows information relating to the process variable. The photodetector detects a light level. The display controller is capable of switching the display on and off in response to changes in the light level detected by the photodetector.