Lighting Control Failsafe Circuit for Daylight Harvesting
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Solution Overview
Problem
Daylight harvesting systems require complex commissioning procedures and adjustments to optimize light level setpoints, often involving multiple controls and calibration methods, which can be inaccurate and time-consuming.
Innovation Solution
A rotary potentiometer-based actuator with multiple functional regions allows for automatic and manual setpoint calibration, enabling precise adjustment of light level setpoints through a user-friendly interface, eliminating inaccuracies and simplifying the commissioning process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex commissioning procedures with multiple controls and calibration methods are used, then the system can achieve proper operation, but the commissioning process becomes time-consuming and inaccurate
Solution Approach 1:
The patent extracts the essential calibration function into a dedicated automated calibration circuit that separately handles setpoint determination. This circuit is pulled out from the complex commissioning interface and performs calibration autonomously based on measured light levels, eliminating the need for manual intervention while maintaining reliability.
Solution Approach 2:
The calibration system performs self-calibration by automatically measuring light levels with the photocell and adjusting the setpoint without requiring external commissioning tools or manual adjustments. The system serves itself by using its own sensors and processing capabilities to determine optimal operating parameters.
2Adaptability or versatility
If multiple DIP switches and trimming potentiometers are used for parameter adjustment, then comprehensive control is achieved, but the device complexity increases
Solution Approach 1:
The patent replaces mechanical adjustment interfaces (DIP switches and potentiometers) with an electronic automated calibration system. The microcontroller-based circuit electronically determines setpoints based on photocell measurements, substituting physical adjustment mechanisms with software-driven calibration that maintains adaptability while reducing hardware complexity.
Solution Approach 2:
The automated calibration circuit serves multiple functions: it determines setpoints, measures light levels, adjusts calibration parameters, and stores configuration data all through a single integrated system. This multi-functional approach replaces multiple separate controls with one universal calibration mechanism.
3Productivity
If manual calibration methods are used, then the commissioning process can be completed, but measurement precision and accuracy are reduced
Solution Approach 1:
The calibration system uses feedback from the photocell's light level measurements to automatically adjust the setpoint. The microcontroller continuously monitors the measured light levels and adjusts calibration parameters based on this feedback, ensuring accurate setpoint determination without manual intervention. This closed-loop feedback mechanism replaces imprecise manual calibration with precise automated adjustment.
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 provides accurate and efficient calibration of light level setpoints, reducing the complexity of commissioning and improving the precision of daylight harvesting systems, allowing for quicker and more reliable adjustments to maintain optimal lighting levels.
Implementation Method 1
A typical daylight harvesting system includes a photocell or other light sensor to measure light in a specific building space
Implementation Method 2
A rotary potentiometer-based actuator with multiple functional regions allows for automatic and manual setpoint calibration
Data Source
AI summary
A system may include a switch arranged to control a lighting load, a processor arranged to control the switch, and a failsafe circuit arranged to monitor the processor and actuate the switch if the processor fails. The failsafe circuit may have a time constant, and may be arranged to actuate the switch if the monitor signal does not include a pulse during a period of time equal to the time constant.