Light Controller Using Photosensor Night Length Estimation
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Solution Overview
Problem
Outdoor lighting systems, particularly in parking lots, face challenges in reducing energy consumption as high intensity discharge lamps do not respond quickly to changes in light intensity and require accurate timekeeping for control methodologies, which is difficult to maintain without continuous power and synchronized clocks.
Innovation Solution
A method that estimates the occurrence of midnight based on the average night length determined by photosensors, allowing lights to operate at different intensities and energy levels without the need for individual clocks or synchronization, and automatically adjusts for daylight savings time, using a processor and relay to control the lights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If high intensity discharge lamps are turned off and on quickly to save energy, then energy consumption is reduced, but the lamp response time is too slow to achieve quick switching
Solution Approach 1:
The system dynamically adjusts the light intensity of HID lamps by controlling the power level rather than simply switching on/off. This allows the lamps to respond quickly to control signals by changing intensity levels, resolving the contradiction between energy savings and response time.
Solution Approach 2:
The invention changes the operational parameter from binary on/off switching to continuous intensity modulation. By controlling the power level to HID lamps, the system can rapidly adjust between different intensity states, achieving both energy efficiency and quick response times.
2Measurement precision
If individual clocks are installed in each control to maintain accurate timekeeping, then time synchronization is improved, but device complexity and cost increase
Solution Approach 1:
The invention merges the timekeeping function into the existing pole-mounted lighting control system rather than installing separate clocks in each control unit. This consolidation maintains accurate time synchronization while reducing overall system complexity and cost.
Solution Approach 2:
The lighting control system is designed to perform multiple functions including timekeeping, light intensity control, and energy management within a single integrated unit. This multi-functionality eliminates the need for separate clock devices while maintaining accurate time synchronization across the system.
3Illumination intensity
If lights operate at full intensity continuously to ensure visibility, then illumination quality is maintained, but energy consumption increases
Solution Approach 1:
The system dynamically adjusts light intensity based on real-time conditions such as presence detection and time of day. Lights operate at full intensity when needed for visibility and reduce to lower intensity levels during periods when full illumination is not required, optimizing both visibility and energy consumption.
Solution Approach 2:
The lighting system implements periodic intensity adjustments throughout the operating day, switching between full intensity and reduced intensity modes based on scheduled times and sensor inputs. This periodic action maintains adequate visibility while significantly reducing overall energy consumption.
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 efficient energy management by reducing power consumption without the need for continuous electric power or accurate timekeeping, allowing for adaptive lighting control based on the local daylight cycle, thereby optimizing energy usage in outdoor lighting systems.
Implementation Method 1
determining the average night length (NLAVE) by averaging the night lengths (NL) between a night starting time (NST) as determined by a photosensor and a night ending time (NET) determined by a photosensor
Data Source
AI summary
A method of estimating the occurrence of midnight on a given day comprises the steps of determining the average night length (NLAVE) by averaging the night lengths (NL) between a night starting time (NST) as determined by a photosensor and a night ending time (NET) determined by a photosensor for each of a plurality of days, and estimating midnight to occur at the time that is one half of the average night length (NLAVE) after the night starting time (NST) for the given day. This estimate of midnight to control the operation of lights or other equipment without the need for clocks or constant power.