Integrated LED Traffic Signal with Independent Color Groups
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Solution Overview
Problem
Current LED signal designs for automotive, rail, and ship traffic require multiple lamps to achieve multi-color signaling, which is inefficient and prone to color mixing failures due to poor insulation, whereas incandescent systems use heat to produce light and have higher current draw for monitoring purposes.
Innovation Solution
A single integrated LED signal with three groups of disparate colored LEDs, each powered independently, using a power supply unit with a flyback transformer, dummy load, and monitoring circuits to ensure uniform light output and reliability, including a light out detection circuit and current detection to maintain safe operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple incandescent lamps are used for multi-color signaling, then color variety is achieved, but device complexity and susceptibility to color mixing failure increase
Solution Approach 1:
The patent combines three separate incandescent lamps into a single integrated LED signal housing containing three groups of LEDs (red, yellow, green). This merging approach maintains the multi-color signaling capability while reducing the number of separate lamp assemblies, thereby decreasing device complexity and eliminating color mixing failures associated with multiple separate lamps.
Solution Approach 2:
The LED array is segmented into three distinct groups of disparate colored LEDs (red, yellow, green), each group independently controllable. This segmentation allows each color to be independently activated without interference, maintaining color purity while using a single integrated housing, thus resolving the contradiction between color variety and device complexity.
2Loss of energy
If LED arrays are used instead of incandescent lamps, then energy efficiency and lifetime are improved, but current monitoring capability deteriorates
Solution Approach 1:
The patent incorporates a monitoring circuit that includes a light out detection circuit with an optical sensor to detect LED failures. This feedback mechanism compensates for the low current draw of LEDs by providing an alternative detection method (optical sensing) that monitors light output rather than relying on current measurement, thus maintaining failure detection capability while preserving LED energy efficiency.
Solution Approach 2:
The optical sensor acts as an intermediary between the LED light output and the monitoring system. Instead of directly measuring the low current drawn by LEDs, the system uses the optical sensor to detect light presence or absence, translating the LED's optical output into a measurable signal for failure detection, thereby overcoming the limitation of low current monitoring.
3Adaptability or versatility
If three separate lamps are used in a single housing, then multi-color signaling is achieved, but insulation quality and reliability worsen due to poor insulation design
Solution Approach 1:
The patent segments the LED array into three electrically isolated groups (red, yellow, green) with dedicated power supply circuits for each group. This segmentation, combined with proper insulation design within the single housing, prevents electrical interference and color mixing failures between the different colored LED groups, thereby maintaining reliability while achieving multi-color signaling in an integrated structure.
4Device complexity
If a single integrated LED signal is used, then device complexity is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent segments the LED array into three distinct groups of disparate colored LEDs with dedicated mounting areas and electrical connections. This segmentation allows for modular assembly and testing of each color group independently, reducing the overall manufacturing precision requirements compared to integrating all components into a monolithic structure, while still achieving a compact single-housing design.
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 a robust, energy-efficient, and reliable single-head LED signal that maintains uniform light output and safety by redistributing current in case of LED failures, reducing mechanical vibration issues and assembly errors, while meeting industry safety standards.
Implementation Method 1
A flyback transformer converts the power received from the power line from an alternating or a continuous current signal to a direct current signal output to the LED array
Implementation Method 2
A light out detection circuit monitors the light output of the LED array via an optical sensor
Data Source
AI summary
A signal is described herein that provides light output for automotive, rail, ship traffic and/or illumination control that includes a light emitting diode (LED) array, wherein the LED array includes three groups of disparate colored LEDs. A power supply unit provides independent power to each of the three LED groups. Each LED group power supply unit includes an input controlled switch connected to a power line to provide power to the LED array. An input under voltage/over voltage circuit monitors the voltage level of the power line and for enabling and/or disables the input controlled switch according to the voltage level of the power line. A flyback transformer converts the power received from the power line from an alternating or a continuous current signal to a direct current signal output to the LED array. A dummy load draws power additional to the LED array and a dummy load detection circuit monitors the dummy load to insure that the power drawn by the load is greater than or equal to a predetermined threshold. A light out detection circuit monitors the light output of the LED array via an optical sensor.