Remote LED Traffic Signal Controller Eliminates Head-Integrated Power Supply
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Solution Overview
Problem
Conventional LED traffic signals face issues due to the presence of a power supply and control module in the signal head, leading to environmental exposure, inconvenient maintenance, potential radio interference, and abrupt end-of-life indications that can cause safety hazards and premature failures.
Innovation Solution
A traffic signal system with a remote traffic signal controller that provides a DC input voltage to a power regulator associated with the LED light source, allowing for controlled input current adjustment based on conditions such as ambient temperature, time, and weather, eliminating the need for a power supply and control module in the signal head.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a power supply and control module are located inside the traffic signal head, then the signal can be controlled and powered, but the signal head is exposed to extreme temperatures and environmental damage
Solution Approach 1:
The patent extracts the power supply and control module from the signal head and relocates them to a protected electrical cabinet. This separation removes the sensitive electronic components from direct exposure to extreme temperatures, UV radiation, and other environmental factors that would otherwise damage them, while the signal head itself remains in its optimal location for traffic control visibility.
2Ease of operation
If a power supply and control module are located inside the traffic signal head, then the signal can be controlled, but maintenance requires closing traffic lanes and using bucket trucks
Solution Approach 1:
By extracting the power supply and control module from the elevated signal head and placing them in a ground-level electrical cabinet, the patent enables maintenance personnel to access and service these components without requiring traffic lane closures or specialized bucket truck equipment. The signal head itself remains in its elevated position for optimal visibility, while the maintenance-accessible components are located at ground level.
3Loss of information
If a separate communications line is installed to transmit information from the control module to the traffic signal controller, then information can be communicated, but the system complexity and installation cost increase
Solution Approach 1:
The patent combines the communications function with the existing power supply wiring by superimposing data signals on the same electrical conductors that deliver power to the signal head. This eliminates the need for separate communication cables or wireless communication systems, reducing overall system complexity while maintaining full bidirectional communication capability between the electrical cabinet and signal head.
4Object-generated harmful factors
If the power supply is enclosed in a metal electrical cabinet, then radio interference is shielded, but the cabinet must be placed at the street corner exposing it to environmental factors
Solution Approach 1:
The patent extracts the power supply from the signal head and places it in a protected electrical cabinet located in a more favorable environmental position. The metal cabinet provides necessary shielding against radio frequency interference generated by the switching regulator, while its relocated position protects it from direct sunlight and extreme temperatures that would otherwise be unavoidable at the signal head location.
5Difficulty of detecting and measuring
If voltage measurement is used to detect malfunctioning bulbs, then simple detection is possible, but LED light output loss cannot be detected
Solution Approach 1:
The patent replaces simple voltage measurement with a sophisticated control algorithm that monitors multiple parameters including forward voltage, forward current, and junction temperature of the LED. This algorithmic approach substitutes the inadequate electrical measurement method with a comprehensive diagnostic system that can accurately detect LED degradation and predict end-of-life conditions before complete failure occurs.
6Loss of information
If a fuse is broken to emulate a burned-out bulb, then end-of-life indication is provided, but abrupt loss of signal causes unsafe conditions
Solution Approach 1:
The patent implements preliminary action by using the control algorithm to detect LED degradation trends and predict end-of-life conditions before the LED actually fails. This early warning system allows maintenance to be scheduled proactively, preventing abrupt signal loss and ensuring continuous safe operation of the traffic signal without requiring fuse-based emulation of bulb failures.
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 reduces costs, minimizes maintenance risks, eliminates radio interference, and provides safe and efficient LED light output adjustments, enabling predictive end-of-life monitoring without abrupt failures, thus enhancing driver safety and operational efficiency.
Implementation Method 1
A traffic signal includes a light source having a light emitting diode (LED) array
Data Source
AI summary
A traffic signal is provided for controlling vehicular traffic. The traffic signal includes a light source (10) having a light emitting diode (LED) array (D1, D2, D3, D4). A power regulator (14) is associated with the light source and is constructed and arranged to control input current to the light source. A traffic signal controller (16) is remote from the light source and the power regulator. The traffic signal controller is constructed and arranged to provide an input voltage signal to the power regulator, with the input current being based on the input voltage signal.