Adaptive Load Circuit for LED Traffic Lights
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing street traffic light controllers often malfunction when switching from high power consumption incandescent or halogen lamps to low power consumption LED lamps, as they fail to recognize the LED lamps as operational and stop sending control signals.
Innovation Solution
An adaptive load circuit that periodically increases power consumption to mimic the behavior of higher power lamps, allowing low power consumption lamps like LEDs to operate seamlessly with controllers designed for higher power lamps by generating synchronized signals to match the expected power consumption patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If LED lamps are used to replace incandescent or halogen lamps, then energy consumption is reduced and lifespan is extended, but the controller malfunction occurs because the power consumption is too low for the controller to recognize the lamp as operational
Solution Approach 1:
The patent implements periodic action by using a timer circuit to periodically activate the dummy load resistor during specific time intervals. The controller sends test signals at regular intervals, and the dummy load is activated only during these test periods to simulate high power consumption, while remaining inactive during normal operation to save energy. This resolves the contradiction by providing the necessary power consumption signal periodically without continuously consuming excessive energy.
Solution Approach 2:
The patent introduces a dummy load resistor as an intermediary component between the LED lamp and the controller. This intermediary element absorbs excess power during controller test periods, creating the appearance of high power consumption that matches the controller's expectations for incandescent or halogen lamps. The dummy load acts as a mediator that decouples the actual low power consumption of LED lamps from the controller's high power consumption expectations, thereby maintaining reliable controller recognition.
2Reliability
If a dummy load is added to simulate higher power consumption, then controller recognition is maintained, but device complexity increases
Solution Approach 1:
The patent merges the dummy load circuit with the existing LED lamp circuit by integrating the dummy load resistor, switch, and timer components into a unified circuit board that works together with the LED lamp. The components are combined into a single functional unit that can be installed as one integrated assembly, reducing the need for separate independent circuits and simplifying the overall system architecture despite adding functionality.
Solution Approach 2:
The circuit implements self-service by using the controller's own test signals to automatically trigger the dummy load activation. When the controller sends a test signal, the timer circuit detects this signal and automatically activates the dummy load without requiring external control or manual intervention. The system serves itself by using the controller's periodic testing mechanism to drive the dummy load activation, eliminating the need for additional control circuitry.
Data Source
Figure 1
Figure 2
AI summary
The present subject matter is directed to an adaptive load circuit for use with traffic light control systems so as to permit operation using low current consumption lamps where the traffic light control systems were originally manufactured for operation with higher current consuming lamps. The adaptive load circuit provides a mechanism whereby an existing traffic light control system is fooled into accepting use of a low current consuming lamp by creating a specifically timed signal during an interval that the traffic light control system normally checks to determined lamp load characteristics.