Short Circuit Detection Module for Automotive LED Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED lighting systems in vehicles struggle to detect short circuit conditions in LED arrays, which is a requirement for compliance with automotive lighting standards, and this detection is often costly and difficult to implement.
Innovation Solution
A short circuit detection system that includes an LED light source, an incandescent light source, and a failure detection circuit with an LED driver circuit and an outage detection module, which monitors current or voltage across the LED light source and transmits a lamp failure signal to a body control module to cause a driver warning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the LED driver circuit monitors current or voltage across the LED light source to detect open circuit failures, then the reliability of the lighting system is improved, but the ability to detect short circuit conditions remains insufficient
Solution Approach 1:
The patent introduces an intermediary incandescent light source and dedicated detection circuit that acts as a mediator between the LED array and the control system. This intermediary component enables short circuit detection without requiring direct modification of the LED driver circuitry, allowing the system to detect short circuits through the incandescent bulb's electrical characteristics while maintaining the original LED system's integrity.
Solution Approach 2:
The detection circuit is designed with multi-functionality, serving both open circuit detection (through the LED driver's existing current monitoring) and short circuit detection (through the incandescent bulb's voltage/current characteristics). This universal detection approach eliminates the need for separate detection mechanisms for different failure modes, improving reliability while reducing system complexity.
2Reliability
If additional electronics are added to enable short circuit detection capability, then compliance with automotive lighting standards is achieved, but the device complexity and cost increase
Solution Approach 1:
The system uses the incandescent light source's own electrical characteristics (voltage drop, current flow) as the detection mechanism. The incandescent bulb essentially detects its own short circuit condition through the detection circuit, eliminating the need for external sensors or complex electronics. This self-service approach achieves compliance while minimizing added complexity.
Solution Approach 2:
The patent employs a low-cost incandescent light source as the detection element. Rather than using expensive specialized sensors or complex electronic circuits, the system uses an inexpensive incandescent bulb that can be easily replaced if needed. This approach achieves regulatory compliance while keeping the added complexity and cost to a minimum.
3Measurement precision
If the LED driver circuit is modified to sense each LED individually, then short circuit detection accuracy is improved, but the cost and area for additional electronics increase
Solution Approach 1:
The patent segments the detection function by separating the LED array into two functional groups: the LED light sources for illumination and the incandescent light source for detection. This segmentation allows the detection circuit to monitor the incandescent bulb's electrical characteristics independently, achieving accurate short circuit detection without requiring individual sensing for each LED. The segmentation simplifies the detection architecture while maintaining precision.
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 system effectively detects short circuit failures in LEDs within a series connection, enabling compliance with automotive lighting standards while reducing the complexity and cost of additional electronics.
Implementation Method 1
monitoring the current or voltage across the LED light source for detecting an LED light source outage
Implementation Method 2
monitoring by the outage detection module the current to the incandescent light source for detecting an incandescent light source outage
Implementation Method 3
LED light source
Implementation Method 4
incandescent light source
Implementation Method 5
incandescent light source
Data Source
AI summary
A Short Circuit Detection module capable of detecting a fail related with the Short circuit condition in one or more LEDs contained in a series connection string comply with the failure mode (One out-All out) and can send a single failure signal to a body control module (BCM). The Short Circuit Detection module also includes a lamp driver circuit adapted to detect a change in LED current or voltage that is indicative of a LED light source failure and thereafter output the failure signal to the BCM.