Vehicle Lamp Control Device for Uniform LED Brightness
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Solution Overview
Problem
Conventional lamp control devices for vehicles face challenges in uniformly controlling LED brightness across multiple channels due to installation constraints, leading to current deviations and issues like power efficiency degradation and heat generation, especially when an LED channel is open or shorted, which can result in accidents if not monitored properly.
Innovation Solution
A lamp control device that includes a converter and a controller to regulate output voltage and channel currents using feedback voltages, allowing for independent dimming control and precise monitoring of LED channels, converting a turn signaling lamp into an emergency lamp upon sudden stop, and excluding faulty channels from voltage regulation to prevent accidents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of LED channels is increased to meet installation requirements, then the lamp can conform to vehicle installation circumstances, but current deviation between channels occurs and uniform brightness control becomes difficult
Solution Approach 1:
The patent divides the LED lamp system into multiple independent channels, each with its own current control circuit. This segmentation allows each channel to be controlled independently, compensating for current deviations caused by installation variations while maintaining overall system adaptability to different vehicle configurations.
Solution Approach 2:
The patent implements local quality control by providing individual current regulation for each LED channel based on its specific installation position and characteristics. This allows optimization of brightness uniformity for each channel according to its local requirements rather than applying a uniform control approach to all channels.
2Ease of operation
If conventional FET/BJT and OP-AMP are used for lamp control, then basic lamp driving function is achieved, but power efficiency degrades and heat generation increases when LED channel faults occur
Solution Approach 1:
The patent implements feedback control by monitoring the actual current in each LED channel and adjusting the drive signal accordingly. This feedback mechanism detects channel faults (open or short conditions) and automatically adjusts operating parameters to maintain power efficiency and reduce heat generation, preventing the energy loss that occurs with conventional open-loop control methods.
3Device complexity
If LED channel faults are not monitored, then device complexity is reduced, but power efficiency degrades and heat generation increases
Solution Approach 1:
The patent enables the LED lamp system to self-diagnose and self-adjust by incorporating fault monitoring capabilities directly into the control circuitry. The system automatically detects channel faults and adjusts its operation accordingly, eliminating the need for external monitoring equipment while maintaining power efficiency and preventing energy loss.
4Adaptability or versatility
If multiple LED channels are used, then the lamp can provide various lighting functions, but current deviation between channels causes difficulty in implementing uniform brightness control
Solution Approach 1:
The patent adjusts operating parameters (such as drive current, PWM duty cycle, or switching frequency) for each LED channel based on feedback from current sensors. By dynamically changing these parameters, the system compensates for variations in LED characteristics and installation positions, achieving uniform brightness across multiple channels while maintaining diverse lighting functions.
Data Source
AI summary
A lamp control device includes a converter configured to provide an output voltage and an internal voltage; a lamp including an LED module which has a plurality of LED channels, and configured to emit light in correspondence to the output voltage of the converter; and a controller configured to operate by using the internal voltage of the converter, control the output voltage of the converter to be retained at a level equal to or higher than a predetermined level, by using feedback voltages of the plurality of LED channels, and control channel currents of the plurality of LED channels to be regulated in correspondence to memory values which are set in advance.