Vehicle LED Circuit Topology for Voltage Fluctuation Management
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Solution Overview
Problem
Vehicle lighting devices with LEDs connected in series face issues with voltage fluctuations, leading to reduced luminous flux and rapid increases in current, which can result in inadequate light emission when the applied voltage decreases.
Innovation Solution
A vehicle lighting device with a control portion that detects input voltage and connects circuit portions in series or parallel to maintain a consistent luminous flux, using diodes and resistors to manage current flow and prevent sudden increases in current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light emitting diodes are connected in series to maintain stable operation, then reliability is improved, but when voltage decreases the total luminous flux becomes less than specified value
Solution Approach 1:
The patent applies dynamics by making the connection configuration of light emitting diodes changeable based on operating conditions. The control portion dynamically switches between series connection (for high voltage stability) and parallel connection (for adequate luminous flux at low voltage), allowing the system to adapt to varying voltage conditions and maintain both reliability and illumination requirements.
2Illumination intensity
If some light emitting diodes are disconnected to maintain required luminous flux at decreased voltage, then illumination intensity is improved, but current through remaining diodes suddenly increases causing rapid luminous flux increase
Solution Approach 1:
The control portion dynamically adjusts the connection configuration based on detected voltage levels. When voltage decreases, it switches from series to parallel connection, gradually adjusting the circuit configuration to prevent sudden current spikes while maintaining adequate luminous flux output.
Solution Approach 2:
The control portion detects the voltage level and uses this feedback information to determine the appropriate connection configuration. This feedback mechanism ensures that the system responds appropriately to voltage changes, switching between series and parallel connections to maintain stable operation and prevent harmful current fluctuations.
3Illumination intensity
If light emitting diodes are connected in parallel to increase current flow at decreased voltage, then luminous flux is maintained, but current control becomes difficult causing instability
Solution Approach 1:
The system dynamically selects between series and parallel connection configurations based on voltage conditions. The control portion detects voltage levels and switches the connection type accordingly, providing stable current control in series mode when voltage is adequate, and transitioning to parallel mode only when necessary to maintain luminous flux at lower voltages.
Solution Approach 2:
The patent changes the electrical connection parameters (series vs. parallel) based on operating conditions. By adjusting the connection configuration parameter according to detected voltage levels, the system optimizes both current control stability and luminous flux output for different operating scenarios.
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 ensures a stable and required total luminous flux even at decreased voltages, suppressing fluctuations and maintaining efficient light emission by adjusting the connection state of circuit portions based on input voltage.
Implementation Method 1
a vehicle lighting device includes a plurality of circuit portions each having at least one light emitting element
Implementation Method 2
The control portion detects an input voltage
Data Source
AI summary
A vehicle lighting device includes a plurality of circuit portions that have at least one light emitting element; and a control portion that is electrically connected to the plurality of circuit portions. The control portion detects an input voltage and connects the plurality of circuit portions in series when the detected input voltage exceeds a predetermined value and connects at least a part of the plurality of circuit portions in parallel when the detected input voltage is equal to or less than the predetermined value.